Epidural analgesia versus oral morphine for postoperative pain management following video-assisted thoracic surgery: A randomised, controlled, double-blind trial

Background: The use of thoracic epidural analgesia for postoperative pain management in video-assisted thoracic surgery (VATS) is controversial. Still, the evidence on omitting it in favour of systemic opioids is inconclusive, and studies are small and non-blinded.

Objective: We aimed to compare pain after VATS using epidural analgesia or enteral opioids for postoperative pain management.

Design/setting/patients/intervention: A randomised, double-blind, controlled trial at a Danish tertiary hospital. Adult patients scheduled for VATS were assigned to multimodal non-opioid baseline analgesia supplemented with either thoracic epidural analgesia (TE Group) or oral morphine (OM Group) for postoperative pain management. We recorded pain five times a day, both at rest and during activity, using the Numeric Rating Scale (NRS) and categorised it into "acceptable pain" or "unacceptable pain". Unacceptable pain was defined as NRS (at rest) ≥3 or NRS (with activity) ≥5 when supplementary analgesics were given.

Main outcome measures: The primary outcomes were the proportions of patients experiencing "unacceptable pain" during the postoperative period and the use of intravenous "rescue" opioids.

Results: Of the 161 included patients, 146 received the allocated treatment and their data were analysed. At rest, 34% of patients in the TE Group and 64% of patients in the OM Group experienced unacceptable pain during the study period, a significant between-group difference of 30% ( P < 0.0005). During activity these percentages were 32% of patients in the TE Group and 59% in the OM group, a difference of 27% ( P < 0.005). The median intravenous rescue morphine consumption during the study period was 4.5 [interquartile range (IQR), 0-10.0] mg in the TE Group and 7.5 [0-19.0] mg in the OM Group ( P < 0.005).

Conclusion: Epidural analgesia provided better pain relief after VATS than oral morphine. The between-group difference in rescue intravenous morphine consumption was statistically significant but clinically irrelevant.

Trial registration: ClinicalTrials.gov (NCT02359175).