Anaesthesia and Intensive Care Prince of Wales Hospital Hong Kong

Sir,—I read with great interest the recent review on pre-hospital monitoring of trauma patients1. This raised many important issues which need to be addressed further as expectations of out of hospital care increase. In Scotland there has been a fully integrated air ambulance service following a major reorganization in 1993. In addition to providing a primary patient transport service, there are also a large number of secondary inter-hospital transfers. Because of the distances involved and terrain, many of these involve air travel, using fixed-wing or rotary aircraft. In addition to adopting the Association of Anaesthetists’ guidelines on minimum standards of monitoring, it has also been suggested that the recommendations for assistance should be followed in such situations2.. Dr Morley highlighted in his review that monitoring can interfere with aircraft electrical systems. Most monitors give out a small amount of electrical activity to the surroundings; this is not true of defibrillators which, despite having been used successfully in-flight, still pose a greater hazard. It is recommended that authority is gained from the aircraft captain before defibrillators are discharged when airborne3. In addition to the function of monitors in the air environment, associated alarm systems have also come under scrutiny. The noise levels present in the back of an aircraft can render auditory alarms ineffective. It has also been demonstrated that relying on visual scanning for detection of problems leads to delays before alarm conditions are detected. Consideration is currently being given to incorporation of alarms into intercom systems to further increase safe practice4. All adverse events are more likely with prolonged journey times. With the move to centralize specialist facilities and notably paediatric intensive care units5, patient transfer requiring sophisticated monitoring is set to increase. Only by continued vigilance and debate will standards improve to keep pace with these developments.