Preoperative quadratus lumborum block reduces opioid requirements in the immediate postoperative period following hip arthroscopy: a randomized, blinded clinical trial.

Abstract

Purpose:

The purpose of this study was to examine acute postoperative opioid consumption in patients undergoing hip arthroscopy and randomized to either receive a preoperative lateral quadratus lumborum block or sham injection.

Methods:

This trial randomized 46 subjects undergoing hip arthroscopy with a single surgeon to receive a preoperative lateral quadratus lumborum block (40 ml, ropivacaine 0.25%) or sham injection. The primary outcome was postoperative opioid consumption in patients with and without a block. All opioid medications were converted to morphine milligram equivalents for comparisons. Categorical data were compared with Chi-square tests and Fisher Exact Tests where appropriate. Continuous data were compared with 2-sided t-test and Wilcoxon rank-sum tests.

Results:

Forty-six subjects scheduled for elective hip arthroscopy were successfully consented and randomized. Demographic and clinical characteristics did not differ. Postoperative opioid consumption decreased 28.3% in patients that received a preoperative lateral quadratus lumborum block (P=0.04). Total perioperative opioid consumption (intraoperative and postoperative combined) was reduced 20% in the block group; however, this did not achieve statistical significance (P=0.05). Three subjects in the sham group (12.5%) required unblinding for a rescue block in PACU for uncontrolled pain despite systemic analgesics. While cold sensation was decreased postoperatively over the abdomen (P<0.001) and anterior thigh (P=0.03) in the block group, other PACU variables did not differ including VAS pain scores, motor function, side effects, PACU duration, and patient satisfaction.

Conclusions:

Opioid consumption was reduced in patients that received a preoperative lateral quadratus lumborum block combined with a standardized, multimodal protocol as compared to patients who did not receive a block. Our findings support the growing evidence that quadratus lumborum blocks are an effective component of multimodal analgesia options for patients undergoing elective hip arthroscopy.

Level of Evidence:

Level I – Randomized controlled trial

Introduction

When compared to open procedures, arthroscopic procedures are generally associated with decreased morbidity, but postoperative pain control remains a major concern for hip arthroscopy.¹ In the setting of a national opioid epidemic in the United States, physicians and patients are seeking safe and effective strategies to reduce postoperative opioid administration while optimizing analgesia.²

As hip arthroscopy is usually performed as an outpatient procedure in the United States, effective and safe postoperative management is a priority.³ Ineffective pain management can adversely affect patient experience and delay discharge due to increased postoperative opioid consumption, nausea, vomiting, and opioid induced sedation.¹ Regional anesthesia plays a significant role in perioperative pain control and has been investigated as a means of controlling postoperative pain.^{4, 5} While several regional anesthesia techniques have been investigated for hip arthroscopy, no consensus on an optimal approach has been reached.

The quadratus lumborum (QL) block is an ultrasound-guided fascial plane block that focuses injecting local anesthetic near the thoracolumbar nerves between two myofascial layers. It has been targeted as a potential treatment for postoperative pain from hip arthroscopy.^6–8 Historically described for analgesia for intraperitoneal, retroperitoneal, and pelvic surgery,⁷ multiple case reports have suggested the QL block may provide analgesia for hip surgery.^8–11 While retrospective studies have examined the efficacy of the QL block for analgesia after hip arthroscopy^{3, 5, 12} their results differed and further investigation is warranted.

The purpose of this study was to examine acute postoperative opioid consumption in patients undergoing hip arthroscopy and randomized to either receive a preoperative lateral quadratus lumborum block or sham injection. We hypothesized that preoperative QL block would decrease postoperative opioid consumption compared to not receiving a block.

Methods

This prospective, randomized trial was reviewed and approved by the Institutional Review Board and registered on www.ClinicalTrials.gov (NCT03557125) prior to patient enrollment. The trial was conducted in accordance with the original protocol and written informed consent was obtained from all subjects. This manuscript adheres to applicable CONSORT guidelines¹³ and the protocol was not altered after study initiation. Enrollment occurred from May 2018 to March 2020 and concluded once 46 subjects scheduled for elective hip arthroscopy with a single surgeon were successfully consented. No patients were excluded, and 46 subjects were randomized, treated and analyzed (Figure 2).

Figure 2.

Consolidated Standards of Reporting Trial (CONSORT) diagram detailing patient enrollment throughout the study.

