Principal Investigator is Moving Institutions

The investigators propose to conduct a randomized, control trial of β-hydroxy-β-methylbutyrate (HMB) supplementation in elderly patients (≥65 years of age) with acute respiratory failure, who are identified at high risk for malnutrition by ICU-specific nutritional risk scores. Patients will receive either 3g of HMB daily, or control, daily until day 28 following randomization (even if discharged).The investigators will measure functional outcomes using standard, validated measures prior and after discharge.

The investigators propose to conduct a randomized, control trial of HMB supplementation in elderly patients (≥65 years of age) with acute respiratory failure, who are identified at high risk for malnutrition by ICU-specific nutritional risk scores. Patients will receive either 3g of HMB daily, or control, daily until day 28 following randomization (even if discharged).the investigators will measure functional outcomes using standard, validated measures prior and after discharge.

The investigators hypothesize that this inexpensive nutrient, HMB, along with our supportive measures, reduces muscle loss, improves physical muscle function, and improves quality of life in the longer term following critical illness.

Inclusion Criteria:

1. Patients age ≥65 years.
2. Acute respiratory failure (ARF, defined by expected mechanical ventilation for > 72 hours from the point of screening)
3. Elevated nutritional risk (NUTRIC score>5 - see below).

Exclusion Criteria:

1. Over 72 hours from ICU admission.
2. Not expected to survive another 48 hours
3. Lack of commitment to full, aggressive care
4. Patients who have an absolute contraindication to EN (obstruction, perforation, high output fistula),
5. Pregnant women
6. Prisoners
7. Known allergy to study nutrients
8. Unable to walk prior to current illness.