Deleterious Effects of Liberal Fluid Therapy During Extracorporeal Cardiopulmonary Resuscitation in a Porcine Model...

During extracorporeal cardiopulmonary resuscitation (ECPR), fluid therapy is often required to maintain adequate blood flow. Here, we aimed to compare the impact of 2 fluid strategies on organ edema, tissue perfusion, and systemic and cerebral hemodynamics in a porcine model of ECPR.

Swine were subjected to 15 minutes of ventricular fibrillation followed by 30 minutes of ECPR. After defibrillations and return of spontaneous beating, animals were followed for 120 minutes. Swine were randomly assigned to a conservative group (n=7), in which fluid loading was limited to a maximum of 20 mL/kg per hour of Ringer's lactate, or a liberal group (n=7), in which fluid loading was allowed as long as right atrial pressure remained <18 mm Hg. In both groups, fluid loading was triggered by suction events, flow drops, and arterial hypotension defined as mean arterial pressure <65 mm Hg.

Extracorporeal membrane oxygenation flow and mean arterial pressure were similar between groups. Fluid administration was higher in the liberal group (48.2±18.5 versus 19.3±4.6 mL/kg per hour, P=0.001). The conservative group was associated with higher norepinephrine exposure (2.8±0.1 versus 0.6±0.1 μg/kg per minute, P=0.011) and lower lactate clearance. Lung, brain, myocardial, and bowel water contents were not significantly different between groups. Intracranial pressure variation from baseline to 150 minutes after ECPR was significantly higher in the liberal group (10±3 versus 1.4±2 mm Hg, P=0.034). All animals from the liberal group showed intra-abdominal hypertension.

During ECPR, liberal strategy resulted in a detrimental increase in intracranial and intra-abdominal pressures. Nevertheless, conservative strategy was associated with high vasopressor load and lower lactate clearance.