Sublingual sufentanil after orthopaedic and abdominal surgery: long-term outcome and safety.

Background: Acute postoperative pain management often requires opioid treatment with patient-controlled analgesia (PCA). Non-invasive PCA with a sublingual sufentanil tablet system (SSTS) may reduce acute pain sufficiently, but opioids are associated with central nerve system side effects and risk of long-term opioid use postoperatively. The objective of this study was to observe the SSTS to assess the incidence of postoperative chronic pain (PCP) and postoperative delirium (POD).

Methods: This was a longitudinal cohort study based at a university hospital between November 2017 and November 2021. Adults undergoing elective orthopaedic knee or abdominal surgery planned for PCA as postoperative pain management were included. They received the SSTS in addition to a standardised pain medication protocol depending on the surgery they underwent. Exclusion criteria were pregnancy, emergency surgery, concurrent participation in another clinical trial and chronic opioid use before surgery. Patients were followed after surgery in hospital and over 3 and 12 months for pain, cognitive function and side effects.

Results: Altogether N = 80 patients were included with SSTS postoperatively. Daily pain experience decreased from pre-operatively 89.2% of patients to 45.7% and 22.5% at 3 and 12 months. None of our patients developed postoperative delirium after surgery. Patients reported high overall satisfaction with SSTS (median 8.0/10 points, IQR 3). However, 51% of patients had difficulties with handling the SSTS and required acute replacement of the authentication tag.

Conclusions: SSTS sufficiently treated acute postoperative pain without incidence of POD and demonstrated good tolerability and overall ease. Postoperative pain improved significantly over time but 22% still reported chronic pain related to surgery. Technical issues with the identification thumb tag limited the feasibility of SSTS.

Trial registration: This prospective longitudinal cohort study was approved by the ethics committee of the Charité Universitätsmedizin Berlin (Ethics committee 2, Campus Charité Virchow Klinikum, EA2/041/17, Prof. Dr. jur. R. Seeland, 21.03.2017) and was registered in the study register ( https://clinicaltrials.gov/ct2/show/NCT03133858 ).