Effect of probe design on accuracy and reliability of pulse oximetry in pediatric patients.

STUDY OBJECTIVE

To determine if the traditional band-wrap disposable pulse oximeter probe is more accurate or reliable for oxygen monitoring in children than the reusable clip-type probe.

DESIGN

Prospective, observational clinical study.

SETTING

Operating room of a large university hospital.

PATIENTS

18 children 11 years of age or younger, who were scheduled for general anesthesia with placement of an intraarterial catheter.

INTERVENTIONS

Pulse oximetry values were obtained using both band and clip probes of three pulse oximeters (Nellcor, Hayward CA; Novametrix, Wallingford, CT; Ohmeda, Boulder, CO) and compared with simultaneous hemoximetry values. Dropout rate (percent of down time) also was recorded for each probe-machine combination.

MEASUREMENTS AND MAIN RESULTS

Data were analyzed using bias and precision and t-test. p < 0.05 is considered significant. Bias (mean SpO2-SaO2) is less than 2% for all probe-machine combinations. The range of error observed between SpO2 and SaO2 for all data points was greatest using the Nellcor band (27.8%) and least using the Ohmeda band (11.4%). In cyanotic children, the greatest bias and precision were observed with Nellcor band (N = 11, -5.12 +/- 9.74) and the best agreement with Novametrix band (N = 17, 0.08 +/- 4.21). The difference in bias for any test units above or below the median weight of 13.75 kg did not vary by more than 1%. Dropout rate was minimal for all units in nonbypass situations. After cardiopulmonary bypass, no data dropout was observed with Ohmeda band; observed down time with the other units varied between 34% and 55%.

CONCLUSIONS

The type of probe selected has little effect on accuracy of pulse oximetry in children. After cardiopulmonary bypass, using the Ohmeda band combination may improve the likelihood of obtaining consistent readings and decreasing down time.