No quadriceps muscle weakness following anterior quadratus lumborum block compared with placebo: a randomized, non-inferiority, blinded, volunteer trial.

BACKGROUND AND AIMS: Anterior quadratus lumborum block is a truncal block, applied in close proximity to the lumbar plexus, potentially causing lower limb weakness. This trial aimed to evaluate whether a unilateral anterior quadratus lumborum block caused quadriceps muscle weakness compared with placebo. METHODS: In this randomized, non-inferiority, triple-blind trial, 20 healthy volunteers received an active unilateral anterior quadratus lumborum block with 30 mL ropivacaine 0.75% and a placebo block on the contralateral side. Primary outcome was change in maximal quadriceps muscle strength from baseline to 60 min postblock compared with placebo. Secondary outcomes were change in single-leg 6 m timed hop test, change in Timed-Up and Go test, change in mean arterial pressure from baseline to 30 min postblock and dermatomal affection. RESULTS: There was no statistically significant difference in changes in maximal quadriceps muscle strength between active and placebo block; 15.88 N (95% CI -12.19 to +43.94), pnon-inf=0.003, indicating non-inferiority. Timed-Up and Go test was performed significantly faster 60 min postblock; -0.23 s (95% CI -0.38 to -0.08, p=0.005). Mean change in mean arterial pressure from baseline to 30 min postblock was 4.25 mm Hg (95% CI 0.24 to 8.26, p=0.04). Dermatome testing revealed an affection primarily of the lower abdomen (Th10-L1) with the active block. CONCLUSION: In this randomized controlled trial including healthy volunteers a unilateral anterior quadratus lumborum block does not cause statistical or clinical significant motor block of the quadriceps muscle compared with placebo. When administered correctly, the block can be used for procedures where early postoperative mobilization is essential. TRIAL REGISTRATION NUMBER: NCT05023343.

Anterior quadratus lumborum catheters for elective cesarean section: A double-blind, randomized, placebo-controlled trial.

BACKGROUND: Optimizing pain management following cesarean section is crucial for the well-being of both mother and infant. Various types of quadratus lumborum blocks have exhibited reduced opioid consumption and pain scores after cesarean section. However, duration of block effect is relatively short. The aim of this study was to investigate the analgesic efficacy of the anterior quadratus lumborum catheters for cesarean section. METHODS: All 32 enrolled participants were allocated to postoperative bilateral ultrasound-guided anterior quadratus lumborum catheter placement with injection of 60 mL ropivacaine 0.375% after cesarean section. Randomization at 2 h resulted in either 60 mL ropivacaine 0.2% or 60 mL isotonic saline injected through the catheters, with subsequent 22-h infusion of either ropivacaine 0.2% or isotonic saline with an infusion rate of 4 mL h-1 per catheter. Participants in the active group received a total of 697 mg ropivacaine during the first 24 h. All participants received the standard postoperative multimodal pain regimen, and a final bilateral injection at 24-h post-catheter placement of 60 mL ropivacaine 0.375% in total. The primary outcome was time to first opioid administration. Secondary outcomes were pain scores, time to first ambulation, nausea and vomiting, accumulated opioid consumption, and catheter displacement rates. RESULTS: No significant intergroup differences were observed following the randomized intervention. Median time to first opioid (IQR) was (active vs. placebo) 414 (283, 597) vs. 428 (245, 552) minutes, with a median difference (CI) of -14 (-184 to 262) min, p = .32. CONCLUSION: Bilateral anterior quadratus lumborum catheters with continuous infusion did not prolong time to first opioid after elective cesarean section.

Insignificant influence of the intertransverse process block for major breast cancer surgery: a randomized, blinded, placebo-controlled, clinical trial.

