Dynamics of the baroreflex sensitivity during combined anesthesia with sevoflurane or propofol: a randomized trial

INTRODUCTION: A significant number of complications is still a serious problem in abdominal surgery. It is known that patients with low baroreflex sensitivity are more prone to hemodynamic instability during general anesthesia, which allows them to be identified as a risk group. OBJECTIVE: To evaluate the dynamics of baroreflex sensitivity (BRS) during major abdominal surgery in patients with different risk of critical incidents under combined anesthesia with propofol or sevoflurane. MATERIALS AND METHODS: A randomized study was conducted in 160 patients (80 high-risk and 80 low-risk patients), who were randomized into subgroups according to the type of anesthesia (propofol or sevoflurane) to assess the effect of the type of anesthesia critical incidents and baroreflex dynamics. RESULTS: After the induction there was a trend towards a decrease in BRS, while in subgroups with initially low values of BRS, it decreased below 3 ms/mmHg. After the end of operation and 6 hours after ex-tubation, there were no significant changes in comparison with intraoperative values. Evaluation of BRS after 24 hours showed that BRS in all subgroups was significantly higher than at previous time points, but did not return to baseline values. At 6 hours postoperatively, in low-risk patients, BRS values were below 3 ms/mmHg in 12.5 % with propofol, and in 10 % with sevoflurane, in high-risk patients - in 45 % and 42.5 % of cases, respectively. At 24 hours, in the low-risk group, only two patients in the propofol anesthesia group and one in the sevoflurane anesthesia subgroup experienced this dysfunction. CONCLUSIONS: Both anesthesia with propofol and anesthesia with sevoflurane lead to a decrease in the sensitivity of the arterial baroreflex, which is not fully restored 24 hours after the end of the operation. High-risk patients with initially reduced baroreflex sensitivity show more frequent postoperative baroreflex dysfunction.