Comparison of human smartwatch and transmittance pulse oximetry for evaluating peripheral oxygen saturation in anesthetized dogs.

Background: Pulse oximetry is a valuable tool for monitoring animals during anesthesia and assessing the adequacy of administered oxygen therapy.

Aims: To compare the pulse oximeter readings obtained by the Garmin Fenix 5X plus (GF5Xp) smartwatch and transmittance pulse oximetry (TPO) in anesthetized dogs.

Methods: Twelve clinical canine patients requiring anesthesia for castration were prospectively enrolled in this study. The animals were premedicated with intramuscular dexmedetomidine at a dose of 5 µg/kg. Anesthesia was induced through intravenous administration of propofol and maintained using sevoflurane. The arterial hemoglobin oxygen saturation (SpO₂) readings obtained from the tongue using TPO (238 readings) were compared with measurements taken over the lateral side of the tibia using a GF5Xp smart wearable device (238 readings). This comparison was performed using a Bland-Altman plot, where the differences (%) between the methods were plotted against their mean SpO₂ (Gold standard - Device), and the limits of agreement were represented as the mean ± 1.96 times the standard deviation.

Results: The SpO₂ levels in dogs were overestimated by the GF5Xp relative to the readings obtained by the TPO, with the bias of -0.3% (95% CI: -3.1%-2.5%).

Conclusion: GF5Xp may be interchangeable with TPO in dogs. Further studies are required to validate the accuracy of the GF5Xp in non-anesthetized dogs or dogs outside the physiological range.