Accuracy and precision of buccal pulse oximetry

Abstract

Objective: We sought to describe the accuracy and precision of buccal pulse oximetry (SbpO2) compared with arterial oxygen saturation (SaO2) and pulse oximetry (SpO2) in healthy adults at normoxemia and under 3 induced hypoxemic conditions. Methods: In this prospective, correlational study, SbpO2, SaO2, and SpO2 values were recorded at normoxemia and at three hypoxemic conditions (SpO2=90%, 80%, and 70%) for 53healthy, nonsmoking adults who were without cardiac or pulmonary disease, baseline hypoxemia, peripheral edema, dyshemoglobinemia, and fever. Bland-Altman analyses were used to assess agreement and precision between SbpO2 and SaO2 measures and between SbpO2 and SpO2 measures. Data were adjusted to account for a lag time between buccal and finger sites. Results: When comparing SbpO2 and SaO2 values, mean differences of -1.8%, .3%, 2.4%, and 2.6% were evident at the normoxemia, 90%, 80%, and 70% levels, respectively. When comparing SbpO2 and SpO2 values, the mean differences were -1.4%, .1%, 3.3%, and 4.7% at the normoxemia, 90%, 80%, and 70% levels, respectively. The SbpO2 and SaO2 values met a priori precision criteria (1.6%; 95% confidence limit, -4.9% to 1.3%) at normoxemia. The SbpO2 and SpO2 values met precision criteria at normoxemia (1.5%; 95% confidence limit, -4.4% to 1.5%) and 90% (1.9%; 95% confidence limit, -3.6% to 3.8%) conditions, but exceeded precision criteria at the other tested conditions. On average, SpO2 lagged 21 seconds behind SbpO2. Conclusion: Buccal oximetry is an inaccurate and imprecise method of assessing SpO2 when oxygen saturation is