HIGH-VOLUME HEMOFILTRATION IMPROVES HEMODYNAMICS AND SURVIVAL OF PIGS EXPOSED TO GUT ISCHEMIA AND REPERFUSION

This study assesses the influence of high volume continuous hemofiltration on hemodynamics of pigs subjected to bowel ischemia/reperfusion. Twelve anesthetized and ventilated pigs were studied for 60 min during clamping of the superior mesenteric artery (SMA) and subsequently for 90 min after release of the clamp, while measuring global hemodynamics, SMA flow, and jejunal pCO(2). They were randomly divided into two groups: pigs in ''control'' group were subjected to SMA clamping only. Pigs in ''hemofiltered'' group received zero-balanced, high volume, veno-venous hemofiltration with the removal of 6000 mi of ultrafiltrate/h, starting 30 min before clamping until 90 min after removal of the SMA clamp. Thereafter, pigs were allowed to awake and sacrificed after 24 h for macroscopic assessment of bowel damage. The drop in cardiac output (CO) during SMA clamping in the hemofiltered group was 2.5 +/- .3 L/min (mean +/- SE) (1.1/4.0; 95% confidence interval) smaller than in the control group. At the end of the experiment, mean arterial pressure (MAP) in the hemofiltered group was 33 +/- 6 (19/48) mmHg higher than in the control group, CO was 2.0 +/- .2 (1.2/2.8) L/min higher in the hemofiltered group. After 60 min of SMA clamping, left ventricular stroke work in the hemofiltered group was 35 +/- 4 (14/56) g higher than in the control group, and higher by 33 +/- 3 (21/46) g at 90 min after release of the SMA clamp. The mean pulmonary artery pressure, right atrial pressure, pulmonary artery wedge pressure, SMA flow and bowel wall pCO(2) at different time points did not differ between groups. None of the pigs in the control group survived until 24 after the start of the experiment, versus four pigs in the hemofiltered group. Macroscopic bowel damage at autopsy was less severe in the hemofiltered group than in the control group. We conclude that in this model, high volume veno-venous hemofiltration not only improves short-term hemodynamics, but also reduces bowel damage and improves survival after gut ischemia/reperfusion.