In medical cyber-physical environments, synchronizing supervisory medical systems, physicians' behavior and patient conditions in compliance with best practice workflow is essential for patient safety. However, patient conditions change rapidly and asynchronously, so workflows have to be adapted to the changes safely. In this paper, we propose a workflow adaptation and validation protocol to help physicians safely adapt workflows to react to patient adverse events based on the path physiological models. Unlike conventional validation protocols, the medical cyber-physical systems cannot lock or recover the states of physical components, such as patient conditions. Therefore, the proposed protocol dynamically adapts the workflow to the patient conditions while validating safety requirements in collaboration with physicians. Moreover, we use cardiac arrest resuscitation as a case study to verify the safety and correctness properties of the proposed protocol.