Feeding enterally the hemodynamically unstable critically ill patient: experience from a multicentre trial (the REDOXS^© study)

Introduction

The delivery of adequate enteral nutrition (EN) in critically ill patients with shock is problematic. The purpose of this study is to describe how EN is delivered in patients with shock from the REDOXS^© study, a multicentre, randomized controlled trial of pharmaconutrition.

Methods

In 20 centres in Canada and Europe, we randomized mechanically ventilated adults with two or more organ failures to one of four groups: (1) glutamine, (2) antioxidants, (3) glutamine plus antioxidants, (4) placebo. EN and parenteral nutrition were initiated and maintained independently as per the Canadian Clinical Practice Guidelines. Shock was defined as the presence of hypoperfusion requiring vasopressors for at least 2 hours. Daily data including the timing of EN, volumes received, incidence of high gastric residual volumes (hGRVs), use and timing of motility agents and small bowel feeding were collected.

Results

From May 2007 to July 2008, 159 patients with shock were randomized, 122 (77%) received EN only, and 13 (8%) patients received EN in combination with parenteral nutrition. EN was started 20.2 hours (median, range 0 to 204.8 hours) after ICU admission. The mean duration of EN was 9.2 days (median 6.8, range 0.1 to 30 days) and the mean volume of EN received was 67% (range 2.5 to 199%) of that prescribed. In total 73/135 (55%) had hGRVs >250 ml, and in these patients motility agents and small bowel feeding were used in 78.1% and 41.1% of patients, respectively. Motility agents were started before onset of hGRVs in 21% patients, on the same day as hGRVs in 40% patients and on average 1.6 ± 0.9 days after hGRVs in 39% patients. The percentage mean prescribed volume of EN received 24 hours before and after the start of motility agents was 35.1% vs. 55.9% (P = 0.009). Small bowel feeding was started before onset of hGRVs in 20% patients, on the same day as hGRVs in 14% patients and was started on average 4.7 ± 3.5 (mean, SD) days after hGRVs in 67% patients. The percentage mean prescribed volume of EN received 24 hours before and after the start of small bowel feeding was 54.2% vs. 67.3% (P = 0.36).

Conclusion

In critically ill patients with shock, EN can be provided in the early phases of acute illness to the majority of patients. The delivery of EN in this population can be maximized by better adoption of motility agents and small bowel feeding.