Sepsis after coronary bypass grafting: Evidence for loss of the gut mucosal barrier

Postoperative infections may originate from a patient's gastrointestinal tract. We studied infections after coronary artery revascularization. Three hundred twenty-nine patients underwent coronary artery revascularization from January 1987 to March 1990. Eight of the 329 (2.4%) died; none of the deaths were infection related. Fifty-five culture-proven infections were identified in 22 of 321 survivors (6.8%); 9 infections (16%) were gram-positive, 5 (9%) were fungal, and 41 (75%) were gram-negative. Site of infections were respiratory tract, 58%; urinary tract, 18%; blood, 13%; and mediastinum, 11%. Ninety-six percent of respiratory tract and all urinary tract infections were gram-negative or fungal. There was no significant difference between infected and noninfected groups in sex, age, smoking history, preoperative hematocrit or leukocyte count, serum albumin level, or time on extracorporeal bypass. The infected group required intubation and nasogastric suction for a significantly longer time than the noninfected group (p < 0.001). Time to enteral alimentation was significantly longer in the infected group (p < 0.02). We were unable to correlate the number of infections with the lengths of intubation, nasogastric suction, or time to enteral alimentation. This study supports the concept of postoperative infections arising from bacterial translocation across the patient's gastrointestinal tract. The most significant risk factor is the length of the gastrointestinal tract disuse.