Lingual pulse oximeter probe location and weight category influence reported pulse oximeter values in healthy...

To describe contact forces of 3 pulse oximeter clips and to evaluate, in healthy anesthetized dogs and cats, if perfusion index (PI) or peripheral arterial blood oxygen saturation (SpO2) is influenced by lingual clip location or weight category.

Benchtop investigation of 3 clips occurred in February 2024 to determine contact force with increasing opening distances. In live animals, 1 clip was evaluated at 2 lingual locations. Enrollment of client-owned dogs and cats occurred from March 13, 2024, through June 21, 2024, including 10 each of dogs < 10 kg, dogs > 20 kg, and cats. Data included SpO2, PI, and magnitude of clip-induced lingual compression.

Clips exhibited a positive relationship between opening distance and mean force generation. Clip location and weight category in dogs influenced SpO2 and PI values. At thicker tongue locations, median SpO2 values in dogs < 10 kg and cats were 5% and 2% greater, respectively, compared to thinner locations. Dogs > 20 kg displayed a median SpO2 value 1% lower at the thicker tongue location compared to the thinner location. Median PI values were lower at the thinner tongue site in dogs and cats.

Pulse oximeter clip opening distance and contact force exhibited a positive relationship. Thicker lingual sites generated higher SpO2 and PI values in cats and dogs < 10 kg.

Pulse oximeter position at 2 different locations on the tongue influence SpO2 and PI values in healthy anesthetized dogs < 10 kg, dogs > 20 kg, and cats.