Automated hemodynamic management system for the prevention of hypotension and cardiac output reduction during general...

Intraoperative hypotension and cardiac output (CO) reduction adversely affect outcomes and require cause-specific treatment against vasodilation and/or hemorrhage. However, tight hemodynamic management increases anesthesiologists' workloads. We aimed to develop an automated hemodynamic management system that maintains arterial pressure (AP) and CO according to the causes, and to experimentally validate the system in anesthetized dogs.

The system automatically titrates norepinephrine (NE) and fluid to control systemic vascular resistance and stressed blood volume, respectively, thereby maintaining AP and CO. Experiment 1 (n = 8) examined whether the system could maintain hemodynamics during 80 min of induced hemodynamic perturbations-high-dose sodium nitroprusside infusion (vasodilation) and 30 mL/kg blood withdrawal (hemorrhage)-while monitoring CO invasively but precisely. Experiment 2 (n = 12) compared the system's hemodynamic control with manual control by eight board-certified anesthesiologists during the 80-min perturbation. To improve clinical feasibility, a minimally invasive CO monitor utilizing machine learning technology was integrated into the system.

In Experiment 1, the system significantly improved AP and CO, and reduced hypotension duration (mean AP < 65 mmHg) compared to when the system was deactivated. In Experiment 2, between the system's control and anesthesiologists' control, there were no significant differences in AP, total NE and fluid doses, and hypotension duration. The thermodilution technique confirmed that the system prevented CO from falling below the baseline level during the perturbation. Each anesthesiologist titrated the drugs approximately 40 times, whereas the system required only supervision.

The system is potentially an attractive clinical tool to support anesthesiologists in perioperative hemodynamic management.