Analgesic sparing effect of dexamethasone with levobupivacaine in quadratus lumborum block in patients undergoing unilateral inguinal hernia repair: A prospective randomised controlled trial

Analgesic effects of ultrasound-guided preoperative posterior Quadratus Lumborum block in laparoscopic hepatectomy: A prospective double-blinded randomized controlled trial

STUDY OBJECTIVE

To determine if single-injection bilateral posterior quadratus lumborum block (QLB) with ropivacaine would improve postoperative analgesia in the first 24 h after laparoscopic hepatectomy, compared with 0.9% saline.

DESIGN

Prospective, double blinded, randomized controlled trial.

SETTING

A single tertiary care center from November 2021 and January 2023.

PATIENTS

A total of 94 patients scheduled to undergo laparoscopic hepatectomy due to hepatocellular carcinoma.

INTERVENTIONS

Ninety-four patients were randomized into a QLB group (receiving 20 mL of 0.375% ropivacaine on each side, 150 mg in total) or a control group (receiving 20 mL of 0.9% saline on each side).

MEASUREMENTS

The primary outcome was the cumulative opioid consumption during the initial 24-h post-surgery. Secondary outcomes included pain scores and intraoperative and recovery parameters.

MAIN RESULTS

The mean cumulative opioid consumption during the initial 24-h post-surgery was 30.8 ± 22.4 mg in the QLB group (n = 46) and 34.0 ± 19.4 mg in the control group (n = 46, mean differences: -3.3 mg, 95% confidence interval, -11.9 to 5.4, p = 0.457). The mean resting pain score at 1 h post-surgery was significantly lower in the QLB group than in the control group (5 [4-6.25] vs. 7 [4.75-8], p = 0.035). No significant intergroup differences were observed in the resting or coughing pain scores at other time points or in other secondary outcomes.

CONCLUSIONS

Preoperative bilateral posterior QLB did not reduce cumulative opioid consumption during the first 24 h after laparoscopic hepatectomy.

The effects of dexamethasone added to ilioinguinal/iliohypogastric nerve (IIN/IHN) block on rebound pain in inguinal hernia surgery: a randomized controlled trial

PURPOSE

The purpose of the present study was to evaluate the effects of IV dexamethasone added to one single injection Ilioinguinal/Iliohypogastric Nerve (IIN/IHN) block on tramadol consumption and Modified Rebound Pain Score (MRPS) in the first postoperative 24 h in inguinal hernia surgery.

METHODS

Five mg IV dexamethasone as an analgesic adjunct in the multimodal analgesia was administered to the patients who were scheduled for Inguinal Hernia Surgery and randomized to Group Dex and normal saline was administered to the patients who were randomized to the Control Group in addition to IIN/IHN Block. Postoperative tramadol consumption, Modified Rebound Pain Score (MRPS), the incidence of Rebound Pain, Rebound Pain time, postoperative 48-h opioid consumption, Numerical Rating Scale (NRS) scores, Quality of Recovery Score (QoR-15), Sleep Quality, and adverse events were evaluated in the patients.

RESULTS

The mean scores of MRPS were lower in Group Dex than in the Control Group, both at rest (p = 0.001) and with motion (p = 0.001). Tramadol consumption in the first postoperative 24 h was 45.17 ± 49.59 mg in Group Dex and 95 ± 59.23 mg in the Control Group. The difference between the groups was statistically significant (p < 0.001).

CONCLUSIONS

In conclusion, adding IV dexamethasone as a part of multimodal analgesia to IIN/IHN block for inguinal hernia surgery resulted in lower MRPS and lower postoperative opioid (tramadol) consumption. For this reason, IV dexamethasone can be added to the IIN/IHN block after inguinal hernia surgery to reduce the incidence of rebound pain, rebound pain scores, and NRS scores for pain, decrease postoperative opioid consumption, and improve the quality of recovery.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: Ref; NCT05172908, Date: December 29, 2021.

Effect of a single intraoperative dose of dexamethasone on glycaemic profile in postoperative patients - A double-blind randomised controlled study

Background and Aims

The effect of a single intraoperative dose of steroids on perioperative blood sugar levels is uncertain. We hypothesised that a single dose of dexamethasone would not unfavourably alter the glucose levels of non-diabetic patients. This study aimed to evaluate the post-operative glycaemic profile after a single dose of intraoperative dexamethasone in non-diabetic patients. The presence of post-operative nausea and vomiting (PONV), pain, surgical site infection (SSI) and length of hospital stay were also evaluated.

Methods

This randomised, double-blind, controlled study was done by recruiting 150 non-diabetic adult patients of the American Society of Anesthesiologists physical status I/II undergoing elective surgery. Patients in the study group were administered a single dose of dexamethasone (0.15 mg/kg). Blood glucose levels were assessed at various time points for up to 72 hours post-operatively using point-of-care testing. Secondary outcomes such as PONV, pain, fever and SSI were also documented. Data were compared and analysed using Student's t-test, Chi-square test, Mann-Whitney test and analysis of variance test.

