Closed-loop systems have been designed to assist anesthetists in controlling anesthetic drugs and also maintaining the stability of various physiological variables in the normal range. In the present study, we describe and clinically evaluated a novel closed-loop automated blood pressure control system (CLAPS) in patients undergoing cardiac surgery under cardiopulmonary bypass. Forty ASA II–IV adult patients undergoing elective cardiac surgery were randomly allocated to receive adrenaline, noradrenaline, phenylephrine and nitroglycerine (NTG) adjusted either through CLAPS (CLAPS group) or manually (Manual group). The desired target mean arterial blood pressure (MAP) for each patient in both groups was set by the attending anesthesiologist. The hemodynamic performance was assessed based on the percentage duration of time the MAP remained within 20% of the set target. Automated controller performances were compared using performance error criteria of Varvel (MDPE, MDAPE, Wobble) and Global Score. MAP was maintained a significantly longer proportion of time within 20% of the target in the CLAPS group (79.4% vs. 65.5% p < 0.001, 't' test) as compared to the manual group. Median absolute performance error, wobble, and Global score was significantly lower in the CLAPS group. Hemodynamic stability was achieved with a significantly lower dose of Phenyepherine in the CLAPS group (1870 μg vs. 5400 μg, p < 0.05, 't' test). The dose of NTG was significantly higher in the CLAPS group (3070 μg vs. 1600 μg, p-value < 0.05, 't' test). The cardiac index and left ventricular end-diastolic area were comparable between the groups. Automated infusion of vasoactive drugs using CLAPS is feasible and also better than manual control for controlling hemodynamics during cardiac surgery. Trial registration number and date This trial was registered in the Clinical Trial Registry of India under Registration Number CTRI/2018/01/011487 (Retrospective; registration date; January 23, 2018).

闭环系统的设计目的是帮助麻醉师控制麻醉药物，并在正常范围内维持各种生理变量的稳定性。在本研究中，我们描述并临床评估了一种新型闭环自动血压控制系统 (CLAPS)，用于在体外循环下接受心脏手术的患者。40 名接受择期心脏手术的 ASA II-IV 成年患者被随机分配接受通过 CLAPS（CLAPS 组）或手动（手动组）调整的肾上腺素、去甲肾上腺素、去氧肾上腺素和硝酸甘油 (NTG)。两组中每位患者的理想目标平均动脉血压 (MAP) 均由主治麻醉师设定。根据 MA​​P 保持在设定目标的 20% 以内的持续时间百分比来评估血液动力学性能。使用 Varvel（MDPE、MDAPE、Wobble）和 Global Score 的性能误差标准比较了自动控制器的性能。与手动组相比，CLAPS 组中 MAP 在目标的 20% 以内保持了明显更长的时间比例（79.4% 对 65.5% p < 0.001，'t' 检验）。CLAPS 组的中位绝对性能误差、摆动和全局得分明显较低。在 CLAPS 组中，使用显着较低剂量的苯叶肾上腺素可实现血流动力学稳定性（1870 μg 对比 5400 μg，p < 0.05，'t' 检验）。CLAPS 组中 NTG 的剂量显着更高（3070 μg 与 1600 μg，p 值 < 0.05，'t' 检验）。心脏指数和左心室舒张末期面积在各组之间具有可比性。使用 CLAPS 自动输注血管活性药物是可行的，并且在心脏手术期间控制血液动力学方面也优于手动控制。试验注册号和日期本试验已在印度临床试验登记处注册，注册号为 CTRI/2018/01/011487（追溯；注册日期；2018 年 1 月 23 日）。