Department of Anaesthesia, Birmingham Women's and Children's Hospital NHS Foundation Trust, Birmingham, UK.
Paediatr Anaesth. 2023 Jun;33(6):486-491. doi: 10.1111/pan.14664. Epub 2023 Mar 30.
Propofol target-controlled infusion is now used in many countries for the administration of total intravenous anesthesia (TIVA) and uses population pharmacokinetic data incorporated into the target-controlled infusion pump to administer a dose which will achieve a target concentration selected by the practitioner. Modern target-controlled infusion pumps can include an estimate of how long it will take for the plasma propofol concentration to fall to a value programmed into the pump, once the propofol infusion is stopped. This is known as decrement time. Many users consider decrement time to be equivalent to recovery time for the patient, despite the several assumptions that makes.
To determine if the decrement time estimated by the target-controlled infusion pumps at the end of anesthesia could be reliably used to predict recovery time for individual patients.
Target-controlled infusion pumps at Birmingham Children's Hospital are programmed with a propofol decrement concentration of 1.5 μg.mL . Patients for a variety of surgical procedures were anesthetised with propofol-remifentanil TIVA. Eye opening was used as a surrogate of recovery time. Data were analyzed using median absolute deviation, Mann-Whitney U test, and linear regression to see if there was any correlation with decrement time and recovery time, total dose of propofol administered, duration of anesthesia and patient age.
A total of 55 patients were audited. Median age was 7.2 years (range 0.9-15.9), and median weight was 26 kg (range 8.5-77). Median decrement time was 11.8 min (IQR 8.3-21), while median recovery time was 15 min (IQR 9-20). Recovery time was the same as decrement time in 2% of patients, less than in 40% of patients and more in 58% of patients. Two thirds of patients opened eyes at an estimated plasma propofol concentration between 1.2 and 1.8 μg.mL . The median absolute deviation for the difference between decrement time and recovery time was 5.7 min, from a median of 1 min. Analysis demonstrated there was no statistical correlation between decrement time to 1.5 μg.mL and recovery time, age, total propofol dose administered, or duration of anesthesia, for individual patients.
There was variation between decrement time to 1.5 μg.mL and recovery time of over 5 min in nearly half of patients. Decrement time to 1.5 μg.mL must be used with caution when trying to predict recovery time for individual patients following TIVA.
异丙酚靶控输注现在在许多国家用于全静脉麻醉（TIVA）的管理，并使用纳入靶控输注泵的群体药代动力学数据来给予将达到由从业者选择的目标浓度的剂量。现代靶控输注泵可以包括对一旦停止异丙酚输注，血浆异丙酚浓度下降到泵中编程的值所需时间的估计。这被称为减量时间。尽管有几个假设，许多用户认为减量时间等同于患者的恢复时间。
确定麻醉结束时靶控输注泵估计的减量时间是否可用于可靠地预测个体患者的恢复时间。
伯明翰儿童医院的靶控输注泵编程为 1.5μg.mL 的异丙酚减量浓度。各种手术的患者接受异丙酚-瑞芬太尼 TIVA 麻醉。睁眼被用作恢复时间的替代指标。使用中位数绝对偏差、Mann-Whitney U 检验和线性回归来分析数据，以查看减量时间与恢复时间、给予的异丙酚总剂量、麻醉持续时间和患者年龄之间是否存在任何相关性。
共审核了 55 名患者。中位年龄为 7.2 岁（范围 0.9-15.9），中位体重为 26kg（范围 8.5-77）。中位减量时间为 11.8 分钟（IQR 8.3-21），而中位恢复时间为 15 分钟（IQR 9-20）。在 2%的患者中，恢复时间与减量时间相同，在 40%的患者中少于减量时间，在 58%的患者中多于减量时间。三分之二的患者在估计的血浆异丙酚浓度在 1.2 到 1.8μg.mL 之间睁开眼睛。减量时间与恢复时间之间的差异中位数为 5.7 分钟，中位数为 1 分钟。分析表明，对于个体患者，减量至 1.5μg.mL 与恢复时间、年龄、给予的总异丙酚剂量或麻醉持续时间之间没有统计学相关性。
在近一半的患者中，减量至 1.5μg.mL 与恢复时间之间的差异超过 5 分钟。在尝试预测 TIVA 后个体患者的恢复时间时，必须谨慎使用减量至 1.5μg.mL。
