Abstract: Objective To evaluate the effect of modified and traditional subcostal and anterior quadratus lumborum block on postoperative analgesia in patients with laparoscopic nephrectomy.Methods 46 patients underwent laparoscopic nephrectomy.They were randomly divided into two groups:traditional subcostal quadratus lumborum block(group T) and modified subcostal quadratus lumborum block(group M),with 23 cases in each group.Before anesthesia induction,the T group was subjected to the traditional subcostal and anterior quadratus lumborum block under ultrasound guidance,and the M group was subjected to the modified subcostal quadratus lumborum block under ultrasound guidance.All were given 0.5% ropivacaine 20 ml.Patients controlled intravenous analgesia(PCIA) was performed in both groups.The dermatomal levels of 5min,10 min and 15min after block was recorded.VAS pain scores at rest and cough were recorded at 6,24 and 48 h after the block.The dosage of Sufentanil,the number of analgesic pump compressions and the flurbiprofen rescue were recorded 24 h after surgery.Results The number of block plane segments in group M at 5, 10 and 15 minutes after block were 6(4,8), 8(6, 9) and 8(6, 9), respectively,which were significantly more than the T group[4(2,6), 6(2,9), 6(2,9)] (P<0.05).The VAS pain scores of patients in group M were (1.6±0.5) points at rest and (3.7±0.6) points at cough 6 hours after block,24 hours after the block were (2.3±0.4) points and (3.4±0.4) points, respectively,48 hours after the block were (2.5±0.8) min and (3.2±0.7) min, respectively.The VAS pain scores of and at rest and cough 6 hours after block in T group were (2.5±0.7) points and (5.6±0.8) points, respectively,24 hours after the block were (3.1±0.5) points and (4.5±0.7) points, respectively,48 hours after the block were (3.3±0.6) min and (4.2±0.6) min, respectively.Group M was lower than group T(P<0.05).In group M, the dosage of sufentanil, the times of analgesic pump and the rate of analgesic relief 24 hours after operation were (23.1±4.3)μg, 5(4,7) times and 4.3%, respectively,which were significantly lower than those in T group[(34.7±6.8)μg,11(9，12)times,21.7%](P<0.05).Conclusion Ultrasound-guided modified subcostal and anterior quadratus lumborum block has better analgesic effect than traditional technique in patients undergoing laparoscopic nephrectomy,which can reduce the amount of postoperative analgesic drugs and effectively relieve postoperative pain.

Key words: regional anesthesia；quadratus lumborum；ultrasound；postoperative pain