Transmuscular quadratus lumborum block for percutaneous nephrolithotomy reduces opioid consumption and speeds ambulation and discharge from hospital: a single centre randomised controlled trial

Abstract

Background: Percutaneous nephrolithotomy (PNL) is associated with severe postoperative pain. The current study aimed to investigate the analgesic efficacy of transmuscular quadratus lumborum (TQL) block for patients undergoing PNL surgery.

Methods: Sixty patients were enrolled in this single centre study. The multimodal analgesic regime consisted of oral paracetamol 1 g and i.v. dexamethasone 4 mg before surgery and i.v. sufentanil 0.25 μg kg-1 30 min before emergence. After operation, patients received paracetamol 1 g regularly at 6 h intervals. Subjects were allocated to receive a preoperative TQL block with either ropivacaine 0.75%, 30 ml (intervention) or saline 30 ml (control). Primary outcome was oral morphine equivalent (OME) consumption 0-6 h after surgery. Secondary outcomes were OME consumption up to 24 h, pain scores, time to first opioid, time to first ambulation, and hospital length of stay. Results were reported as mean (standard deviation) or median (inter-quartile range).

Results: Morphine consumption was lower in the intervention group at 6 h after surgery (7.2 [8.7] vs 90.6 [69.9] mg OME, P<0.001) and at 24 h (54.0 [36.7] vs 126.2 [85.5] mg OME, P<0.001). Time to first opioid use was prolonged in the intervention group (678 [285-1020] vs 36 [19-55] min, P<0.0001). Both the time to ambulation (302 [238-475] vs 595 [345-925] min, P<0.004) and length of stay (2.0 [0.8] vs 3.0 [1.2] days, P≤0.001) were shorter in the intervention group.

Conclusions: This is the first blinded, RCT that confirms that unilateral TQL block reduces postoperative opioid consumption and hospital length of stay. Further study is required for confirmation and dose optimisation.

Clinical trial registration: NCT02818140.

Keywords: length of hospital stay; local anaesthetic; multimodal analgesia; nerve block; postoperative pain; quadratus lumborum block; ultrasonography.

Conflict of interest statement

The authors declare that they have no conflicts of interest.

Copyright © 2019 British Journal of Anaesthesia. All rights reserved.

Figures

Fig. 1

Consolidated Standards of Reporting Trials (CONSORT) flow diagram. PNL, percutaneous nephrolithotomy; TQL, transmuscular quadratus lumborum.

Fig. 2

Kaplan–Meier survival plot. Time to first opioid from arrival at PACU (T0). Kaplan–Meier survival plot of time to first opioid (min), defined as time from T0 until first request for opioid.

Fig. 3

Numeric Rating Scale (NRS) scores at rest and at activity. Median NRS pain scores 0–10/10 with inter-quartile range (IQR). Both figure parts show the median (IQR) NRS scores at the intervals between 0–6, 6–12, 12–18, 18–24 h. (A) median (IQR) NRS score at rest, defined as lying in bed; (B) median (IQR) NRS score with activity.

Fig. 4

Kaplan–Meier survival plot. Time to first ambulation from arrival at PACU. Kaplan–Meier survival plot of time to first ambulation (min), defined as time from PACU (T0) until the subject was able to stand up and walk unassisted.

Fig. 5

Anatomical details at vertebral levels L1 and L3. At level L1 (left), the psoas major (PM) and quadratus lumborum (QL) muscles are visible postero-medial to the diaphragm (indicated by pink colour). At level L3 (right), the perirenal and pararenal fat compartments are distinct and clearly visible. Modified excerpt from VH Dissector with permission from Touch of Life Technologies Inc (www.toltech.net). Built on real anatomy from the National Library of Medicine Visible Human Project. Red arrows indicate the perirenal fat compartment, yellow arrows indicate the pararenal fat compartment, white arrows indicate the needle pathway. C, costae; ES, erector spinae muscle; K, kidney.