Last month I was called to assist a passenger on a flight from Toronto to Los Angeles. The passenger was a woman in her early 60s who was feeling weak and dizzy and had blurred vision. Her only chronic medical condition was hypertension, for which she received an angiotensin converting enzyme inhibitor. She had had similar symptoms once when she had a condition with low blood volume. Her physical examination result was unremarkable, except for a systolic blood pressure of 100 mm Hg (by radial artery palpation). Although the most likely diagnosis was hypotension caused by dehydration, with her symptoms I wanted to check her blood sugar level and used the glucometer from the plane’s emergency medical kit. The result was 5.6 mmol/L. All of my medical training and practice have been in the United States, and I was unfamiliar with the normal blood sugar range in these units. The abbreviated instruction manual that came with the glucometer did not list a normal range or a conversion factor to milligrams per deciliter. I was unable to change the units on the glucometer with its setup menu. The plane Wi-Fi was spotty, prohibiting me from looking up the conversion on the Internet. The patient’s symptoms resolved with oral hydration. It was only after we landed that I was able to convert the glucometer result to 101 mg/dL.

Syncope and presyncope are the most common medical emergencies encountered on commercial airline flights, and oral hydration is recommended in these cases. Although glucometers are not found in standard emergency medical kits on commercial planes, providers may find them in enhanced emergency kits. Glucose results in millimoles per liter are common outside of the United States. Glucometer results from airplane emergency medical kits will likely be in the units of the home country of the carrier (Canada in this case, in which glucose results are mandated to be in only millimoles per liter). In an in-flight emergency, physicians need to not only know appropriate dosages of medications found in the plane emergency medical kit but also know or find the reference values of test results supplied by instruments in the emergency medical kit. Options for this include having a physical “pocket card” or stand-alone electronic reference, reviewing the instruction manual that comes with the device, or contacting the ground-based medical communication center contracted by the airline. In the case of glucometers, the blood sugar reference range may also be on the test strip canister if the canister is provided in the kit.