Original Article: Ruling Out Pulmonary Embolism in the Primary Care Setting
Issue Date: June 1, 2018
See additional reader comments at:https://www.aafp.org/afp/2018/0601/p750.html
To the Editor: We appreciated Dr. Yunyongyings's article and believe that it is also applicable during air travel for an in-flight medical event. When a physician responds to a request to aid an ill passenger, the Wells or Geneva score can be used in a diagnostic workup. However, the Pulmonary Embolism Rule-out Criteria cannot be used because it includes oxygen saturation level, and medical emergency kits on U.S. airplanes do not contain pulse oximeters.
In 2013, a study reported respiratory symptoms as the second most common in-flight medical emergency, and literature reports a range from 8.1% to 12.1%.1,2 Thromboembolic episodes may occur during air travel, especially with long flights.3,4 In 2018, a 28-year-old woman died from a pulmonary embolism (PE) during a flight from Hawaii to Texas.5 Because a central registry does not exist for in-flight medical events,6 it is difficult to estimate the number of cases of PE classified under respiratory symptoms.
A physician responding to an emergency during a flight must make a diagnosis from findings obtained in the restrictive confines of the airplane. The suspected presence of deep venous thrombosis is supportive of a PE diagnosis, but its absence does not rule it out. Tachycardia is often an important finding. A Wells or Geneva score of less than 2 indicates a low risk of PE.
U.S. airlines contract with medical agencies to provide an on-the-ground, on-call physician specialized in aeronautical medical emergencies. After the specialist evaluates findings from the history, physical, and Wells or Geneva score, guidance is then provided; the medical goal is stabilization of the ill passenger for the remainder of the flight. If stabilization is not possible, the decision to divert the airplane is made by the pilot. The nearest airport chosen should have a medical facility that can provide the necessary care.