Helicopter emergency medical services for interfacility transfers: an Italian expert consensus

Abstract

Background

Helicopter Emergency Medical Services (HEMS) play a pivotal role in time-dependent interfacility transfers; however, the absence of standardized activation criteria in Italy contributes to heterogeneous decision-making and variable resource utilization. This expert consensus aimed to develop structured, context-informed recommendations to support appropriate HEMS activation for secondary transfers within the Italian EMS–HEMS system.

Methods

A multidisciplinary panel of Italian clinicians with expertise in prehospital emergency medicine, critical care, and HEMS operations conducted a modified Delphi process. Clinical domains were structured using the PICO framework. A PICO-specific scoping review (2010–2026) was performed across MEDLINE, EMBASE, Cochrane Library, and major international guideline repositories to inform deliberations. Evidence was narratively synthesized and integrated with expert judgment. Statements were subjected to anonymous voting using a 1–9 Likert scale, with a predefined consensus threshold of ≥ 80% agreement.

Results

Consensus-based statements were developed across major time-critical domains, including acute coronary syndromes, stroke, traumatic injuries, aortic emergencies, cardiac tamponade, toxicological conditions, and hyperbaric emergencies. HEMS was considered most appropriate when transfer time reduction is clinically meaningful and when advanced in-transit care may improve stabilization. The panel proposed the RATIONAL-HEMS model, integrating clinical priority (A–C classification) with logistical and system-level constraints to guide transparent and reproducible decision-making.

Conclusions

This Italian expert consensus provides a structured framework for secondary HEMS activation tailored to the national organizational context. The proposed model emphasizes time to definitive care, resource stewardship, and adaptability, and may support regional harmonization and future prospective validation studies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13049-026-01636-y.

Background

Timely access to definitive care is a major determinant of outcome in several time-dependent conditions. This is well established for acute coronary syndromes, particularly STEMI and very high-risk NSTEMI, where system delays and interfacility transfer delays are associated with delayed reperfusion and worse outcomes [1–8]. Similar time-dependent considerations apply to acute cerebrovascular emergencies, especially candidates for reperfusion therapy or neurosurgical intervention [9–15]. Major trauma, aortic emergencies, and selected hyperbaric or toxicological emergencies also require rapid access to specialized definitive care when specific interventions are not available at the referring facility [16–29].

Interfacility transfers represent a critical and often under-structured phase of care in time-dependent conditions. When patients initially present to facilities without access to definitive treatment, transfer delays may substantially offset the benefits of specialized therapies. Helicopter Emergency Medical Services (HEMS) may provide clinical and organizational advantages in selected secondary interfacility transfers by reducing transport time, overcoming geographic or infrastructural barriers, and enabling advanced medical support during transfer [30–32]. This potential role is particularly relevant when ground ambulance transport is limited by distance, terrain, or traffic congestion, and when the receiving facility provides highly specialized and time-dependent interventions such as primary percutaneous coronary intervention, mechanical thrombectomy, neurosurgical procedures, advanced trauma care, endovascular repair, or hyperbaric oxygen therapy [2, 31, 32].

In Italy, although HEMS is widely available, activation criteria for secondary interfacility transfers remain heterogeneous across regions. Italy’s geographically complex terrain—41.6% hills, 35.2% mountains, and 23.2% plains—may further contribute to regional variability in HEMS utilization. This variability may result in differences in access to advanced therapeutic options and inconsistent use of HEMS resources [31–33]. Inappropriate activation may also affect availability for primary missions or other time-critical emergencies, underscoring the need for clear, standardized, and evidence-informed decision-making criteria [31].

While several international systems have developed frameworks to support HEMS utilization, no national consensus in Italy currently exists specifically addressing secondary interfacility transfers. This lack of standardization contributes to variability in clinical practice, inequity in patient management, and potential inefficiencies in resource allocation [30, 34].

This expert consensus document was therefore developed to provide context-informed recommendations to support decision-making regarding HEMS activation for secondary interfacility transfers. By integrating available evidence with expert clinical judgment, the document aims to promote consistency in clinical practice, optimize resource utilization, and support equitable and timely access to definitive care.

Methods

Scope and target audience

This document provides consensus-based recommendations on the use of HEMS in interfacility transfers. It defines the scope of clinical and organizational criteria considered for HEMS activation, including transport time, geographic and logistical factors, and system-level resource constraints.

This consensus focuses on rotor-wing HEMS, which represent the standard modality for interfacility transfers within the Italian EMS system, and on adult secondary interfacility transfers for time-dependent or time-relevant conditions. Fixed-wing aeromedical transport is used in selected long-distance or specialized scenarios but follows different organizational pathways and was therefore considered outside the scope of this document. Neonatal transfers, incubator transport, pediatric transfers, and highly specialized ICU-to-ICU transfers, including patients requiring advanced organ support (e.g., ECMO), were also considered outside the scope, as they involve distinct clinical pathways, dedicated transport systems, and specific organizational frameworks.

This consensus was developed within the context of the Italian EMS–HEMS system and reflects its specific organizational, regulatory, and geographic characteristics. It is not intended to function as a universal European standard; rather, it offers a context-informed decision model that may be adapted to healthcare systems with comparable structures. Differences in governance, dispatch models, infrastructure, and interfacility transfer pathways across countries may require modification of the proposed criteria.

The document is intended for healthcare professionals involved in the activation, coordination, and execution of secondary interfacility transfers, as well as healthcare administrators and policymakers responsible for the organization of emergency medical networks.

Operational context of the Italian HEMS system

In Italy, HEMS is organized at a regional level, and activation pathways may differ across regions.

Primary missions (scene response) are typically activated through the national emergency call system (National Emergency Number, NUE 112), which is routed to the regional EMS dispatch center. Activation generally includes an initial feasibility assessment (e.g., weather and flight conditions), followed by mission authorization and rapid deployment of the HEMS crew.

In contrast, secondary interfacility transfers are usually initiated by the referring hospital (spoke center or local facility). The EMS coordination center evaluates the clinical indication, logistical factors, and resource availability, and determines whether HEMS activation is appropriate.

Final decision-making is performed by the EMS dispatch physician in coordination with the HEMS medical crew, considering clinical urgency, transport feasibility, and operational constraints. Operational capabilities and availability may vary across bases (e.g., night operations and instrument flight capability where applicable).

In Italy, HEMS crews include one or two pilots and a dedicated medical team composed of a physician and a nurse. The physician is trained in anesthesia and intensive care or emergency medicine, while the nurse has specific expertise in emergency and critical care. This configuration enables the provision of advanced airway management, hemodynamic support, and other critical care interventions during transport.

In some regions, additional technical personnel may be part of the crew, particularly for missions involving hoist operations or mountain rescue (e.g., HEMS technical crew members or National Alpine and Speleological Rescue Corps – CNSAS). As such, crew composition may vary depending on mission profile and regional organization.

The Italian emergency care system is based on a hub-and-spoke model, in which advanced treatments are concentrated in tertiary referral centers, while many patients initially present to peripheral hospitals. In this context, interfacility transfer represents a critical step in the care pathway. The relative contribution of HEMS versus ground EMS depends on geographic factors, transport distances, and system organization, and may significantly influence access to definitive care in time-sensitive conditions.

Panel selection and organisation

A panel of Italian experts in pre-hospital emergency medicine, critical care, and HEMS operations was convened to develop this consensus. Panel members were selected through purposive sampling to ensure representation of key domains relevant to interfacility transfer and HEMS operations. Efforts were made to minimize selection bias by including participants from different geographic regions, institutional settings, and professional roles, and by avoiding over-representation of single institutions or local operational models. The panel included clinicians with roles in EMS dispatch coordination, HEMS operational leadership, and active clinical involvement in aeromedical services, as well as individuals with academic and scientific society engagement in emergency and critical care.

This composition reflects the organizational and clinical diversity of the Italian EMS–HEMS system, including representation across Northern, Central, and Southern regions.

Eligibility for panel participation required direct clinical involvement in secondary interfacility transfers and active experience within EMS or HEMS operational systems. Recognized expertise in time-critical emergency care at clinical, organizational, or academic level was also considered. Expertise was defined as a combination of sustained clinical practice, operational responsibility within EMS–HEMS systems, and/or relevant scientific contribution in the field.

Ten clinicians constituted the voting panel and participated in the modified Delphi process. A designated methodologist (G.A.) supervised question formulation, evidence synthesis, and consensus procedures to ensure internal methodological consistency but did not participate in the voting process. Methodological oversight was further supported by the involvement of authors with experience in clinical research design and evidence appraisal.

All ten panelists are included among the listed authors. The remaining authors did not participate in the Delphi voting phase and contributed to study conception, methodological supervision, evidence synthesis, and manuscript drafting and revision. All authors meet the International Committee of Medical Journal Editors (ICMJE) authorship criteria.

The panel size was deliberately limited to ensure feasibility, effective discussion, and consistent participation across all phases of the consensus process, while maintaining representation of key domains relevant to HEMS operations and interfacility transfer.

Clinical question formulation

Clinical domains were identified through structured preliminary discussions among panel members, focusing on conditions characterized by high time sensitivity, the need for specialized interventions, or potential benefit from advanced in-transit care. For each domain, key clinical questions were formulated using the PICO framework (Population, Intervention, Comparator, Outcome) to ensure standardized question structure and internal consistency across statements. Each PICO question was addressed independently within the evidence review and consensus process.

Literature review and evidence synthesis

A scoping review of the literature was conducted to inform statement development. Literature searches were performed across major biomedical databases, including MEDLINE, EMBASE, and the Cochrane Library, as well as relevant international guideline repositories and specialty society documents (e.g., ESC, AHA/ASA, ATLS, UHMS).

Search strategies were developed separately for each PICO-defined clinical domain to allow targeted retrieval of relevant evidence. Predefined keywords and Boolean operators were adapted to each database. The review focused on publications from 2010 to 2026 and included randomized trials, observational studies, secondary evidence syntheses, position statements, and international guidelines addressing HEMS utilization, interfacility transfer, and time-dependent emergency conditions. Study selection and data extraction were performed by the coordinating authors in a structured manner and used to inform the narrative synthesis and subsequent panel discussion.

