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

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.

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.

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.

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.