Articles: anesthetics.
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Paediatric anaesthesia · Oct 2024
Observational StudyUnderstanding time to peak effect of propofol as sole agent on bispectral index in children aged 2-12 years.
The pharmacodynamics of propofol in children have previously been described with the proprietary bispectral index (BIS) as an effect-site marker, and it has been suggested that the rate of onset of propofol might be age dependent, that is, a shorter time to peak effect in younger children. However, these analyses were potentially confounded by co-administered drugs, in particular opioids and benzodiazepines. Thus, the goal of this prospective study was to characterize the influence of age and weight on the onset of hypnotic effects from propofol, reflected by the time to peak of propofol effect-site concentration in the absence of additional drugs. ⋯ In children, the age and weight have an influence on time to peak effect of propofol. In the absence of opioids and benzodiazepines, time to peak effect was approximately 20% longer in children aged 8-12 years as compared to younger children. Such clinically relevant age and weight effects are an important consideration in the individualized titration of propofol dosing.
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Journal of anesthesia · Oct 2024
Randomized Controlled TrialInvestigation of the analgesic effects of rhomboid intercostal and pectoral nerve blocks in breast surgery.
The objective of this study was to examine the hypothesis that the opioid consumption of patients who receive a rhomboid intercostal block (RIB) or a pectoral nerve (PECS) block after unilateral modified radical mastectomy (MRM) surgery is less than that of patients who receive local anesthetic infiltration. ⋯ Compared to local anesthetic infiltration, the RIB and PECS blocks applied as part of multimodal analgesia in MRM surgery reduced opioid consumption in the first 24 h and improved the quality of recovery in the early period.
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Comparative Study
Predictive pharmacodynamic performance of the Eleveld pharmacokinetic-pharmacodynamic model for propofol: comparison of predicted and measured bispectral index.
The Eleveld pharmacokinetic-pharmacodynamic model for propofol predicts bispectral index (BIS) processed electroencephalogram values from estimated effect-site concentrations. We investigated agreement between measured and predicted BIS values during total intravenous anaesthesia (TIVA). ⋯ BIS predictions by the Eleveld model should be interpreted with caution. In spite of the acceptable MDPE and MDAPE, there are unacceptable degrees of both within-subject and between-subject variation during propofol target-controlled infusions. This limits the use of adjusting targeted concentrations to achieve desired simulated BIS values with confidence.
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Target-controlled infusion (TCI) is a mature technology that enables the delivery of intravenous anaesthetics in the concentration domain. The accuracy of the pharmacologic models used by TCI systems is imperfect, especially regarding pharmacodynamic predictions. ⋯ In this sense, TCI functions as a 'gain switch'. Achieving a steady state is more important than perfect accuracy.
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Ni Eochagain and colleagues report that programmed intermittent bolus and continuous infusion regimens in continuous erector spinae plane (ESP) block catheters produced similar quality of recovery (QoR-15) scores, pain scores, and use of rescue opioids after video-assisted thoracic surgery. This is a reassuring finding for practitioners without access to pumps with programmed intermittent bolus functionality. Nevertheless, it remains plausible that the benefit of one regimen over another might vary depending on the specific infusion parameters. There continues to be scope for research into optimising programmed intermittent bolus delivery and dosing regimens and identifying the most appropriate clinical applications for this mode of infusion.