Initial efficacy and tolerability of early enteral nutrition with immediate or gradual introduction in intubated patients

Objective: To compare the initial ( D7) calorie intake and tolerability of two early enteral nutrition protocols in which the optimal flow rate was introduced either immediately or gradually. Design: Open, prospective, randomized study. Setting: Two medical-surgical intensive care units. Patients: One hundred consecutive intubated and mechanically ventilated patients. Interventions: Early enteral nutrition was started within 24 h following intubation, and the optimal flow rate ( 25 Kcal/kg day(-1)) was either introduced immediately or reached in increments. Flow rate of the nutritional solution was adapted to the residual gastric volume, measured every 8 h, and the use of prokinetic agents was encouraged. Vomiting, regurgitation, colectasia, and suspected aspiration were defined as serious adverse events requiring withdrawal of enteral nutrition. Measurements and results: When introduced immediately at optimal flow rate, early enteral nutrition led to a significant improvement in actual calorie supply ( p < 0.0001). Although high residual gastric volume (> 300 ml) was more frequent when optimal flow rate was introduced immediately ( p = 0.04), frequency of serious adverse events necessitating withdrawal of enteral nutrition was similar in the two groups ( p = 0.64). Conclusions: When residual gastric volume is measured regularly and prokinetic agents are used, enteral nutrition can be started early and be introduced at optimal dose regimen, thereby providing better calorie intake. Serious adverse events required early enteral nutrition withdrawal in only 15 patients, with no difference in frequency between the groups.