Early postsurgical bacterial contamination of the airways: a study on 28 open-heart patients.

One pre- and two postoperative cultures of tracheo-bronchial secretions were obtained from 28 cardiac patients, subjected to open-heart surgery. Four patients received preoperative antibiotics, and all but one received postoperative prophylactic antibiotics. Preoperatively, only one patient had potential pathogens; after surgery (mean intubation time 4.2 h), four patients (14.3%) had organisms; and after 19 h of intubation, 28% of the patients had potential pathogens in their tracheo-bronchial secretions. Only three of the seven organisms recovered from the last sample were clearly sensitive to the antibiotics given prophylactically; and two of these organisms were Group A beta-haemolytic streptococci. The early presence of organisms in the airways after intubation, the high incidence of colonization, and the ineffectiveness of prophylactic antibiotics in preventing this contamination are pointed out. The factors that may possibly influence colonization of airways among these patients are commented on.