Improving the Safety of Patient-Controlled Analgesia Infusions with Safety Interlocks and Closed-Loop Control

Patient-controlled analgesia (PCA) treatment for post-operative pain management is commonly employed in hospitals and its usage is steadily increasing. However, despite the apparent "inherent" safety strategy of requiring active participation of the patient to administer each opioid dose, adverse drug events have been reported. The major reasons for the adverse events are factors such as pump programming errors, patient risk factors, human interactions, equipment malfunctions and drug prescription errors. These conditions can lead to situations where patients develop severe complications such as respiratory depression due to overmedication. Another significant aspect to be addressed is the requirement for interoperability of medical devices connected to the patient for diagnosis and therapy, which can mitigate some of the cited problems and result in enhancement of patient safety and treatment efficacy. The objective of the proposed study is to develop requirements for an interoperable system that prevents the occurrence of respiratory depression due to adverse drug events experienced while using a PCA pump. A system of networked medical devices is being proposed to continuously monitor patients on PCA systems to detect evidence of deteriorating respiratory functions or similar critical states, and then to activate a safety interlock to suspend the medication delivery if the cause of the patient state is attributed to overmedication, and to activate the nurse-call system to initiate a prompt assessment by clinicians.