Buprenorphine versus dexamethasone as perineural adjuvants in femoral and adductor canal nerve blocks for total knee arthroplasty: a randomized, non-inferiority clinical trial

Adductor canal block in total knee arthroplasty: a scoping review of the literature

Background

An adductor canal block is commonly used to reduce pain after total knee arthroplasty. Practice varies in terms of site of injection, local anaesthetic, and adjuncts used, with poor consensus in relation to the best approach. The aim of this scoping review was to assess the evidence for efficacy and safety of adductor canal block, determine variation in the technique used, type and dose of medication, and compare the efficacy of adductor canal block with other nerve block techniques.

Methods

Four databases were searched to identify relevant studies (Medline, Embase, Cochrane, and ClinicalTrials.gov). A total of 285 articles were found, and data was extracted from 130 randomised controlled trials.

Results

Adductor canal block is a safe and potentially effective peripheral nerve block for reducing postoperative pain after total knee arthroplasty while preserving motor function. Of all adjuncts to adductor canal block assessed, either dexamethasone or dexmedetomidine provide additional analgesic benefit. Adductor canal block combined with peri-articular local anaesthetic injection provides the best outcomes. Continuous infusion of local anaesthetic through a catheter placed in the adductor canal provides no additional benefit over a single injection. The site of injection used for adductor canal block does not seem to affect efficacy. There was no evidence to support the superiority of any single local anaesthetic agent.

Conclusion

This scoping review has identified variation in the use of medications, doses, techniques, and adjuncts for adductor canal block. As such, definitive conclusions regarding the most effective practice for adductor canal block cannot be made.

Endogenous opiates and behavior: 2022

This paper is the forty-fifth consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2022 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).