EHAC medical working group best practice advice on the role of air rescue and pre hospital critical care at major incidents

A major incident can be defined as an incident that requires the mobilisation of extraordinary emergency medical service (EMS) resources and is identified as a major incident in that system [1, 2]. Major incidents cause a terrible global burden of fatalities, injury, disruption and expense, but for individual EMS they are infrequent and present extreme clinical and logistical challenges.

Helicopter EMS (HEMS) teams may perform a variety of clinical, managerial and transport functions during major incident management. Helicopters have the capability to bring specialised teams and equipment to incident scenes, transport patients, provide search and rescue services, and perform overhead surveillance. When a site is remote or conventional access routes are compromised, helicopters may be the only way to transport personnel, equipment and patients to and from an incident [3].

HEMS services differ nationally and internationally in the medical expertise of team members, aviation platform, funding model and integration into state EMS. Despite these variations, the rapid delivery of HEMS personnel with advanced skills in Major Incident management and clinical scene leadership has been crucial to the delivery of an effective medical response at previous Major Incidents [4–6].

This document outlines the Best Practice Advice of the EHAC Medical Working Group on how HEMS and Pre Hospital Critical Care teams may maximise the positive impact of their resources in the event of Major Incidents. This document is intended to compliment and not supplant existing local and international Major Incident guidance.

Fixed-wing Air Ambulance rarely have a role in the initial response phase of Major Incidents, but are often used for secondary/interhospital transport to relieve local hospital capacity or transport patients to definitive care in the development and conclusion phase of a Major Incident response. The EHAC Medical Working Group have decided to not describe fixed-wing Air Ambulance separately in this document, but recommend that the same Best Practice Advise be valid for fixed-wing as for HEMS.

Major incident planning, training, resources and exercises are not only central to the delivery of an effective emergency response but are legal requirements in some countries http://www.legislation.gov.uk/ukpga/2004/36/contents. Moreover, healthcare organisations have a legal duty of care for their employees and must appropriately equip and prepare them to work in such rare, high risk but foreseeable circumstances. Failure to adequately train or protect staff has resulted in severe short and long term health consequences for medical staff at incidents such as the sarin attacks in Tokyo [10, 11] and following the collapse of the World Trade Centre, New York on 9/11 2001 [12]. Conversely, specialist training and equipment allowed medical personnel to effectively operate in the ballistic environment during the November 2014 Paris attacks and deliver emergency patient care far earlier than is conventional in most systems [9].

The medical management of a Major Incident will be guided by local and international protocols [1]. The focus of the BPA below is upon the specific benefit and role of HEMS teams in the wider Major Incident response.

A systematic review of the utilisation of HEMS during the early response to major incidents demonstrated that, in addition to their conventional patient treatment and transport functions, these resources have been used in a diverse range of roles at previous incidents [3]. This diversity reflects the heterogeneous nature of both international HEMS systems and of Major Incidents. During the 7th July 2005 London bombings, despite over 700 patients being triaged or treated by HEMS teams, no patients were transported by helicopter and the aviation resource was used solely as a delivery vector for medical staff and equipment to multiple sites [4]. In other situations helicopters have been used very effectively for primary and secondary transfer of patients to specialist care such as Major Trauma care or ECMO [5, 14].

Effective triage and major incident management by skilled pre hospital physicians has been demonstrated to reduce critical mortality and over triage rates [15]. Appropriate training facilitates rapid and accurate major incident triage [16]. In ballistic or CBRNE situations, triage decisions and the level of medical care delivered will evolve depending on the ongoing threat and it has been proposed that the sophistication of such decisions requires specially trained and equipped senior personnel [17].

A recent systematic literature review found little or no systematic reporting of the utilisation of HEMS in the early medical management of major incidents [3]. This compromises the opportunity to learn from such events and develop systems that could improve the response to future Major Incidents. Several Major Incident reporting templates have been published [18] and one online template has been developed to specifically assess the pre hospital response [2, 19].

Despite the predominant focus upon minimizing the physical risk to emergency responders at Major Incidents, there is a significant evidence base demonstrating psychopathological sequelae [13]. Critical incident stress debriefing may mitigate the impact of an event [20].