Septicemia mortality reduction in neonates in a heart rate characteristics monitoring trial

BACKGROUND: Abnormal heart rate characteristics (HRC) wax and wane in early stages of culture-positive, late-onset septicemia (LOS) in patients in the neonatal intensive care unit (NICU). Continuously monitoring an HRC index leads to a reduction in mortality among very low birth weight (VLBW) infants. We hypothesized that the reduction in mortality was due to a decrease in septicemia-associated mortality. METHODS: This is a secondary analysis of clinical and HRC data from 2989 VLBW infants enrolled in a randomized controlled trial of HRC monitoring in 9 NICUs from 2004–2010. RESULTS: LOS was diagnosed 974 times in 700 patients, and the incidence and distribution of organisms were similar in HRC display and non-display groups. Mortality within 30 days of LOS was lower in the HRC display compared to the non-display group (11.8% vs 19.6%, RR 0.61, 95% CI 0.43, 0.87, p<0.01), but mortality reduction was not statistically significant for patients without LOS. There were fewer large, abrupt increases in the HRC index in the days leading up to LOS diagnosis in infants whose HRC index was displayed. CONCLUSIONS: Continuous HRC monitoring is associated with a lower septicemia-associated mortality in VLBW infants, possibly due to diagnosis earlier in the course of illness.