The literature was screened and narratively synthesized to support expert deliberation. Given the objectives of this consensus, the review was not designed as a formal systematic review. No predefined study selection flow diagram, formal risk-of-bias assessment, or PRISMA methodology was applied. The aim of the review was to contextualize available evidence and inform expert discussion rather than to produce a quantitative pooled estimate. The detailed search strategies, including keywords and database-specific queries for each clinical domain, are provided in the Electronic Supplement.

The review also incorporated international literature to contextualize HEMS utilization across different healthcare systems. However, a formal comparative system analysis was not performed, as this was beyond the scope of the present consensus.

Consensus process

A modified Delphi approach was used to develop and validate consensus statements. This approach was designed as a pragmatic, expert-informed process integrating structured discussion with anonymous voting.

This design reflects commonly adopted pragmatic adaptations of Delphi methodology in clinical consensus development.

Draft statements were initially developed by designated panel members based on PICO-defined clinical questions and available literature. All panel members participated both in statement development and in the subsequent anonymous voting process. These statements were circulated to the full panel and discussed in structured sessions to refine wording and resolve ambiguities. Discussions were moderated to ensure balanced participation and to minimize the influence of dominant individuals during the statement refinement phase.

Following this discussion phase, statements were submitted to anonymous online voting by all panel members using a 1–9 Likert scale (1 = strongly disagree; 9 = strongly agree). Anonymity was preserved during voting to reduce the potential influence of seniority or dominant participants.

A predefined consensus threshold of ≥ 80% agreement was required for statement approval. All statements reached the predefined threshold during the first voting round. The high level of agreement reflects the preliminary structured discussion and iterative refinement of statements prior to voting, which minimized ambiguity and aligned interpretation. No statements required substantial reformulation; therefore, additional Delphi rounds were predefined but not required, as all statements reached the predefined consensus threshold in the first round.

Agreement percentages for each approved statement are reported in Supplementary Table S1.

Consensus statements reflect the integration of available evidence and expert clinical judgment. Given the heterogeneity and largely observational nature of the evidence base across clinical domains, a formal GRADE methodology was not applied. Nevertheless, the supporting rationale and key references underpinning each statement are explicitly described to enhance transparency.

All authors reviewed and approved the final version of the manuscript prior to submission.

This consensus is grounded in a pragmatic, evidence-informed approach integrating available literature and expert clinical judgment through a structured modified Delphi process.

Conflict of interest management

All panel participants were informed about the purpose and structure of the consensus process and agreed to participate. Participation was voluntary, and all contributors consented to the use of anonymized voting data for the development of this manuscript.

All panel members were required to disclose any intellectual or financial conflicts of interest that could potentially influence their participation. No financial compensation was provided for involvement in the project, and no industry funding or external sponsorship was involved in the development of this document. No conflicts of interest were declared.

Results

Acute coronary syndromes (ACS)

STEMI — Primary PCI within 120 min

Question 1.1

In patients with STEMI admitted to a non–PCI-capable hospital, does secondary transfer by HEMS, compared with ground ambulance, reduce the First Medical Contact (FMC)-to-PCI time when the expected arrival to the PCI center by ground exceeds guideline-recommended thresholds?

PICO 1.1

• Population: Patients with STEMI confirmed clinically and by ECG, located in non-PCI centers with expected FMC-to-PCI time ≥ 120 min.

• Intervention: Secondary transfer by HEMS.

• Comparator: Ground ambulance transfer.

• Outcome: Reduced FMC-to-PCI time; improved access to reperfusion.

Statements

• The panel suggests considering HEMS when it shortens FMC-to-PCI time in patients requiring secondary interfacility transfer.

• The panel suggests HEMS activation when expected FMC-to-PCI time by ground exceeds the 120-minute guideline-recommended threshold and HEMS can meaningfully reduce this delay.

Background

Time to reperfusion is a major determinant of survival and myocardial salvage in patients with ST-elevation myocardial infarction (STEMI) [1]. System-related delays, particularly those related to interfacility transfer, may adversely affect clinical outcomes in time-dependent conditions. Even modest reductions in ischemic time may have clinical relevance; however, activation decisions should balance potential myocardial salvage with overall system efficiency and resource stewardship. Current international guidelines recommend primary percutaneous coronary intervention (PCI) within 120 min from first medical contact [2, 3].

When the expected FMC-to-PCI time via ground transport exceeds this threshold, rapid transfer to a PCI-capable center becomes critical. In geographically remote areas or in the presence of significant logistical barriers, Helicopter Emergency Medical Services (HEMS) may substantially reduce transfer time, facilitate early access to the catheterization laboratory, and allow appropriate monitoring and stabilization during transport [4]. In these settings, HEMS use may be justified when it results in a clinically meaningful reduction in time to reperfusion compared with ground ambulance transfer [5, 6].

The magnitude of clinically meaningful time reduction should be interpreted within the operational and system-level framework described in the RATIONAL-HEMS model.

STEMI — Post-fibrinolysis / Rescue PCI

Question 1.2

In patients with STEMI who receive fibrinolysis and require rescue or urgent early PCI, does secondary transfer by HEMS reduce time to coronary angiography compared with ground ambulance?

PICO 1.2

• Population: Patients with STEMI treated with fibrinolysis, requiring rescue PCI or early angiography.

• Intervention: Transfer by HEMS.

• Comparator: Ground ambulance transfer.

• Outcome: Reduced time to angiography; improved reperfusion success.

Statements

• The panel suggests HEMS for rescue PCI after failed fibrinolysis when it ensures faster arrival to the PCI center.

• The panel suggests HEMS when early post-thrombolysis angiography is indicated and ground transport would cause significant delays.

Background

Rescue percutaneous coronary intervention (PCI) after failed fibrinolysis is a time-sensitive intervention, as delays to coronary angiography are associated with lower rates of successful reperfusion and increased ischemic complications [4, 7]. International guidelines recommend prompt transfer to a PCI-capable center for patients with failed or incomplete reperfusion after thrombolysis, as well as early routine angiography in selected cases [4].

Interfacility transfer represents a major source of delay in pharmaco-invasive pathways, particularly in regions with long distances or limited road accessibility. In these settings, HEMS may reduce transfer time, facilitate early catheterization laboratory activation, and provide advanced monitoring and hemodynamic support during transport. HEMS may be justified when it results in a clinically meaningful reduction in time to coronary angiography compared with ground ambulance transfer [5, 6].

NSTEMI — Very high risk

Question 1.3

In patients with NSTEMI who fulfill Very High Risk criteria, does secondary transfer by HEMS enable earlier invasive management compared with ground transport?

PICO 1.3

• Population: NSTEMI patients with Very High Risk features: hemodynamic instability, shock, malignant arrhythmias, refractory chest pain, acute pulmonary edema, cardiac arrest with ROSC.

• Intervention: HEMS transfer to invasive cardiology center.

• Comparator: Ground ambulance transfer.

• Outcome: Earlier invasive treatment; improved stabilization.

Statements

• The panel suggests HEMS transfer for NSTEMI patients with Very High Risk features when HEMS reduces time to coronary angiography.

• The panel suggests that these patients require immediate invasive management and that transport time is clinically relevant.

Background

Very High Risk NSTEMI patients are characterized by a markedly increased short-term risk of mortality and life-threatening complications. According to current international guidelines, the presence of Very High Risk features warrants an immediate invasive strategy, ideally within 2 h from diagnosis [7].

In this subgroup, interfacility transfer delays are clinically relevant, as prolonged time to coronary angiography may exacerbate hemodynamic instability and ischemic burden. Interhospital transfer has been identified as a major contributor to treatment delay in acute coronary syndromes, particularly for patients initially admitted to non–PCI-capable hospitals [5, 6].

In geographically remote areas or in the presence of significant logistical barriers, HEMS may facilitate faster mobilization, direct routing to the catheterization laboratory, and provision of advanced critical care support during transport. In these settings, HEMS may be considered when it results in a clinically meaningful reduction in time to invasive management compared with ground ambulance transfer [5–7].

In this high-risk subgroup, the choice of transport modality should not be based solely on expected time reduction, but also on the level of clinical support required during transfer. Patients with hemodynamic instability, malignant arrhythmias, acute pulmonary edema, or post–cardiac arrest status may require physician-led monitoring, vasoactive support, advanced airway management, and real-time clinical decision-making during transport. In such cases, HEMS may offer an advantage not only in terms of speed but also in terms of the capability to deliver advanced critical care en route [34].

NSTEMI — High risk

Question 1.4

In patients with High Risk NSTEMI but without Very High Risk features, does HEMS transfer confer meaningful benefit compared with early ground transfer, considering the prioritization of limited HEMS resources?

PICO 1.4

• Population: High Risk NSTEMI (dynamic ST/T changes, transient ST elevation, GRACE > 140), without Very High Risk criteria.

• Intervention: Transfer by HEMS.

• Comparator: Ground transfer within early invasive strategy (≤ 24 h).

• Outcome: Reduced transfer time; improved workflow; resource optimization.

Statements

• The panel suggests considering HEMS only when ground transfer would significantly delay angiography.

• The panel suggests that HEMS should not be used for High Risk NSTEMI if it jeopardizes availability for higher-priority missions.

Background

High Risk NSTEMI patients benefit from an early invasive strategy, typically within 24 h from diagnosis, which has been shown to reduce recurrent ischemic events but has a limited impact on short-term mortality [8, 35]. Unlike Very High Risk NSTEMI, these patients are usually hemodynamically stable and do not require immediate (< 2 h) coronary angiography according to current international guidelines [7].

Given the finite availability of HEMS, prioritization of time-critical conditions is essential. In most healthcare settings, early invasive management for High Risk NSTEMI can be safely achieved through organized ground transfer within recommended timelines [35]. Routine use of HEMS in this subgroup is therefore unlikely to confer a meaningful clinical advantage and may negatively affect system efficiency and availability for higher-priority missions.

