Development of a vasopressor control module for testing hemorrhagic shock resuscitation controllers.

INTRODUCTION: Patients in hemorrhagic shock who are unresponsive to fluid administration can potentially benefit from and may even require vasopressor therapy. However, manual vasopressor titration in mass casualty or resource-limited settings can be arduous, increasing the risk of under- or over-treatment. Closed-loop vasopressor adaptive resuscitation controllers (V-ARCs) offer a potential solution, but their development is hindered when the iterative tuning and design process is primarily dependent on large-scale animal studies. To solve this problem, we developed a Vasopressor Control Module (VCM) for a hardware-in-loop automated testbed for resuscitation controllers (HATRC) to enable the systematic evaluation of V-ARCs.

METHODS AND RESULTS: The VCM's design was informed by vasopressor administration data captured in a hemorrhagic shock swine model, which revealed four key physiological variables that defined the hemodynamic response to vasopressor infusion: lag time, real response, overshoot, and pressure-time responsiveness. The incorporation of these variables enabled the VCM to replicate physiological variability, dose-dependent responsiveness, and disturbance conditions representative of the clinical setting. Proof-of-concept testing was achieved by comparing multiple V-ARC designs under different testing conditions and successfully differentiating their performance.

CONCLUSIONS: This work establishes a flexible, physiologically grounded platform for vasopressor controller development, reducing dependence on animal testing while enabling rapid and robust controller evaluation. Future work will expand physiological modeling, incorporate additional hemodynamic variables, and support multiagent resuscitation.