Automated systems for perioperative goal-directed hemodynamic therapy.

Perioperative goal-directed hemodynamic therapy (GDHT) has evolved from invasive "supra-physiological" maximization of oxygen delivery to minimally or even noninvasively guided automated stroke volume optimization. Over the past four decades, investigators have simultaneously developed novel monitors, updated strategies, and automated technologies to improve GDHT. Decision support technology, which proposes an intervention based on the patient's real time physiologic status, was an important step towards automation. Closed-loop systems have now been created to both increase GDHT compliance and decrease physician workload. These automated systems offer an elegant approach to optimize cardiac output and end-organ perfusion during the perioperative period. Most notably, automated preload optimization guided by dynamic indicators of fluid responsiveness has shown its feasibility, safety, and impact. Making the leap into fully automated GDHT has been accomplished on a small scale, but there are considerable challenges that must be surpassed before integrating all hemodynamic components into an automated system during general anesthesia. In this review, we will discuss the evolution and potential future of automated GDHT during the perioperative period.