Our cadaveric study demonstrates that injection of dye on the posterior aspect of quadratus lumborum muscle led to injectate spread through the lateral and posterior abdominal wall but with limited cranial spread, whereas the anterior approach produced broader coverage of the lower to mid-thoracic region. Clinical translation of these findings to determine the practical significance is warranted.

The local anesthetic injectate spread with fascial plane blocks and corresponding clinical outcomes may vary depending on the site of injection. We developed and evaluated a supra-iliac approach to the anterior quadratus lumborum (QL) block and hypothesized that this single injection might successfully block the lumbar and sacral plexus in cadavers and provide analgesia for patients undergoing hip surgery. Permission to use images was obtained from the Cleveland Clinic Department of Art Photography.

We present a case of acute postoperative abdominal pain after proctosigmoidectomy and colorectal anastomosis that was treated by bilateral continuous quadratus lumborum block. The block was performed in the lateral position under ultrasound guidance with a 15-mL bolus of 0.5% bupivacaine injected anterior to the quadratus lumborum muscle followed by bilateral catheter placement. Each catheter received a continuous infusion of 0.1% bupivacaine at 8 mL/h and an on-demand bolus 5 mL every 30 minutes. Sensory level was confirmed by insensitivity to cold from T7 through T12. The block was devoid of hemodynamic side effects or motor weakness. This case demonstrates that bilateral continuous quadratus lumborum catheters can provide extended postoperative pain control.

for the FACTOR Study Group IMPORTANCE Opioid-induced ventilatory depression and hypoxemia is common, severe, and often unrecognized in postoperative patients. To the extent that nonopioid analgesics reduce opioid consumption, they may decrease postoperative hypoxemia.OBJECTIVE To test the hypothesis that duration of hypoxemia is less in patients given intravenous acetaminophen than those given placebo. DESIGN, SETTING, AND PARTICIPANTS Randomized, placebo-controlled, double-blind trial conducted at 2 US academic hospitals among 570 patients who were undergoing abdominal surgery, enrolled from February 2015 through October 2018 and followed up until February 2019.INTERVENTIONS Participants were randomized to receive either intravenous acetaminophen, 1 g (n = 289), or normal saline placebo (n = 291) starting at the beginning of surgery and repeated every 6 hours until 48 postoperative hours or hospital discharge, whichever occurred first. MAIN OUTCOMES AND MEASURESThe primary outcome was the total duration of hypoxemia (hemoglobin oxygen saturation [SpO 2 ] <90%) per hour, with oxygen saturation measured continuously for 48 postoperative hours. Secondary outcomes were postoperative opioid consumption, pain (0-10-point scale; 0: no pain; 10: the most pain imaginable), nausea and vomiting, sedation, minimal alveolar concentration of volatile anesthetic, fatigue, active time, and respiratory function.RESULTS Among 580 patients randomized (mean age, 49 years; 48% women), 570 (98%) completed the trial. The primary outcome, median duration with SpO 2 of less than 90%, was 0.7 (interquartile range [IQR], 0.1-5.1) minutes per hour among patients in the acetaminophen group and 1.1 (IQR, 0.1-6.6) minutes per hour among patients in the placebo group (P = .29), with an estimated median difference of −0.04 (95% CI,−0.18 to 0.11) minutes per hour. None of the 8 secondary end points differed significantly between the acetaminophen and placebo groups. Mean pain scores within initial 48 postoperative hours were 4.2 (SD, 1.8) in the acetaminophen group and 4.4 (SD, 1.8) in the placebo group (difference, −0.28; 95% CI, -0.71 to 0.15); median opioid use in morphine equivalents was 50 mg (IQR, 18-122 mg) and 58 mg (IQR, 24-151 mg) , respectively, with a ratio of geometric means of 0.86 (95% CI, 0.61-1.21).CONCLUSIONS AND RELEVANCE Among patients who underwent abdominal surgery, use of postoperative intravenous acetaminophen, compared with placebo, did not significantly reduce the duration of postoperative hypoxemia over 48 hours. The study findings do not support the use of intravenous acetaminophen for this purpose.