Articles: anesthetics.
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Curr Opin Anaesthesiol · Oct 2023
ReviewGeneral purpose models for intravenous anesthetics, the next generation for target-controlled infusion and total intravenous anesthesia?
There are various pharmacokinetic-dynamic models available, which describe the time course of drug concentration and effect and which can be incorporated into target-controlled infusion (TCI) systems. For anesthesia and sedation, most of these models are derived from narrow patient populations, which restricts applicability for the overall population, including (small) children, elderly, and obese patients. This forces clinicians to select specific models for specific populations. ⋯ This article examines the usability of these general-purpose models in relation to the more traditional models.
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Reg Anesth Pain Med · Oct 2023
Crystallization of short-acting and intermediate-acting local anesthetics when mixed with adjuvants: a semiquantitative light microscopy analysis.
The addition of adjuvants to short-acting local anesthetics (LA) is common practice in clinical routine to speed up block onset and decrease pain on injection. In a previous study, we observed the development of microscopic crystal precipitations after bupivacaine or ropivacaine were mixed with adjuvants; this follow-up study is intended to clarify whether crystallization (A) also occurs in short-acting or intermediate-acting LA-adjuvant mixtures, (B) changes over time, and (C) is associated with the solutions' pH. ⋯ Lidocaine 2% and mepivacaine 2% plus sodium bicarbonate 8.4%, and mepivacaine 2% plus dexamethasone developed delayed grade 5 crystallization over 1 hour. Prilocaine-based, procaine-based and chloroprocaine-based mixtures showed much less pronounced crystallization, with a maximum of grade 2. Initial pH and grade of crystallization showed weak monotonic relationships at time points t0, t15 and t30 (ρ=-0.17, 0.31 and 0.32, (all p>0.05)) and a moderate relationship time point t60 (ρ=0.57 (p=0.0003)) CONCLUSIONS: Our study revealed high grades of crystallization in lidocaine/mepivacaine-bicarbonate and mepivacaine-dexamethasone mixtures, although these were previously considered safe for local, perineural or neuraxial use. Our findings cast particular doubt on the safety of preparing these formulations for later use.
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Right ventricle (RV) assessment is critical during cardiac surgery. Traditional assessment consists of visual estimation and measurement of validated parameters. Cardiac magnetic resonance imaging (cMRI) is the gold standard for RV analysis, and transthoracic three-dimensional (3D) echocardiography is validated against this. We aimed to show that intraoperative 3D transesophageal echocardiography (TEE) RV assessment is feasible and can produce results that correlate with cMRI. ⋯ Intraoperative TEE RV, EDV, and ESV are underestimated relative to cMRI because of analysis, anesthetic, and ventilation factors. The EF showed a low mean difference, and all values showed strong correlation with MRI. Reproducibility and feasibility were excellent and increased use in clinical practice should be considered.
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Journal of anesthesia · Oct 2023
Divided method of intercostal nerve block reduces ropivacaine dose by half in thoracoscopic pulmonary resection while maintaining the postoperative pain score and 4-h mobilization: a retrospective study.
This study investigated whether the divided method of multi-level intercostal nerve block (ML-ICB) could reduce the ropivacaine dose required during thoracoscopic pulmonary resection, while maintaining the resting postoperative pain scores. ⋯ The divided method of ML-ICB could reduce the intraoperative remifentanil dose, decrease the postoperative pain score at 24 h, and curtail postoperative intravenous rescue drug use, despite using half the total ropivacaine dose intraoperatively.
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The volatile anaesthetic sevoflurane induces time (single or multiple exposures)-dependent effects on tau phosphorylation and cognitive function in young mice. The underlying mechanism for this remains largely undetermined. ⋯ Multiple exposures to sevoflurane can induce sequential tau phosphorylation, leading to cognitive impairment in young mice, highlighting the need to investigate the underlying mechanisms of anaesthesia-induced tau phosphorylation in developing brain.