Information regarding the study was provided to patients scheduled for elective hip arthroscopy in the orthopedic clinic. On the day of surgery, patients were approached by the study staff, invited to participate, provided with informed consent, and enrolled if eligible. All study staff had a bachelor’s degree or higher and were trained in all study protocols.

Inclusion criteria consisted of age >18 years, scheduled for hip arthroscopy, ability to consent to the study, and willingness to participate in follow-up. Exclusion criteria included local anesthetic allergy, chlorhexidine allergy, weight less than 40 kg, urgent or emergent surgery, preoperative substance abuse, and preoperative opioid use for over three months, indicating long term opioid use.

Consenting subjects meeting enrollment criteria were consecutively assigned a two-digit number (01–46) and randomized to one of two study arms with equal allocation: 1) preoperative, lateral quadratus lumborum (QL) block or 2) sham block. Subject randomization was based on a computer-generated list created by a statistician before study initiation using permuted block randomization. This scheme ensures that the number of subjects in each group never differs by more than two. Randomization lists were kept by the research office in sealed envelopes and opened by the regional team just prior to positioning for the block. Other than the regional team, staffed by a senior anesthesia resident or regional anesthesia fellow and a regional anesthesiologist, who did not participate in the patients intraoperative or postoperative care, all patients, care team members, and research staff remained blinded to the randomization throughout the study period.

Protocol

Following informed consent in the preoperative holding area, subjects were then placed in the lateral decubitus position (operative side superior) and administered intravenous (IV) sedation. A high-frequency (10–12 MHz), linear ultrasound probe was used to visualize the external oblique, internal oblique, and transversus abdominus muscles and moved laterally to identify the lateral aponeurosis of the transversus abdominus muscle and the anterolateral aspect of the QL muscle (Figure 1). Skin was then aseptically prepped with chlorhexidine. The regional anesthesia team then either placed a skin wheel and injected subcutaneous saline (sham) or proceeded with a QL block. In the QL block group, following a lidocaine skin wheel, a 10cm, 21-gauge, echogenic needle (B Braun Medical Inc., Bethlehem, PA, USA) was then inserted using an in-plane technique and advanced (anterior to posterior) until the needle tip was deep to the aponeurosis of the transversalis abdominus muscle and lateral to the QL muscle. Ropivacaine (40 ml of 0.25%) was injected in 3–5 ml aliquots with frequent aspiration as local anesthetic injection and spread was observed with ultrasound imaging.

Figure 1.

Sonographic anatomy for a lateral quadratus lumborum block. After anatomy is identified, the needle is inserted around the anterior axillary line on the operative side and advanced in a posterior lateral direction (arrow). Local anesthetic is injected deep to the aponeurosis of the transversus abdominus muscle (arrow heads) and lateral to the quadratus lumborum muscle.

EOM: external oblique muscle; IOM: internal oblique muscle; QLM: quadratus lumborum muscle; TAM: transversus abdominus muscle.

Anesthetic care was standardized, and all patients were prescribed our standard perioperative multimodal protocol, unless contraindicated. This protocol included preoperative oral acetaminophen (1000 mg), gabapentin (300 or 600 mg based on age and renal function), and celecoxib (200 or 400 mg based or weight and renal function). If celecoxib was not given, ketorolac (15 or 30 mg IV based on renal function) was administered at the end of the surgery unless contraindicated. Intraoperatively, all patients received a general anesthetic and analgesia was supplemented with IV ketamine (0.5 mg/kg IV on induction).

Surgery was performed by a single fellowship-trained sports medicine surgeon with over 12 years of practice in shoulder, knee and hip arthroscopy at the time of the study. Access to the hip joint was achieved in all cases with a spinal needle placed into the joint through the anterolateral portal using fluoroscopic guidance. Hip arthroscopy dilators were used to place the arthroscope cannula. Once in the joint, under direct visualization, a mid-anterior portal was established. A distal anterolateral accessory portal was created as needed for suture anchor placement or suture management. Interportal and transverse capulotomy was created in all cases using consistent technique.

Stable labral tears were debrided only. Unstable tears or split tears amenable to repair were repaired with suture anchors. Pincer lesions were contoured or resected with a 4 mm round burr, labral detachment and refixation. Femoroplasty was performed with the burr when cam impingement was identified.

The transverse capsulotomy was repaired typically using at least 2 #2 non-absorbable sutures passed side-to-side. Then the interportal capsulotomy was repaired with 3 or 4 sutures in each case.

