A bundle for thoracic segmental spinal anaesthesia: it is time to move forward!

Main text

Thoracic segmental spinal anaesthesia (TSSA) is an “old but gold” technique that is re-emerging within the scientific community [1]. Its potential benefits are numerous (fewer respiratory and cardiac complications, better perioperative pain control, earlier recovery of gastrointestinal function, less postoperative nausea and vomiting, earlier ambulation and discharge from hospital, lower incidence of deep vein thrombosis), with the primary point of interest being its role as a valid anaesthetic alternative in high-risk patients undergoing surgical procedures (open, laparoscopic and robotic) that are typically performed under general anaesthesia [2, 3]. However, as recently highlighted by Paliwal [4], the broader adoption of this technique remains limited by ongoing debates regarding its safety. The main concerns include technical challenges associated with thoracic-level puncture, off-label use of adjuvant drugs in the anaesthetic mixture, haemodynamic implications, management of spontaneous breathing during laparoscopic or robotic surgery [5, 6] and the type of sedation for patients required to maintain uncomfortable positions during surgery. What is clearly lacking is a standardized approach to TSSA that could help to regulate its application, reduce practitioner apprehension, minimize and manage possible side effects and enhance patient safety.

In this context, based on the analysis of recent literature, after 3 years of local experience, in the absence of specific indications, we propose a structured “operative 7-item bundle” (“MEL bundle”—Table 1) that could serve as a valuable guide to reduce technical variability, counteract complications, ensure safety for both patient and anaesthesiologist and promote this uncommon technique as a viable option within the broader anaesthetic armamentarium.

Table 1.

Thoracic segmental spinal anaesthesia “MEL bundle”

1	Patient selection
2	Technical consideration and drug selection
3	Ethical and legal consideration
4	Spontaneous breathing and sedation
5	Monitoring
6	Haemodynamic management
7	Teamwork and strategy

Patient selection

Departing from a widely accepted anaesthetic approach for major surgery must be well justified. LeRoux and colleagues [2] clearly define current indications for TSSA in patients with high respiratory risk, frailty, or where general anaesthesia poses a higher perioperative risk [3]. These characteristics should be objectively assessed. Tools such as the ARISCAT score [7] can identify patients at high risk (≥ 45) for postoperative respiratory complications. Similarly, the ACS NSQIP surgical risk calculator [8] or Clinical Frailty Scale [9] can help identify patients at high risk for functional or care-related complications. In such cases, adopting an anaesthetic technique that avoids mechanical ventilation and prevents the neurological impact of general anaesthesia could be (at present) justifiable.

Technical considerations and drug selection

Anatomical studies have shown that the space between the dura mater and the spinal cord is wider in the thoracic region than in the lumbar area [10]. Ultrasound guidance is recommended to ensure accurate identification of the puncture level. Due to the angulation of the thoracic spinous processes, an entry angle of approximately 10–30° cranially is required [10]. To avoid spinal cord injury, the needle should be advanced in 2-mm increments, with removal of the stylet and brief pauses, due to the lower cerebral spinal fluid pressure in the thoracic region. Low concentrations (0.25%–0.33%) of local anaesthetics (levobupivacaine, bupivacaine or ropivacaine with both hyperbaric and isobaric formulations—5–15 mg) are widely proposed for optimal block spread [2]; however, adjuvants are often requested to enhance block intensity, extension and duration. Dexmedetomidine (3–15 mcg) appears to be the most promising adjuvant [11]. To better understand the anaesthetic effects of this nonconventional approach and minimize confounding factors, a “minimalist approach”—using a single local anaesthetic and a single adjuvant—is advisable.

Ethical and legal considerations

The off-label use of drugs remains one of the most debated aspects of TSSA. Obtaining specific informed consent is therefore essential, in accordance with local regulations. Furthermore, when offering TSSA as an alternative to general anaesthesia, the anaesthesiologist must clearly explain risks, benefits and potential complications to the patient.

Spontaneous breathing and sedation

A well-calibrated and executed block can cover all metameres involved in surgery without interference with diaphragmatic function and effective breathing [12]. Preserving spontaneous breathing offers potential significant benefits, especially in patients with respiratory comorbidities [2]. Autonomic regulation of respiration also facilitates carbon dioxide clearance, even during laparoscopic procedures [12]. High-flow nasal cannula (HFNC) oxygen therapy during surgery could be considered, as it may reduce postoperative pulmonary complications [13]. Sedation is a crucial component during TSSA; it should ensure patient comfort without compromising respiratory function while also reducing delirium risk and promoting neuroprotection. In this regard, dexmedetomidine and ketamine show significant promise due to their favourable pharmacological profiles [14].

Monitoring

As in general anaesthesia, to ensure maximum patient safety, advanced monitoring is mandatory, including SpO₂, respiratory rate, EtCO₂, ECG and noninvasive blood pressure. Invasive arterial blood pressure monitoring is strongly suggested, particularly in high-risk patients and during early experiences with TSSA, to assess beat-to-beat haemodynamic changes [15]. Processed EEG (pEEG) monitoring is advisable to titrate sedatives.

Haemodynamic management

Haemodynamic variations occur in approximately 28.5% of cases [16] due to sympathetic thoracolumbar involvement. These changes can be anticipated—as in lumbar neuraxial anaesthesia or general anaesthesia [17]—through appropriate fluid management and vasopressor use. Thomsen and colleagues [18] recently suggested that prophylactic norepinephrine administration after induction in high-risk patients reduces hypotensive episodes; a similar proactive strategy is suggested for TSSA.

Teamwork and strategy

Performing surgery under a nonconventional anaesthetic approach requires a fully shared strategy with the entire operative team. A personalized plan should be developed in agreement with surgeons and operating room staff to eliminate unexpected events and ensure the highest safety levels (choice of drugs for TSSA and sedation, type of monitoring, material available for managing any complications, surgical technique and timing, possible critical issues). It is suggested to adopt a dedicated team model: familiarity in the team contributes to performance on operative efficiency [19, 20]. This collaborative approach fosters trust and encourages shared decision-making in perioperative care.

TSSA is a concrete, effective and increasingly popular technique. It continues to evolve with broader clinical applications and a better understanding of its mechanisms. The proposed bundle aims to improve the efficacy and safety of TSSA, a technique that—despite being widely applied—still suffers from significant variability. While fragile patients are currently its main beneficiaries, an important question arises: if a patient refuses general anaesthesia, can we still claim there is no viable alternative? We can no longer ignore this question. It is time to move forward!

Authors’ contributions

D.V. and B.B.: writing the main manuscript text. R.S. and F.F.. conceptualization. All authors reviewed the manuscript.

Funding

Not applicable.

Data availability

No datasets were generated or analysed during the current study.

Declarations

Ethics approval and consent to participate

Not applicable.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.