Integrating Paediatric Intermediate Care Units Into Tiered Care Systems: A Narrative Review and Italian Perspective

ABSTRACT

Aim

Paediatric hospital care has become increasingly complex with many children requiring monitoring and support beyond general ward capabilities. This review evaluated the role of paediatric intermediate care units (PIMCUs) within tiered paediatric care systems, with a focus on organizational impact and implementation in Italy.

Methods

We conducted a narrative review using PubMed, Embase, Scopus and the Cochrane Library up to 31 December 2025. Studies addressing PIMCUs were included, together with selected adult studies on organizational and economic aspects. The PIMCU model at the Gaslini Institute in Genoa, Italy, was also described.

Results

PIMCUs provided intermediate care for children requiring enhanced monitoring and noninvasive support without full intensive care. Paediatric studies suggested improved patient allocation, reduced inappropriate intensive care admissions and safer transitions of care, findings supported by adult literature with potential cost‐effectiveness. In Italy, limited intensive care capacity, regional disparities and lack of formal recognition of PIMCUs contributed to fragmented care pathways. The model developed by our Institute showed that an integrated PIMCU within a hub‐and‐spoke network improved patient flow, preserved intensive care capacity and enhanced system resilience.

Conclusions

PIMCUs are key components of acuity‐based paediatric care systems. Their implementation may improve efficiency, equity and patient safety.

Summary

• Increasing complexity in paediatric hospital care and lack of a clearly defined intermediate level highlight the need to synthesize current evidence on paediatric intermediate care units (PIMCUs)

• This narrative review, supported by an Italian model, highlighted that PIMCUs improved patient allocation, supported safer transitions and optimized critical care resource use.

• Implementing PIMCUs within tiered, network‐based systems may enhance efficiency and equity. Research is needed to standardize models and evaluate outcomes.

Abbreviations

AAP

American Academy of Paediatrics

ICU

Intensive Care Unit

IMCU

Intermediate Care Unit

PICU

Paediatric Intensive Care Unit

PIMCU

Paediatric Intermediate Care Unit

1. Introduction

Paediatric hospital care has become increasingly complex, with a growing proportion of children requiring levels of monitoring and support that exceed the capabilities of standard wards but do not warrant full intensive care. This mismatch has led to the development of paediatric intermediate care units (PIMCUs), also referred to as high‐dependency or step‐up/step‐down units, designed to provide enhanced monitoring and targeted therapies for patients at risk of clinical deterioration [1].

In 2022, the American Academy of Paediatrics (AAP) formally recognized paediatric intermediate care as an integral component of modern healthcare systems. This highlighted its role in improving patient safety and optimizing resource allocation [2]. However, implementation remains highly variable across countries, reflecting differences in healthcare organization, funding and critical care capacity [2].

In settings with limited paediatric intensive care resources, the absence of an intermediate level may lead to inefficient care pathways. Italy has a limited number of Paediatric Intensive Care Units (PICUs), with uneven geographic distribution [3], and the lack of formal recognition of PIMCUs contributes to PICU overuse and fragmented management of moderately ill children.

This review adopted a systems‐oriented perspective, considering PIMCUs not only as clinical units but as structural components of a tiered, acuity‐based model of paediatric critical care. The aim was to synthesize current evidence, analyse the organizational role of PIMCUs, and explore its implementation within the Italian healthcare context, integrating literature findings with a representative institutional model.

2. Methods

We conducted a narrative literature review of studies addressing paediatric intermediate care. The literature search was performed in PubMed, Embase, Scopus and the Cochrane Library, including studies published up to 31 December 2025. The main search terms included paediatric intermediate care, high‐dependency unit and step‐up/step‐down unit. Additional relevant articles were identified through manual screening of reference lists.

The population of interest included paediatric patients aged 0–18 years, in accordance with standard definitions. Given the limited availability of specific paediatric advice, selected adult studies on intermediate care models were also considered to inform organizational and economic aspects.

Studies were included based on their relevance to organizational structure, clinical outcomes, safety and health system impact. Observational studies, organizational reports and relevant clinical guidelines were considered.

Because this was a narrative review we did not perform a formal systematic selection process, risk‐of‐bias assessment or meta‐analysis.