However, in selected geographic contexts characterized by long distances, complex terrain, or significant logistical barriers, ground transfer may result in substantial delays beyond guideline-recommended timeframes. In such cases, HEMS may be considered when it provides a clinically relevant reduction in time to coronary angiography compared with ground ambulance transfer [5–7].

NSTEMI — Low risk

Question 1.5

In patients with NSTEMI without High or Very High Risk criteria, does HEMS transfer provide clinical benefit over scheduled ground transfer?

PICO 1.5

• Population: NSTEMI without High/Very High Risk criteria.

• Intervention: HEMS transfer.

• Comparator: Planned ground transfer (< 72 h).

• Outcome: No expected difference in mortality or ischemic events.

Statements

• The panel suggests ground transport as the standard modality for Low Risk NSTEMI.

• The panel suggests that HEMS should be reserved for exceptional logistic or geographic situations.

Background

Low Risk NSTEMI patients do not derive a prognostic benefit from accelerated invasive management in terms of mortality or major ischemic outcomes. International guidelines support a delayed or selective invasive strategy in this subgroup, with coronary angiography typically performed within 72 h when clinically indicated [7, 8, 35, 36].

In most healthcare settings, transfer within this timeframe is generally feasible through planned ground ambulance transport without compromising patient outcomes. Routine use of HEMS in low-risk NSTEMI is therefore unlikely to provide additional clinical benefit, and may impact system efficiency by reducing availability for higher-priority, time-critical missions. HEMS activation should be considered only in exceptional circumstances, such as when ground transfer is not feasible due to geographic or logistical constraints.

Stroke

Initial triage

Question 2.1

In patients with suspected acute neurological deficit evaluated via telephone triage or at first medical contact in a non-stroke center, does the systematic use of a structured stroke screening tool improve early recognition and appropriate activation of stroke pathways?

PICO 2.1

• Population: Patients with suspected focal neurological deficits.

• Intervention: Triage using a structured stroke screening tool (e.g., CPSS or BEFAST) by dispatchers or first responders.

• Comparator: Non-standardized or non-structured triage.

• Outcome: Increased early identification of stroke; improved activation of appropriate transfer pathways.

Statements

• The panel suggests systematic use of a validated structured stroke screening tool (e.g., CPSS or BEFAST) during initial triage to identify suspected stroke.

• The panel suggests that a positive result on structured stroke screening should prompt rapid clinical evaluation and early activation of regional stroke pathways.

• The panel suggests that the choice of screening tool may reflect local protocols and system organization, provided that its use is standardized and consistently applied.

Background

Structured prehospital stroke screening tools, such as the Cincinnati Prehospital Stroke Scale (CPSS) and BEFAST (Balance, Eyes, Face, Arms, Speak, Time), support early identification of suspected stroke during initial medical contact. These tools are designed to rapidly detect focal neurological deficits and facilitate timely pathway activation within organized stroke systems of care [37–39].

In the context of secondary interfacility transfers, structured neurological screening is not intended as a diagnostic instrument, but rather as a trigger for early pathway activation and coordination with stroke-capable centers. Early recognition is considered essential for appropriate transfer decisions, including consideration of HEMS in time-dependent scenarios such as candidates for intravenous thrombolysis or mechanical thrombectomy [40].

Systematic use of standardized stroke screening during initial triage reduces variability, improves communication between referring and receiving centers, and supports timely mobilization of specialized stroke resources within regional networks [41].

Screening-positive patient within therapeutic windows

Question 2.2

In screening-positive patients within the therapeutic window for reperfusion (IV thrombolysis and/or mechanical thrombectomy), does HEMS transfer reduce time to a stroke center compared with ground transport?

PICO 2.2

• Population: Screening-positive patients within the therapeutic window for reperfusion (thrombolysis or thrombectomy).

• Intervention: Secondary transfer by HEMS to a stroke center.

• Comparator: Ground ambulance transfer.

• Outcome: Reduced time to reperfusion therapy; improved neurological outcomes.

Statements

• The panel suggests using HEMS when it provides a clinically meaningful reduction in time to a stroke-capable center compared with ground transport.

• The panel suggests prioritizing HEMS for suspected large vessel occlusion (LVO) when ground transport may delay access to thrombectomy-capable centers.

Background

Time is a crucial determinant of functional outcome in ischemic stroke. Delays in reaching reperfusion therapy significantly worsen disability and mortality. Early pre-notification and parallel activation of stroke teams are critical determinants of effective time reduction. HEMS can shorten transfer times in areas with long distances, limited road access, or traffic constraints [9–11]. Early recognition of LVO is essential because mechanical thrombectomy is strongly time-dependent, with the greatest benefit within the first hours from onset. In drip-and-ship models, initiation of intravenous thrombolysis at a primary stroke center followed by expedited transfer to a thrombectomy-capable center may further optimize time to reperfusion, and HEMS may facilitate this strategy in geographically complex regions [40].

HEMS may be justified when it reduces door-in–door-out and time to arrival at a thrombectomy-capable center [12–14].This section specifically addresses secondary interfacility transfers and does not replace prehospital direct-to-center bypass strategies [11].

Intracerebral hemorrhage — Surgical candidate

Question 2.3

In patients with spontaneous intracerebral hemorrhage (ICH) who require urgent neurosurgical intervention, does HEMS transfer reduce time to neurosurgical care compared with ground ambulance?

PICO 2.3

• Population: Patients with ICH requiring neurosurgical evaluation/intervention.

• Intervention: Transfer by HEMS to neurosurgical center.

• Comparator: Ground ambulance transfer.

• Outcome: Reduced time to neurosurgical treatment; improved outcomes.

Statements

• The panel suggests HEMS transfer for patients with ICH requiring surgical evaluation when HEMS shortens transfer time.

• The panel suggests that teleconsultation with neurosurgery should support the decision.

Background

Urgent neurosurgical consultation and, when indicated, surgical evacuation can improve outcomes in selected ICH patients [15, 42]. Transfer delay is harmful, especially for expanding hematomas or deteriorating patients. HEMS offers faster interfacility transfer in geographically complex regions, enabling earlier neurosurgical management [15, 42].

Intracerebral hemorrhage — Non-surgical

Question 2.4

In patients with ICH without neurosurgical indications, is HEMS transfer superior to ground transport in improving outcomes?

PICO 2.4

• Population: Patients with ICH without surgical indication.

• Intervention: HEMS transfer.

• Comparator: Ground ambulance transfer.

• Outcome: No difference expected in neurological outcomes.

Statements

• The panel suggests using ground transport when ICH does not require neurosurgical intervention.

• The panel suggests teleconsultation before deciding on transport modality.

Background

Most ICH patients without surgical indication benefit primarily from medical stabilization and neurocritical monitoring rather than urgent transfer [15]. HEMS should be preserved for time-critical missions. For stable patients without a surgical target, ground transport is typically sufficient and avoids unnecessary utilization of HEMS resources [15].

Airway management in neurological emergencies

Question 2.5

In patients with acute neurological deficits requiring interfacility transfer, what are the indications for airway protection prior to transport?

PICO 2.5

• Population: Neurological patients undergoing secondary transfer.

• Intervention: Endotracheal intubation before transfer.

• Comparator: Non-intubated transfer.

• Outcome: Airway protection, prevention of hypoxia/hypercapnia, maintenance of neurological evaluation.

Statements

• The panel suggests intubation before transfer when:

  • GCS ≤ 8 or a drop ≥ 2 points.
  • SpO₂ < 94% despite oxygen therapy.
  • inability to maintain airway patency.
  • hemodynamic instability requiring vasopressors.

• The panel suggests that routine intubation should be avoided when neurological assessment is required and the patient is clinically stable.

Background

Airway protection should be considered when altered consciousness or respiratory compromise places the patient at risk of hypoxia or aspiration. However, unnecessary intubation may delay transfer, worsen hemodynamic instability, and impede neurological assessment. Decisions should therefore balance risks, benefits, and the need for ongoing neurological evaluation. Adequate oxygenation remains a key determinant in minimizing secondary brain injury [43, 44].

Continuous capnography (ETCO₂) monitoring is mandatory in intubated patients during transfer to ensure appropriate ventilation and avoid hypo- or hypercapnia, particularly in patients with suspected or confirmed intracranial pathology. In selected non-intubated patients at risk of neurological deterioration, ETCO₂ monitoring may also be considered to facilitate early detection of hypoventilation or respiratory compromise.

The decision to perform endotracheal intubation prior to transfer should be individualized based on clinical status, anticipated transport duration, and available expertise [45]. When clear indications for airway protection are present, early intubation at the referring hospital may be appropriate to avoid delays and ensure physiological stabilization before transport. Conversely, in borderline cases or when neurological assessment remains critical, deferring intubation until the arrival of an experienced HEMS team may be reasonable [43].

Final airway management decisions should ultimately rely on the clinical judgment of the transferring physician, considering patient stability, logistical constraints, and in-transit management capabilities.

These indications are extrapolated from general airway management principles in acute brain injury and critical care, as specific evidence for interfacility transfer settings remains limited.

Trauma

Traumatic spinal cord injury

Question 3.1

In patients with traumatic spinal cord injury requiring urgent neurosurgical or spine surgical evaluation, does secondary transfer by HEMS reduce time to definitive care compared with ground transport?

PICO 3.1

• Population: Patients with traumatic spinal cord injury and neurological deficit, requiring evaluation at a spine/neurosurgery center.

• Intervention: HEMS transfer.

• Comparator: Ground ambulance transfer.

• Outcome: Reduced time to decompression, stabilization, or operative management.

Statements

• The panel suggests HEMS transfer for spinal trauma with suspected or confirmed spinal cord injury when HEMS shortens time to neurosurgical/spine evaluation.

• The panel suggests that early (< 12 h) decompression or stabilization may improve neurological outcomes, supporting expedited transfer.

• The panel suggests early communication with the receiving spine center to reduce door-in–door-out delays.

