Intraoperative Hypotension and Vasoactive Treatment: An International Survey of Anaesthesiologists

BACKGROUND: Intraoperative hypotension is a common occurrence in patients undergoing anaesthesia, although there is no standardised definition of hypotension. International consensus statements provide some guidelines for the management of intraoperative hypotension, but general clinical practice is unknown. We aimed to survey anaesthesiologists' values and preferences regarding intraoperative blood pressure management, including whether they would support future research on this topic.

METHODS: We conducted an international, online survey of routine practice and opinion. The target population was anaesthesiologists who regularly anaesthetise adult patients. Results are reported descriptively and in accordance with the Consensus-Based Checklist for Reporting of Survey Studies (CROSS) checklist.

RESULTS: A total of 1640 anaesthesiologists from 11 European countries participated in the survey. The majority of respondents were specialists (1322 of 1640, 80.6%, 95% CI 78.7-82.6). Almost all respondents worked in public hospitals (1613 of 1640, 98.4%). The overall response rate was 22.7%. Most respondents reported using absolute mean arterial pressure as their main unit of measurement to quantify hypotension (1098 of 1640, 67.0%, 95% CI 64.6-69.2). Respondents were most likely to initiate vasoactive treatment at a mean arterial pressure below 60 or 65 mmHg. Chronic arterial hypertension, traumatic brain injury and surgical procedures involving head-up positioning of the patient were the three most common scenarios where respondents would raise their threshold for treatment. Most respondents considered the establishment of safe intraoperative blood pressure thresholds a critical research question, and almost all respondents (1509 of 1640, 92.0%) indicated a willingness to randomise patients to specific blood pressure targets. For 72.9% (1196 of 1640), the lowest acceptable mean arterial pressure for randomisation was 60 mmHg. Respondents were also interested in the comparison of efficacy and safety of vasoactive agents, and the most sought-after comparison was phenylephrine versus noradrenaline (1252 of 1640, 76.3%). The willingness of respondents to administer these agents in peripheral venous access differed according to geography.

CONCLUSION: In this international survey, mean arterial pressures of 60 or 65 mmHg were the most commonly reported blood pressure thresholds leading to initiation of treatment with vasoactive agents. Almost all respondents indicated patient groups for whom they would alter their treatment threshold, namely those suffering from chronic arterial hypertension, those undergoing surgery in a head-up position, and patients with traumatic brain injury. The majority of respondents supported future trials establishing optimal mean arterial pressure threshold and choice of vasoactive agent. We noticed a geographical variation in willingness to administer vasoactive agents in peripheral venous access.

EDITORIAL COMMENT: This survey of anaesthesiologists from European countries queried practitioner perceptions of blood pressure management in adults during anaesthesia with focus on hypotension. Queries and responses also concerned circumstances and blood pressure levels which clinicians report being willing to treat actively, and how they might do this practically.