Abstract
Hemodynamic resuscitation in septic shock requires aggressive fluid replacement and appropriate use of vasopressors to optimize arterial pressure (AP) and cardiac output (CO). Because responses to these drugs vary between patients and within patient over time, strict monitoring of patient condition and repetitive adjustment of drug dose are required. This task is time and labor consuming and is associated with poor adherence to resuscitation guidelines. To overcome this issue, we have developed a computer-controlled closed-loop drug infusion system for automated hemodynamic resuscitation in septic shock. Our system continuously computes arterial resistance (R) and stressed blood volume (V). Negative-feedback algorithm in the system controls R with noradrenaline (NA), and V with Ringer acetate solution (RiA), thereby controlling AP and CO. When our system was applied to dogs with septic shock, it automatically titrated the infusion of NA and RiA, controlled R and V, and restored AP and CO at target levels precisely (absolute % error < 6 %) over 4h-period. With use of this system, we also examined the effect of the use of short acting β -blocker, landiolol, on the initial hemodynamic resuscitation of septic shock. Use of the landiolol was associated with reduction in cardiac oxygen consumption and arterial lactate level without compromising the initial hemodynamic resuscitation. In this review, we introduce several previous closed-loop systems developed by other groups and our novel approach to control the hemodynamics in septic shock, and discuss the implications of these developments.
