Effects of early enteral feeding on the outcome of critically ill mechanically ventilated medical patients

Study objectives: To determine the impact of early enteral feeding on the outcome of critically ill medical patients. Design: Retrospective analysis of a prospectively collected large multi-institutional ICU database. Patients: A total of 4,049 patients requiring mechanical ventilation for > 2 days. Measurements and results: Patients were classified according to whether or not they received enteral feeding within 48 h of mechanical ventilation onset. The 2,537 patients (63%) who did receive enteral feeding were labeled as the "early feeding group," and the remaining 1,512 patients (37%) were labeled as the "late feeding group." The overall ICU and hospital mortality were lower in the early feeding group (18.1% vs 21.4%, p = 0.01; and 28.7% vs 33.5%, p = 0.001, respectively). The lower mortality rates in the early, feeding group were most evident in the sickest group as defined by quartiles of severity of illness scores. Three separate models were done using each of the different scores (acute physiology and chronic health evaluation II, simplified acute physiology score II, and mortality prediction model at time 0). In all models, early enteral feeding was associated with an approximately 20% decrease in ICU mortality and a 25% decrease in hospital mortality. We also analyzed the data after controlling for confounding by matching for propensity score. In this analysis, early feeding was again associated with decreased ICU and hospital mortality. In all adjusted analysis, early feeding was found to be independently associated with an increased risk of ventilator-associated pneumonia (VAP) developing. Conclusion: Early feeding significantly, reduces ICU and hospital mortality based mainly on improvements in the sickest patients, despite being associated with an increased risk of VAP developing. Routine administration of such therapy in medical patients receiving mechanical ventilation is suggested, especially in patients at high risk of death.