British journal of anaesthesia
-
Ketamine attenuates morphine tolerance by antagonising N-methyl-d-aspartate receptors. However, a pharmacokinetic interaction between morphine and ketamine has also been suggested. The interaction between oxycodone and ketamine is unclear. We studied the effects of ketamine and norketamine on the attenuation of morphine and oxycodone tolerance focusing on both the pharmacodynamic and pharmacokinetic interactions. ⋯ Ketamine and norketamine attenuated morphine tolerance more effectively than oxycodone tolerance. Ketamine and norketamine increased morphine, but not oxycodone brain concentrations, which may partly explain this difference. Norketamine is effective in attenuating morphine tolerance with minor effects on motor coordination. These results warrant pharmacokinetic studies in patients who are co-treated with ketamine and opioids.
-
Caloric restriction (CR) increases both average and maximum lifespan, retards physiological signs of ageing, and delays the onset of several diseases and may mediate neuropathic pain. Neuropathic pain seriously affects the quality of life of patients. In this study, we investigated whether CR exerts anti-nociceptive effects on neuropathic pain, and probed its potential mechanisms. ⋯ These results suggest that the effects of CR on pain behaviours in a rat model of nerve injury are via inhibition of excessive neuro-inflammation induced by the injury. CR may be of benefit in patients with neuropathic pain.
-
Exposure of the developing brain to propofol results in cognitive deficits. Recent data suggest that inhibition of neuronal apoptosis does not prevent cognitive defects, suggesting mechanisms other than neuronal apoptosis play a role in anaesthetic neurotoxicity. Proper neuronal growth during development is dependent upon growth cone morphology and axonal transport. Propofol modulates actin dynamics in developing neurones, causes RhoA-dependent depolymerisation of actin, and reduces dendritic spines and synapses. We hypothesised that RhoA inhibition prevents synaptic loss and subsequent cognitive deficits. The present study tested whether RhoA inhibition with the botulinum toxin C3 (TAT-C3) prevents propofol-induced synapse and neurite loss, and preserves cognitive function. ⋯ Inhibition of RhoA prevents propofol-mediated hippocampal neurotoxicity and associated cognitive deficits.
-
Review Meta Analysis
Should continuous rather than single-injection interscalene block be routinely offered for major shoulder surgery? A meta-analysis of the analgesic and side-effects profiles.
Major shoulder surgery is associated with moderate-to-severe pain, but consensus on the optimal analgesic approach is lacking. Continuous catheter-based interscalene block (CISB) prolongs the analgesic benefits of its single-injection counterpart (SISB), but concerns over CISB complications and difficulties in interpreting comparative evidence examining major and minor shoulder procedures simultaneously, despite their differences in postoperative pain, have limited CISB popularity. This meta-analysis evaluates the CISB analgesic role and complications compared with SISB for major shoulder surgery. ⋯ High-level evidence indicates that CISB provides superior analgesia up to 48 h after major shoulder surgery, without increasing side-effects, compared with SISB. The importance of CISB-related changes in respiratory indices is questionable.
-
Maximising patient comfort during and after surgery is a primary concern of anaesthetists and other perioperative clinicians, but objective measures of what constitutes patient comfort in the perioperative period remain poorly defined. The Standardised Endpoints in Perioperative Medicine initiative was established to derive a set of standardised endpoints for use in perioperative clinical trials. ⋯ As standardised outcomes will support benchmarking and pooling (meta-analysis) of trials, one or more of these recommended endpoints should be considered for inclusion in clinical trials assessing patient comfort and pain after surgery.