The relationship between nutritional intake and clinical outcomes in critically ill patients: results of an international multicenter observational study

The objective of this study was to examine the relationship between the amount of energy and protein administered and clinical outcomes, and the extent to which pre-morbid nutritional status influenced this relationship. We conducted an observational cohort study of nutrition practices in 167 intensive care units (ICUs) across 37 countries. Patient demographics were collected, and the type and amount of nutrition received were recorded daily for a maximum of 12 days. Patients were followed prospectively to determine 60-day mortality and ventilator-free days (VFDs). We used body mass index (BMI, kg/m(2)) as a marker of nutritional status prior to ICU admission. Regression models were developed to evaluate the relationship between nutrition received and 60-day mortality and VFDs, and to examine how BMI modifies this relationship. Data were collected on 2,772 mechanically ventilated patients who received an average of 1,034 kcal/day and 47 g protein/day. An increase of 1,000 cal per day was associated with reduced mortality [odds ratio for 60-day mortality 0.76; 95% confidence intervals (CI) 0.61-0.95, p = 0.014] and an increased number of VFDs (3.5 VFD, 95% CI 1.2-5.9, p = 0.003). The effect of increased calories associated with lower mortality was observed in patients with a BMI < 25 and a parts per thousand yen35 with no benefit for patients with a BMI 25 to < 35. Similar results were observed when comparing increasing protein intake and its effect on mortality. Increased intakes of energy and protein appear to be associated with improved clinical outcomes in critically ill patients, particularly when BMI is < 25 or a parts per thousand yen35.