Individualized hemodynamic management during surgery relies on accurate titration of vasopressors and fluids. In this context, computer systems have been developed to assist anesthesia providers in delivering these interventions. This study tested the hypothesis that computer-assisted individualized hemodynamic management could reduce intraoperative hypotension in patients undergoing intermediate- to high-risk surgery.
This single-center, parallel, two-arm, prospective randomized controlled single blinded superiority study included 38 patients undergoing abdominal or orthopedic surgery. All included patients had a radial arterial catheter inserted after anesthesia induction and connected to an uncalibrated pulse contour monitoring device. In the manually adjusted goal-directed therapy group (N = 19), the individualized hemodynamic management consisted of manual titration of norepinephrine infusion to maintain mean arterial pressure within 10% of the patient’s baseline value, and mini-fluid challenges to maximize the stroke volume index. In the computer-assisted group (N = 19), the same approach was applied using a closed-loop system for norepinephrine adjustments and a decision-support system for the infusion of mini-fluid challenges (100 ml). The primary outcome was intraoperative hypotension defined as the percentage of intraoperative case time patients spent with a mean arterial pressure of less than 90% of the patient’s baseline value, measured during the preoperative screening. Secondary outcome was the incidence of minor postoperative complications.
All patients were included in the analysis. Intraoperative hypotension was 1.2% [0.4 to 2.0%] (median [25th to 75th] percentiles) in the computer-assisted group compared to 21.5% [14.5 to 31.8%] in the manually adjusted goal-directed therapy group (difference, −21.1 [95% CI, −15.9 to −27.6%]; P < 0.001). The incidence of minor postoperative complications was not different between groups (42 vs. 58%; P = 0.330). Mean stroke volume index and cardiac index were both significantly higher in the computer-assisted group than in the manually adjusted goal-directed therapy group (P < 0.001).
In patients having intermediate- to high-risk surgery, computer-assisted individualized hemodynamic management significantly reduces intraoperative hypotension compared to a manually controlled goal-directed approach.
- Hemodynamic management strategies bracketing predetermined ranges of arterial pressure and flow variables have been demonstrated to reduce certain perioperative complications
- Individualized hemodynamic management using closed-loop control of blood pressure and a decision support system for fluid titration appears feasible using proprietary monitors and software
- The authors demonstrate in a prospective randomized trial of 38 intermediate- or high-risk patients undergoing abdominal or orthopedic surgery that a closed-loop system titrating a norepinephrine infusion based on an invasive arterial pressure monitoring system alongside a separate decision support system using mini-fluid challenges results in a significant decrease in the percentage of intraoperative time with a mean arterial pressure less than 90% of the patients preoperative baseline value when compared to the same approach applied manually