Abstract: Objective To investigate the efficacy of retrolaminar block(RLB) for postoperative analgesia in patients undergoing modified radical mastectomy.
Methods Fifty female patients,scheduled for modified radical mastectomy,were randomly divided into 2 groups(n=25 each):group RLB and control group(group C).Retrolaminar block were performed on the side of operation with 0.5% ropivacaine 20 ml in group RLB after surgery.All the patients received patient controlled intravenous analgesia(PCIA) with sufentanil after operation.The total consumption of sufentanil,the number of demand times and requirement for rescue analgesic within 24h after surgery were recorded.Visual analogue scale(VAS) scores and Ramsay sedation scores were registered at 2,4,6,12,and 24h after surgery.All adverse reactions were recorded.
Results The amount of sufentanil consumed and the number of PCIA attempts in group RLB were(20±4) μg and(13±4) time,which were less than(29±3) μg and(19±3) time of group C after surgery(P<0.05).The VAS scores at rest in group RLB were(1.9±0.5),(2.1±0.5),(1.9±0.7) at 4,6,12 h after surgery,which were lower than(2.6±0.6),(2.5±0.5),(2.3±0.5) of group C(P<0.05).There were no significant difference in Ramsay sedation scores at different time points after operation(P>0.05).The incidence of nausea and vomiting in group RLB was 16%,which was lower than 44% of group C(P<0.05).The other adverse effects were no significant difference on two groups(P>0.05).RLB-related complications were not found in all patients.
Conclusion Retrolaminar block is a safe and effective technique that reduces the postoperative opioid consumption and the occurrence of nausea and vomiting,enhances the efficacy of postoperative analgesia in patients undergoing modified radical mastectomy.

Key words: Retrolaminar block, Modified radical mastectomy, Analgesia