Early enteral nutrition in patients with severe traumatic brain injury: a propensity score–matched analysis using a nationwide inpatient database in Japan

Whether enteral nutrition (EN) should be administered early in severe traumatic brain injury (TBI) patients has not been fully addressed. The present study aimed to evaluate whether early EN can reduce mortality or nosocomial pneumonia among severe TBI patients. Using the Japanese Diagnosis Procedure Combination inpatient database from April 2014 to March 2017 linked with the Survey for Medical Institutions, we identified patients admitted for intracranial injury with Japan Coma Scale scores ≥30 (corresponding to Glasgow Coma Scale scores ≤8) at admission. We designated patients who started EN within 2 d of admission as the early EN group, and those who started EN at 3–5 d after admission as the delayed EN group. The primary outcome was in-hospital mortality. The secondary outcome was nosocomial pneumonia. Propensity score–matched analyses were performed to compare the outcomes between the 2 groups. We identified 3080 eligible patients during the 36-mo study period, comprising 1100 (36%) in the early EN group and 1980 (64%) in the delayed EN group. After propensity score matching, there was no significant difference in in-hospital mortality (difference: −0.3%; 95% CI: −3.7%, 3.1%) between the 2 groups. The proportion of nosocomial pneumonia was significantly lower in the early EN group than in the delayed EN group (difference: −3.2%; 95% CI: −5.9%, −0.4%). Early EN may not reduce mortality, but may reduce nosocomial pneumonia in patients with severe TBI.