First closed-loop goal directed fluid therapy during surgery: a pilot study

Intraoperative haemodynamic optimization based on fluid management and stroke volume optimization (Goal Directed Fluid Therapy [GDFT]) can improve patients' postoperative outcome. We have described a closed-loop fluid management system based on stroke volume variation and stroke volume monitoring. The goal of this system is to apply GDFT protocols automatically. After conducting simulation, engineering, and animal studies the present report describes the first use of this system in the clinical setting.

Prospective pilot study.

Patients undergoing major surgery.

Twelve patients at two institutions had intraoperative GDFT delivered by closed-loop controller under the direction of an anaesthesiologist. Compliance with GDFT management was defined as acceptable when a patient spent more than 85% of the surgery time in a preload independent state (defined as stroke volume variation<13%), or when average cardiac index during the case was superior or equal to 2.5l/min/m(2).

Closed-loop GDFT was completed in 12 patients. Median surgery time was 447 [309-483] min and blood loss was 200 [100-1000] ml. Average cardiac index was 3.2±0.8l/min/m(2) and on average patients spent 91% (76 to 100%) of the surgery time in a preload independent state. Twelve of 12 patients met the criteria for compliance with intraoperative GDFT management.

Intraoperative GDFT delivered by closed-loop system under anaesthesiologist guidance allowed to obtain targeted objectives in 91% of surgery time. This approach may provide a way to ensure consistent high-quality delivery of fluid administration and compliance with perioperative goal directed therapy.