# Autonomous precision resuscitation during ground and air transport of an animal hemorrhagic shock model

## TL;DR

A new algorithm called ReFit can stabilize animals in severe blood loss during transport, showing promise for treating critically ill patients in remote or challenging environments.

## Contribution

ReFit is the first closed-loop algorithm to autonomously resuscitate hemorrhagic shock during both ground and air transport.

## Key findings

- ReFit stabilized all animals for ~3 hours after severe liver injury-induced hemorrhage.
- The algorithm maintained target mean arterial pressure and heart rate during transport simulations.
- Results suggest ReFit is effective in remote and contested environments.

## Abstract

We tested the ability of a physiologically driven minimally invasive closed-loop algorithm, called Resuscitation based on Functional Hemodynamic Monitoring (ReFit), to stabilize for up to 3 h a porcine model of noncompressible hemorrhage induced by severe liver injury and do so during both ground and air transport. Twelve animals were resuscitated using ReFit to drive fluid and vasopressor infusion to a mean arterial pressure (MAP) > 60 mmHg and heart rate < 110 min−1 30 min after MAP < 40 mmHg following liver injury. ReFit was initially validated in 8 animals in the laboratory, then in 4 animals during air (23nm and 35nm) and ground (9 mi) to air (9.5nm and 83m) transport returning to the laboratory. The ReFit algorithm kept all animals stable for ~ 3 h. Thus, ReFit algorithm can diagnose and treat ongoing hemorrhagic shock independent to the site of care or during transport. These results have implications for treatment of critically ill patients in remote, austere and contested environments and during transport to a higher level of care.

The online version contains supplementary material available at 10.1186/s40635-024-00628-5.