Background

Traumatic spinal cord injury is a time-sensitive condition, with growing evidence suggesting improved neurological outcomes when surgical decompression is performed early after injury. International guidelines and recent meta-analyses support expedited access to specialized spine or neurosurgical centers, particularly within the first 12–24 h following injury [24, 25].

In geographically complex regions or when distances to spine centers are substantial, HEMS may significantly reduce interfacility transfer times. In addition, HEMS crews can ensure advanced spinal movement restriction, physiological monitoring, and prevention of secondary insults during transport. Early coordination with the receiving neurosurgical unit is strongly encouraged to optimize workflow and minimize door-in–door-out delays [26].

Thoracic trauma

Question 3.2

In patients with severe thoracic trauma requiring urgent surgical, endovascular, or critical care interventions, does HEMS transfer offer advantages over ground transport in reducing time to definitive management?

PICO 3.2

• Population: Patients with severe thoracic trauma (e.g., massive hemothorax, suspected aortic injury, pericardial tamponade).

• Intervention: HEMS transfer to trauma center or cardiothoracic surgery unit.

• Comparator: Ground ambulance transfer.

• Outcome: Reduced time to surgical/endovascular management; improved stabilization.

Statements

• The panel suggests HEMS transfer for thoracic trauma requiring emergent surgical or endovascular intervention when HEMS provides faster access to a trauma center.

• The panel suggests considering chest drainage before transfer in patients with clinically significant pneumothorax, particularly when positive-pressure ventilation is required or anticipated.

• The panel suggests that small, stable pneumothoraxes without planned positive-pressure ventilation may be transported with appropriate monitoring and contingency planning, taking into account flight altitude and in-flight management capabilities.

Background

Thoracic trauma may require time-critical interventions such as thoracotomy, Video-Assisted ThoracoScopy (VATS), endovascular repair, or management of hemorrhagic shock [27]. HEMS may reduce transfer times, especially when terrain, distance, or road conditions hinder ground transport [44]. In intubated patients receiving positive-pressure ventilation, even relatively small pneumothoraces may progress to tension pneumothorax during transport. Therefore, a lower threshold for pre-transfer chest drainage is generally recommended in this subgroup, particularly when prolonged transport or limited in-flight procedural capability is anticipated. However, routine drainage of all pneumothoraces is not universally required and should be individualized based on clinical stability, imaging findings, and anticipated transport conditions. In non-ventilated patients, small pneumothoraces may tolerate helicopter transport with appropriate monitoring, particularly when flight profiles allow for low-altitude operations (e.g., near sea level or below 1000 feet where operationally feasible) [27–29].

Unlike most fixed-wing aircraft, helicopter cabins are typically not pressurized; therefore, changes in ambient pressure may influence pneumothorax expansion depending on flight altitude. In the Italian setting, typical HEMS missions are conducted at relatively low altitudes in inland settings, although higher flight levels may be required in mountainous regions [46].

Decisions regarding pre-transfer chest drainage should be based on overall clinical assessment, associated injuries, and anticipated in-flight management constraints.

Abdominal and pelvic trauma

Question 3.3

In patients with severe abdominal or pelvic trauma requiring urgent surgical or angio-embolization management, does HEMS transfer reduce time to definitive care compared with ground transport?

PICO 3.3

• Population: Patients with abdominal or pelvic trauma requiring emergent laparotomy, packing, pelvic stabilization, or angio-embolization.

• Intervention: HEMS transfer.

• Comparator: Ground ambulance transfer.

• Outcome: Reduced time to definitive surgical or interventional radiology treatment.

Statements

• The panel suggests HEMS transfer for abdominal or pelvic trauma when advanced surgical or endovascular treatment is required and HEMS shortens transfer time.

• The panel suggests that unstable or potentially unstable patients benefit from more rapid transfer to a trauma center capable of damage-control surgery or interventional radiology.

• The panel suggests appropriate resuscitation (blood products if available, permissive hypotension where indicated) prior to and during transfer.

Background.

Abdominal and pelvic trauma are major causes of potentially preventable death due to hemorrhage [47].

In the context of interfacility transfer, these patients may initially present to non–trauma centers or peripheral hospitals lacking immediate access to surgical or interventional radiology capabilities. Initial management typically focuses on rapid assessment and hemodynamic stabilization, including hemorrhage control measures when feasible.

When life-threatening bleeding cannot be definitively controlled at the referring facility, early transfer to a trauma center becomes a critical priority. Damage control interventions may be performed prior to transfer when immediately available and necessary to achieve temporary hemorrhage control; however, transfer should not be delayed for definitive procedures that can be more appropriately performed at the receiving center [44, 48].

Definitive management often requires rapid access to operating rooms or interventional radiology. In many regions, HEMS offers faster transfer than ground ambulance and provides the ability to maintain active resuscitation en route including blood product administration. Rapid transfer is crucial for unstable patients, as delays are associated with worse outcomes [48–51].

Gastrointestinal bleeding

Variceal hemorrhage

Question 4.1

In patients with suspected or confirmed variceal upper gastrointestinal bleeding (VUGIB) requiring urgent endoscopic or interventional radiology (IR) management, does HEMS transfer reduce time to definitive treatment compared with ground ambulance?

PICO 4.1

• Population: Patients with acute variceal bleeding requiring emergent endoscopic therapy or possible IR intervention (e.g., TIPS, embolization).

• Intervention: Secondary transfer by HEMS to a center with 24/7 endoscopy/IR capability.

• Comparator: Ground ambulance transfer.

• Outcome: Reduced time to definitive haemostatic intervention; improved stabilization.

Statements

• The panel suggests HEMS transfer for variceal hemorrhage when urgent endoscopy or IR is required and HEMS shortens transfer time to a specialized center.

• The panel suggests that early haemostatic control is critical to reduce mortality and rebleeding risk in VUGIB.

• The panel suggests initiating pharmacologic therapy (vasoconstrictors, antibiotics) and appropriate resuscitation before transfer, regardless of modality.

Background

Variceal upper gastrointestinal bleeding is a life-threatening emergency associated with high short-term mortality if early haemostatic control is not achieved [52, 53]. International guidelines recommend prompt initiation of vasoactive therapy and antibiotics, followed by urgent endoscopic intervention, typically within 12 h, to reduce mortality and rebleeding risk [54]. In selected cases with uncontrolled bleeding or endoscopic failure, interventional radiology procedures or transjugular intrahepatic portosystemic shunt (TIPS) placement may be required [52, 54].

Hospitals without 24/7 endoscopic or interventional radiology availability should rapidly transfer patients to specialized centers. In regions characterized by long distances or complex geography, (HEMS may significantly reduce transfer time, facilitate advanced monitoring during transport, and improve timely access to definitive haemostatic therapy when compared with ground ambulance transport [28]. Early pharmacologic management and hemodynamic stabilization remain essential prior to transfer, regardless of transport modality.

Non-variceal upper GI bleeding (NVUGIB)

Question 4.2

In patients with severe non-variceal upper gastrointestinal bleeding requiring urgent endoscopic hemostasis, does HEMS transfer offer advantages over ground transport?

PICO 4.2

• Population: Patients with severe NVUGIB requiring emergent endoscopic therapy (e.g., Forrest Ia–IIb).

• Intervention: HEMS transfer to a center with 24/7 therapeutic endoscopy.

• Comparator: Ground ambulance transfer.

• Outcome: Reduced time to endoscopic therapy; decreased rebleeding and mortality.

Statements

• The panel suggests considering HEMS for severe NVUGIB only when ground transport causes clinically significant delays to therapeutic endoscopy.

• The panel suggests that hemodynamic stabilization and transfusion protocols should be optimized before transfer.

Background

Non-variceal upper gastrointestinal bleeding requires early risk stratification to identify patients who may benefit from timely endoscopic hemostasis. Current guidelines recommend early endoscopy, generally within 24 h, while more urgent intervention may be considered in selected high-risk or hemodynamically unstable patients [55, 56].

Although the optimal timing of endoscopy in unstable patients remains debated, delays in endoscopic management in high-risk presentations may be associated with worse clinical outcomes, including increased risk of rebleeding and need for intervention [55].

In most healthcare settings, ground ambulance transport is sufficient to ensure access to endoscopic treatment within recommended timeframes. Therefore, HEMS transfer should be considered primarily in situations where ground transport is expected to result in clinically significant delays and where expedited transfer is likely to influence patient management [33].

Lower GI bleeding (LGIB)

Question 4.3

Does HEMS transfer provide benefit for patients with severe lower gastrointestinal bleeding requiring urgent interventional radiology?

PICO 4.3

• Population: Patients with severe LGIB requiring emergent IR embolization.

• Intervention: HEMS transfer.

• Comparator: Ground ambulance transfer.

• Outcome: Time to IR intervention; stabilization.

Statements

• The panel suggests HEMS only when the time-saving relative to ground transport is substantial.

• The panel suggests that most LGIB cases can be transferred safely by ground if stable.

Background

Lower gastrointestinal bleeding is heterogeneous and, in most cases, does not require immediate endoscopic intervention. Initial management prioritizes hemodynamic stabilization, correction of coagulopathy when appropriate, and risk stratification. In stable patients, diagnostic work-up and colonoscopy are typically performed after adequate bowel preparation and are generally not considered time-critical in the absence of ongoing instability [57].

In patients with ongoing severe bleeding or hemodynamic instability, early computed tomography angiography may help localize active bleeding and guide interventional radiology (IR) embolization, which may be time-sensitive in selected cases [58]. In many healthcare settings, ground transport is often sufficient to ensure access to definitive management. Therefore, HEMS activation should be reserved for selected situations in which (i) rapid access to IR-capable centers is expected to alter management, and (ii) ground transfer is likely to result in clinically significant delays due to distance, geography, or logistic barriers [33].

Aortic emergencies

Acute aortic dissection (AAD)

Question 5.1

In patients with suspected or confirmed acute aortic dissection requiring referral to a specialized aortic center, does secondary transfer by HEMS reduce time to definitive treatment compared with ground transport?

PICO 5.1

• Population: Patients with acute aortic dissection (Stanford A or complicated B) requiring urgent surgical or endovascular management.

