Microcomputer-controlled administration of vasodilators following cardiac surgery: technical considerations

Area of Science:

• Biomedical Engineering
• Anesthesiology
• Critical Care Medicine

Background:

• Postoperative hypertension following cardiopulmonary bypass increases patient morbidity.
• Current management relies on short-acting vasodilators, often requiring manual control.
• Closed-loop automated systems demonstrate superiority over manual control for blood pressure management.

Purpose of the Study:

• To develop and evaluate a novel closed-loop arterial pressure control system for managing postoperative hypertension.
• To assess the system's safety, efficacy, and clinical staff acceptance.

Main Methods:

• Development of a closed-loop arterial pressure control system utilizing an Atari 1040ST microcomputer.
• Implementation of a proportional-integral-derivative (PID) control algorithm with digital waveform sampling and artifact detection.
• Integration of safety features, including computer-pump communication monitoring and alarms.
• Novel use of a computer mouse for data entry and program control by clinical staff.

Main Results:

• The developed system is in routine clinical service in the cardiac intensive care unit (CICU).
• The system has been utilized for both direct patient care and research on arterial pressure control.
• Clinical staff found the system acceptable and easy to use, with keyboard skills being unnecessary.

Conclusions:

• The automated closed-loop arterial pressure control system is a viable and acceptable method for managing postoperative hypertension after cardiopulmonary bypass.
• The system incorporates advanced features for safety and ease of use, enhancing patient care in the CICU.