3. Results

3.1. Definition, Rationale and Evidence

PIMCUs are intended for children whose clinical needs exceed the capabilities of general paediatric wards but do not require full intensive care support [1]. According to the AAP, these units manage patients who require enhanced monitoring, noninvasive respiratory support or postoperative observation, without the need for invasive ventilation or advanced organ support [2]. They function as both step‐up units for clinical deterioration and step‐down units following critical illness, supporting continuity of care across levels of acuity.

In the absence of an intermediate level, paediatric care systems rely on a binary model, ward versus ICU, which may lead to inefficient resource use. Clinically stable patients may remain in the ICU longer than necessary, while others may be transferred prematurely to general wards, increasing the risk of deterioration and readmission [4, 5]. The introduction of an intermediate level improves patient allocation and supports safer transitions of care (Figure 1).

FIGURE 1.

The figure depicts a three‐level, acuity‐based model of paediatric care, ranging from general paediatric wards to the Paediatric Intensive Care Unit (PICU), with the Paediatric Intermediate Care Unit (PIMCU) positioned as an intermediate level. The PIMCU is designed for patients requiring enhanced monitoring and therapies, such as non‐invasive ventilation (NIV), but not full intensive care support. Arrows represent patient flow across levels of care, including escalation from the ward to higher‐acuity settings and de‐escalation following clinical stabilization. The model highlights the role of the PIMCU in improving patient allocation, reducing inappropriate PICU admissions and facilitating safe transitions within the care continuum. NIV, non‐invasive ventilation; PICU, Paediatric Intensive Care Unit; PIMCU, Paediatric Intermediate Care Unit.

Paediatric evidence remains limited and heterogeneous. A multi‐institutional North American study of 108 PICUs found that only one‐third were associated with a PIMCU [6]. Although the availability of a PIMCU was not associated with reduced PICU length of stay and was linked to modest discharge delays, these metrics may not capture broader system‐level benefits [6].

More consistent findings emerged from triage‐focused studies. In hospitals without PIMCUs, children with medical complexity, such as those requiring tracheostomy care, chronic ventilation or noninvasive respiratory support, were more frequently admitted directly to PICUs, even in relatively low‐acuity conditions resulting in overtriage [7, 8].

Available safety data are limited but reassuring. A Canadian single‐centre study reported that most transfers from a PIMCU to a PICU were anticipated and occurred in a controlled manner, supported by structured monitoring and early warning systems [9]. Similarly, a French multi‐centre study showed that admission severity scores can identify patients at higher risk of escalation or prolonged stay [10]. The implementation of paediatric early warning systems was also associated with reduced unplanned PICU transfers [11, 12].

3.2. Adult Evidence, Cost‐Effectiveness and Organization Models

Evidence from adult critical care systems provides more robust support for intermediate care. Large observational studies have shown associations with lower ICU and in‐hospital mortality, reduced readmissions, shorter ICU stays and improved bed utilization. No substantial increases in overall costs were observed [5, 13, 14].

Transfer from ICUs to intermediate care, rather than directly to general wards, has been associated with improved outcomes, particularly among higher‐risk patients, while also facilitating timely ICU discharge and reducing capacity strain [15, 16].

Economic analyses consistently demonstrated cost savings, mainly through the substitution of high‐cost ICU days with lower‐cost monitored care [17, 18]. Although paediatric‐specific economic data remain limited [19], these findings support the potential value of PIMCUs in optimizing resource allocation.

Organizational models varied across settings. Recommended nurse‐to‐patient ratios typically ranged from 1:2 to 1:3, depending on patient acuity. Physician staffing included paediatric intensivists, hospitalists or mixed models, reflecting local expertise and institutional organization [2, 20]. Structural integration with the ICU appeared advantageous, as proximity facilitated rapid escalation and de‐escalation of care, promoted shared expertise and enhanced operational efficiency [13, 21].

3.3. The Italian Context

Paediatric critical care in Italy is characterized by structural limitations and marked geographic heterogeneity [3]. The availability of PICUs remains below European standards, with significant regional disparities that contribute to inequities in access and increased risk of inappropriate patient allocation.

