Effect of Enteral Versus Parenteral Nutrition on Outcome of Medical Patients Requiring Mechanical Ventilation

Background: Early enteral nutrition (EN) in patients receiving mechanical ventilation commonly has been advocated, based mainly on studies conducted in mixed populations of trauma and surgery patients. In this study, ventilator-associated pneumonia rates and outcomes were compared in mechanically ventilated medical intensive care unit (ICU) patients receiving enteral versus parenteral nutrition. Methods: Patients fulfilling inclusion criteria between February 1, 2004, and January 31, 2006, were included. Patients were randomized to enteral or parenteral nutrition (PN) within 48 hours of intubation. Development of ventilator-associated pneumonia, assessment as to whether day feeding goal was attained, duration of mechanical ventilation, ICU and hospital length of stay (LOS), and mortality rates were recorded. Results: Of 249 consecutive patients receiving mechanical ventilation, 71 patients were included. Thirty (42.3%) patients received EN, and 41 (57.7%) received PN. There was no difference between groups for age, sex, body mass index, and scores on the Acute Physiology and Chronic Health Evaluation II. Ventilator-associated pneumonia rate, ICU and hospital LOS, and mortality rates were similar for both groups. In the parenterally fed group, duration of mechanical ventilation was longer (p = .023), but the feeding goal was attained earlier (p = .012). Conclusions: In mechanically ventilated patients in the medical ICU, ventilator-associated pneumonia rates, ICU and hospital lengths of stay, and ICU and hospital mortality rates of patients receiving PN are not significantly different than those in patients receiving EN, and feeding goals can more effectively be attained by PN. Yet, duration of mechanical ventilation is slightly longer in patients receiving PN.