INTRODUCTION: The intertransverse process (ITP) block mimics the thoracic paravertebral block and allegedly ameliorates hemithoracic postoperative pain. However, concerning major reconstructive breast cancer surgery the modality has never been tested against placebo in a randomized clinical trial. We aimed to assess the efficacy of the multiple-injection ITP block and hypothesized that the blockade would reduce postoperative opioid consumption. METHODS: We screened 58 patients with breast cancer scheduled for unilateral subpectoral implant-based primary breast reconstruction, involving mastectomy with complete fascial dissection of the major pectoral muscle. A randomization procedure allowed for the allocation of 36 patients to receive either unilateral multiple-injection active ITP block (0.5% ropivacaine 3×10 mL) or placebo ITP block (isotonic saline 3×10 mL) at T2, T4, T6 in a prospective, blinded, clinical trial. The primary outcome was total opioid consumption within the first 24 postoperative hours. Secondary outcomes included opioid consumption at 4-hour intervals, postoperative pain, patient satisfaction with block application, time to first opioid, ambulation and discharge, opioid-related side effects, and quality of recovery. RESULTS: Opioid consumption within the first 24 postoperative hours showed no significant reduction when comparing the active and placebo group median (IQR): 75.0 mg (45-135) vs 62.5 mg (30-115), p=0.5, respectively. We did not find any consequential clinically relevant results of the secondary outcomes. CONCLUSIONS: Following major reconstructive breast cancer surgery, a preoperative multiple-injection ITP block neither reduces 24-hour opioid consumption postoperatively nor promotes substantial clinical positive outcomes. TRIAL REGISTRATION NUMBER: EudraCT2019-001016-35.

Effect of anterior quadratus lumborum block with ropivacaine on the immune response after laparoscopic surgery in colon cancer: a substudy of a randomized clinical trial.

BACKGROUND: Surgery induces a temporal change in the immune system, which might be modified by regional anesthesia. Applying a bilateral preoperative anterior quadratus lumborum block has proven to be a safe and effective technique in pain management after abdominal and retroperitoneal surgery, but the effect on the immune response is not thoroughly investigated. METHODS: This study is a substudy of a randomized, controlled, double-blinded trial of patients undergoing laparoscopic hemicolectomy due to colon cancer. Twenty-two patients were randomized to undergo either a bilateral anterior quadratus lumborum nerve block with a total of 60 mL ropivacaine 0.375% or placebo with corresponding isotonic saline injections. The main objective of this exploratory substudy was to investigate the systemic immune response in the first postoperative day by examining changes in blood transcript levels (n=750) and stimulated secretion of cytokines (n=17) on ex vivo activation with microbial ligands and anti-CD3/CD28. RESULTS: Using unsupervised data analysis tools, we observed no effect of the bilateral anterior quadratus lumborum nerve block on gene expression in immune cells (permutational multivariate analysis of variance using distance matrices: F=0.52, p=0.96), abundances of major immune cell populations (Wilcoxon rank-sum test: p>0.05), and stimulated cytokine secretion (Wilcoxon rank-sum test: p>0.05). CONCLUSIONS: Our study provides evidence that administration of bilateral anterior quadratus lumborum nerve block as a part of a multimodal analgesic regimen in an enhanced recovery after surgery for laparoscopic hemicolectomy in this cohort does not alter the systemic immune response.Trial registration number NCT03570541.

Efficacy of the intertransverse process block: single or multiple injection? A randomized, non-inferiority, blinded, cross-over trial in healthy volunteers.

INTRODUCTION: The intertransverse process block is increasingly used to ameliorate postoperative pain following a plethora of surgical procedures involving the thoracic wall. Nevertheless, the optimal approach and cutaneous extent of the sensory block are currently unknown. We aimed to further describe the intertransverse process block, single injection versus multiple injection, and we hypothesized that the single-injection intertransverse process block is a non-inferior technique. METHODS: Twelve healthy male volunteers were cross-over randomized to receive either single-injection intertransverse process block with 21 mL ropivacaine 7.5 mg/mL, including two sham injections, at the thoracic level T4/T5 or multiple-injection intertransverse process block with three injections of 7 mL ropivacaine 7.5 mg/mL at the thoracic levels T2/T3, T4/T5 and T6/T7 at the first visit. At the second visit, the other technique was applied on the contralateral hemithorax. A non-inferiority margin of 1.5 anesthetized thoracic dermatomes was chosen. RESULTS: The mean difference (95% CI) in the number of anesthetized thoracic dermatomes was 0.82 (-0.41 to 2.05) pnon-inf<0.01 indicating non-inferiority favoring the single-injection technique.Both techniques anesthetized the ipsilateral thoracic wall and demonstrated contralateral cutaneous involvement to a variable extent. The multiple-injection intertransverse process block anesthetized a significantly larger cutaneous area on the posterior hemithorax and decreased mean arterial pressure at 30 and 60 min postblock application. Thoracic thermography showed no intermodality temperature differences yet compared with baseline temperatures both techniques showed significant differences. CONCLUSIONS: Single-injection intertransverse process block is non-inferior to multiple injection in terms of anesthetized thoracic dermatomes. Both techniques generally anesthetize the hemithoracic wall to a variable extent. EU CLINICAL TRIALS REGISTER: 2022-501312-34-01.

