Evaluation of Automated Vasopressor Administration Algorithms Using Lower-Limit Control for Intraoperative...

Area of Science:

• Anesthesiology
• Biomedical Engineering
• Pharmacology

Background:

• Intraoperative hypotension can lead to adverse patient outcomes.
• Effective vasopressor control is crucial for maintaining hemodynamic stability.
• Current evaluation metrics may not fully capture the nuances of lower-limit control strategies.

Purpose of the Study:

• To develop and evaluate novel metrics for assessing lower-limit vasopressor control.
• To compare different vasopressor dosing strategies in simulated hypotension scenarios.
• To identify optimal metrics for preventing prolonged intraoperative hypotension.

Main Methods:

• Developed a blood pressure generation model and an automated vasopressor administration model using simulation software.
• Simulated four vasopressor dosing strategies: bolus, repeated low-dose bolus, and continuous infusion.
• Calculated evaluation metrics: proportion of time below threshold (PTBT), mean value below threshold (MVBT), average systolic blood pressure (sBP), median performance error (MDPE), and median absolute performance error (MDAPE).

Main Results:

• Continuous infusion strategies significantly reduced the duration and severity of hypotension (lower PTBT and MVBT).
• PTBT and MVBT effectively quantified hypotension and the extent sBP exceeded the threshold.
• MDPE and MDAPE showed high variability and were less suitable for evaluating lower-limit control without a fixed target.

Conclusions:

• PTBT, MVBT, and average sBP are valuable metrics for assessing vasopressor control stability and hypotension avoidance.
• MDPE and MDAPE are less appropriate for quantitative assessment when the goal is to exceed a threshold rather than achieve a specific target.
• The developed metrics provide a more comprehensive evaluation of lower-limit vasopressor control strategies.