Comparison of intrathecal low-dose bupivacaine and morphine with intravenous patient control analgesia for postoperative analgesia for video-assisted thoracoscopic surgery

BACKGROUND: Thoracoscopic surgical techniques continue to advance, yet the intensity of postoperative pain remains significant, impeding swift patient recovery. This study aimed to evaluate the differences in postoperative pain and recuperation between patients receiving intrathecal morphine paired with low-dose bupivacaine and those administered general anesthesia exclusively. METHODS: This randomized controlled trial enrolled 100 patients, who were allocated into three groups: Group M (5 μg/kg morphine intrathecal injection), Group B (5 μg/kg morphine combined with bupivacaine 3 mg intrathecal injection) and Group C (intrathecal sham injection). The primary outcome was the assessment of pain relief using the Numeric Rating Scale (NRS). Additionally, intraoperative remifentanil consumption was quantified at the end of the surgery, and postoperative opioid use was determined by the number of patient-controlled analgesia (PCIA) compressions at 48 h post-surgery. Both the efficacy of the treatments and any complications were meticulously recorded. RESULTS: Postoperative NRS scores for both rest and exercise at 6, 12, 24, and 48 h were significantly lower in groups M and B than in group C (P<0.05). The intraoperative remifentanil dosage was significantly greater in groups M and C than in group B (P<0.05), while there was no significant difference between groups M and C (P>0.05). There was no significant difference in intraoperative propofol dosage across all three groups (P>0.05). Postoperative dosages of both sufentanil and Nonsteroidal anti‐inflammatory drugs (NSAIDs) were significantly less in groups M and B compared to group C (P<0.05). The time of first analgesic request was later in both groups M and B than in group C (P<0.05). Specific and total scores were elevated at 2 days postoperative when compared to scores at 1 day for all groups (P<0.05). Furthermore, at 1 day and 2 days postoperatively, both specific scores and total scores were higher in groups M and B compared to group C (P<0.05). CONCLUSION: Intrathecal administration of morphine combined with bupivacaine has been shown to effectively ameliorate acute pain in patients undergoing thoracoscopic surgery. TRIAL REGISTRATION: The trial was registered on ClinicalTrials.gov: ChiCTR2200058544, registered 10/04/2022.