MODIFIED ULTRAFILTRATION VERSUS CONVENTIONAL ULTRAFILTRATION - A RANDOMIZED PROSPECTIVE-STUDY IN NEONATAL PIGLETS

Cardiopulmonary bypass in neonates generates large increases in inflam matory mediators, causing edema formation that may lead to multiple or gan dysfunction. Clinical strategies aimed at removing inflammatory me diators, reducing edema formation, and improving organ function includ e conventional and modified ultrafiltration, Objective: This study exa mines the effectiveness of conventional and modified ultrafiltration i n preventing weight gain, myocardial edema formation, and left ventric ular dysfunction in neonatal piglets undergoing cardiopulmonary bypass . Methods: In this randomized prospective study, 18 1-week-old piglets were supported with cardiopulmonary bypass at 100 ml kg(-1).min(-1), cooled to 25 degrees C, exposed to 75 minutes of cardioplegic arrest, rewarmed to 37 degrees C, and weaned from bypass, Left ventricular myo cardial contractility was assessed by the preload-recruitable stroke w ork method, with the use of a sonomicrometric two-dimensional cylindri cal model, before bypass and at 10, 60, and 120 minutes after separati on from bypass. Results: Total body weight gain was significantly less in the modified ultrafiltration group than in either the conventional ultrafiltration group or the control group (no filtration). Myocardia l wet/dry ratios were also improved with modified ultrafiltration, but not with conventional ultrafiltration, when compared with no filtrati on (control group). Hemodynamically, modified ultrafiltration was supe rior to conventional ultrafiltration and no filtration (control) in ra ising the mean arterial pressure and increasing the left ventricular p reload-recruitable stroke work after bypass. Conclusion: Modified ultr afiltration is superior to conventional ultrafiltration and no filtrat ion in reducing the total body weight gain, lessening myocardial edema , raising mean arterial pressure, and improving left ventricular contr actility in neonatal piglets undergoing cardiopulmonary bypass and car dioplegic arrest.