EAR OXIMETRY - ACCURACY AND PRACTICABILITY IN ASSESSMENT OF ARTERIAL OXYGENATION

Abstract

The accuracy of 3 ear oximeters (Waters XP-350, Waters 0-1100, Hewlett-Packard 47201A) was evaluated on 52 subjects during acute progressive and steady-state hypoxia. Ear oximeter readings were compared with measured arterial saturation SaO2 in arterial or arterialized capillary blood samples. Hewlett-Packard (HP) 47201A ear oximeter readings most closely approximated measured SaO2 (y = 0.99x - 1.52, r = 0.97), although both the HP 47201A and Waters 0-1100 oximeters provided similarly accurate estimates of SaO2 once the characteristics of the individual oximeters were known (SE of estimate; 2.52 and 2.98% SaO2, respectively). The HP 47201A ear oximeter was relatively insensitive to changes in ear-piece position and differences in skin pigmentation, and offered the added advantages of comfort, simplicity of operation and stability of characteristics.