Monitoring blood pressure in wild brown bears: From the field to the Journal

Description

This veterinary thesis deals with arterial blood pressure monitoring during the anaesthesia of brown bears in the field and was defended by the author prior his graduation at the University of Pisa in April 2018. Being addressed to veterinarians, biologists, nature lovers and all bear enthusiasts, this work represents the first international project of the author regarding wildlife anaesthesia in the field and led to the publication of two articles in relevant scientific journals. The objective of the study was to test agreement between standard oscillometry and Korotkoff’s technique in anaesthetized free-ranging brown bears in Croatia and Scandinavia, and to assess the seriousness of hypertension in both contexts. Five bears were snared and darted with xylazine and ketamine in Croatia, while 20 bears were darted with medetomidine and tiletamine-zolazepam from the helicopter in Scandinavia, within national and international projects. Blood pressure (BP) was simultaneously measured with both non-invasive techniques every 5 minutes, as well as other physiological parameters. Correlation between techniques, trends of BP variation, and the factors of the capture which most likely induced hypertension were assessed. Oscillometry succeeded in measuring BP in 29.3% of total attempts vs 93.3% when performing Korotkoff’s technique. The former method provided lower values than the latter in yearlings, with the opposite effect in adults. Although all bears presented the common finding of a generally decreasing trend of SAP and MAP over time, consistent between the two techniques, in 11 of 20 bears several increments occurred mostly during the abdominal surgery (n = 8) in Scandinavia. All bears were hypertensive: the auscultatory technique detected moderate to severe systolic hypertension in 84.2% of bears in Scandinavia whereas 3 of 4 bears achieved at most a mild systolic hypertension in Croatia.