RESUMEN
OBJECTIVE: To evaluate the influence of enteral application of an immunoglobulin enriched bovine milk preparation on endotoxin plasma levels, endotoxin neutralizing capacity of plasma (ENC) and the acute phase response (IL-6, CRP) during and after cardiac surgery, in a pilot study. DESIGN, PATIENTS AND METHODS: 60 patients who underwent coronary bypass operations, were evenly enrolled in a placebo-controlled randomized study. The patients were treated by enteral application of either 42 g of a bovine colostrum milk preparation per day or placebo, for 2 days preoperatively. Endotoxin and ENC were sequentially determined intra- and postoperatively by a chromogenic modification of the limulus amebocyte lysate test. Interleukin-6, CRP, transferrin, alpha-2-macroglobulin, albumin, apo-A, apo-B, IgG, IgA, IgM were determined by ELISA and nephelometrically. The clinical course was followed up by daily evaluation of the Apache-II-score. MAIN RESULTS: Demographic data were comparable in both groups. No differences of the Apache-II-score (verum group: 6.5 +/- 1.9 vs. controls: 6.8 +/- 1.8 on admission) were observed. Endotoxin and ENC levels were elevated at the end of the operation and seemed to have a trigger function for the acute phase response. However, there was no reduction (calculated as the area under the curve) in patients receiving the colostrum milk preparation throughout the observation period. Plasma levels of endotoxin binding proteins did not differ. Plasma IL-6 concentrations increased to maximal median values of 655 pg/ml in the verum and 786 pg/ml in the control group, respectively 2 and 6 h after surgery. In the colostrum group, there was a tendency to reduced IL-6 levels throughout the observation period. CRP-levels of all patients peaked 48 h after the operation but were lower (p = 0.034) in the verum group. CONCLUSION: This study revealed that endotoxemia occurs early in an elective non-intestinal surgical intervention, and is followed by a subsequent increase in mediators of the acute phase reaction. The prophylactic enteral application of a bovine milk preparation for two days in cardiac patients did reduce postoperative CRP-plasma levels but, contrary to a former double-blind study in abdominal surgery, failed to curtail perioperative endotoxemia. One reason could be the amount of colostrum preparation administered was too small.