Abstract
BACKGROUND: At present, the median effective dose (ED50) and effective dose for 95% of patients (ED95) of liposomal bupivacaine for local infiltration analgesia following cesarean section have not been established. This study aimed to determine the ED95 of liposomal bupivacaine for local infiltration analgesia in patients following cesarean section. METHODS: A total of 72 primiparas scheduled to undergo lower segment cesarean sections, were randomly divided into four groups: Group 1, Group 2, Group 3, and Group 4, with 18 cases in each group. When suturing to the fascial layer, the four groups received 66.5 mg, 133 mg, 199.5 mg, and 266 mg of liposomal bupivacaine for incision infiltration analgesia, respectively. The pain intensity at coughing was assessed using a visual analog scale (VAS) within 48 hours postoperatively. Effective analgesia was defined as a VAS score of ≤ 3. The ED95 and the 95% confidence interval (CI) of liposomal bupivacaine for local infiltration analgesia after cesarean section were calculated using probit regression analysis. RESULTS: The ED50 and ED95 of liposomal bupivacaine for local infiltration analgesia following cesarean section were 128.5mg (95% CI, 106.8 to 194.4mg) and 206.1 (95% CI, 178.6 to 262.5mg), respectively. CONCLUSION: This study indicated that the ED95 of liposomal bupivacaine for local infiltration analgesia following cesarean section was 206.1 mg (95% CI, 178.6, 262.5 mg). (registration number: ChiCTR2300076315).