Comparison between intrathecal morphine and intravenous patient control analgesia for pain control after video-assisted thoracoscopic surgery: A pilot randomized controlled study

Background Video-assisted thoracoscopic surgery (VATS) is a minimally invasive procedure, but patients may still experience intense pain, especially during the early postoperative period. Intrathecal morphine (ITM) is an effective pain control method that involves a simple maneuver and has a low risk of complications. This study aimed to study the effectiveness of ITM for pain control in patients who undergo VATS. Materials and methods A randomized controlled study was conducted who were in ASA classes 1-3, aged over 18 years, and scheduled for elective VATS. Patients were randomized into two groups: the ITM group (n = 19) received a single shot of 0.2 mg ITM before general anesthesia; and the control group (n = 19) received general anesthesia only. For 48 hours after surgery, other than intravenous patient-controlled analgesia (IVPCA) morphine, patients received no sedatives or opioid medications except for 500 mg acetaminophen four times daily orally. Postoperative pain scores and IVPCA morphine used, side effects, sedation at specific time-points, i.e., 1, 6, 12, 24, and 48-hours and overall treatment satisfaction scores were assessed. Results Postoperative pain scores (median [IQR]) in ITM group were significantly lower than control group (repeated-measure ANOVA, p = 0.006) and differed at the first (7 [2, 7] vs 8 [6, 9], p = 0.007) and sixth hours (3 [2, 5] vs 5 [5, 7], p = 0.002). The cumulative dose of post-operative morphine (median [IQR]) in ITM group was also lower (6 [3, 20] vs 19 [14, 28], p = 0.006). The incidence of pruritus was significantly higher in ITM group (68.42% vs. 26.32%, p = 0.009). No significant differences in nausea and vomiting, sedation scores, and satisfaction scores were observed between the two groups. Conclusion ITM could reduce pain scores and opioid consumption after VATS compared to IVPCA-opioids. However, pain scores and opioid consumption still remained high. No difference in patient satisfaction was detected.