ENDOGENOUS ENDOTOXEMIA OF INTESTINAL ORIGIN DURING CARDIOPULMONARY BYPASS - ROLE OF TYPE OF FLOW AND PROTECTIVE EFFECT OF SELECTIVE DIGESTIVE DECONTAMINATION

Objective: To evaluate the possible related factors to endotoxemia and cytokine activation during the ischemic phase of extracorporeal surge ry, and the effect of selective digestive decontamination (SDD) as a p reventive measure. Design: Prospective, open, randomized trial. Settin g: Two multidisciplinary ICUs (tertitary care hospitals). Patients: On e hundred consecutive patients undergoing cardiopulmonary bypass (CPB) , randomly allocated to two groups: gut decontamination (group I = 50 cases) and controls (group II = 50 cases). Interventions: Preoperative administration of oral non-absorbable antibiotics (polymyxin E, tobra mycin and amphotericin B) versus no administration. Measurements and r esults: The assessment of decontamination by means of the bacteriologi c control of rectal swabs. Determinations of gastric intramucosal pH ( gastric pHi) and plasma endotoxin, tumor necrosis factor (TNF) and int erleukin-6 (IL-6) before surgery and during the ischemic and reperfusi on phases of bypass. Rectal aerobic Gram negative bacilli (AGNB) were significantly reduced in the treated patients and in 56% total eradica tion was achieved. Endotoxin, TNF and IL-6 plasma levels were signific antly lower in this group. By contrast, both endotoxin and TNF/IL-6 le vels and gastric pHi correlated with the type of surgical flow (pulsat ile versus non-pulsatile). Conclusions: SDD reduces the gut content of enterobacteria. This may explain the lower endotoxin and cytokine lev els detected in decontaminated patients. In addition to SDD, the type of flow employed during bypass seems to influence endotoxemia and cyst okine levels.