Changes in cardiac output during air ambulance repatriation

Area of Science:

• Cardiovascular Physiology
• Aerospace Medicine
• Critical Care Transport

Background:

• Air ambulance repatriation involves unique physiological stressors.
• Understanding hemodynamic responses during flight is crucial for patient safety.
• Previous research has not fully elucidated these changes in diverse populations.

Purpose of the Study:

• To quantify hemodynamic alterations in patients and healthy volunteers during air ambulance repatriation.
• To utilize suprasternal Doppler ultrasound for non-invasive hemodynamic monitoring.
• To assess the impact of flight conditions on cardiovascular parameters.

Main Methods:

• Prospective observational study involving international air ambulance repatriations.
• Inclusion of six medical crew and seven patients.
• Continuous monitoring of non-invasive blood pressure, ECG, heart rate, oxygen saturation, and hemodynamic variables via suprasternal Doppler ultrasound.

Main Results:

• Systolic and mean arterial blood pressure decreased in patients upon airborne.
• Oxygen saturation declined in both groups at cruising altitude.
• Stroke and minute distances increased significantly in patients; peak velocity increased significantly in patients.
• Systemic vascular resistance reduced during takeoff and at cruising altitude.

Conclusions:

• Air ambulance transport induces measurable hemodynamic changes in both healthy individuals and patients.
• Hypobaric hypoxia and gravitational forces are potential contributing factors.
• Further research is required to determine the clinical significance and long-term effects on critically ill patients.