[Reproducibility of pulse oximetry in the fingers of the hands].

BACKGROUND

Partial oxygen saturation from pulse oximetry is most often obtained from the fingers of the hands; however, it is not known whether any of the fingers are ideal for estimating partial oxygen saturation.

OBJECTIVE

To describe the partial oxygen saturation behaviour obtained from the fingers of both hands.

MATERIAL AND

METHODS

Using a cross-sectional analytical design, the partial oxygen saturation was consecutively estimated in the fingers of both hands. Demographic data were obtained from healthy subjects, and they were analyzed using repeated-measures analysis of variance; reproducibility was calculated using the mean difference (limits of agreement) and its magnitude using the intraclass correlation coefficient or ICC (95% confidence interval [95% CI]); a p value < 0.05 was considered significant.

RESULTS

1000 determinations of partial oxygen saturation were studied from the fingers of both hands of 100 subjects (64% women) whose average age was 34 ± 10 years old and whose body mass index (BMI) was of 23.5 ± 5 kg/m2. Partial oxygen saturation was 90.3 ± 4% and reproducibility was almost perfect in all combinations; however, the right index finger versus right ring finger combination was the best: 90.3 ± 4.1% versus 90.5 ± 4% mean difference (limits of agreement) -0.2 (2.5, -2.8) between both and the ICC (95% CI) 0.942 (0.916, 0.961).

CONCLUSIONS

Partial oxygen saturation is reproducible in all fingers, with no clinically relevant differences.