Intraoperative and postoperative care was standardized. Fentanyl and hydromorphone were administered and titrated to respiratory rate. Postoperative anesthetic care unit (PACU) orders were also standardized and included hydromorphone (0.2 mg IV every 10 mins for severe pain) and oxycodone (5 mg moderate pain; 10mg severe pain). PACU nurses called the attending anesthesiologists and regional team for patients that continued to have severe pain despite systemic analgesics for further evaluation. If study subjects continued to have inadequate analgesia despite systemic analgesics, the anesthesia team, surgical team, or patient could request to be unblinded to the block status and receive a block if in the sham group. However, the patient would remain in their randomized group for data collection purposes and the need to break blinding noted.

Outcomes and Data Collection

Collected data included demographics data, procedure type (CPT), PACU opioid consumption, pain rating using the visual analog scale (VAS), patient satisfaction with pain control (measured on a 10cm scale), non-opioid analgesic consumption, neurologic evaluation (motor and sensory) of the operative extremity, time to meeting discharge criteria, presence of side effects, and any complications. Demographic data collected included patient age, gender, race, body mass index (BMI), and American Society of Anesthesiologists Physical Status classification (ASA score). CPT codes were collected for each operation and include simple debridement (29862) as the primary code addressing diagnoses labral tear, chrondral lesion or psoas release, femoroplasty (29914), acetabuloplasty (29915) and labral repair (29916) addressing femoral impingement, acetabular impingement and labral tear, respectively. VAS measurements were taken preoperatively, on PACU arrival, and prior to discharge home. Non-opioid analgesics (e.g., acetaminophen, gabapentin, celecoxib, ketorolac, and ketamine) were recorded. Neurologic assessment was conducted preoperative (after consent and prior to block) and postoperative (PACU) on the operative side. Neurologic assessment included sensation assessment to cold (normal or decreased) on the anterior thigh, lateral thigh, and anterior abdomen and strength assessment of the quadriceps muscles and foot plantar and dorsiflexion (0: none; 1: muscle flicker without movement; 2: movement, but not against gravity; 3: movement against gravity; 4: movement against some resistance; 5: normal strength). Sensory and motor examination were completed by a member of the research staff with consistent technique applied. Opioid side effects were assessed by patient report or PACU administration of medications for nausea (i.e., ondansetron or promethazine) or pruritus (i.e., diphenhydramine).

The primary outcome of interest was PACU opioid consumption. All opioids were converted to IV morphine milligram equivalents (MME) for comparison (1 mg morphine IV equal to fentanyl 10 μg IV, hydromorphone 0.15mg IV, oxycodone 2 mg oral, and meperidine 7.5 mg IV).¹⁴ All subject data remained in the originally randomized group (i.e., any patient randomized to the sham group that required a postoperative block remained in the sham group for data collection).

Power Calculation

Using preliminary data, mean (±SD) IV MME consumption in PACU after hip arthroscopy with no preoperative block was anticipated to be 18.0 mg (±3.0). An a priori power analysis determined that 19 subjects were needed in each group to have sufficient power (80%) at alpha=0.05 to test the hypothesis of a 30% decrease in IV MME PACU consumption in patients having a preoperative QL block. Accounting for a possible 20% subject withdrawal, we enrolled 46 total subjects. Sample size was determined using G*Power software (version 3.1.9.2).^{15, 16}

Statistical Analysis

Demographic and clinical characteristics were described for all patients. The primary analysis evaluated the percent change in PACU opioid consumption between the two groups. The primary variable of interest was PACU opioid consumption in patients with and without a preoperative lateral QL block. Individuals randomized to the sham group that received a postoperative rescue QL block were analyzed in their original group. Categorical data were compared with Chi-square tests and Fisher Exact Tests where appropriate. Continuous data were compared with 2-sided t-test (for normally distributed data) and Wilcoxon rank-sum tests (for data non-normally distributed). Statistical analyses were performed with SAS software Version 9.4 (Cary, NC)¹⁷ and Stata software Version 16 (College Station, TX).¹⁸