The absence of a formally recognized intermediate level further contributes to inefficiencies. Children with moderate‐to‐severe conditions may be overtriaged to PICUs or managed in settings lacking adequate monitoring. In some cases, they are admitted to adult ICUs or alternative non‐specialized pathways [22].

National data on paediatric intermediate care are scarce. A 2019 survey identified a limited number of PIMCUs, unevenly distributed and highly heterogeneous in structure, staffing and monitoring capacity [23]. Most units lacked formal integration with PICUs, and standardized national criteria were not established.

In contrast, specialty‐specific intermediate care models, particularly in respiratory care, have developed more consistently, demonstrating feasibility within the Italian system [24]. However, these experiences did not translate into a structured, general paediatric framework.

Overall, the Italian context highlights a mismatch between clinical needs and organizational capacity, supporting the need for a coordinated, tiered model that includes a formal intermediate level.

3.4. The Gaslini Experience

As national PIMCU models remain heterogeneous and not yet fully standardized, real‐world implementations from established centres may help illustrate how such units can be integrated into structured care pathways. The PIMCU model of the IRCCS Giannina Gaslini Children's Hospital in Genoa, Italy, is one example. This unit is a 12‐bed stand‐alone facility located adjacent to the PICU, enabling seamless bidirectional patient flow. Each room is equipped with continuous multi‐parameter monitoring and can be rapidly converted into a fully equipped intensive care space if needed. An extra bed is provided in the child's room, allowing one parent to stay continuously with the child and supporting family‐centred care. This architectural integration enhances both safety and flexibility.

The PIMCU was formally established during the COVID‐19 pandemic, when its system‐level value became evident. Among 550 children hospitalized for acute severe acute respiratory syndrome coronavirus 2 infection or multi‐system inflammatory syndrome in children, nearly one‐fifth were managed in the PIMCU. PICU admission rates remained lower than in comparable series [25], highlighting its role in absorbing surge demand and preserving ICU capacity.

The unit manages a heterogeneous population, including step‐up admissions from the emergency department or wards, step‐down transfers from the PICU and selected postoperative patients. Respiratory and neurological conditions are the most common indications [26].

Safety has been formally evaluated. Of 893 admissions from January 2022 to June 2023, 2.8% of cases were transferred to the PICU within the first 48 h, supporting the appropriateness of the admission criteria [26]. Predictors of escalation included tachypnea and nasogastric tube use at admission, while prolonged length of stay was associated with respiratory support and medical devices [26].

Noninvasive respiratory support is a core component of activity. Structured protocols, including bubble continuous positive airway pressure combined with mild sedation, have enabled safe management of higher‐acuity patients outside the PICU. This approach helped mitigate seasonal PICU overcrowding [27]. Consistent with AAP recommendations, the unit has also proven effective for children with medical complexity, particularly neuromuscular disorders, with associated reductions in PICU admissions and length of stay [28].

Beyond its institutional role, the PIMCU is integrated within the regional Gaslini Diffuso hub‐and‐spoke network, linking the tertiary centre with peripheral hospitals through structured referral pathways and paediatric transport systems. Within this framework, the PIMCU acts as an intermediate node that optimizes patient allocation and enhances system resilience (Figure 2). A recent regional evaluation of bronchiolitis management further supported the effectiveness of this integrated model [29].

FIGURE 2.

The model illustrates a hub‐and‐spoke organization in which the tertiary referral centre (HUB), located in Genoa, is connected to four peripheral hospitals (SPOKE centers) located in Imperia, Savona, Lavagna and La Spezia. The Paediatric Intermediate Care Unit (PIMCU) is positioned between the general paediatric ward and the Paediatric Intensive Care Unit (PICU), enabling bidirectional patient flow. It functions both as a step‐up unit for patients requiring escalation of care from the emergency department or general wards and as a step‐down unit for patients discharged from the PICU or admitted directly from the operating room who still require enhanced monitoring or noninvasive support. Arrows indicate referral pathways within the network, including inter‐hospital transfers from SPOKE centers to the HUB for higher‐acuity care, as well as patients referred from outside the region requiring initial assessment and stabilization. The model emphasizes the role of the PIMCU in optimizing patient allocation, reducing inappropriate PICU admissions and facilitating safe transitions across levels of care. HUB, tertiary referral centre; PICU, Paediatric Intensive Care Unit; PIMCU, Paediatric Intermediate Care Unit; SPOKE, peripheral hospitals within the regional network.