The intertransverse process block single- or multiple-injection? A study protocol.

BACKGROUND AND AIMS: Intertransverse process (ITP) blocks are applied on the posterior side of the thoracic paravertebral space. The modality is described as being a paravertebral block by proxy, possibly providing a similar analgesic effect as the thoracic paravertebral block. However, systematic evidence on anaesthetised dermatomes and the extent of cutaneous sensory loss following ITP blocks is sparse. This study aims to test the single- versus the multiple-injection ITP block. The primary outcome is the number of anaesthetised thoracic dermatomes for each block type. METHODS: Twelve healthy male volunteers will participate in this randomised, procedure-related, double-blinded, non-inferiority crossover trial after informed consent. Blinded participants will receive either a unilateral single-injection ITP block with 21 mL ropivacaine 7.5 mg/mL including two sham blocks or a unilateral multiple-injection ITP block with 3 × 7 mL ropivacaine 7.5 mg/mL on study Day 1, and the other modality on study Day 2. Block applicants will be blinded from outcome assessment and vice versa. Following block application sensory test by mechanical pinprick and temperature discrimination will be performed. Anterior truncal thermography will be measured three times after block application to compare skin temperature in the mid-clavicular line between the blocked and the contralateral non-blocked hemithorax. In addition, blood pressure changes are measured three times non-invasively. DISCUSSION: The current study will provide substantial knowledge regarding the cutaneous sensory loss of the ITP block. Furthermore, the study might provide insight regarding the possible clinical usage of thermography as a reliable instrument for measuring nerve block efficacy.

Anterior quadratus lumborum block does not reduce postoperative opioid consumption following laparoscopic hemicolectomy: a randomized, double-blind, controlled trial in an ERAS setting.

BACKGROUND AND AIMS: An opioid-sparing postoperative analgesic regimen following laparoscopic hemicolectomy is optimal to promote minimal postoperative pain, early mobilization, and improved quality of recovery. Various regional anesthesia techniques have been tested to improve postoperative pain management after laparoscopic hemicolectomy. In this study, we aimed to assess the effect of administering a preoperative bilateral ultrasound-guided anterior quadratus lumborum nerve block on postoperative opioid consumption after laparoscopic colon cancer surgery. METHODS: In this randomized, controlled, double-blinded trial, 69 patients undergoing laparoscopic hemicolectomy due to colon cancer were randomized to receive an anterior quadratus lumborum block with ropivacaine 0.375% 30 mL on each side or isotonic saline (placebo). The primary outcome measure was total opioid consumption during the first 24 hours postsurgery. The secondary outcome measures were pain scores, accumulated opioid consumption in 6-hour intervals, nausea and vomiting, ability of postoperative ambulation, time to first opioid, orthostatic hypotension or intolerance, postoperative Quality of Recovery-15 scores, surgical complications, length of hospital stay, and adverse events. RESULTS: The total opioid consumption in the first 24 hours postsurgery was not significantly reduced in the ropivacaine group compared with the saline group (mean 129 mg (SD 88.4) vs mean 127.2 mg (SD 89.9), p=0.93). In addition, no secondary outcome measures showed any statistically significant intergroup differences. CONCLUSION: The administration of a preoperative bilateral anterior quadratus lumborum nerve block as part of a multimodal analgesic regimen for laparoscopic hemicolectomy did not significantly reduce opioid consumption 24 hours postsurgery. Trial registration number NCT03570541.

Ultrasound-guided multiple-injection costotransverse block for mastectomy and primary reconstructive surgery. A study protocol.

