In this prospective randomized controlled trial the investigators intend to compare the use of a nutritional therapy based on caloric intake determined by indirect calorimetry and a high protein intake (2.0 to 2.2 g/kg/day) with a nutritional regimen based on 25 Kcal/kg/day and protein intake usually recommended to critically ill patients (1.4 to 1.5 grams/kg/day).

OBJECTIVES

To evaluate the effect of nutritional therapy with caloric intake determined by indirect calorimetry and high protein intake (2.0 to 2.2 g/kg/day) compared to nutritional therapy with 25 kcal/kg/day and 1.4 to 1, 5 g/kg/day of protein on short-term outcomes and physical component (PCS) of quality of life after 3 and 6 months of randomization in severe ICU patients.

The primary objective will be the evaluation of the physical component summary (PCS) of SF-36 (Short Form 36), a questionnaire used to evaluate quality of life, validated for the Brazilian population. Patients will be assessed at least 3 and 6 months after randomization.

Secondary objectives: Measurement of handgrip strength measured on the 7th and 14th day of the study and on discharge from the ICU, ICU mortality, hospital mortality, mechanical ventilation time and length of stay in the ICU.

METHODS

The study will include patients over 18 years of age, not pregnant, submitted to mechanical ventilation, whose expectation of stay in the ICU is greater than 3 days.

The sample size was calculated based on the following parameters: patient population under mechanical ventilation, 528, 15% relative risk reduction in the evaluation parameter of the SF-36 tool, Level of significance (α) of 5%, test power of 80%, thus the number of individuals to be sampled will be 294, i.e., two groups of 147 patients. A computer-generated list for randomization and sequentially numbered opaque sealed envelopes is used. The level of significance to reject the null hypothesis will be 5%, that is, a value of p <0.05 will be considered as statistically significant.

Informed consent was obtained from the patient or a next of kin.

Inclusion Criteria:

• Critically ill patients Mechanically ventilated Expected length in the ICU > 3 days

Exclusion Criteria:

• Pregnancy Requirement for inspired oxygen (FIO2) > 0.60 High output bronchopleural fistula