Analgesic efficacy of two approaches of ultrasound-guided quadratus lumborum block for laparoscopic renal surgery: A randomised controlled trial.

BACKGROUND Moderate-to-severe pain exists in the early postoperative period after laparoscopic renal surgery. OBJECTIVE We investigated the analgesic effect of quadratus lumborum block (QLB) via two approaches in patients undergoing laparoscopic renal nephrectomy. DESIGN A randomised controlled trial. SETTING An academic tertiary care hospital in Beijing, China. PARTICIPANTS Ninety-six patients aged 18 to 70 years who were scheduled for elective laparoscopic radical or partial nephrectomy. INTERVENTIONS Eligible patients were allocated randomly to a control group (no block), lateral QLB group or posterior QLB group. Ultrasound-guided QLB was performed via either the lateral or posterior approach with 30 ml of 0.4% ropivacaine before surgery. MAIN OUTCOME MEASURES The primary outcome was sufentanil equivalent consumption within 24 h. Among secondary outcomes, somatic and visceral pain intensity at rest and on coughing were assessed with a numerical rating scale (where 0 = no pain and 10 = the worst pain) until 24 h postoperatively. RESULTS Sufentanil equivalent consumption did not differ among the three groups (118 ± 36 μg in the control group, 115 ± 47 μg in the lateral QLB group and 119 ± 40 μg in the posterior QLB group; P = 0.955). However, both somatic (lateral QLB vs. control, median difference -1, P < 0.001 at rest and -2 to -1, P < 0.001 on coughing; posterior QLB vs. control, -1, P < 0.001 at rest and -2 to -1, P < 0.001 on coughing) and visceral pain scores (lateral QLB vs. control, -1 to 0, P < 0.001 at rest and -1, P < 0.001 on coughing; posterior QLB vs. control, -1 to 0, P < 0.001 at rest and -2 to -1, P < 0.001 on coughing) were significantly lower in the two QLB groups than in the control group. CONCLUSION For patients undergoing laparoscopic renal surgery, a pre-operative single-shot QLB via the lateral or posterior approach did not decrease opioid consumption, but improved analgesia for up to 24 h after surgery. TRIAL REGISTRATION www.chictr.org.cn identifier: ChiCTR1800019883.