Alterations in oropharyngeal flora in patients with a nasogastric tube: a cohort study.

Abstract

The authors undertook this prospective study to determine whether the presence of a nasogastric tube results in a change in the bacterial flora in the oropharynx. Patients scheduled to undergo an elective surgical procedure under general endotracheal anesthesia were studied. Sixteen patients had a nasogastric tube placed and 14 patients did not. The two patient groups were comparable in terms of age, gender, severity of underlying illness, and use of perioperative antibiotics. A commercially available, presterilized, clear plastic nasogastric tube was used in all patients. The tube was placed either for gastric decompression or feeding. All patients had a high oropharyngeal swab taken just before surgery. A similar swab was obtained 48 and 72 hours later. Patients were examined for evidence of otitis, sinusitis, and pharyngitis at the beginning of the study and 48 hours later. The authors found a significant increase in the frequency of oropharyngeal colonization by pathogenic Gram‐negative bacteria after 48 to 72 hours of nasogastric intubation as compared with the preintubation period (p <.01) as well as when compared with the nonintubated group (p <.001). Thirteen of 16 patients who had a nasogastric tube placed had growth of bacterial pathogens in their oropharynx within 48 to 72 hours. The pathogens included Pseudomonas, Klebsiella, Proteus, and Escherichia coli. There also seemed to be a tendencey to suppress the normal oropharyngeal flora. No significant change in the flora of the nonintubated group was seen postoperatively. The investigators concluded that the presence of a nasogastric tube predisposes to colonization by Gram‐negative bacterial pathogens within 48 to 72 hours.