RESUMEN
BACKGROUND: Unblinded studies suggested that sucralfate prophylaxis for stress ulcers is associated with a lower rate of nosocomial pneumonia than acid-reducing approaches. We performed a randomized, double-blind, double-sham clinical trial comparing the exact microbial effects of each treatment. METHODS: One hundred forty patients entered this study before major elective surgery, allowing baseline cultures of gastric and pulmonary secretions to be obtained intraoperatively. Postoperatively, the patients were treated with standard doses of either sucralfate or antacids, plus a sham of the other drug. Cultures were repeated twice daily for 3 days. Molecular epidemiological typing was used to track the appearance of specific microbes and their transmission from site to site, and clinical end points were compared. The number of patients chosen was for sufficient statistical power to detect differences in the microbial measures, as detecting differences in clinical measures would have required increasing the sample size by an order of magnitude. RESULTS: Gastric pH was affected by the form of stress ulcer prophylaxis throughout the study, and this pH effect affected the number of new gastric organisms appearing in the 2 different groups. Colonization of the airway with new gastric organisms occurred more frequently in the antacid than in the sucralfate group, and colonization of the airway with organisms of gastric origin was associated with occurrence of postoperative pneumonia. CONCLUSIONS: Both sucralfate and antacids offered safe and effective stress ulcer prophylaxis in this double-blind clinical trial of postoperative patients in an intensive care unit. In association with the drug's effects on gastric pH, more new pathogens appeared in the gastric contents of antacid-treated than sucralfate-treated patients.
Asunto(s)
Antiácidos/uso terapéutico , Antiulcerosos/uso terapéutico , Infección Hospitalaria/prevención & control , Úlcera Péptica/microbiología , Úlcera Péptica/prevención & control , Neumonía/prevención & control , Estómago/microbiología , Sucralfato/uso terapéutico , Infección Hospitalaria/etiología , Método Doble Ciego , Esquema de Medicación , Procedimientos Quirúrgicos Electivos/efectos adversos , Humanos , Úlcera Péptica/complicaciones , Úlcera Péptica/etiología , Úlcera Péptica Hemorrágica/etiología , Neumonía/etiología , Estómago/efectos de los fármacos , Resultado del TratamientoRESUMEN
We applied restriction endonuclease analysis of genomic DNA using pulsed field gel electrophoresis (PFGE) to study gastric colonization with Enterococcus faecalis among patients hospitalized in the surgical intensive care unit (SICU). Isolates were obtained by culturing prospectively the gastric contents of 140 patients in the SICU. In addition, cultures of respiratory specimens were obtained daily and cultures of blood, normally sterile body fluids, wounds, and urine were obtained when indicated clinically. A total of 177 isolates were obtained from 45 patients. Concentrations of E. faecalis in gastric fluid ranged from 1 x 10(2) colony forming units (CFU)/ml to greater than 5 x 10(7) CFU/ml (mean 8.0 x 10(6) CFU/ml). Overall, 33 different DNA types were identified by PEGE. In examining strain variation among isolates obtained from multiple anatomic sites over time, we found that the same DNA type was recovered from gastric aspirates, sputum, and wounds in a given patient and that these strains were carried over time. In general, given individuals were colonized with their own unique DNA type; however, one DNA type (type C) was shared by 11 different patients, and seven DNA types were shared by two individuals each. These results demonstrate the potential importance of gastric colonization as a reservoir for nosocomial strains of E. faecalis in an SICU setting.
Asunto(s)
Infección Hospitalaria/epidemiología , ADN Bacteriano/análisis , Enterococcus faecalis/genética , Infecciones por Bacterias Grampositivas/epidemiología , Estómago/microbiología , Recuento de Colonia Microbiana , Infección Hospitalaria/microbiología , Enzimas de Restricción del ADN , Electroforesis en Gel de Campo Pulsado , Enterococcus faecalis/aislamiento & purificación , Lavado Gástrico , Genoma Bacteriano , Infecciones por Bacterias Grampositivas/microbiología , Humanos , Unidades de Cuidados Intensivos , Masculino , Epidemiología Molecular , Estudios Prospectivos , Esputo/microbiologíaRESUMEN
BACKGROUND: Postoperative pneumonia (PP) is a major complication that has been linked to microaspiration of pathogens originating in the gastrointestinal tract. This prospective study was performed to define the role of gastric bacterial aspiration in the development of PP. METHODS: Informed consent was obtained before operations from 140 veterans scheduled for major elective procedures requiring nasogastric tubes, and cultures were obtained of the gastric contents and sputum twice daily after operation. RESULTS: PP developed in 26 (18.6%) of 140 patients. The patients who had PP did not differ from those with no pneumonia after operation except for a history of chronic obstructive pulmonary disease, which was found in 38.5% of those with PP compared with 20% of patients with no pneumonia (p < 0.05). Morbidity was increased in association with PP, because length of stay in the surgical intensive care unit (6.2 vs 2.6 days), days intubated (2.7 vs 0.6), total postoperative days (15.3 vs 8.4), and mortality rates (19.2% vs 1.7%) were greater than in patients with no pneumonia. Gastric pathogens were present on entry in 38% of patients, and 32% of these had PP compared with 13% whose initial gastric cultures were sterile (p = 0.01). Colonization of sputum for greater than 24 hours with gastric pathogens occurred in 28% of patients. These patients had a 40% incidence of PP compared with 12% in patients without such evidence of microaspiration (p < 0.01). CONCLUSIONS: PP is a morbid postoperative complication associated with not only chronic obstructive pulmonary disease but also the presence of gastric bacteria during operation and transmission of gastric bacteria to the pulmonary tree after operation.