4. Discussion

This review highlights the role of PIMCUs as a key component of modern paediatric critical care systems. Paediatric‐specific evidence remained limited and European experiences were also relatively scarce and heterogeneous. However, available data consistently suggested that PIMCUs improved patient allocation, enhanced safety during transitions and reduced inappropriate use of intensive care resources [2, 6, 7, 8, 9, 25]. Evidence from adult populations further supported these findings, showing improved outcomes, more efficient bed utilization and favourable cost profiles associated with intermediate care implementation [13, 14, 15, 16, 17, 18].

By combining a narrative synthesis of the literature with a real‐world organizational model, this review provides a system‐level perspective on PIMCU implementation. The experience of the IRCCS Giannina Gaslini Children's Hospital illustrates how a PIMCU can be effectively embedded within a tiered, network‐based system, supporting patient flow, resource optimization and system resilience. This combined approach strengthens the relevance of the findings, particularly in healthcare settings where structured frameworks for PIMCUs are still lacking.

From a systems perspective, the introduction of an intermediate level enabled a shift from a binary ward versus ICU model to a tiered, acuity‐based framework. This allowed better alignment between patient needs and resource intensity. It also reduced both ICU overuse and the risks associated with premature transfer to lower‐acuity settings. In addition, it supported more flexible responses during periods of increased demand.

The Italian healthcare system represents a paradigmatic context in which the absence of a structured intermediate level amplifies existing constraints. Limited PICU capacity, geographic disparities and lack of formal recognition of PIMCUs contribute to fragmented pathways and suboptimal resource allocation. The findings of this review suggest that the implementation of PIMCUs, particularly within coordinated regional networks, could improve efficiency, promote more equitable access to care and enhance overall system performance.

Beyond organizational aspects, environmental design and family‐centred care are integral to the effectiveness of PIMCUs. Single rooms that allow parents to stay with their children at all times are a key feature of high‐quality PIMCU models. These configurations may improve infection control, privacy and communication, while supporting parental involvement, patient comfort, adherence to treatment and early recognition of clinical changes. In this context, parental presence should be considered an essential component of care delivery rather than an ancillary feature.

Despite these advantages, several barriers continue to limit the widespread adoption of PIMCUs in Italy. The lack of formal recognition hinders the definition of standardized organizational criteria and dedicated funding mechanisms, while current reimbursement structures do not adequately capture intermediate levels of care. Regional variability and workforce constraints, particularly shortages of trained nursing staff, further contribute to heterogeneous implementation [30]. Addressing these challenges will require coordinated policy and organizational efforts, including formal recognition of PIMCUs, standardized admission and staffing criteria, integration with existing PICU infrastructure and investment in workforce training and prospective research.

Overall, the growing, although still limited, body of evidence converges in supporting PIMCUs as a necessary evolution of paediatric critical care systems. Adopting intermediate paediatric care models in settings that have limited PICU capabilities is not only a matter of efficiency, but also of equity and patient safety.

The aim of this narrative review was to evaluate the role of PIMCUs within tiered paediatric critical care systems, with a focus on organizational impact and implementation in Italy. It found that available evidence, although still limited, consistently supported the role of PIMCUs in improving patient flow and care transitions. The findings suggest that integrating PIMCUs within structured paediatric critical care networks may improve resource allocation, support safer care pathways and strengthen healthcare systems with limited PICU capacity.

Author Contributions

Marta Romanengo: supervision, validation, visualization, writing – review and editing, investigation. Daniela Pirlo: validation, investigation, supervision, visualization, writing – review and editing. Andrea Moscatelli: validation, visualization, writing – review and editing, supervision. Giacomo Brisca: conceptualization, investigation, writing – original draft, writing – review and editing, validation, methodology, formal analysis, data curation.

Funding

The authors have nothing to report.

Conflicts of Interest

The authors declare no conflicts of interest.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.