BACKGROUND: Post-operative pain amelioration following breast cancer surgery is inconsistent. The novel multiple-injection costotransverse block (MICB) mimics the thoracic paravertebral block by possible anaesthetising the ventral rami of the thoracic spinal nerves and the sympathetic trunk. Proof of concept has been determined in a cadaveric study and needs further clinical testing. METHODS: This double-blinded, randomised and placebo-controlled study investigates the efficacy of the ultrasound-guided MICB versus placebo in 36 patients undergoing unilateral mastectomy and primary subpectoral reconstruction surgery. Oral pre-operative medicine is standardised for all patients. Active group is pre-operatively administered MICB with three injections of each 10 ml of ropivacaine (5 mg/ml). The placebo group is pre-operatively administered three injections of each 10 ml of saline (0.9%). Standard general anaesthesia is induced and 30 min before emergence 0.2 µg/kg total body weight sufentanil IV, 1 g of paracetamol IV and 4 mg of ondansetron IV (post-operative nausea and vomiting, PONV, prophylaxis) will be administered. All patients are provided with a patient-controlled analgesia pump with morphine. The primary aim is total morphine consumption in the first 24 post-operative hours. Secondary aims are pain intensity, duration of the block, patient satisfaction, side effects, time to ambulation, time to discharge, and quality of recovery. DISCUSSION: Recruitment began in November 2019 and is expected to finish ultimo 2021. Results are expected to be published in an international peer-reviewed medical journal. The results will hopefully provide a substantial contribution to the knowledge of these new 'intertransverse process blocks' providing regional anaesthesia of the thoracic wall.

Standardizing nomenclature in regional anesthesia: an ASRA-ESRA Delphi consensus study of abdominal wall, paraspinal, and chest wall blocks.

BACKGROUND: There is heterogeneity in the names and anatomical descriptions of regional anesthetic techniques. This may have adverse consequences on education, research, and implementation into clinical practice. We aimed to produce standardized nomenclature for abdominal wall, paraspinal, and chest wall regional anesthetic techniques. METHODS: We conducted an international consensus study involving experts using a three-round Delphi method to produce a list of names and corresponding descriptions of anatomical targets. After long-list formulation by a Steering Committee, the first and second rounds involved anonymous electronic voting and commenting, with the third round involving a virtual round table discussion aiming to achieve consensus on items that had yet to achieve it. Novel names were presented where required for anatomical clarity and harmonization. Strong consensus was defined as ≥75% agreement and weak consensus as 50% to 74% agreement. RESULTS: Sixty expert Collaborators participated in this study. After three rounds and clarification, harmonization, and introduction of novel nomenclature, strong consensus was achieved for the names of 16 block names and weak consensus for four names. For anatomical descriptions, strong consensus was achieved for 19 blocks and weak consensus was achieved for one approach. Several areas requiring further research were identified. CONCLUSIONS: Harmonization and standardization of nomenclature may improve education, research, and ultimately patient care. We present the first international consensus on nomenclature and anatomical descriptions of blocks of the abdominal wall, chest wall, and paraspinal blocks. We recommend using the consensus results in academic and clinical practice.

Anatomical considerations for obturator nerve block with fascia iliaca compartment block.

This report reviews the topographical and functional anatomy relevant for assessing whether or not the obturator nerve (ON) can be anesthetized using a fascia iliaca compartment (FIC) block. The ON does not cross the FIC. This means that the ON would only be blocked by an FIC block if the injectate spreads to the ON outside of the FIC. Such a phenomena would require the creation of one or more artificial passageways to the ON in the retro-psoas compartment or the retroperitoneal compartment by disrupting the normal anatomical integrity of the FI. Due to this requirement for an artificial pathway, an FIC block probably does not block the ON.

Transmuscular quadratus lumborum block for total laparoscopic hysterectomy: a double-blind, randomized, placebo-controlled trial.

