title: Changes in cardiac output during air ambulance repatriation.
abstract: OBJECTIVE
  To measure, with the use of suprasternal Doppler ultrasound, the hemodynamic changes in patients and volunteers during air ambulance repatriation.
  
  
  METHODS
  Unblinded prospective observational study.
  
  
  METHODS
  Chartered air ambulances for the international repatriation of patients.
  
  
  METHODS
  Six medical crew members and seven patients transported back to hospitals in the UK.
  
  
  METHODS
  The measurement of non-invasive blood pressure, ECG, heart rate, oxygen saturation and hemodynamic variables with suprasternal Doppler.
  
  
  RESULTS
  There was a drop in systolic and mean arterial blood 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 significantly 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 during air ambulance transportation in fit and healthy volunteers and patients alike. These may be due to a combination of hypobaric hypoxia and gravitational forces. It is necessary to establish if these changes have short- or long-term effects in the critically ill.
authors.affiliation: UMDS Division of Anaesthetics, Guy's Hospital, London, UK. i.malagon@umds.ac.uk
authors.forename: I
authors.initials: I
authors.lastname: Malagon
authors.forename: R M
authors.initials: RM
authors.lastname: Grounds
authors.forename: E D
authors.initials: ED
authors.lastname: Bennett
mesh_terms: D000328:Adult; D000368:Aged; D017732:Air Ambulances; D000531:Altitude; D001784:Blood Gas Analysis; D001794:Blood Pressure; D002302:Cardiac Output; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D011446:Prospective Studies; D015203:Reproducibility of Results; D014187:Transportation of Patients; D018608:Ultrasonography, Doppler