Intensive Nutrition Therapy Compared to Usual Care in Critically Ill Adults: A Randomised Pilot Trial

Background:

Nutrition is a commonly provided therapy in critical illness, but data about effectiveness is sparse. Best practice guidelines recommend enteral nutrition (EN), a specialised solution delivered into the gastrointestinal tract, as the first line of nutrition therapy. The majority of best practice guidelines also recommend delivery of energy and protein amounts close to predicted requirements in critical illness over the course of Intensive Care Unit (ICU) admission, however the only evidence to support this is from observational data. Although recommended that energy and protein requirements be met, and observational data suggests this is of benefit, there are practical challenges with the provision of EN. International practice surveys report the average energy and protein provided is approximately 59% of the patients predicted requirements, for multifactorial reasons. The addition of parenteral (intravenous) nutrition has been proposed as a method to provide additional energy when EN is insufficient, termed supplemental parenteral nutrition (PN). The ability of this strategy to deliver additional energy and protein to patients during critical illness has been proven in several feasibility/pilot trials, but the benefit on clinical and functional outcomes is unknown.

Despite observational data suggesting benefit when energy and protein delivery is optimised close to requirements, no large scale randomised controlled trials (RCTs) have confirmed improved clinical outcomes in critical illness, with some showing no effect with delayed nutrition or even harm. There are several possible reasons for the lack of observed benefit from RCTs to date; the interventions may have been applied at a time when the patient's metabolism is not in a phase of recovery; interventions have been short in duration and; studies have not addressed what happens to nutrition intake in the post ICU period of hospitalisation in critically ill individuals.

Aims:

To determine whether the use of a pre-tested supplemental PN strategy in the ICU and an intensive nutrition intervention after discharge to the hospital ward is feasible and will deliver more total energy than standard nutrition care over the entire hospital stay, in critically ill patients with at least one organ system failure.