Ultrasound-guided quadratus lumborum block for perioperative analgesia in robot-assisted partial nephrectomy: a randomized controlled trial

BACKGROUND: Recently, several case reports and limited randomized studies have shown that quadratus lumborum blocks (QLB) are effective in providing pain relief after intra-abdominal and retroperitoneal operations. Additionally, robot-assisted partial nephrectomy (RAPN) has been proposed as a promising operative treatment for renal carcinoma because it enables early recovery and ambulation. Therefore, we aimed to evaluate the analgesic and opioid-sparing effects of a single-injection QLB in patients undergoing RAPN to determine its role in an early recovery program. METHODS: Fifty-six patients undergoing elective RAPN under general anesthesia were randomized to two equally sized groups. Patients were randomly allocated to receive either a unilateral QLB (n = 28) with 0.375% bupivacaine 0.5 mL/kg (QLB group) or a conventional scheme (n = 28) (control group). The QLB technique, termed QLB2, was performed as first described by Blanco. The primary outcome was visual analog scale (VAS) scores with movement at 6 h postoperatively. The secondary endpoints were morphine consumption at different time periods after surgery, morphine-related side effects, and assessment of postoperative rehabilitation. RESULTS: Both the VAS pain scores and cumulative opioid consumption were significantly lower in the QLB group at 6 h after surgery as compared with results in the control group (all P < 0.05). There were significant differences in pain scores at all time points except at 4 h with movement and 48 h at rest. However, at 12–24 h no significant differences between the two groups were observed in cumulative opioid consumption or in the duration of PACU and hospital stays. The patient recovery scores were significantly higher in the QLB group. CONCLUSIONS: Single-injection pre-emptive QLB applied to RAPN was effective and provided satisfactory analgesia and opioid-sparing effects in combination with typical patient-controlled analgesia. In addition, it may provide an effective technique for early recovery in the perioperative period for RAPN.