Ultrasound-guided Quadratus Lumborum Block for Postoperative Analgesia in Patients Undergoing Nephrectomy: A Systematic Review and Meta-analysis.

Background: Ultrasound-guided quadratus lumborum block (QLB) is used for intraoperative and postoperative pain relief in laparoscopic total and partial nephrectomy. The analgesic efficacy of QLB in nephrectomy remains under-explored and needs evaluation.

Methods: A comprehensive literature search was done to assess the effectiveness of preoperative QLB for nephrectomy. The primary objective was to evaluate postoperative opioid consumption following laparoscopic total and partial nephrectomy. In total nephrectomy, the opioid requirement was recorded at 24 h interval. In partial nephrectomy patients, postoperative opioid requirement was recorded at 6-12 h, 12-24 h and 24-48 h. The secondary objective was to assess the incidence of nausea and vomiting in both the groups.

Results: Single-shot QLB was compared with no block or sham block in laparoscopic total and partial nephrectomy. In total laparoscopic nephrectomy, significant reduction of postoperative opioid consumption in patients with QLB (weighted mean difference [WMD]: -549.11, 456.07; P = 0.004) than the control group seen. Nausea was 35% lower in the QLB group than the control group (risk ratio [RR]: 0.65, 95% confidence interval [CI]: 0.39-1.10). In partial nephrectomy, QLB group had less opioid use at 6-12 h (WMD: -6.23, 95% CI: -9.76--2.70), 12-24 h (WMD: -5.40, 95% CI: -10.10--0.70) and 24-48 h (WMD: -1.12, 95% CI: -6.52-4.29). Partial nephrectomy group QLB showed 28% decrease in the vomiting than the control group (RR: 0.72, 95% CI: 0.3-1.50).

Conclusion: Significant reduction in the requirement of postoperative opioid, nausea and vomiting in group receiving single-shot QLB in laparoscopic nephrectomy patients was seen. The results suggest that QLB can serve as an important part of multimodal analgesia strategies.