Objectives: The aim of this study was to assess, in a selected population, the effects of selective decontamination of the digestive tract on colonization of the oropharynx, trachea, stomach and rectum, and on the infection rate. An economical assessment was also performed.
Design: A prospective, double-blind, randomized, placebo-controlled, dual-center trial.
Setting: Two neurosurgical intensive care units.
Patients: A total of 191 comatose patients admitted emergently and intubated within < 24 hrs were enrolled. Of these patients, 68 were excluded because they either died, got an early infection, or were extubated within the first 5 days. A total of 123 patients were analyzed: 63 treated and 60 placebo patients.
Interventions: Topical antibiotics (tobramycin, polymyxin E, amphotericin B) were applied in the oropharynx and in the stomach. Vancomycin was added in the oropharyngeal paste. Placebo patients received the same regimen (i.e., a suspension of fluid and a paste) but without antibiotics. No parenteral antibiotics were given during the study period.
Measurements and main results: Bronchopneumonia episodes were diagnosed with protected specimen brush or plugged telescoping catheter and other infections were diagnosed according to the Center for Disease Control of Atlanta criteria. Antibiotic costs and cost per survivor were calculated. Selective decontamination of the digestive tract significantly reduced Gram-negative bacilli colonization as well as the number of episodes of bronchopneumonia, urinary tract infections, and sinusitis. Despite the addition of vancomycin, Staphylococcus aureus remained the main potential pathogen causing tracheal colonization and subsequent bronchopneumonia. The reduction in bronchopneumonia rate was observed in head-trauma patients only. We were able to show that: a) the trachea was the main reservoir of microorganisms responsible for pneumonia; b) pneumonia developed after tracheal colonization. Total charges for antibiotics were 2.8 times higher in the treated group than in the placebo group; in calculating the cost per survivor, selective decontamination of the digestive tract might be beneficial due to the reduced length of stay.
Conclusions: Selective decontamination of the digestive tract is an effective technique in reducing infectious morbidity in comatose neurosurgical patients. Because of its cost, this technique should be used only in selected populations.