A Buccal Mucosal Oximeter Accurately Measures Arterial Oxyhemoglobin Saturation.

Purpose: While arterial oxyhemoglobin saturation (SaO₂) decreases during sleep in many patients with sleep apnea and pulmonary diseases, personalized oximeters suitable for multi-night monitoring of SpO₂ are not readily available. The present report describes a custom buccal mucosal intraoral oximeter that might provide the opportunity for such long-term monitoring given its strong accuracy in measuring SpO₂ over a range of clinically relevant hypoxemia.

Patients and methods: The intraoral buccal mucosal oximeter was constructed by encapsulating a reflectance pulse oximeter in an overlay of the maxillary dentition. Accuracy was assessed during non-motion conditions in normal participants (n = 12) made progressively hypoxic by decreasing the partial pressure of end-tidal oxygen (PETO₂). CO-oximeter values of SaO₂ from arterial blood constituted the "gold standard" for comparison with the buccal mucosal oximeter's values. The oximeter's pulse rate and an electrocardiogram (ECG) determined heart rate were also compared.

Results: Analysis of 325 paired SaO₂ values from the CO-oximeter and buccal mucosal oximeter yielded the following: r = 0.95; bias = 0.72; and accuracy root-mean-square (A_RMS) = 2.94%. Results from the pulse rate/ECG analysis were: r = 0.99; bias = 0.30; and A_RMS = 2.08 bpm.

Conclusion: These results reveal robust accuracy of the buccal mucosal oximeter measurement of SaO₂ and pulse rate, as shown by good agreement with a "gold standard" over a wide range of arterial hypoxemia. Such clinically acceptable accuracy indicates that this novel reflectance oximeter may prove useful in management of patients with sleep-induced hypoxemia by allowing for long-term monitoring of SaO₂.