Practice and bias in intraoperative pain management: results of a cross-sectional patient study and a survey of anesthesiologists

Stephen Ward,1 Charlotte Guest,2 Ian Goodall,2 Carsten Bantel3,4 1Pain Service, Barts Health, St Bartholomew’s Hospital, London, UK; 2Pain Medicine, Chelsea and Westminster Hospital NHS Foundation Trust, London, UK; 3Section of Anaesthetics, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, UK; 4Department of Anesthesiology, Intensive Care Medicine, Emergency Medicine and Pain Management, Universität Oldenburg, Oldenburg, Germany Background: Perioperative pain carries a considerable risk of becoming persistent; hence aggressive preventive approaches are advocated. Persistently high prevalence of postoperative pain, however, suggests anesthesiologists underuse these strategies. A prospective cross-sectional study of patients in the postanesthetic care unit (PACU) and a survey of anesthesiologists were thus conducted to evaluate practice and uncover bias in intraoperative pain management. Methods: Notes of PACU patients were reviewed and information regarding surgical context, comorbidities, and analgesic administration was retrieved. Variables were analyzed for their predictive properties on pain and intraoperative analgesic management. Furthermore, clinical dose–effect estimates for intraoperative morphine were determined. Finally, anesthesiologists completed a questionnaire comprising statements regarding pain relating to surgical context and morphine administration. Results: Data of 200 patients and 55 anesthesiologists were analyzed. Prevalence of pain in PACU was 28% and was predicted by local anesthetic (LA) and low-dose morphine administration. Additionally, when LA was used, little coanalgesics were employed. These results suggest a restrained approach by anesthesiologists toward intraoperative pain management. It is supported by their reluctance to administer more than 10 mg morphine, despite these individuals regarding this practice as insufficient. The hesitancy toward morphine also transpired in the dose–effect estimates with the average applied dose operating on an ED63 instead of an ED95 level. Conclusion: This study confirmed a high prevalence of pain in PACU. It also indicated conservative intraoperative analgesic administration by anesthesiologists. The modest morphine usage and overreliance on LA application, which are not supported by published evidence, additionally suggest bias in current intraoperative pain management. Keywords: intraoperative morphine, multimodal analgesia, local anesthetic infiltration, clinical decision making, effective-dose, postoperative pai