V06 Evaluation of an oesophageal Doppler monitoring based treatment algorithm for reducing intraoperative hypotension in dogs undergoing general anaesthesia. Preliminary data of a randomized prospective clinical study

Objective Perioperative hypotension is associated with severe complications. Objective of this pilot study was to investigate if using an oesophageal Doppler monitor (ODM) reduces hypotensive periods in dogs undergoing general anaesthesia compared to standard monitoring.

Material and methods Fourteen dogs undergoing surgery were anaesthetized with a protocol adapted to the dog’s clinical history and were randomized to one of 2 treatment groups. Each dog received one initial fluid bolus (5 ml/kg). General anaesthesia, administration of further fluid boli and vasopressor support were directed by a heart rate and blood pressure based algorithm in group standard. In group ODM, fluids were repeated if stroke distance increased≥10% and vasopressor support was chosen based on peak velocity and flow time values. Data were recorded every minute for heart rate and blood pressure and every 5 minutes for the remaining data. Data were tested for normality and compared with appropriate tests. P-values<0.05 were deemed significant.

Results In both groups, 2/7 dogs had an ASA status>2 and hypotension (mean arterial blood pressure<60 mmHg) occurred in 3/7 dogs during more than 10% of the included time. Percentage hypotensive time was not different between ODM (1.5 [0–63]%) and standard group (9.1 [0–39]%) (p=0.55). The total amount of fluids was not different between ODM (22 [11–65] ml/kg; median [range]) and standard group (21 [14–26] ml/kg) (p=0.34).

Conclusion Dogs in the ODM group did not experience significantly shorter hypotensive periods than dogs in the standard group.

Publication History

Article published online:
03 December 2021