Pulse Oximeters
Your article on pulse oximeters in the March issue correctly pointed out that they increase safety, however, there is one situation where they do not and can give a pilot a false sense that all is well. The symptoms of carbon monoxide (CO) poisoning are the same as the symptoms of low blood oxygen—hypoxia—a feeling of well-being.
CO poisoning causes a pulse oximeter to give a normal or high blood oxygen concentration reading, the CO displaces the oxygen in the blood. This can cause a pilot who might otherwise be concerned to see a normal blood oxygen reading and get a false sense of security.
To be protected, a pilot should also carry a sensitive CO detector in the airplane.