Results

Patient characteristics and procedure types did not differ between groups (Table 1). Eighty-six hip arthroscopies were performed by a single surgeon during the study time period of May 2018 and March 2020 and 46 patients consented and participated in the study. Common procedures included simple debridement (CPT 29862) n=30, femoroplasty (CPT 29914), n = 29, acetabuloplasty (CPT 29915), n=13 and labral repair (CPT 29916), n=15. For evaluation, a distinction was made between repair and bone work (299xx, n=36) with or without debridement versus simple debridement alone (29862, n = 10) to stratify by the severity of the surgery. Opioid and non-opioid analgesic consumption are summarized in Table 2. PACU opioid consumption decreased 28.3% in patients that received a preoperative QL block (P=0.04). Intraoperative opioid consumption did not differ between groups. Total perioperative mean IV MME consumption (intraoperative and postoperative combined) was reduced 5.6 IV MME (20%) in the QL block group; however, this did not achieve statistical significance (P=0.05). Non-opioid analgesic consumption did not differ between groups.

Table 1.

Patient and procedural characteristics

	QL Block N=22	No block N=24	P
Age (years)	29.8 ± 11.1	37.1 ± 13.2	0.05
Gender (Female)	14 (63.6)	14 (58.3)	0.71
Race (White)	14 (63.6)	21 (87.5)	0.06
BMI (kg/m 2 )	26.2 ± 4.3	27.4 ± 5.5	0.43
ASA score			0.38
I	9 (40.9)	6 (25.0)
II	13 (59.1)	14 (58.3)
III	0 (0.0)	4 (16.7)
Primary CPT code *
299xx	17 (77.3)	19 (79.2)	0.88
29862	5 (22.7)	5 (20.8)
OR duration	149.9 ± 53.1	163.6 ± 51.1	0.38

Data are presented as mean ± SD or n (%).

^*CPT codes are stratified by repair and bone work (299xx) without or without debridement versus debridement alone (29862).

CPT: current procedural terminology; OR: Operating room

Table 2.

Opioid and non-opioid analgesic consumption

	QL Block N = 22	No Block N = 24	P
Intraoperative opioids *
Fentanyl (μg)	102 (81–123)	108 (90–127)	0.65
Hydromorphone (mg)	0.8 (0.5– 1.1)	0.8 (0.6– 1.0)	0.97
Intraoperative IV MME *	15.7 (13.6– 17.7)	16.3 (14.6– 18.0)	0.61
PACU opioids *
Hydromorphone (mg)	0.8 (0.5– 1.1)	1.2 (0.9– 1.5)	0.09
Oxycodone (mg)	4.8 (2.7– 6.9)	6.9 (5.0– 8.7)	0.13
PACU IV MME *	8.1 (6.0– 10.2)	11.3 (9.0– 13.6)	0.0374
Total IV MME * ‡	23.5 (20.4– 26.6)	27.7 (24.7– 30.7)	0.05
Non-opioid analgesics †
Acetaminophen (mg)	1000 (1000–1000)	1000 (1000–1000)	0.89
Gabapentin (mg)	600 (600–600)	600 (600–600)	0.85
Ketamine (mg)	37.5 (35–50)	41.5 (35–50)	0.39
NSAIDs
Celecoxib (mg)	0 (0 – 400)	0 (0 – 400)	0.89
Ketorolac (mg)	0 (0–30)	22.5 (0–30)	0.55

^*Opioid data are presented as mean (95% CI)

^‡Total IV MME is the summation of intraoperative and PACU IV MME.

^†Non-opioid analgesic data are presented as median (IQR)

IV MME: Intravenous morphine mg equivalents; NSAIDs: Nonsteroidal anti-inflammatory drugs; PACU: Postoperative anesthesia care unit

Other clinical characteristics are presented in Table 3. Postoperative VAS pain scores and assessment of motor function for the operative extremity did not differ between groups. However, cold sensation was decreased over the abdomen (P < 0.001) and anterior thigh (P=0.03) in the QL block group on postoperative sensory assessment. Other PACU variables did not differ between the groups including side effects, PACU duration, and patient satisfaction. While not statistically significant, it is notable that three subjects in the sham group required a rescue block in the PACU. No complications, including instances of harm or unintended events, occurred in either group.

Table 3.

