Nutrition in the Surgical Intensive Care Unit: The Cost of Starting Low and Ramping Up Rates.

BACKGROUND

Calorie/protein deficit in the surgical intensive care unit (SICU) is associated with worse clinical outcomes. It is customary to initiate enteral nutrition (EN) at a low rate and increase to goal (RAMP-UP). Increasing evidence suggests that RAMP-UP may contribute to iatrogenic malnutrition. We sought to determine what proportion of total SICU calorie/protein deficit is attributable to RAMP-UP.

MATERIALS AND METHODS

This is a retrospective study of a prospectively collected registry of adult patients (N = 109) receiving at least 72 hours of EN in the SICU according to the RAMP-UP protocol (July 2012-June 2014). Subjects receiving only trophic feeds or with interrupted EN during RAMP-UP were excluded. Deficits were defined as the amount of prescribed calories/protein minus the actual amount received. RAMP-UP deficit was defined as the deficit between EN initiation and arrival at goal rate. Data included demographics, nutritional prescription/delivery, and outcomes.

RESULTS

EN was started at a median of 34.0 hours (interquartile range [IQR], 16.5-53.5) after ICU admission, with a mean duration of 8.7 ± 4.3 days. The median total caloric deficit was 2185 kcal (249-4730), with 900 kcal (551-1562) attributable to RAMP-UP (41%). The protein deficit was 98.5 g (27.5-250.4), with 51.9 g (20.6-83.3) caused by RAMP-UP (53%).

CONCLUSIONS

In SICU patients initiating EN, the RAMP-UP period accounted for 41% and 53% of the overall caloric and protein deficits, respectively. Starting EN immediately at goal rate may eliminate a significant proportion of macronutrient deficit in the SICU.