Conflicting interactions in multiple closed-loop controlled critical care Treatments: A hemorrhage resuscitation-intravenous propofol sedation case study

Closed-loop automation of critical care therapy has the potential to reduce the workload of clinical personnel while maintaining the quality of care. In the real-world clinical arena, critically ill patients receive multiple medical treatments. However, existing body of work has predominantly focused on closed-loop automation of isolated individual treatments. How these individual treatment loops interact with each other has not been investigated. The goal of this work is to garner insights on the safety of critical care therapy and potential deleterious conflicts therein when multiple isolated and individually closed-loop controlled medical treatments act upon a patient, using a case study of hemorrhage resuscitation and intravenous propofol sedation. For this purpose, a physiological model of a critically ill patient was developed and experimentally validated to describe the collective cardiovascular and pharmacological effects of these treatments. Then, isolated and individually closed-loop controlled hemorrhage resuscitation and intravenous propofol sedation treatments were simultaneously applied to the physiological model and their interactive behavior was investigated. The results showed that (i) the influence of one treatment on the other must be taken into account in selecting treatment set point to maintain the safety of overall therapy, and that (ii) information sharing between control loops may enhance the efficacy and robustness of individual treatment loops. In sum, it was concluded that hemorrhage resuscitation and intravenous propofol sedation treatments may benefit from coordination both at the set point and the loop levels. The conclusion may generalize to a wide spectrum of multiple closed-loop controlled medical treatments.