Effect of using disposable polyethylene bag as a probe cover or finger cover in pulse oximetry

An innovative method to prevent infection when measuring the arterial blood gas SpO2 saturation

Background

Patients are hospitalized for extended periods, particularly in intensive care units (ICUs). As a result, the saturation probe (pulse oximeter) remains attached for an extended period and microorganisms can grow in the wet environment. If the pulse oximeters are not reprocessed, cross-infection may occur. The literature contains several studies in which gloves were used for the measurement while various SpO2 (peripheral arterial oxygen saturation) measurements were compared with each other. However, such comparisons have yet to be made with the results of arterial blood gas SpO2 measurements by pulse oximeter, considered as the gold standard. The present study aimed to compare arterial blood gas values with the fingertip saturation measurement performed by having adult patients wear gloves of different colors, one after the other, on their fingers and determining the effect of the differently colored gloves (transparent, white, black, light blue) on saturation values.

Methods

The study was conducted on 54 patients in an ICU. Intra-arterial blood gas SpO2 results were measured. Oxygen saturation was measured while the patient 1. did not wear gloves and 2. sequentially wore a series of gloves of different colors. Paired t-test, correlation analysis, and Bland Altman charts were used to evaluate the results.

Results

The mean SpO2% value of the participants' intra-arterial blood gas measurements was 97.76±2.04. The mean SpO2% value obtained from the measurements of the fingers with a transparent glove was 0.43 points lower than the mean SpO2% value of the intra-arterial blood gas measurements (t=0.986, p=0.61). The mean SpO2% value obtained from the measurements of the fingers with a white glove was 0.93 points lower than the mean SpO2% value of the intra-arterial blood gas measurements (t=1.157, p=0.093).

Conclusion

Of the measurements performed with a glove, the mean SpO2% value obtained from the measurements of the fingers with a transparent glove was more consistent with the mean SpO2% value of the intra-arterial blood gas measurements than measurement of the fingers without a glove.

A Cross-Sectional Study on the Agreement of Perfusion Indexes Measured on Different Fingers by a Portable Pulse Oximeter in Healthy Adults

Background

Pulse oximeters measure oxygen saturation, heart rate, and perfusion index (PI) by analyzing photoplethysmographic signals. PI is an indirect measure of peripheral perfusion expressed as a percentage of pulsatile signals to non-pulsatile signals. PI measured from different sites may show variation. PI may vary when measured on different fingers. In this study, we aimed to observe the variation of PI among different fingers of both hands.

Methodology

This cross-sectional, observational study was conducted using a convenience sample recruited from a tertiary care hospital in eastern India. PI was measured in apparently healthy adults in a sitting posture after a five-minute rest. The pulse oximeter probe was attached to each finger and readings were taken after one minute. The analysis of variance and intraclass correlation coefficient (ICC) were calculated to compare and find agreement among PI.

Results

Data from a total of 391 (229 [58.57%] male and 162 [41.43%] female) adult research participants with a mean age of 34.88 ± 10.65 years were analyzed. The PI was the highest on the middle finger in both hands. There was a significant difference among the PI measured on different fingers, F (9, 3900) = 15.49, p <0.0001. The ICC was 0.474, 0.368, and 0.635 for overall, right-hand, and left-hand fingers, respectively, which indicate poor (ICC < 0.5) to moderate (ICC = 0.5-0.75) levels of reliability.

Conclusions

The PI measured using consumer-grade pulse oximeters on different fingers may provide different readings. The highest PI reading is found on the middle finger. Clinicians and primary care physicians should consider the differences in measured PI among different fingers and should use the readings with caution for any diagnostic purposes.