• Intervention: HEMS transfer to an aortic/vascular surgery center.

• Comparator: Ground ambulance transfer.

• Outcome: Reduced time to surgery/TEVAR; improved stabilization during transfer.

Statements

• The panel suggests HEMS transfer for patients with suspected or confirmed acute aortic dissection requiring urgent surgical or endovascular treatment when HEMS shortens transfer time.

• The panel suggests that hemodynamically unstable patients should undergo rapid initial stabilization while expediting transfer to an aortic center.

• The panel suggests coordination with the receiving surgical center before activation to reduce interfacility delays.

Background

Acute aortic dissection is a life-threatening condition with mortality increasing by approximately 1–2% per hour in the early phase if untreated [16]. Rapid access to specialized surgical or endovascular management significantly improves survival, particularly in Stanford type A and complicated type B dissections [16, 17]. Transfer delays increase the risk of aortic rupture, end-organ malperfusion, and cardiovascular collapse [17].

In regions where aortic surgery or advanced endovascular capability is centralized, HEMS may substantially reduce interfacility transfer time and allow advanced hemodynamic monitoring and pharmacologic stabilization during transport. Early communication with the receiving aortic center facilitates immediate surgical readiness upon arrival and reduces door-in–door-out delays [16, 18].

Aortic rupture or impending rupture (ANEURYSM)

Question 5.2

In patients with ruptured or impending rupture of an abdominal or thoracic aortic aneurysm, does transfer by HEMS accelerate access to surgical or endovascular management compared with ground transport?

PICO 5.2

• Population: Patients with ruptured or symptomatic (impending rupture) abdominal or thoracic aortic aneurysm.

• Intervention: Rapid HEMS transfer to a center with vascular surgery or endovascular capability.

• Comparator: Ground ambulance transfer.

• Outcome: Reduced time to operative/endovascular repair; improved hemodynamic stabilization.

Statements

• The panel suggests HEMS transfer for ruptured or imminently rupturing aortic aneurysms when HEMS reduces transfer time to definitive repair.

• The panel suggests maintaining permissive hypotension and appropriate resuscitation strategies during transfer, in accordance with established vascular emergency management principles.

• The panel suggests that transfer should not be delayed for non-essential imaging when clinical suspicion is high and access to definitive repair is time-critical.

Background

Ruptured or imminently rupturing thoracic or abdominal aortic aneurysm is associated with extremely high mortality unless emergent surgical or endovascular repair is achieved. Survival is strongly time-dependent, and delays to definitive repair markedly worsen outcomes [17, 19].

Current management principles emphasize permissive hypotension, rapid hemorrhage control, and expedited transfer to centers with vascular surgery or endovascular capability. In this context, HEMS may reduce transport time and provide advanced critical care support during transfer. When clinical suspicion is high and definitive care is distant, additional imaging should not delay transfer to a specialized center [17, 59].

Complex aortic conditions with end-organ malperfusion

Question 5.3

In patients with aortic pathology associated with end-organ malperfusion (e.g., spinal cord, renal, mesenteric ischemia), does HEMS transfer facilitate faster access to advanced surgical/endovascular management?

PICO 5.3

• Population: Patients with aortic dissection or aneurysm with signs of malperfusion.

• Intervention: Transfer by HEMS to advanced aortic centers.

• Comparator: Ground ambulance transfer.

• Outcome: Faster access to TEVAR/surgery; improved organ salvage.

Statements

• The panel suggests HEMS for aortic emergencies complicated by organ malperfusion when rapid access to an advanced center is required.

• The panel suggests that persistent pain, refractory hypertension, neurological deficits, or organ ischemia may justify expedited transfer.

Background

Aortic syndromes complicated by end-organ malperfusion—including spinal cord, renal, mesenteric, or cerebral ischemia—require urgent access to advanced surgical or endovascular management. Delays in restoring aortic flow or treating branch vessel compromise increase the risk of irreversible organ damage and mortality [19, 60].

Management of these complex conditions is typically available only in high-volume aortic centers with multidisciplinary expertise. HEMS may facilitate rapid transfer, continuous hemodynamic control, and early coordination with specialized teams, thereby improving the likelihood of organ salvage and survival in selected patients [19].

As in other time-dependent conditions, activation of HEMS should be guided by expected time gain and system-level considerations within the RATIONAL-HEMS framework.

Cardiac tamponade

Cardiac tamponade requiring urgent drainage

Question 6.1

In patients with suspected or confirmed cardiac tamponade requiring urgent pericardial drainage or cardiothoracic intervention, does secondary transfer by HEMS offer advantages over ground transport in reducing time to definitive treatment and ensuring safe hemodynamic stabilization?

PICO 6.1

• Population: Patients with suspected or confirmed cardiac tamponade causing hemodynamic compromise.

• Intervention: HEMS transfer to a center capable of urgent pericardiocentesis or surgical drainage.

• Comparator: Ground ambulance transfer.

• Outcome: Reduced time to definitive treatment; improved hemodynamic stability during transfer.

Statements

• The panel suggests HEMS transfer for hemodynamically unstable patients with suspected or confirmed tamponade when HEMS shortens time to a facility capable of urgent drainage.

• The panel suggests early coordination with the receiving cardiology or cardiothoracic team to minimize in-hospital delays.

• The panel suggests initiating appropriate hemodynamic stabilization measures without delaying transfer to definitive care.

Background

Cardiac tamponade is a life-threatening emergency in which rapid diagnosis and immediate pericardial drainage are essential to prevent cardiovascular collapse. Delays in definitive treatment are associated with rapid clinical deterioration, particularly in the presence of hypotension, tachycardia, or evolving shock [61].

Emergency pericardiocentesis may represent a life-saving intervention; however, safe execution typically requires appropriate expertise, imaging guidance, and immediate access to specialized cardiovascular care. Patients presenting to facilities without 24/7 capability for urgent pericardial drainage should therefore be promptly transferred to specialized centers [62].

When geographic distance, traffic, or logistical barriers significantly prolong ground transport, HEMS may reduce transfer time and facilitate continuous monitoring during transport. Early coordination with the receiving cardiology or cardiothoracic team is essential to ensure timely intervention upon arrival. Supportive measures instituted before or during transfer should be limited to stabilization and should not delay access to definitive care [2, 63].

Carbon monoxide poisoning (CO)

Carbon monoxide poisoning requiring hyperbaric oxygen therapy (HBOT)

Question 7.1

In patients with suspected or confirmed carbon monoxide (CO) poisoning who meet criteria for hyperbaric oxygen therapy (HBOT), does secondary transfer by HEMS reduce time to a hyperbaric facility and improve access to definitive treatment compared with ground ambulance?

PICO 7.1

• Population: Patients with symptomatic CO poisoning requiring evaluation for hyperbaric oxygen therapy (e.g., neurological signs, syncope, pregnant patients, severe metabolic acidosis, myocardial injury).

• Intervention: Secondary transfer by HEMS to a hyperbaric facility.

• Comparator: Ground ambulance transfer.

• Outcome: Reduced time to HBOT; faster initiation of definitive treatment; improved neurological and systemic outcomes.

Statements

• The panel suggests HEMS transfer for patients with CO poisoning who meet criteria for HBOT when HEMS reduces time to the hyperbaric facility.

• The panel suggests that HEMS should be prioritized in cases with severe neurological symptoms, cardiovascular instability, pregnancy, or elevated carboxyhemoglobin associated with altered mental status.

• The panel suggests maintaining high-flow oxygen and continuous monitoring during transfer, regardless of modality.

Background

Carbon monoxide poisoning is a potentially life-threatening condition that can rapidly lead to neurological injury, myocardial ischemia, severe metabolic acidosis, and multi-organ dysfunction. Although normobaric high-flow oxygen remains the cornerstone of initial management, HBOT is recommended in selected patients to accelerate CO elimination and reduce the risk of delayed neurological sequelae, particularly when initiated early after exposure [20, 21, 64].

Current guidelines and consensus statements identify several high-risk features that support HBOT evaluation, including loss of consciousness, focal neurological deficits, significant metabolic acidosis, pregnancy, and evidence of myocardial injury [20, 64]. However, access to hyperbaric facilities is often limited and geographically uneven, leading to potentially harmful delays in definitive treatment.

In this context, HEMS may reduce transfer time to hyperbaric centers and facilitate advanced monitoring during transport. Patients with neurological impairment, cardiovascular instability, pregnancy, or severe systemic involvement are particularly likely to benefit from expedited access to HBOT when ground transport is substantially delayed [30, 34].

Severe CO poisoning without HBOT indications

Question 7.2

In patients with CO poisoning who do not meet criteria for HBOT, is HEMS transfer beneficial over ground transport?

PICO 7.2

• Population: Patients with moderate CO poisoning without HBOT indications.

• Intervention: HEMS transfer.

• Comparator: Ground ambulance transfer.

• Outcome: No expected difference in clinical outcome.

Statements

• The panel suggests ground transport for patients without HBOT indications unless geographic barriers make HEMS clearly advantageous.

• The panel suggests high-flow oxygen and close clinical monitoring are generally sufficient pending arrival at appropriate medical facilities.

Background

Patients with mild-to-moderate carbon monoxide poisoning without indications for hyperbaric oxygen therapy generally respond well to high-flow normobaric oxygen and supportive care. In these cases, clinical improvement is typically rapid, and delayed neurological sequelae are uncommon when appropriate oxygen therapy is promptly administered [21, 64].

Urgent transfer to specialized facilities is therefore rarely required when HBOT criteria are not met. Ground ambulance transport is usually sufficient, and inappropriate HEMS activation may unnecessarily reduce availability for time-critical emergencies. HEMS should be reserved for exceptional situations in which geographic or logistic barriers significantly delay access to appropriate medical care [64].

Hyperbaric emergencies

Decompression illness (DCI)

Question 8.1

In patients with suspected decompression illness (DCI), does secondary transfer by HEMS reduce time to HBOT compared with ground transport, and does faster arrival improve neurological and functional outcomes?

