Timing of Target Enteral Feeding in the Mechanically Ventilated Patient

Inclusion Criteria: Patients will be eligible for inclusion in the study if they meet the following criteria: Mechanical ventilation expected to last at least 72 hours. Presence of, or primary physician's intent to place, an enteral feeding tube and begin enteral feeds. Exclusion Criteria: More than 48 hours elapsed since both inclusion criteria met. Patient, legal representative, or physician refuses consent or is unavailable to provide consent. Patient, legal representative, or physician not committed to full support (Exception: A patient will not be excluded if he/she would receive all supportive care except for attempts at resuscitation from cardiac arrest). Presence of malignant or irreversible condition and estimated 28 day mortality greater than 50%. Severe or refractory shock. Moribund patients not expected to survive 24 hours from start of enteral feeding (as determined by primary medical team). Child-Pugh score greater than 10. Presence of partial or complete mechanical bowel obstruction, or ischemia, or infarction. Current TPN use or intent to use TPN within 7 days. Severe malnutrition with BMI less than 18.5 and/or loss of more than 30% total body weight in the previous 6 months. Neuromuscular disease impairing the ability to ventilate spontaneously. Laparotomy expected within 7 days. Unable to raise head of bed 45°. greater than 30% total body surface area burns. Absence of GI tract/short bowel syndrome - defined as entire length of small bowel totaling 4 feet or less. Presence of high-output (> 500 cc/day) enterocutaneous fistula. Age less than 13 years Allergy to enteral formula