Accuracy of pulse oximetry to estimate HbO2 fraction of total Hb during exercise.

摘要: The accuracy of two pulse oximeters (Ohmeda 3700 and Biox IIa) was evaluated during cycle ergometer incremental exercise in 10 healthy subjects. protocol began at 30 W with the power output being increased 15 W.min-1 until volitional fatigue. Ear finger probe oximetry measurements available hemoglobin (%Spo2) were compared arterial oxyhemoglobin fraction total (%HbO2) measured directly from blood samples using a CO-oximeter. To provide wide range %HbO2 values, four subjects exercised under hypoxic conditions [inspired partial pressure O2 (PIo2) = 107 Torr], while remaining six normoxic (PIo2 150 Torr). Because carboxyhemoglobin (HbCO) or methemoglobin (MetHb) is not by oximeters, corrected for HbCO MetHb expressed as percent saturation Hb (%Sao2). Small insignificant differences (P greater than 0.05) existed between SpO2 (all 3 instruments) %SaO2 lowest work rate highest achieved. Regression analyses %SpO2 vs. produced correlation coefficients r 0.82 [standard error estimate [(SEE) 1.79], 0.89 (SEE 1.48), 0.93 1.14) IIa, Ohmeda (ear), (finger) respectively. We conclude that oximetry, within above limits accuracy, useful estimating