PICO 8.1

• Population: Divers or patients at risk with suspected DCI (neurological, vestibular, musculoskeletal, cutaneous).

• Intervention: Secondary transfer by HEMS to a hyperbaric facility.

• Comparator: Ground ambulance transfer.

• Outcome: Reduced time to HBOT; improved neurological recovery; decreased long-term sequelae.

Statements

• The panel suggests HEMS transfer for suspected DCI when HEMS significantly shortens time to HBOT (preferably as early as possible, ideally within the first 6 h from symptom onset).

• The panel suggests that neurological, vestibular, or severe musculoskeletal symptoms may justify priority HEMS activation.

• The panel suggests administering 100% oxygen, adequate hydration, and immobilization during transfer, with continuous monitoring.

• The panel suggests direct communication with the hyperbaric center before takeoff to minimize delays.

Background

Decompression illness encompasses a spectrum of clinical manifestations caused by inert gas bubble formation following exposure to reduced ambient pressure, most commonly during diving. Neurological and vestibular presentations are associated with a high risk of permanent disability if treatment is delayed. HBOT is the definitive treatment and is associated with improved neurological recovery, particularly when initiated as early as possible after symptom onset [22, 23].

Several observational studies and expert consensus documents indicate that outcomes are optimized when HBOT is delivered within the first 6 h, although benefit may still be observed with later treatment. Geographic dispersion of hyperbaric facilities and logistical constraints frequently result in delayed ground transport. In this context, HEMS may significantly reduce time to definitive treatment while allowing continuous monitoring and administration of 100% oxygen during transfer. Early oxygen administration and adequate hydration remain essential adjunctive measures before and during transport [22, 23].

Arterial gas embolism (AGE)

Question 8.2

In patients with suspected arterial gas embolism (AGE), does HEMS transfer reduce time to hyperbaric therapy and improve outcomes compared with ground ambulance?

PICO 8.2

• Population: Patients with suspected AGE (neurological deficits, stroke-like symptoms, cardiovascular instability after diving or barotrauma).

• Intervention: Secondary transfer by HEMS to HBOT-capable center.

• Comparator: Ground ambulance transfer.

• Outcome: Rapid initiation of HBOT; improved neurological outcomes; reduced mortality.

Statements

• The panel suggests HEMS transfer for suspected AGE due to the high risk of permanent neurological injury and the time-sensitive nature of HBOT.

• The panel suggests that any diver with sudden neurological deficit, altered mental status, seizures, or cardiovascular collapse after surfacing must be considered for emergent HBOT.

• The panel suggests administering high-flow 100% oxygen and maintaining controlled ventilation and hemodynamics during transfer.

• The panel suggests minimizing altitude changes during flight (sea-level cabin pressure when possible).

Background

Arterial gas embolism is a rare but life-threatening diving-related emergency, typically presenting with sudden neurological deficits, seizures, altered mental status, or cardiovascular instability immediately after surfacing or barotrauma. The condition is highly time-dependent, as intravascular gas bubbles can rapidly compromise cerebral and coronary perfusion. Immediate HBOT is the treatment of choice, as it reduces bubble size, restores tissue perfusion, and limits secondary ischemic injury [23].

Clinical outcomes are strongly associated with time to recompression, with the best neurological recovery reported when HBOT is initiated within 4–6 h. Because many hyperbaric facilities are regionally centralized, rapid transfer is essential. HEMS may provide the fastest access to definitive care and allows controlled flight profiles, including maintenance of sea-level cabin pressure when required. Early administration of 100% oxygen and careful hemodynamic and ventilatory management are critical during transfer [65].

In the Italian geographic context, typical HEMS flight altitudes rarely reach levels associated with clinically significant expansion of intravascular gas bubbles; nevertheless, sea-level cabin pressure should be maintained whenever feasible.

Combined DCI/AGE presentation or uncertain diagnosis

Question 8.3

When the distinction between DCI and AGE is uncertain, or when symptoms overlap, does HEMS transfer remain the preferred modality to ensure rapid HBOT?

PICO 8.3

• Population: Patients with mixed or uncertain presentation after diving.

• Intervention: HEMS transfer.

• Comparator: Ground ambulance transfer.

• Outcome: Timely HBOT; improved neurological outcomes.

Statements

• The panel suggests HEMS transfer when DCI and AGE cannot be distinguished and HBOT is indicated or potentially indicated.

• The panel suggests that diagnostic uncertainty should not delay transfer.

Background

Differentiating between DCI and AGE in the acute setting may be challenging, as clinical presentations can overlap and initial information regarding dive profile or exposure may be incomplete. Importantly, both conditions share the same definitive treatment strategy—early hyperbaric oxygen therapy—and diagnostic uncertainty should not delay transfer to a hyperbaric facility [23, 65].

When HBOT is indicated or potentially indicated, transport decisions should prioritize minimizing time to recompression. In many geographic contexts, HEMS represents the most efficient means of transport to hyperbaric centers and ensures optimal oxygen delivery and continuous monitoring during transfer. A pragmatic approach favoring early transfer may therefore be considered appropriate when clinical suspicion is high, even in the absence of a definitive diagnosis [22, 23, 65].

Hydrocarbon / Oxidizing solvent poisoning

Hydrocarbon / Oxidizing solvent exposure with respiratory or methemoglobinemia complications

Question 9.1

In patients exposed to hydrocarbons or oxidizing aromatic solvents who develop respiratory compromise or significant methemoglobinemia, does HEMS transfer reduce time to specialized ICU or hyperbaric care compared with ground transport?

PICO 9.1

• Population: Patients with inhalation or ingestion of hydrocarbons or oxidizing aromatic solvents (e.g., aniline, nitrobenzene, benzene derivatives) with:

  • respiratory distress OR.
  • methemoglobinemia with neurological/cardiovascular compromise.

• Intervention: HEMS transfer to ICU and, when indicated, to a HBOT facility.

• Comparator: Ground ambulance transfer.

• Outcome: Faster access to advanced respiratory support, antidotal therapy, and HBOT in refractory cases.

Statements

• The panel suggests HEMS transfer when hydrocarbon/solvent exposure causes respiratory compromise, impaired consciousness, or hemodynamic instability.

• The panel suggests early evaluation of methemoglobin levels in suspected exposure to aromatic oxidizing solvents.

• The panel suggests HBOT in cases of severe methemoglobinemia not responsive to methylene blue or when methylene blue is contraindicated (e.g., G6PD deficiency).

• The panel suggests administering high-flow oxygen, early supportive measures, and avoiding gastric lavage/emesis induction.

• The panel suggests that early coordination with ICU and hyperbaric centers can minimize delays in cases of refractory methemoglobinemia.

Background

Acute exposure to hydrocarbons and industrial solvents may occur in a variety of environmental, occupational, or accidental settings and can result in aspiration pneumonitis, acute lung injury, or central nervous system depression. Severe cases may progress to hypoxemic respiratory failure requiring advanced ventilatory support and intensive care admission. Early recognition of respiratory compromise and timely access to critical care resources are essential to prevent clinical deterioration [66].

Exposure to specific oxidizing aromatic compounds (e.g., aniline, nitrobenzene, and related benzene derivatives), can induce clinically significant methemoglobinemia by oxidizing hemoglobin iron and impairing oxygen delivery. Severe methemoglobinemia may present with cyanosis, altered mental status, cardiovascular instability, or refractory hypoxemia despite supplemental oxygen [67].

Methylene blue is the first-line antidotal therapy and is effective in most cases. However, severe methemoglobinemia refractory to standard treatment, or situations in which methylene blue is contraindicated (e.g., glucose-6-phosphate dehydrogenase deficiency), have been described. In these selected cases, hyperbaric oxygen therapy may be considered as a rescue strategy to improve oxygen delivery and tissue perfusion. When rapid access to advanced ICU support or hyperbaric facilities is limited by distance or logistical constraints, HEMS may reduce transfer time and facilitate timely access to advanced critical care or hyperbaric facilities in geographically or logistically constrained settings [68].

Integrated decision algorithm for secondary HEMS activation (Rational-HEMS Model)

The panel developed an integrated decision algorithm (RATIONAL-HEMS model) to support secondary HEMS activation in time-critical interfacility transfers. The model combines:

1. Clinical priority of the condition, and

2. Logistical and temporal factors, to stratify missions into three priority classes (A, B, C) and to guide the choice between HEMS and ground ambulance.

Step 1 – Clinical priority classification (A, B, C)

Clinical priority reflects the expected impact of time-to-definitive treatment on outcome.

• Priority A (time-critical / life- or organ-saving)

Conditions in which shortening transfer time is strongly associated with improved survival or functional outcome, and where HEMS may provide time advantage and access to advanced in-transit care when needed (Table 1).

Table 1.

Priority A – Time-critical conditions

Category	Conditions (examples)	Clinical Rationale
STEMI / ACS	STEMI with FMC-to-PCI delay ≥ 120 min; Post-fibrinolysis requiring rescue PCI; Very High Risk NSTEMI	Survival strongly time-dependent; need for immediate reperfusion
Stroke	Suspected LVO ischemic stroke (thrombectomy candidates); CPSS-positive within thrombolysis window; ICH with neurosurgical indication	Rapid reperfusion or neurosurgical intervention improves outcome
Trauma	Spinal cord injury with deficit; Major trauma with hemorrhage; Thoracic trauma with massive hemothorax or suspected aortic injury; Abdominal/pelvic trauma needing urgent OR/IR	Definitive surgical/endovascular care is time-sensitive
Aortic syndromes	Acute aortic dissection requiring urgent surgery/TEVAR; Ruptured or impending rupture aneurysm	Very high mortality without rapid intervention
Cardiac	Cardiac tamponade with hemodynamic compromise	Requires emergent pericardial drainage
Hyperbaric emergencies	CO poisoning with HBOT indications; Decompression illness (DCI); Arterial gas embolism (AGE)	HBOT most effective if started early (< 6 h)
Toxicology	Hydrocarbon/oxidizing solvent exposure with severe respiratory failure or refractory methemoglobinemia	Rapid ICU/HBOT access improves survival

HEMS generally indicated when time gain is significant

Examples include:

• STEMI requiring primary PCI when FMC-to-PCI by ground is ≥ 120 min.

