Raffaele Silani, University of Padova

Anaesthetising free-ranging brown bears entails substantial cardiovascular risk, exacerbated by limited baseline health information and the routine use of hypertensive sedative agents. Although cardiovascular monitoring is essential, blood pressure is not routinely measured due to limitations of non-invasive techniques.
This prospective experimental study aimed to evaluate the feasibility and accuracy of non-invasive blood pressure (NIBP) measurements obtained from the tongue compared with invasive blood pressure (IBP) measurements in brown bears (Ursus arctos). The accuracy of heart rate (HR) measurements obtained using the non-invasive device was also evaluated.
Sixteen brown bears were anaesthetised with medetomidine–tiletamine–zolazepam. Paired IBP (femoral arterial catheter) and NIBP (lingual cuff) measurements were recorded every three minutes. Agreement between methods was assessed using American College of Veterinary Internal Medicine (ACVIM) and American Association for the Advancement of Medical Instrumentation (AAMI) criteria.
A total of 172 paired measurements were included in the analysis. Mean invasive arterial pressures were 186±50 mmHg for systolic, 131±34 mmHg for mean, and 111±30 mmHg for diastolic arterial pressure. NIBP and IBP measurements showed moderate to strong correlations (r=0.58–0.84), with closer agreement at lower pressure ranges.
HR measured by the non-invasive device showed good accuracy and precision compared with ECG (r=0.79, mean bias −1.04 bpm, 95% limits of agreement −14.35 to +12.27 bpm).
Although NIBP measurements did not meet ACVIM or AAMI validation criteria, the technique provided consistent blood pressure and heart rate trends across individuals, making it a valuable monitoring tool in field conditions where invasive blood pressure measurement is impractical.