Pulse oximetry

The human eye is poor at recognizing hypoxemia. Even under idealconditions, skilled observers cannot consistently detect hypoxemia until theoxygen (O2) saturation is below 80% [1]. Thedifficulty that physicians have in detecting hypoxemia was recently exemplifiedin a study of over 14000 patients being evaluated at the UCLA EmergencyDepartment [2]. Patients were monitored by oximetry butrecordings were given to physicians only after they completed their initialassessment. Changes in diagnostic testing and treatment were most likely at anO2saturation of 89%, and changes were actually less common at lowersaturations, probably because the physicians were able to detect evidence ofhypoxemia without requiring a pulse oximeter.