VAS pain scores, neurologic exam findings, and other PACU variables

	QL Block N=22	No block N=24	P
VAS Pain Scores
Preoperative	35.1 ± 21.0	32.5 ±21.4	0.70
PACU arrival	58.6 ± 27.1	59.6 ± 31.5	0.91
PACU discharge	57.9 ± 22.2	59.2 ± 22.6	0.84
Motor strength assessment of operative extremity (0–5) *
Preoperative
Quadriceps strength	4.5 ± 0.9	4.3 ± 0.9	0.55
Plantar flexion (foot)	4.7 ± 0.6	4.6 ± 0.6	0.57
Dorsiflexion (foot)	4.5 ± 0.7	4.5 ± 0.7	0.84
Postoperative
Quadriceps strength	1.8 ± 1.4	2.0 ± 1.5	0.58
Plantar flexion (foot)	3.2 ± 1.4	3.3 ± 1.6	0.88
Dorsiflexion (foot)	3.0 ± 1.5	3.3 ± 1.5	0.5
Other PACU variables
Side effects (Any)	9 (40.9)	10 (41.7)	0.86
PACU time (minutes)	99.9 ± 27.9	110.3 ± 34.0	0.26
Rescue block (yes)	0	3 (12.5)	0.09
Patient satisfaction	7.5 ± 3.5	8.6 ± 2.3	0.26

Data are presented as mean ± SD or n (%).

^*Motor strength assessment (0: none; 1: muscle flicker without movement; 2: movement, but not against gravity; 3: movement against gravity; 4: movement against some resistance; 5: normal strength). Preoperative neurologic assessments occurred prior to any sedation or regional anesthesia procedures.

PACU: Postoperative anesthetic care unit

Discussion

In this randomized trial of patients undergoing elective hip arthroscopy with a standardized multimodal protocol, acute postoperative opioid consumption was decreased by preoperative lateral QL block. While this did achieve statistical significance, it did not meet our goal of a 30% reduction in IV MME. Three patients in the no block group also requested and received a rescue block. As it was specified in our protocol to all patients were to be evaluated intention to treat based on their preoperative randomization group, this did not affect the intervention studied. The request for a postoperative block may be an indicator of patients’ pain in the postoperative period; however, it is notable that two of the three patients requesting a rescue block were within the range of overall PACU MME consumption and not outliers.

Successful hip arthroscopy in the ambulatory setting requires adequate pain control, limited motor weakness and decreased opioid consumption. Prior retrospective trials have found the lateral QL blocks to reduce postoperative opioid consumption by 44–53% and reduce total opioid consumption by 25% following hip arthroscopy.⁵ Our findings likely differ due to oral multimodal standardization, local anesthetic concentration, and the absence of perineural additives in our protocol. First, while both of these prior studies used their institutional multimodal protocols, this is more difficult to standardize in a retrospective manner. Our study utilized both standardized pre-operative oral non-opioid analgesics and a standardized dose of intraoperative ketamine to optimize systemic analgesia. Next, both prior publications used ropivacaine 0.5% (20–30 ml), while our study used 0.25% ropivacaine (40 ml) in order to improve local anesthetic spread and minimize any potential motor weakness. Finally, both earlier studies included perineural additives in their QL blocks. Specifically, one study utilized 2 mg dexamethasone⁵ while the other included both 4 mg dexamethasone and 20–30 μg dexmedetomidine.³ While both perineural dexamethasone and dexmedetomidine have been shown to improve block duration and quality,^19–21 this is an off-label use of these medication and were consequently excluded from our study protocol. Thus, these results suggest that postoperative analgesia may be greater if local anesthetic concentration is increased and perineural additives included in the QL block.

