EditorialTrauma systems and medical helicopters in the UK
Introduction
It now seems likely that a network of Level 1 major trauma centres will be established in the UK.1, 2 Given that there will be relatively few of these units, and that they will be situated in inner city hospitals, clinicians working in outlying and rural areas will be wondering how their trauma patients will be transported to these centres.
There are twenty medical helicopter services in the UK, and clearly these will play an important role in transporting patients to Level 1 centres. However the conditions in which such aircraft can operate are significantly restricted. The purpose of this article is to describe these restrictions and to consider how this might affect the proposed trauma systems.
Section snippets
General considerations
Medical helicopters perform two main tasks. Firstly they are used to provide an emergency response to the seriously ill or injured at ad hoc landing sites. These are referred to as Helicopter Emergency Medical Service (HEMS) operations. Secondly they are used to transfer stabilised patients from one established landing site to another. These are referred to as Air Ambulance (AA) operations. The same helicopter may be used for either task but the restrictions, and risks, associated with the two
Helicopter Emergency Medical Services
In the UK HEMS aircraft are generally sent to the scene of an accident (or serious illness) following a ‘high risk’ emergency call, or after an assessment by a land based ambulance crew. These landing sites will usually be ad hoc, i.e. unmarked and not previously surveyed. As previously indicated such missions can only be conducted in VMC.
There is some uncertainty about the distance at which transportation by helicopter is faster than by land based vehicles, but distances in excess of 45 miles
Air Ambulance operations
An Air Ambulance (AA) operation will generally involve the transfer of a patient between hospitals, i.e. between recognised landing sites. A HEMS helicopter will often be used but not necessarily so. Because the patient is judged to be in no immediate danger the Civil Aviation Authority (CAA) consider an Air Ambulance flight to be no different to any other ‘public transport’ passenger carrying flight, and no latitude is permitted in terms of flying conditions.
Depending upon pilot
Visibility
CAA regulations9 stipulate that helicopters may not fly with the surface in sight (i.e. on HEMS operations) unless visibility exceeds 800 m during the day and 5000 m at night. If there is a low cloud base the daylight minimum visibility increases to 3000 m. Regulations further require that HEMS operations must effectively be flown above 500 feet, or above 1000 feet at night or over built up areas.
Temperature
Most helicopters are not permitted to fly in potential or actual icing conditions. This means that
Night flying
The regulations for night flying require the use of multi-engine helicopters which are either crewed by two pilots or are fitted with an autopilot. The helicopter must be equipped to be flown on instruments.
Whilst regulations permit HEMS flights at night, the associated level of risk is significantly higher than for day operations and there are currently no night HEMS operations in the UK.
Air Ambulance flights can occur at night, but the level of risk should be no greater than for any other
Servicing and mechanical failure
Helicopters are complex machines with high standards of mechanical reliability. Routine maintenance is required in proportion to flying time. Unscheduled repairs are also needed, and on average each of the West Midland helicopters has 29 flying days affected each year because of this (Table 2).
Safety
HEMS services in the UK have enjoyed a good safety record, although accident statistics relating exclusively to EMS helicopters in the UK are not readily available.10 In the US there has been a recent rise in EMS helicopter accidents, and in 2008 there were nine HEMS crashes with 35 people killed.7 This led to a debate about the appropriateness of transportation by helicopter. A separate study of 182 EMS helicopter crashes in the US suggested that safety could be improved by enhancing
Discussion
It is clear that EMS helicopters in the UK will not fly to accident sites in adverse weather conditions or at night. Additional flying time is lost for scheduled and unscheduled maintenance, and for all these reasons HEMS aircraft are unable to operate for at least half of the time. The obvious conclusion is that trauma patients in outlying areas cannot be reliably transported to Level 1 centres by helicopter. Several consequences follow.
Firstly, there is a risk that in rural areas a two tier
Conflict of interest statement
TN is a doctor employed by Midlands Air Ambulance but we do not consider this to be a conflict of interest.
Acknowledgments
The authors would like to thank the aviation experts who kindly advised on the technical data in this article. The authors would also like thank the Midlands Air Ambulance service for providing information about unplanned downtime for it's helicopters.
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2014, Emergency Medicine Journal'Interception': A model for specialist prehospital care provision when helicopters are not available
2013, Emergency Medicine JournalTransporting major trauma patients from the margins of a UK trauma system
2012, Emergency Medicine JournalCharacteristics of patients transferred by air: A descriptive epidemiologic study
2012, Turkish Journal of Medical Sciences