Aeromedical Consideration for Patients Acute Respiratory Distress Syndrome (ARDS) during Air Medical Evacuation

Acute respiratory distress syndrome is a clinical syndrome of acute respiratory failure characterized by arterial hypoxemia and bilateral pulmonary opacities. In recent year, the incidence of ARDS has rapidly increase due to Corona Virus 2019 (COVID-19). This has resulted in an increased need of patient’s referral to the more adequate health care facilities using air ambulance through air medical evacuations. Acute hypobaric hypoxia that occurs during air medical evacuation inside of the cabin (altitude 6.000 ft – 8.000 ft) will trigger a hyperventilation response that can lead to respiratory alkalosis. This condition will not only worsen the hypoxemia state but also deteriorate the patient’s clinical symptoms. Additionally, changes in altitude and atmospheric pressure inside the aircraft cabin also pose risks to patients using invasive mechanical ventilation. Not only can it disrupt the settings of medical equipment, but it can also cause pulmonary barotrauma, which can lead to pneumothorax. To prevent these various impacts, air medical evacuation must be carried out by a multidisciplinary team with considerations for the use of medications and manoeuvres for invasive mechanical ventilation.