Differences in effect of early enteral nutrition on mortality among ventilated adults with shock requiring low-, medium-, and high-dose noradrenaline: A propensity-matched analysis

Despite extensive research on early enteral nutrition (EEN), it remains unclear whether EEN is effective for patients with shock requiring vasopressors. This study aimed to compare outcomes between EEN and late enteral nutrition (LEN) in ventilated patients with shock requiring low-, medium-, or high-dose noradrenaline.Using a national inpatient database in Japan, we identified ventilated patients admitted to intensive care units who had shock requiring catecholamines (noradrenaline or dobutamine) from July 2010 to March 2016. We defined patients who started enteral nutrition within 2 days after starting mechanical ventilation as EEN group and the others as LEN group. Propensity score matching was performed between patients undergoing EEN and LEN in each of the low- (<0.1 μg/kg/min), medium- (0.1-0.3 μg/kg/min), and high-dose (≥0.3 μg/kg/min) noradrenaline groups.We identified 52,563 eligible patients during the 69-month study period, including 38,488, 11,042, and 3033 patients in the low-, medium-, and high-dose noradrenaline groups, respectively. One-to-two propensity score matching created 5,969, 2,162, and 477 one-to-two matched pairs in the low-, medium-, and high-dose noradrenaline groups, respectively. The 28-day mortality rate was significantly lower in the EEN than LEN group in the low-dose noradrenaline group (risk difference, -2.9%; 95% confidence interval [CI], -4.5% to -1.3%) and in the medium-dose noradrenaline group (risk difference, -6.8%; 95% CI, -9.6% to -4.0%). In the high-dose noradrenaline group, 28-day mortality did not differ significantly between the EEN and LEN groups (absolute risk difference, -1.4%; 95% CI, -7.4%-4.7%).Although the size of the subgroup requiring high-dose noradrenaline may have been too small to demonstrate a significant difference, the results suggest that EEN was associated with a reduction in mortality in ventilated adults treated with low- or medium-dose noradrenaline but not in those requiring high-dose noradrenaline.