While there is no consensus on the optimal regimen for postoperative pain control for hip arthroscopy, the literature supports a comprehensive multimodal approach in the prevention of chronic pain²² many regional and systemic techniques have been investigated. Prior reviews have examined oral premedications (celecoxib, acetaminophen, gabapentin and cyclobenzaprine), peripheral nerve blocks, and injection of the surgical site.^{1, 4} While these reviews have found regional anesthesia to be associated with less pain and decreased postoperative opioid consumption, they have also been associated with some concerns and few meet all the criteria for the ambulatory setting including adequate analgesia, preserved motor function, stable vital signs and limited nausea and vomiting. Turner et al found that compared to general anesthesia, neuraxial anesthesia reduced morphine equivalent use after hip arthroscopy by 42% (18.2 vs 31.2 P = 0.002).²³ While PACU times were reduced in the neuraxial group and there was not a difference in adverse events, concerns for motor weakness and postoperative falls may dampen integration of neuraxial techniques in ambulatory surgical settings. In terms of peripheral nerve blocks, the fascia iliaca block, lumbar plexus block and femoral nerve blocks have all been previously utilized as analgesic tools in hip arthroscopy.^{1, 4, 24} However, they commonly anesthetize the motor fibers of the femoral nerve and may result in weakness of the quadriceps muscles, increasing the risk of falls.^{1, 4, 24} This is particularly problematic in the outpatient setting. QL blocks address the need for postoperative analgesia with decreased risk of lower extremity motor function. The three approaches for the QL block are named for the location of local anesthetic injection in relation to the QL muscle: lateral (QL1), posterior (QL2), and anterior (QL3).⁶ Compared to placebo, QL blocks have demonstrated improved postoperative analgesia for following total hip arthroplasty.²⁵ The analgesic potential of all three QL approaches have been recently evaluated for hip arthroscopies. In two recent retrospective cohort studies, lateral QL blocks were associated with reduced PACU opioid consumption after hip arthroscopy. In a prospective randomized clinical design, Yuan et al. found that an anterior QL block reduced sufentanil use by patient-controlled analgesia and VAS pain scores.²⁶ In comparison to femoral nerve and fascia iliacus blocks, a recent retrospective study of patients undergoing hip arthroscopy for femoroacetabular impingement, found preoperative, posterior QL blocks to be associated with decreased total opioid requirements, PACU stays, and pain scores at discharge without any reported adverse events.²⁴ Furthermore, Huang et al. did not find any change in postoperative morphine requirements, pain scores, and satisfaction in patients receiving a preoperative fascia iliaca block compared to those who did not receive this block in hip arthroscopic labral repairs.²⁷ While there is limited literature regarding lower extremity motor weakness after QL blocks, Ueshima et al. found lateral QL blocks had a low incidence (1%) of lower extremity weakness compared to posterior (19%) and anterior (90%) approaches with the injection of 40 ml of levobupivacaine 0.375%.²⁸ This is likely due to local anesthetic spread to L1–3 paravertebral space, affecting motor function as hypothesized by a prior case report of postoperative weakness after a QL block.²⁹

As falls are a considerable concern for ambulatory surgical patients, our study specifically evaluated immediate postoperative motor function. Notably, while sensation was decreased to cold in the QL block group, patients receiving the QL block did not experience decreased motor function compared to the control group. Intact motor function was also noted in a prior study evaluating anterior QL blocks for hip arthroplasty.²⁵ Further, opioid consumption is in itself associated with falls, especially among older adults, making opioid sparing techniques increasingly relevant.^{30, 31}

Our findings are both applicable and relevant to the vast majority of patients undergoing elective hip arthroscopy as our study criteria are generalizable to these patients, analgesia optimization while preserving motor function are top priorities for outpatient procedures, and the QL block is a fairly easy block for the regional anesthesia team to learn and perform with limited associated risks.

Limitations

Our study does have some limitations. Notably, the hip arthroscopy volume in our center decreased during the study due external factors, which also impacted recruitment. While ours is not a high-volume center, 86 arthroscopies were performed by a single surgeon during the study time period of which 46 patients agreed to participate in this study. As many patients who were aware of the block often declined to participate in the study and elected to have a preoperative QL block, selection bias is a risk of our study. This also resulted in the study taking longer than expected to complete. Variability in patient’s perception of pain can also account for differences in requirements of rescue block and PACU MME consumption, and it is notable that three patients in the no-block group also requested a rescue block. While this is supportive of the QL block providing postoperative analgesia, the small sample size prevents it from being conclusive. PACU times, dependent on workflow, are also highly variable and hard to control for. It is also notable that the QL block requires ultrasound equipment and is a newer regional anesthesia technique. Additionally, our study looked at VAS scores and opioid requirements in the immediate postoperative period and did not extend to long-term follow up. The wider distribution of IV MME consumption decreased our power to distinguish a difference between the two groups. Further, the a priori power analysis assumed a 30% decrease in postoperative IV MME. Unfortunately, our PACU MME consumption fell short of our target with a 28% reduction. While a 28% reduction may be clinically meaningful and is similar to other reports,²⁴ we did not reach our goal of a 30% reduction.

Conclusions

Opioid consumption was reduced in patients that received a preoperative lateral quadratus lumborum block combined with a standardized, multimodal protocol as compared to patients who did not receive a block. Our findings support the growing evidence that QL blocks are an effective component of multimodal analgesia options for patients undergoing elective hip arthroscopy.