Significant Delay in the Detection of Desaturation between Finger Transmittance and Earlobe Reflectance Oximetry Probes during Fiberoptic Bronchoscopy: Analysis of 104 Cases

Purpose There is clinical significance to a delay in response time for detecting desaturation by pulse oximetry. Our aim in this study was to compare the response time of the reflectance and transmittance saturation probes during fiberoptic bronchoscopy (FOB) under monitored anesthesia care. Methods A prospective study included 104 patients scheduled for FOB. Patients were monitored with transmittance (finger) and reflectance (ear) oximetry probes. The response time was evaluated during desaturation and resaturation. We also acquired blood tests for arterial oxygen saturation to assess the agreement with the oximetry probes. Results Ninety patients had a desaturation episode during FOB and were included in the final analysis. Mean time difference between the reflectance ear probe (reference probe) and transmittance finger probe for the detection of desaturation (SpO2 = 90%) was + 36 s (CI 27.0–45.0, P