• Post-fibrinolysis patients requiring urgent rescue PCI.

• Very High Risk NSTE-ACS.

• Ischemic stroke candidates for reperfusion therapy (intravenous thrombolysis and/or mechanical thrombectomy).

• Intracranial hemorrhage with neurosurgical indication.

• Major trauma with ongoing hemorrhage or spinal cord injury.

• Ruptured or impending rupture aortic aneurysm. acute aortic dissection requiring urgent intervention.

• Cardiac tamponade with hemodynamic compromise.

• Severe carbon monoxide poisoning with HBOT indication.

• Decompression illness and arterial gas embolism requiring urgent HBOT.

• Hydrocarbon / oxidizing solvent exposure with severe respiratory failure or refractory methemoglobinemia.

• Priority B (time-relevant but not strictly time-critical)

Conditions in which earlier access to definitive care is desirable, but the impact of transfer time on survival is less pronounced than in Priority A (Table 2).

Table 2.

Priority B – Time-relevant conditions

Category	Conditions (examples)	Clinical Rationale
ACS	High Risk NSTEMI (GRACE > 140, dynamic ST/T changes) without Very High Risk features	Early invasive strategy (≤ 24 h) beneficial but not as time-critical
GI Hemorrhage	Severe variceal or non-variceal bleeding requiring urgent endoscopy or IR after initial stabilization	Earlier hemostasis desirable; time-sensitive but less immediately life-critical
Trauma	Stable thoracic, abdominal, or pelvic trauma after initial hemorrhage control; stable spinal trauma without evolving deficit	Timely evaluation helpful but does not require “immediate” arrival
Neurological	ICH without clear surgical indication but requiring higher-level neuro ICU	Benefit mainly logistical; not strictly time-dependent
Toxicology	Moderate intoxications requiring specialist evaluation but without cardiorespiratory compromise	Transfer useful but not emergent

HEMS to be considered when time gain is relevant and no competing Priority A missions

Examples include:

• High Risk NSTE-ACS (without Very High Risk criteria).

• Severe variceal or non-variceal upper gastrointestinal bleeding requiring urgent endoscopy or interventional radiology, once initial stabilization is achieved.

• Stable spinal trauma without evolving neurological deficit.

• Stable thoracic, abdominal, or pelvic trauma after initial hemorrhage control.

• Priority C (non–time-critical / low time sensitivity)

Conditions in which transfer timing is not expected to significantly influence mortality or major functional outcomes, and in which ground transport is generally appropriate (Table 3).

Table 3.

Priority C – Non–time-critical conditions

Category	Conditions (examples)	Clinical Rationale
ACS	Low Risk NSTEMI without High/Very High Risk features	Invasive evaluation appropriate within 72 h
Neurology	ICH without surgical indication and stable; minor stroke outside therapeutic windows	No evidence of time-dependent benefit
Toxicology	Mild CO exposure without HBOT indications; mild hydrocarbon/solvent exposure without respiratory or neurological compromise	Supportive care often sufficient
Trauma	Minor or stable trauma without surgical need	No urgency for specialized care
GI Bleeding	Lower GI bleeding, hemodynamically stable	Usually not time-critical

Ground transport generally preferred unless geography makes it impractical

Examples include:

• Low Risk NSTE-ACS.

• Intracerebral hemorrhage without neurosurgical indication.

• Mild CO exposure without HBOT indications.

• Mild hydrocarbon exposure without respiratory compromise or significant methemoglobinemia.

Step 2 – Logistical and temporal assessment

Once clinical priority is defined, the following logistical and temporal variables are evaluated:

• Estimated ground transfer time (T_ground):

  including road distance, traffic, terrain, and expected door-in–door-out delays.

• Estimated HEMS transfer time (T_HEMS):

  including activation time, flight time, landing and handover time.

• Time gain with HEMS = T_ground − T_HEMS.

In the RATIONAL-HEMS model, HEMS may be favored when:

• The expected time gain is clinically meaningful (e.g., a substantial time gain, often in the order of 30–45 min, depending on clinical context) and

• The absolute time to definitive treatment is critical for outcome (Priority A conditions).

Importantly, estimated transfer times should be interpreted in the context of real-world operational workflows. In time-critical secondary transfers, HEMS activation may occur in parallel with patient stabilization and preparation, partially offsetting activation and arrival times. Conversely, ground transport times may be underestimated if additional delays related to staff availability, escort team mobilization, or preservation of local hospital operational capacity are not accounted for. Decision-making efficiency at the dispatch level and the proximity of helipads to referring hospitals further modulate the actual time gain achievable with HEMS. Therefore, time comparisons should reflect the entire transfer process rather than transport time alone.

Step 3 – System and resource constraints

Before activation, EMS and HEMS coordinators should also consider:

• current HEMS availability and concurrent Priority A missions.

• weather and flight safety limitations.

• day vs. night operations and landing site constraints.

• availability of advanced care during ground transport (e.g. physician-staffed Mobile Intensive Care Unit [MICU]).

HEMS activation for lower-priority conditions should be carefully balanced against availability for concurrent Priority A missions.

Step 4 – Final decision classes

By combining clinical priority (A, B, C) and logistic/time assessment, the model identifies three decision outputs:

• HEMS may be appropriate

  • Priority A condition and relevant time gain with HEMS (or lack of safe/adequate ground alternative).

• HEMS may be considered

  • Priority B condition with significant time gain, especially in remote or difficult-to-access areas, and no competing Priority A missions.

• Ground transport preferred

  • Priority C conditions, or any condition in which HEMS does not offer a relevant time advantage, or its activation would jeopardize availability for other time-critical missions.

This integrated approach promotes rational, transparent, and reproducible decisions regarding secondary HEMS activation, balancing patient benefit, system efficiency, and resource stewardship.

The model is intended to support structured decision-making rather than replace clinical judgment or regional organizational autonomy.

Operational and system-level constraints affecting HEMS secondary transfers

Challenges to implementation and system-level considerations

Despite the potential benefits of HEMS in time-critical interfacility transfers, the implementation of standardized activation criteria is challenged by relevant organizational, logistical, and regulatory constraints. We explicitly acknowledge the marked regional variability of emergency medical systems, infrastructural resources, and governance models, which may limit the uniform applicability of the proposed recommendations. For this reason, the following considerations aim to contextualize the recommendations within real-world operational constraints and to highlight pragmatic mitigation strategies, rather than prescriptive solutions.

Previous national recommendations, including those promoted by SIAARTI, have already highlighted the complexity of integrating clinical indications with heterogeneous organizational and infrastructural contexts, reinforcing the need for context-aware and adaptable implementation strategies [34].

Governance and centralization of HEMS coordination

In several regions, HEMS governance is not fully centralized or seamlessly integrated with EMS dispatch centers responsible for primary missions. Fragmented governance may result in suboptimal prioritization, delayed activation, or inaccurate real-time assessment of asset availability. Potential mitigation strategies include the progressive adoption of integrated dispatch models, in which primary and secondary missions are coordinated within a unified operational framework, supported by shared priority algorithms and real-time resource visibility. Evidence from centralized trauma and cardiac networks suggests that integrated governance may improve both efficiency and equity of access to advanced care.

Regulatory constraints on hospital helipads (ENAC/EASA)

Aviation regulations governing hospital helipads frequently limit direct access to emergency departments or impose operational constraints that may be incompatible with extreme time-critical scenarios. While these regulations are essential for flight safety, their clinical impact should be explicitly considered in pathway design. Potential mitigation strategies include the strategic designation of HEMS-receiving hubs, predefined fast-track ground links between helipads and critical care areas, and early activation of receiving teams to offset unavoidable transfer-related delays [69].

Helipad-to-definitive-care distance and multiple transfers

The frequent need for multiple patient transfers (base → referring hospital → helipad → receiving hospital) introduces cumulative delays and increases the risk of physiological instability and adverse events. Each handover represents a potential safety and time penalty. Potential mitigation strategies include minimizing intermediate stops, standardizing handover protocols, and preferentially routing patients directly to definitive-care centers whenever clinically feasible. From a system perspective, reducing unnecessary inter-hospital steps may yield time savings comparable to those achieved by aerial transport itself [33].

Meteorological limitations, daylight constraints, and base operating hours

Weather conditions, night operations, and base-specific service hours substantially influence real-world HEMS availability, often to a greater extent than anticipated in theoretical models. Decision algorithms should therefore incorporate dynamic assessments of operational availability, rather than assuming constant HEMS readiness. Redundant planning with predefined ground-based alternatives is essential to prevent decision paralysis or unsafe pressure on flight crews [70].

Uneven distribution of helipads within hub-and-spoke networks

The heterogeneous availability of certified helipads across hospitals, with pronounced regional differences, limits standardization and challenges national-level recommendations. While full infrastructural homogenization is unrealistic, regional mapping of helipad accessibility and transparent integration into dispatch decision-support tools may improve predictability and reduce ad hoc decision-making [69].

Variability in HEMS crew skills and experience

Crew composition and clinical competencies in HEMS are generally higher than in standard ground EMS; however, variability in experience and exposure to complex interfacility transfers may exist between operators and regions. Potential mitigation strategies include the definition of minimum competency standards along with targeted training and system-level strategies to ensure adequate exposure to high-complexity interfacility transfers [63].

Taken together, these challenges underscore that the effectiveness of HEMS in secondary interfacility transfers depends not only on clinical indication but also on governance, infrastructure, regulation, and human factors. Importantly, in certain organizational settings, these constraints may reduce or even negate the expected time advantage of HEMS over ground transport. Accordingly, the proposed recommendations and the RATIONAL-HEMS framework are intended to be adaptable, supporting informed local implementation rather than rigid standardization, and to stimulate system-level improvements tailored to regional realities.

