CHANGES IN CARDIAC-OUTPUT DURING AIR AMBULANCE REPATRIATION

Objectives. To measure, with the use of suprasternal Doppler ultrasoun d, the hemodynamic changes in patients and volunteers during air ambul ance repatriation. Design. Unblinded prospective observational study. Setting. Chartered air ambulances for the international repatriation o f patients. Patients and participants. Six medical crew members and se ven patients transported back to hospitals in the UK. Interventions. T he measurement of non-invasive blood pressure, EGG, heart rate, oxygen saturation and hemodynamic variables with suprasternal Doppler. Measu rements and results. There was a drop in systolic and mean arterial bl ood pressure in the patient's group once in the air. Oxygen saturation dropped in both groups once at cruising altitude. Heart rate remained unchanged. Stroke distance and minute distance increased significantl y in the patient's group and non-significantly in the volunteers. Peak velocity increased significantly in the patient's group. There was an overall reduction of systemic vascular resistance during take off and once at cruising altitude. Conclusions. Hemodynamic changes happen du ring air ambulance transportation in fit and healthy volunteers and pa tients alike. These may be due to a combination of hypobaric hypoxia a nd gravitational forces;It is necessary to establish if these changes have short- or long-term effects in the critically ill.