Quadratus lumborum (QL) block was first described in 2007 by Blanco and McDonnell1 in a congress abstract; however, this block and its relevant points of injection have only recently been well characterized.2 Publications involving QL block are few and for the most part entail either single case reports3 or small trials4,5 involving abdominal surgery. Parras and Blanco6 recently reported its use as an alternative to femoral nerve block for postoperative analgesia after fractured neck of femur. As yet, there are no confirmatory reports of the use of QL block for hip surgery. We present 2 patients who underwent different surgical procedures of the hip, both of whom showed marked and prolonged analgesia after single-shot QL block.
Oral and written informed consent for publication of patients’ data in an anonymous form were obtained at the time of anesthesia consent.
DESCRIPTION OF THE CASES
A 69-year-old, 60-kg female patient with a medical history of osteopenia, hypertension, fibromyalgia, and placement of a sacral nerve stimulator for urinary/fecal incontinence presented to the emergency department after a fall. She was diagnosed with right subcapital femoral neck fracture and scheduled for open reduction and internal fixation the following day. Overnight pain was reported as severe (numeric rating scale [NRS] between 7 and 10), and she required several rescue doses of intravenous hydromorphone (total of 1.0 mg).
Considering the sacral nerve stimulator and wires in the right lumbosacral region, we decided to refrain from our usual anesthetic plan for hip surgery (lumbar plexus [LP] block + spinal anesthesia) and opted for QL block as the primary analgesic block plus general anesthesia for the surgical procedure. After obtaining written informed consent, we transferred the patient to the preoperative holding area, and standard monitors were applied. She was placed in the supine position, slightly tilted to the left. After sterile preparation and with a standard aseptic technique, a low-frequency curved array probe covered by sterile plastic sleeve was placed horizontally on the umbilicus and moved laterally. Both rectus abdominis and the 3 muscle layers of the abdominal wall were identified and traced posteriorly to the point where the deep fascia of the transversus abdominis merges with the thoracolumbar fascia. A 22-gauge 8-cm nonstimulating Tuohy needle was inserted in plane with the probe until appropriate location for a QL type I block according to Blanco and McDonnell1 was achieved.
Needle positioning was confirmed by careful hydrodissection with normal saline, and after negative aspiration, 20 mL of 0.5% ropivacaine + dexmedetomidine 20 μg + dexamethasone 4 mg were injected and appropriate, posterior spread observed. Within 5 minutes, the patient reported complete absence of pain both at rest and with the initiation of movement. She was then taken to the operating room, and general anesthesia was induced with propofol 80 mg, lidocaine 20 mg, fentanyl 100 μg, and succinylcholine 100 mg intravenously (IV). In addition, ketamine 15 mg IV was given as part of our standard multimodal analgesia protocol. The patient received no further opioid intraoperatively. She woke up reporting no pain at all, and she required no pain medication in the postanesthesia care unit (constant pain scores values of 0). She was quickly discharged to the ward with standard orders of scheduled oral acetaminophen and oral oxycodone as needed. She was able to walk with assistance within hours of surgery. Pain scores ranged between 4 and 5 (with the patient verbalizing comfort) overnight and during the following day until her discharge home in the afternoon of postoperative day 1. During her postoperative course, she requested only 3 doses of oral oxycodone and never needed breakthrough IV narcotics.
A 62-year-old female patient with a medical history of diffuse osteoarthritis status post right total hip arthroplasty, low-back pain, spinal stenosis status post spinal decompression procedures, and hypothyroidism status post thyroidectomy was scheduled for revision of the right total hip arthroplasty. During the preoperative evaluation, she reported chronic low-back and right hip pain (NRS 6–7), in addition to a throbbing pain around the mid-thigh area, both treated with daily use of oral acetaminophen and nonsteroidal anti-inflammatory drugs. Because of the chronic pain and osteoarthritis, she was constantly using crutches for ambulation.
After obtaining written informed consent, we placed the patient in the left lateral decubitus position and standard monitors were applied. Using the same technique and type of needle as in case 1, we injected ropivacaine 0.5% 30 mL (with epinephrine 1:200.000) + dexmedetomidine 30 μg + dexamethasone 4 mg and observed an appropriate, posterior spread. The patient was re-evaluated 5 minutes after completing the block, and she reported complete regression of pain in the right hip area, together with the absence of any throbbing pain in her thigh. In addition, she reported reduced sensation over the T6-L3 dermatomes ipsilateral to the site of nerve block with complete sparing of motor function.
The patient was then brought to the operating room, where spinal anesthesia and multimodal analgesia were administered according to our standard protocol (intravenous magnesium, ketamine, and dexamethasone). The procedure was uneventful, and the patient was then brought to the postanesthesia care unit. After resolution of the spinal block, the patient reported moderate incisional pain over the distal one-fourth of surgical incision, presumably over L4-L5 dermatome areas of the posterolateral thigh. Complete absence of pain and sensation was reported over the other lumbar dermatomes cranial to L4 and encompassing the proximal three-fourth of the surgical incision. Further confirmation of the extent of nerve block (T6-L3) was obtained by performing pinprick and ice-cold tests. After receiving 4 doses (total 0.8 mg) of rescue intravenous hydromorphone for the aforementioned pain, the patient was discharged to the ward with standard analgesic medication orders: scheduled oral acetaminophen 1 g every 6 hours, celecoxib 200 mg every 12 hours, gabapentin 600 mg at bedtime, and oral ketamine 10 mg every 8 hours together with oral oxycodone as needed and rescue intravenous hydromorphone. The extent of the nerve block was retested after 12 (T6-L3) and 24 (T6-L2) hours, with no significant regression seen. No formal evaluation was performed at 36 hours, but after 48 hours the block had completely regressed with recovery of “sensation to light touch” reported by the patient after about 30 hours.
