Intraoperative opioid administrations, rescue doses in the post-anaesthesia care unit and clinician-perceived factors for dose adjustments in adults: A Danish nationwide survey.

Background: The impact of demographic- and surgical factors on individual perioperative opioid requirements is not fully understood. Anaesthesia personnel adjust opioid administrations based on their own clinical experience, expert opinions and local guidelines. This survey aimed to assess the current practice of anaesthesia personnel regarding intraoperative opioid treatment for postoperative analgesia and rescue opioid dosing strategies in the post-anaesthesia care unit in Denmark.

Methods: We conducted a cross-sectional online survey with 37 questions addressing pain management and opioid-dosing strategies. Local site investigators from 46 of 47 public Danish anaesthesia departments distributed the survey. Data collection took place from 5 February to 30 April 2024.

Results: Of the 4187 survey participants, 2025 (48%) answered. Intra- and postoperative opioid doses were adjusted based on chronic pain, age, preoperative opioid use, body weight and type of surgery. Between 84% and 89% of respondents adhered to and had perioperative pain management guidelines available. Respondents preferred intraoperative fentanyl (44%) and morphine (36%) to prevent postoperative pain. Median intraoperative intravenous morphine equivalents ranged from 0.12 to 0.38 mg/kg in clinical scenarios. In these cases, the following variables were assembled in different combinations to assess their impact on dosing: age (30 vs. 65 years), sex (female vs. male), ASA score (1 vs. 3) and type of surgery (anterior cruciate ligament vs. laparoscopic cholecystectomy surgery). Respondents preferred intravenous morphine and fentanyl for moderate and severe postoperative pain, respectively. Median postoperative rescue doses were 0.06-0.12 mg/kg in clinical scenarios based on shifting combinations of the variables: age (30 vs. 65 years), ASA score (1 vs. 3) and degree of expected pain (moderate vs. severe).

Conclusion: Respondents preferred fentanyl and morphine for postoperative pain control with considerable variation in choice of opioid and morphine equivalent dose. Respondents expressed that guidelines were highly available and strongly adhered to. Opioid dosing was predominantly guided by chronic pain, age, preoperative opioid use, body weight and type of surgery.