BACKGROUND: The population of patients scheduled for total laparoscopic hysterectomy at our surgical center is heterogeneous concerning a multitude of demographic variables such as age, collateral surgery and malign or benign pathogenesis. A common denominator is moderate to severe postoperative pain and a substantial opioid consumption. A recent procedure specific postoperative pain management (PROSPECT) review found no gain from the regional techniques included. The transmuscular quadratus lumborum (TQL) block has shown promising results in recent trials for other types of surgery. The aim of the current study was to investigate the analgesic efficacy of the ultrasound-guided TQL block for total laparoscopic hysterectomy. METHODS: We enrolled 70 patients and randomly allocated participants to preoperative bilateral ultrasound-guided TQL block with either 60 mL 0.375% ropivacaine or 60 mL isotonic saline. Preoperatively, all patients received the TQL block (active or placebo) as well as a standardized multimodal analgesic regimen consisting of oral paracetamol, ibuprofen and dexamethasone. Intraoperatively, intravenous sufentanil 0.2 µg/kg was administered 30 min prior to emergence. PRIMARY OUTCOME: Opioid consumption during the first 12 postoperative hours. SECONDARY OUTCOMES: Pain scores, times to first opioid demand and first ambulation, nausea and vomiting, and total opioid consumption during the first 24 postoperative hours. RESULTS: No significant intergroup differences were observed for any outcome. Mean (SD) oral morphine equivalent consumption the first 12 postoperative hours was 58.4 mg (48.3) vs 62.9 mg (48.5), p=0.70, for group ropivacaine versus group saline. CONCLUSION: Preoperative bilateral ultrasound-guided TQL block did not reduce opioid consumption after total laparoscopic hysterectomy. TRIAL REGISTRATION NUMBERS: NCT03650998, EudraCT (2017-004593-34).

Transmuscular quadratus lumborum block reduces opioid consumption and prolongs time to first opioid demand after laparoscopic nephrectomy.

BACKGROUND: Robotic and hand-assisted laparoscopic nephrectomies are often associated with moderate to severe postoperative pain. The aim of the current study was to investigate the analgesic efficacy of the transmuscular quadratus lumborum (TQL) block for patients undergoing robotic or hand-assisted laparoscopic nephrectomy. METHODS: Fifty patients were included in this single-center study. All patients were scheduled for elective hand-assisted or robotic laparoscopic nephrectomy under general anesthesia. Preoperatively, patients were randomly allocated to TQL block bilaterally with ropivacaine 60 mL 0.375% or 60 mL saline and all patients received standard multimodal analgesia and intravenous patient-controlled analgesia. Primary outcome was postoperative oral morphine equivalent (OME) consumption 0-12 hours. Secondary outcomes were postoperative OME consumption up to 24 hours, pain scores, time to first opioid, nausea/vomiting, time to first ambulation and hospital length of stay (LOS). RESULTS: Mean (95% CI) OME consumption was significantly lower in the intervention group at 12 hours after surgery 50 (28.5 to 71.5) mg versus control 87.5 (62.7 to 112.3) mg, p=0.02. At 24 hours, 69.4 (43.2 to 95.5) mg versus 127 (96.7 to 158.6) mg, p<0.01. Time to first opioid was significantly prolonged in the intervention group median (IQR) 4.4 (2.8-17.6) hours compared with 0.3 (0.1-1.0) hours in the control group, p<0.001. No significant intergroup differences were recorded for time to first ambulation, pain scores, nausea/vomiting nor for LOS. CONCLUSION: Preoperative bilateral TQL block significantly reduced postoperative opioid consumption by 43% and significantly prolonged time to first opioid. TRIAL REGISTRATION NUMBER: NCT03571490.

Transmuscular quadratus lumborum block for percutaneous nephrolithotomy: Study protocol for a dose-finding trial.

BACKGROUND: The objective of this trial is to optimize the transmuscular quadratus lumborum (TQL) block, by investigating the minimal effective volume (MEV90 ) of ropivacaine 0.75% for single-shot TQL block in percutaneous nephrolithotomy (PNL) patients. METHODS: This double-blind, randomized and controlled dose-finding trial is based on a biased coin up-and-down sequential design, where the volume of local anaesthetic administered to each patient depends on the response from the previous one. Investigating the TQL block, the first patient recruited receives 20 ml ropivacaine 0.75% preoperatively. In case of block failure, the next patient will receive the same volume with an increment of 2 ml. Given a successful block for the first patient, the next patient will be randomized to either a lower volume (previous volume with a reduction of 2 ml), or the same volume as the previous patient. The respective probabilities being b = 0.11 for a reduced volume and 1-b = 0.89 for the same volume. Block success is defined as patient reported pain score numeric rated scale (NRS) ≤3 (0-10/10) 30 minutes after arrival in the post anaesthesia care unit (PACU). The NRS pain score is our primary and only outcome for block success. A minimum of 25 eligible patients are needed to achieve precise estimation of MEV90 with narrow 95% confidence intervals derived by bootstrapping. DISCUSSION: Recruiting will begin June 2020 and is expected to finish November 2020. Data analysis will be performed at interims during and after the study. Results will be published in an international peer-reviewed medical journal.