Nutritional adequacy in patients receiving mechanical ventilation who are fed enterally

Inadequate nutritional intake in critically ill patients can lead to complications resulting in increased mortality and healthcare costs. Several factors limit adequate nutritional intake in intensive care unit patients given enteral feedings.

To examine the adequacy of enteral nutritional intake and the factors that affect its delivery in patients receiving mechanical ventilation.

A prospective, descriptive design was used to study 60 patients receiving enteral feedings at target or goal rate. Energy requirements were determined for the entire sample by using the Harris-Benedict equation; energy requirements for a subset of 25 patients were also determined by using indirect calorimetry. Energy received via enteral feeding and reason and duration of interruptions in feedings were recorded for 3 consecutive days.

Mean estimated energy requirements (8996 kJ, SD 1326 kJ) and mean energy intake received (5899 kJ, SD 3058 kJ) differed significantly (95% CI 3297-3787; P < .001). A total of 41 patients (68.3%) received less than 90% of their required energy intake, 18 (30.0%) received within +/-10%, and 1 (1.7%) received more than 110%. Episodes of diarrhea, emesis, large residual volumes, feeding tube replacements, and interruptions for procedures accounted for 70% of the variance in energy received (P<.001). Procedural interruptions alone accounted for 45% of the total variance. Estimated energy requirements determined via indirect calorimetry and mean energy received did not differ.

Most critically ill patients receiving mechanical ventilation who are fed enterally do not receive their energy requirements, primarily because of frequent interruptions in enteral feedings.