Their subjects were slightly older (27 ±1.2 years) than ours (Table 1) and the power increments utilized were smaller (15 W/min); however, it is not likely that these differences would have had a significant effect on gas exchange. False arterial desaturation using the ear oximeter has been reported in subjects with a cardiovascular limitation to exercise. Perhaps the desaturation observed was due to decreased ear perfusion and not true arterial desaturation. The reliability of ear oximetry as an indicator of arterial 02 saturation during exercise has recently been questioned; similar questions have been raised in black subjects during exercise. Until further studies are performed, ear oximeter readings during upper extremity exercise should probably be interpreted with caution. antibiotics levaquin
The Pa02 continuously increased from 85 to 97 mm Hg, while 02 saturation remained stable at 96 percent during progressive maximal arm crank exercise. In contrast, the Pa02 decreased from 85 to 82 mm Hg during lower extremity exercise (Table 3). The significant drops in PaOs and the arterial desaturation reported in elite athletes during intense lower extremity exercise were not observed during maximal arm crank exercise.