Results

There was an earlier, higher and prolonged elevation in blood glucose levels in patients receiving dexamethasone. The mean (standard deviation) of fasting/postprandial blood sugars on the first, second and third postoperative days respectively was significantly higher in the study group 98.04 (21.89)/139.16 (20.59), 96.64 (19.20)/138.17 (18.05), 96.60 (17.40)/138.32 (15.10) mg/dl as compared to control group 86.9 6 (10.28)/128.95 (10.53), 88.81 (8.87)/131.97 (9.68), 88.16 (8.50)/130.88 (9.48) mg/dl. About 10.7% of the patients who received dexamethasone had blood glucose levels greater than 180 mg/dl. There were no significant differences in the secondary outcomes.

Conclusion

Even a single dose of dexamethasone in non-diabetic adults causes significant and prolonged postoperative hyperglycaemia.

Comparison of postoperative analgesic effects of posterior quadratus lumborum block and intrathecal morphine in laparoscopic donor hepatectomy: a prospective randomized non-inferiority clinical trial

Background

Posterior quadratus lumborum block (QLB) and intrathecal morphine are accepted analgesic strategies in laparoscopic liver resection, but their effects have not been compared after laparoscopic donor hepatectomy. This study was planned to perform this comparison.

Methods

Fifty-six donors were randomized to receive bilateral posterior (QLB2, 20 mL of 0.375% ropivacaine on each side, 150 mg total) or preoperative injection of 0.4 mg morphine sulfate intrathecally. Primary outcome was resting pain score at 24 hour postsurgery. Secondary outcomes included cumulative opioid consumption and recovery parameters. Serial plasma ropivacaine concentrations were measured in QLB group. Only the outcome assessor was properly blinded.

Results

Mean resting pain score at 24-hour postsurgery was 4.19±1.66 in QLB group (n=27) and 3.07±1.41 in intrathecal morphine group (n=27, p=0.04). Mean difference (QLB group-intrathecal morphine group) was 1.11 (95% CI 0.27 to 1.95), and the upper limit of CI was higher than prespecified non-inferiority margin (δ=1), indicating an inferior effect of QLB. Cumulative opioid consumption was significantly higher in QLB group at 24 hours and 48 hours postsurgery. QLB group exhibited lower incidence of postoperative pruritus at all time points, and there were no differences in other recovery outcomes. All measured ropivacaine concentrations were below the threshold for systemic toxicity (4.3 µg/mL).

Conclusions

Bilateral posterior QLB elicited higher resting pain scores at 24-hour after laparoscopic donor hepatectomy than intrathecal morphine and did not meet the definition of non-inferiority.

Trial registration number

KCT0005360.

Pharmacological and clinical implications of local anaesthetic mixtures: a narrative review

Various techniques have been explored to prolong the duration and improve the efficacy of local anaesthetic nerve blocks. Some of these involve mixing local anaesthetics or adding adjuncts. We did a literature review of studies published between 01 May 2011 and 01 May 2021 that studied specific combinations of local anaesthetics and adjuncts. The rationale behind mixing long- and short-acting local anaesthetics to hasten onset and extend duration is flawed on pharmacokinetic principles. Most local anaesthetic adjuncts are not licensed for use in this manner and the consequences of untested admixtures and adjuncts range from making the solution ineffective to potential harm. Pharmaceutical compatibility needs to be established before administration. The compatibility of drugs from the same class cannot be inferred and each admixture requires individual review. Precipitation on mixing (steroids, non-steroidal anti-inflammatory drugs) and subsequent embolisation can lead to serious adverse events, although these are rare. The additive itself or its preservative can have neurotoxic (adrenaline, midazolam) and/or chondrotoxic properties (non-steroidal anti-inflammatory drugs). The prolongation of block may occur at the expense of motor block quality (ketamine) or block onset (magnesium). Adverse effects for some adjuncts appear to be dose-dependent and recommendations concerning optimal dosing are lacking. An important confounding factor is whether studies used systemic administration of the adjunct as a control to accurately identify an additional benefit of perineural administration. The challenge of how best to prolong block duration while minimising adverse events remains a topic of interest with further research required.

Mechanisms of action of fascial plane blocks: a narrative review

BACKGROUND

Fascial plane blocks (FPBs) target the space between two fasciae, rather than discrete peripheral nerves. Despite their popularity, their mechanisms of action remain controversial, particularly for erector spinae plane and quadratus lumborum blocks.

OBJECTIVES

This narrative review describes the scientific evidence underpinning proposed mechanisms of action, highlights existing knowledge gaps, and discusses implications for clinical practice and research.

FINDINGS

There are currently two plausible mechanisms of analgesia. The first is a local effect on nociceptors and neurons within the plane itself or within adjacent muscle and tissue compartments. Dispersion of local anesthetic occurs through bulk flow and diffusion, and the resulting conduction block is dictated by the mass of local anesthetic reaching these targets. The extent of spread, analgesia, and cutaneous sensory loss is variable and imperfectly correlated. Explanations include anatomical variation, factors governing fluid dispersion, and local anesthetic pharmacodynamics. The second is vascular absorption of local anesthetic and a systemic analgesic effect at distant sites. Direct evidence is presently lacking but preliminary data indicate that FPBs can produce transient elevations in plasma concentrations similar to intravenous lidocaine infusion. The relative contributions of these local and systemic effects remain uncertain.

CONCLUSION

Our current understanding of FPB mechanisms supports their demonstrated analgesic efficacy, but also highlights the unpredictability and variability that result from myriad factors at play. Potential strategies to improve efficacy include accurate deposition close to targets of interest, injections of sufficient volume to encourage physical spread by bulk flow, and manipulation of concentration to promote diffusion.