Digital archive of theses discussed at the University of Pisa


Thesis etd-03272018-104204

Thesis type
Tesi di laurea magistrale LM5
email address
Thesis title
Comparison of two non-invasive blood pressure monitoring techniques in anaesthetized free-ranging brown bears (Ursus arctos)
Course of study
relatore Prof.ssa Briganti, Angela
correlatore Prof. Huber, Djuro
controrelatore Prof. Barsotti, Giovanni
  • Korotkoff
  • hypertension
  • Brown bear
  • blood pressure
  • oscillometry
Graduation session start date
Introduction: monitoring arterial blood pressure (BP), representing a more accurate evaluation of hemodynamics than heart rate alone, is essential for preventing and treating intra- and post-operative complications in wildlife chemical immobilization.
Objective: to test correlation 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.
Materials and Methods: 5 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. 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.
Results: 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.
Discussion and conclusion: several inconsistent values occurred with the oscillometric method, showing lack of precision and low correlation with the auscultatory technique, which, contrarily, provided more reliable trends of variations in all bears. Korotkoff’s method resulted in a reliable and effective tool for BP assessment in brown bears, though further comparative studies with invasive BP are needed to test the accuracy of the method and to assess the incidence of target-organ damage in anaesthetized free-ranging brown bears. The anaesthetic protocol used in the present study in association with the capture methods produced hypertension in all the animals.