Department of Pharmacy, The Affiliated Changzhou No. 2 People's Hospital of Nanjing Medical University, Changzhou, China.
Department of Anesthesiology, The Affiliated Changzhou No. 2 People's Hospital of Nanjing Medical University, Changzhou, China.
J Clin Pharm Ther. 2022 May;47(5):662-667. doi: 10.1111/jcpt.13594. Epub 2022 Jan 11.
In our preliminary study, there were large individual variations at sedation levels during propofol target-controlled infusion (TCI). The present study aimed to assess the effects of body mass index (BMI) on the pharmacodynamic index of propofol TCI.
This prospective, non-randomized controlled trial evaluated 175 female patients undergoing breast lumpectomy. Anesthesia was induced with propofol using the TCI system embedded Schnider model. The effect compartment concentration was set to 3 μg/ml, and the start time of infusion was recorded. When the target concentration reached 3 μg/ml, the patient could not be awakened (Ramsay sedation score ≥4), and when the Bispectral Index (BIS) was <60, the infusion was discontinued, and the time point was recorded. The observation end-point was set at the Observer's Assessment of Alertness/Sedation (OAA/S) score of <4. The correlation between the BMI and the pharmacodynamic index of propofol was evaluated.
Propofol induction time was significantly correlated with the BMI (p < 0.001). The induction time of the underweight subjects was 10.14 ± 2.19 min, which was remarkably higher than that of normal weight (6.48 ± 3.44 min) and overweight (4.75 ± 2.53 min) individuals (p < 0.001). There were still significant differences after multivariable-adjusted regressions (p < 0.001). There were no significant differences in recovery time and sedative effect indicators, such as Ramsay score, BIS value, and effect compartment concentration, between the three groups (p > 0.05 for all).
These results suggest that the BMI is one of the critical factors affecting the pharmacodynamic index of propofol TCI, and the induction time decreased progressively with increasing BMI. The Schnider model might underpredict doses of propofol for underweight individuals.
在我们的初步研究中，异丙酚靶控输注（TCI）期间镇静水平存在较大的个体差异。本研究旨在评估体重指数（BMI）对异丙酚 TCI 药效指标的影响。
这是一项前瞻性、非随机对照试验，评估了 175 名接受乳房肿块切除术的女性患者。使用 TCI 系统嵌入 Schnider 模型诱导麻醉，效应室浓度设定为 3μg/ml，并记录输注开始时间。当目标浓度达到 3μg/ml 时，患者无法被唤醒（Ramsay 镇静评分≥4），当双频谱指数（BIS）<60 时，停止输注，并记录时间点。观察终点设定为观察者警觉/镇静评分（OAA/S）<4。评估了 BMI 与异丙酚药效学指标的相关性。
异丙酚诱导时间与 BMI 显著相关（p<0.001）。体重不足受试者的诱导时间为 10.14±2.19min，明显高于正常体重（6.48±3.44min）和超重（4.75±2.53min）个体（p<0.001）。多变量调整回归后仍存在显著差异（p<0.001）。三组间恢复时间和镇静效果指标（如 Ramsay 评分、BIS 值和效应室浓度）无显著差异（p>0.05 均）。
这些结果表明 BMI 是影响异丙酚 TCI 药效指标的关键因素之一，随着 BMI 的增加，诱导时间逐渐缩短。Schnider 模型可能低估了体重不足个体的异丙酚剂量。