No further follow-up visits were made, but over the course of her postoperative course the patient required only one rescue dose of hydromorphone during the night between postoperative days 1 and 2, presumably because of resolution of the nerve block. The patient verbalized comfort during her hospital stay, and pain scores were satisfactory for the vast majority of the time, despite occasional recorded values in the “moderate” range (NRS up to 7), mainly during movement or physical therapy. She was discharged on postoperative day 4.
We present 2 cases of significant, extensive, and long-lasting analgesia after QL block in which we used 0.5% ropivacaine, dexmedetomidine, and dexamethasone. The term “QL block” encompasses 3 distinct blocks according to the position of the needle with respect to the QL muscle: lateral, posterior, or anterior.1,2 As of now, these 3 separate blocks are considered equivalent because there are no published studies that compare the pattern of spread of the injectate and the efficacy of each block compared with the others. It has been postulated that QL block might act as an “indirect paravertebral” because of posterior spread of the injectate to the lumbar paravertebral space and the existing continuity between fascia transversalis and endothoracic fascia allowing further spread to the thoracic paravertebral space.
On the basis of the results of Carney et al,7 we began performing a single-shot QL type I block as an alternative to fascia iliaca or femoral nerve block in patients with hip fracture to improve comfort and decrease pain before turning patients to a lateral position to perform a continuous LP block for postoperative pain. In light of the quality and the magnitude of pain relief achieved immediately after these QL blocks, we progressed to using it as a primary analgesic technique in patients undergoing open reduction and fixation of hip fracture. More recently, we have further broadened indications for this type of block, including patients undergoing primary hip replacements.
In comparison with the article published by Parras and Blanco,6 we used a greater concentration of local anesthetic (0.5% ropivacaine vs 0.125% levobupivacaine), and this (in addition to the adjuvants we administered) has probably contributed to the longer duration and pain relief experienced by our patients after QL block. We were able to follow the second patient closely and to determine the exact level of dermatome coverage, as well as the regression of sensory block, as opposed to the aforementioned study in which patients were followed for 24 hours postoperatively and the sensory block was evaluated by loss of sensation to cold spray in 3 different areas of the thigh (lateral, medial, and anterior) only. However, we did not perform a systematic evaluation of motor function (eg, Bromage score), but rather we base our claims about motor block on the reports filed by physical therapists.
That shortcoming notwithstanding, a remarkable finding in our patients is the absence of hip flexor or quadriceps weakness observed after QL block even with the high concentration (0.5% ropivacaine) of local anesthetic. This stands in contrast to LP block where a common complaint is the significant degree of weakness seen even with relatively low concentrations of local anesthetic. Avoidance of local anesthetic injection into the psoas muscle may account for this. Lee et al8 reported the use of lumbar paravertebral block in place of LP block for outpatient hip arthroscopy in an attempt to minimize weakness after the surgery. Another possible explanation for the absence of motor block is the limited L3 and virtually absent L4 spread of local anesthetic in our patients, with subsequent limited involvement of the femoral nerve. The unusually long duration of the blocks and the extended comfort displayed by both patients represents another interesting finding which should be confirmed with large, prospective studies. It is also unknown whether the level (L1-L2 vs lower) at which the QL block is performed or whether the injected volume could possibly affect the cranio-caudal spread of local anesthetic and therefore its extent of dermatomal coverage.
On a final note, our assessment of the cost of single-shot QL blocks versus continuous LP blocks is that the former represents a significant savings. If our clinical findings are corroborated by further evidence, we think that the popularity of single-shot QL blocks for hip surgery is likely to increase dramatically, particularly in the light of progressive implementation of bundled payments for joint replacements.
In summary, we report 2 cases of marked and prolonged analgesia of the hip after single-shot QL1 block. Further studies are necessary not only to better characterize the different QL blocks but also to define how the block might best be used and in which surgeries it will prove useful.
3. Shaaban M, Esa WA, Maheshwari K, Elsharkawy H, Soliman LM. Bilateral continuous quadratus lumborum block for acute postoperative abdominal pain as a rescue after opioid-induced respiratory depression. A A Case Rep. 2015;5:107–111.
4. Murouchi T, Iwasaki S, Yamakage M. Quadratus lumborum block: analgesic effects and chronological ropivacaine concentrations after laparoscopic surgery. Reg Anesth Pain Med. 2016;41:146–150.
5. Blanco R, Ansari T, Girgis E. Quadratus lumborum block for postoperative pain after caesarean section: a randomised controlled trial. Eur J Anaesthesiol. 2015;32:812–818.
6. Parras T, Blanco R. Randomised trial comparing the transversus abdominis plane block posterior approach or quadratus lumborum block type I with femoral block for postoperative analgesia in femoral neck fracture, both ultrasound-guided. Rev Esp Anestesiol Reanim. 2016;63:141–148.
7. Carney J, Finnerty O, Rauf J, Bergin D, Laffey JG, Mc Donnell JG. Studies on the spread of local anaesthetic solution in transversus abdominis plane blocks. Anaesthesia. 2011;66:1023–1030.
8. Lee EM, Murphy KP, Ben-David B. Postoperative analgesia for hip arthroscopy: combined L1 and L2 paravertebral blocks. J Clin Anesth. 2008;20:462–465.