Air Ambulance Transport and Acute Coronary Syndrome Management
Date: February 7, 2013.
Acute coronary syndrome is a clinical condition that encompasses non ST elevation myocardial infarctions, ST elevation myocardial infarctions and unstable angina, and requires immediate care. Cardiogenic shock is a complication of ACS that carries a high mortality, and warrants emergency management. Complications like this can occur in a hospital setting or in the community, and would require transport to a facility where emergency/rescue percutaneous coronary intervention (PCI) is performed. Air ambulances are often used for this service, and treatment provided en route bears a significant impact on ACS outcomes. More recently however, air transport is used to transfer patients back to their country of residence, given the economic and social pressures to do so.
Safety of Transfer
The complication rate of an untreated myocardial infarction rises significantly with time if left untreated, with the occurrence of cardiogenic shock and fatal arrhythmias. Safe transport to a hospital providing PCI is essential to ensure survival. While in most cases ground ambulance services are used, air ambulance services have been also used, particularly for inter-facility transfers.
There has been some concern raised in the past of the safety of transferring patients via air ambulance. However, in a retrospective review of a prospective study looking at air medical transfer for ACS, the incidence of adverse medical events was low, indicating a high level of safety in transferring de-compensated ACS patients to treatment centres.1
A number of other studies have been conducted over the years looking at short distance transport and long distance transport. Patients who were transported before 12 to 36 hours since the acute event over a short distance through air ambulance did not suffer any deaths, though the usual complication of hypotension and arrhythmias occurred, that were capably managed by paramedics.2,3 There was no increase in bleeding complications noted.4 Similar data has been shown for long distance air ambulance transport, with no in flight complications.5
The safety of air ambulance transfer of patients for elective coronary procedures has also been established, with no difference in the minor complication rates between 24-48 hrs post MI or 3-7 days post MI.6
Improvement in treatment times
One of the main concerns with ACS management, especially STEMI is medical contact to balloon times. A recent paper assessing the inter-hospital transport of STEMI patients for PCI found that while medical contact to balloon times were reduced, they did not occur in most cases in less than 90 minutes.7
Acute coronary syndromes can present as medical emergencies that require urgent transfer from either the community to a hospital or between facilities. Transfer times are critical to ensure timely intervention. Air ambulance transfer is safe, with no significant complication rate over ground ambulance transfers. Costs remain an issue, and measures must be taken to make this an economical mode of patient transfer.
1. Trojanowski, Jan, and Russell D. MacDonald. Safe transport of patients with acute coronary syndrome or cardiogenic shock by skilled air medical crews. Prehospital Emergency Care 15.2 (2011): 240-245.
2. Kaplan, L, Walsh, D, Burney, R Emergency aeromedical transport of patients with acute myocardial infarction. Ann Emerg Med 1987; 16, 79-81
3. Bellinger, R, Califf, R, Mark, D, et al Helicopter transport of patients during acute myocardial infarction. Am J Cardiol 1988; 61, 718-722
4. Fromm, R, Hoskins, E, Cronin, L, et al Bleeding complications following initiation of thrombolytic therapy for acute myocardial infarction: a comparison of helicopter-transported and non-transported patients. Ann Emerg Med 1991; 20, 892-895
5. Castillo, CY, Lyons, TJ The transoceanic air evacuation of unstable angina patients. Aviat Space Environ Med 1999; 70, 103-106
6. Essebag, V, Lutchmedial, S, Churchill-Smith, M Safety of long distance aeromedical transport of the cardiac patient: a retrospective study. Aviat Space Environ Med 2001; 72, 182-187
7. McMullan, Jason T., et al. “Ground Emergency Medical Services Requests for Helicopter Transfer of ST‐segment Elevation Myocardial Infarction Patients Decrease Medical Contact to Balloon Times in Rural and Suburban Settings.” Academic Emergency Medicine 19.2 (2012): 153-160.