全麻期间预测丙泊酚浓度与实测七氟醚浓度的变异性：单中心回顾性队列研究。

Variability of predicted propofol concentrations and measured sevoflurane concentrations during general anaesthesia: a single-centre retrospective cohort study.

机构信息

Department of Anaesthesia, Intensive Care, Emergency and Pain Medicine, Kantonsspital St. Gallen, Switzerland.

Department of Anaesthesia, North Shore Private Hospital, Sydney, NSW, Australia.

出版信息

Br J Anaesth. 2023 Oct;131(4):687-693. doi: 10.1016/j.bja.2023.06.064. Epub 2023 Aug 3.

DOI:10.1016/j.bja.2023.06.064

PMID:37541948

Abstract

BACKGROUND

Variability is high in predicted propofol concentrations during clinical anaesthesia titrated by target-controlled infusion (TCI) to maintain a processed EEG parameter (bispectral index [BIS]) within a specified range. We have shown that the potential for improving the pharmacokinetic model is minimal. The drug titration paradox revealed that titration challenges the classical relationship between drug dose and effect in both individuals and the population. We hypothesised that dynamic factors during surgery beyond the static genetic, epigenetic, and other factors such as age, height, and weight affect the necessary dose. We compared the variability of measured end-tidal sevoflurane concentrations with predicted effect-site propofol concentrations when titrated to a BIS range of 40-60, with the hypothesis that the variability in measured sevoflurane concentrations would not be less than the variability in estimated propofol concentrations.

METHODS

Clinical data from 2280 surgical procedures >1 h in duration were included in the analysis. Anaesthesia with sevoflurane or propofol was based on an institutional protocol. The titration performance for both drugs was assessed by comparing BIS values 30 min after skin incision. The variability of the required concentrations at the same time point was calculated and compared.

RESULTS

The achieved 30-min post-incision BIS ranges were not significantly different for sevoflurane or propofol TCI (30 [99% CI: 28-33] and 31 [99% CI: 27-36], respectively). The variability of sevoflurane concentrations was not significantly different from measured predicted propofol concentrations during BIS-guided anaesthesia (normalized concentration range of 0.89 [99% CI: 0.78-0.99] and 0.93 [99% CI 0.87-1.02).

CONCLUSIONS

Improvements in prediction accuracy of pharmacokinetic models beyond that of those already in clinical use are unlikely to reduce variability in target anaesthetic concentrations across patients in clinical practice.

摘要

背景

在临床麻醉中，通过靶控输注（TCI）以维持特定范围内的处理脑电图参数（双频谱指数[BIS]）来预测丙泊酚浓度，其变异性很高。我们已经表明，改善药代动力学模型的潜力很小。药物滴定悖论表明，在个体和人群中，药物剂量和效应之间的经典关系受到药物滴定的挑战。我们假设手术过程中的动态因素超出了静态遗传、表观遗传和其他因素（如年龄、身高和体重）会影响所需剂量。我们假设在将七氟醚呼气末浓度滴定至 40-60 的 BIS 范围时，测量的七氟醚呼气末浓度的变异性不会小于预测的效应部位丙泊酚浓度的变异性，因此将测量的七氟醚呼气末浓度与预测的效应部位丙泊酚浓度进行比较，以评估在 BIS 指导下麻醉时两种药物的滴定性能。

方法

分析了 2280 例持续时间超过 1 小时的手术的临床数据。七氟醚或丙泊酚麻醉基于机构方案。通过比较皮肤切开后 30 分钟的 BIS 值来评估两种药物的滴定性能。计算并比较了同一时间点所需浓度的变异性。

结果

七氟醚或丙泊酚 TCI 达到的 30 分钟切口后 BIS 范围没有显著差异（分别为 30[99%置信区间：28-33]和 31[99%置信区间：27-36]）。在 BIS 指导的麻醉中，七氟醚浓度的变异性与测量的预测丙泊酚浓度无显著差异（归一化浓度范围分别为 0.89[99%置信区间：0.78-0.99]和 0.93[99%置信区间：0.87-1.02]）。