Our group addressed this question in a prospective
cohort study of ICU admissions who were assigned total parenteral
nutrition if enteral nutrition was not tolerated by day
3 [36]. TGC was utilized in all. Despite a lower mean glucose
level in the total parenteral compared to the total enteral nutrition
patients, the former increased the risk of infectious complications.
A multiple logistic regression model demonstrated
a nearly fivefold increased risk of catheter-related bloodstream
infections. Sena and colleagues [37] evaluated the outcome of
567 severe blunt injury patients who received enteral versus
parenteral nutrition. Seventy-five percent achieved enteral
nutrition with 17% receiving early parenteral nutrition. In the
parenteral cohort there was a 2.1 relative risk of infection while
the combination of enteral and parenternal nutrition significantly
increased the mortality relative risk by 2.3. Although
SSG 2008 recommends that all patients receiving intravenous
insulin in the ICU receive a glucose calorie source, there is a
lack of consensus about the optimal route of feeding. Since
enteral nutrition is often contraindicated or intolerable for
the patients in the surgical ICU, recent ESPEN guidelines
recommend the initiation of parenteral nutrition within 24
to 48 hours for clinically ill patients who are not expected
to be on normal nutrition within 3 days of admission [38].
However, clinicians must weigh the risk of total parenteral
nutrition when thinking about nutritional support in critically
ill patients who cannot tolerate the enteral route.