Discussion

This Expert Consensus presents a structured and evidence-informed framework for the activation of HEMS in interfacility transfers for time-dependent conditions. The clinical scenarios included—acute coronary syndromes, stroke, trauma, aortic emergencies, and toxicological or hyperbaric emergencies—represent situations in which delays in access to definitive treatment are associated with worse clinical outcomes.

Although the available literature demonstrates heterogeneity across countries and healthcare systems, several consistent themes emerge: [1] early access to specialized centers is associated with improved outcomes; [2, 3, 11, 16] interfacility transfer is a recognized source of delay; and [3] HEMS may help mitigate these delays when ground transfer is prolonged or limited, not only in terms of transport time, but also in relation to operational availability, crew expertise, and the capacity to provide advanced monitoring and critical care interventions during transfer [30, 70].

The consensus aligns with international recommendations emphasizing early reperfusion in STEMI, rapid revascularization in stroke, timely surgical management in trauma and aortic syndromes, and early hyperbaric therapy in selected toxicological conditions.

The RATIONAL-HEMS model proposed herein integrates clinical urgency with logistical considerations, providing a reproducible and transparent decision-making tool. The model also emphasizes resource stewardship, supporting prioritization of HEMS deployment for the highest-yield missions. Decision-making should balance clinical needs, geographic and system constraints, and the operational limitations of HEMS availability.

However, HEMS availability and effectiveness may be influenced by several operational constraints. Weather conditions, visibility, and flight safety considerations may limit deployment. In addition, not all HEMS bases have full instrument flight capability or night operation capacity, and aircraft availability may be affected by concurrent missions, particularly in regions where HEMS resources are heavily engaged in primary emergency response or specialized rescue operations. These factors should be considered when evaluating the potential benefit of HEMS compared with ground transport.

This consensus deliberately focuses on adult interfacility transfers for time-dependent conditions. Pediatric, neonatal/incubator, and highly specialized ICU-to-ICU transfers (e.g., patients requiring ECMO or advanced organ support) were not included, as these populations are typically managed through dedicated transport systems with distinct organizational models and specialized clinical teams. These scenarios involve different decision-making processes, risk profiles, and resource configurations that differ substantially from standard HEMS-based interfacility transfer pathways. Their inclusion within a single framework would have reduced the specificity and applicability of the proposed model; therefore, they warrant dedicated, context-specific consensus efforts.

Importantly, these findings reinforce that the effectiveness of HEMS in interfacility transfers is not determined by transport time alone, but results from the interaction between clinical urgency, transport logistics, system organization, and in-transit care capabilities.

This consensus is intended to support greater harmonization within the Italian EMS–HEMS network and may serve as a foundation for future standardization efforts and outcome-based validation studies. External validation of the RATIONAL-HEMS model in diverse healthcare settings will be important to assess its generalizability and impact on clinical outcomes. Future research should aim to prospectively evaluate the impact of structured HEMS activation frameworks on patient-centered outcomes and system efficiency.

Strengths and limitations

Strengths

• This is the first Italian expert consensus specifically focused on HEMS activation criteria for interfacility transfers in time-dependent and time-relevant clinical scenarios.

• The methodology combines structured PICO-based questions, a scoping review of the literature, and iterative consensus from experienced prehospital and HEMS clinicians.

• The recommendations provide both clinical and operational guidance, including an integrated decision algorithm (RATIONAL-HEMS model) and prioritization framework.

• The document is highly applicable to real-world EMS–HEMS systems and can be adapted regionally or nationally.

Limitations

• For several clinical scenarios, the available evidence is limited or primarily observational, and some statements are informed in part by expert consensus rather than high-level randomized data.

• Geographical, infrastructural, and logistical factors vary significantly across Italy; consequently, the magnitude of time savings achieved by HEMS compared with ground transport may differ from region to region.

• Although a structured Delphi process was used, the panel size was limited to ten experts, which may not fully capture all regional perspectives.

• Panel selection was based on purposive sampling and may be subject to selection bias, potentially limiting the representativeness of all regional or professional perspectives.

• Although anonymous voting was implemented, the statement development phase included structured group discussions in which participants were not blinded to one another. This may have introduced the potential influence of dominant participants or seniority dynamics, which may have influenced the development and framing of statements and represents an inherent limitation of pragmatic consensus processes.

• This consensus does not adopt a formal GRADE methodology and is not intended to function as a national guideline.

• The proposed RATIONAL-HEMS model prioritizes time to definitive care as a key determinant for HEMS activation. While this reflects a deliberate methodological choice, alternative approaches based on effective distance between facilities have also been proposed and may be valid. Future studies should explore the integration or comparison of time-based and distance-based approaches.

• The absence of a second Delphi round may have limited the formal exploration of residual disagreement and minority viewpoints, although high agreement was achieved after structured pre-voting discussion.

Summary of evidence

A scoping review of the literature (2010–2026) was performed across MEDLINE, EMBASE, the Cochrane Library, and major international guideline repositories to evaluate the role of HEMS in secondary interfacility transfers for time-critical conditions. Available evidence indicates that HEMS may provide clinical benefit in scenarios where: [1] time-to-definitive treatment is strongly associated with improved outcomes; [2] ground transfer is expected to exceed guideline-recommended timelines; and [3] advanced in-transit capabilities may support patient stabilization.

In the context of secondary interfacility transfers, including patients initially presenting to non-PCI or non-comprehensive stroke centers, available evidence suggests a potential role for HEMS in selected time-critical scenarios.

For cardiac emergencies requiring secondary interfacility transfer, earlier access to primary PCI or urgent coronary angiography is associated with improved outcomes in STEMI, post-fibrinolysis patients, and very high-risk NSTEMI. HEMS may reduce time to access interventional cardiology centers.

For ischemic stroke requiring secondary transfer, treatment delays negatively impact functional outcomes, particularly in candidates for intravenous thrombolysis or mechanical thrombectomy. HEMS may shorten transfer times to stroke centers in geographically challenging regions. In intracerebral hemorrhage, HEMS may be considered when neurosurgical intervention is indicated.

For major trauma, evidence supports expedited transfer to trauma centers capable of damage-control surgery, neurosurgical assessment, or interventional radiology. HEMS may facilitate access to these services and reduce secondary transport delays.

For aortic syndromes, including acute aortic dissection and ruptured or impending rupture aneurysms, time-to-surgery is a major determinant of survival. HEMS may reduce delays to specialized vascular or cardiothoracic centers.

For toxicological and hyperbaric emergencies, such as carbon monoxide poisoning requiring HBOT, DCI, and AGE, earlier HBOT is associated with improved neurological outcomes. HEMS may facilitate access to hyperbaric facilities, particularly in geographically remote areas. Selected hydrocarbon and oxidizing solvent intoxications may also require ICU support or HBOT in severe cases.

Overall, current evidence supports a selective and context-dependent use of HEMS, prioritizing conditions in which rapid access to advanced treatment is associated with potential clinical benefit. The recommendations presented in this consensus reflect the integration of available literature, expert clinical experience, and system-level considerations within the Italian EMS–HEMS structure.

The available evidence is largely observational and context-dependent and should be interpreted accordingly.

Conclusions

This Italian Expert Consensus provides an evidence-informed and clinically oriented framework for the use of HEMS in interfacility transfers for time-dependent or time-relevant conditions. By integrating clinical urgency, logistical variables, and system-level constraints, the RATIONAL-HEMS model offers a structured approach to support decision-making in selected clinical scenarios.

The proposed framework reflects the integration of available evidence—largely observational—and expert clinical judgment within the context of the Italian EMS–HEMS system. As such, it should be interpreted as a decision-support tool rather than a prescriptive standard.

Its application may support more consistent decision-making and more efficient resource utilization, particularly in settings where timely access to definitive care is critical. However, prospective validation is needed to assess its impact on patient-centered outcomes and system performance.

Supplementary Information

Below is the link to the electronic supplementary material.

Abbreviations

AAD

Acute Aortic Dissection

ACS

Acute Coronary Syndrome

AGE

Arterial Gas Embolism

BEFAST

Balance Eyes Face Arms Speak Time

CNSAS

National Alpine and Speleological Rescue Corps

CPSS

Cincinnati Prehospital Stroke Scale

DCI

Decompression Illness

EASA

European Union Aviation Safety Agency

ECG

ElectroCardioGram

ECMO

Extra Corporeal Membrane Oxygenation

EMS

Emergency Medical Services

ENAC

Ente Nazionale Aviazione Civile

FMC

First Medical Contact

GRACE

Global Registry of Acute Coronary Events

HBOT

Hyperbaric Oxygen Therapy

HEMS

Helicopter Emergency Medical Services

ICH

Intracerebral Hemorrhage

ICMJE

International Committee of Medical Journal Editors

ICU

Intensive Care Unit

IR

Interventional Radiology

LVO

Large Vessel Occlusion

MICU

Mobile Intensive Care Unit

NSTEMI

Non–ST-segment Elevation Myocardial Infarction

NVUGIB

Non-Variceal Upper Gi Bleeding

PCI

Percutaneous Coronary Intervention

STEMI

ST-segment Elevation Myocardial Infarction

TEVAR

Thoracic Endo Vascular Aortic Repair

TIPS

Transjugular Hepatic Portosystemic Shunt

VATS

Video-Assisted ThoracoScopy

VUGIB

Variceal Upper Gi Bleeding

Author contributions

G.A. conceived the study, coordinated the project, supervised the methodological process, and drafted the manuscript. He did not participate in the Delphi voting process.Ten authors constituted the voting panel and participated in the modified Delphi process, contributing to clinical question formulation, literature appraisal, statement drafting, and structured consensus voting. E.G.B., A.G., and M.L. contributed to external review and validation of the final document and were not involved in the Delphi voting phase. All authors critically revised the manuscript and approved the final version prior to submission.

Funding

This work did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Data availability

No new datasets were generated or analyzed during the current study. The search strategy and consensus statements are available in the Supplementary Material.

Declarations

Ethics approval and consent to participate

Not applicable. This study is an expert consensus document based on published literature and did not involve human participants or patient-level data.

Consent for publication

Not applicable.

Author information

Not applicable.

Competing interests

The authors declare no competing interests.