Mortality reduction by heart rate characteristic monitoring in very low birth weight neonates: a randomized trial

Abstract

Objective: To test the hypothesis that heart rate characteristics (HRC) monitoring improves neonatal outcomes.

Study design: We conducted a two-group, parallel, individually randomized controlled clinical trial of 3003 very low birth weight infants in 9 neonatal intensive care units. In one group, HRC monitoring was displayed; in the other, it was masked. The primary outcome was number of days alive and ventilator-free in the 120 days after randomization. Secondary outcomes were mortality, number of ventilator days, neonatal intensive care unit stay, and antibiotic use.

Results: The mortality rate was reduced in infants whose HRC monitoring was displayed, from 10.2% to 8.1% (hazard ratio, 0.78; 95% CI, 0.61-0.99; P = .04; number needed to monitor = 48), and there was a trend toward increased days alive and ventilator-free (95.9 of 120 days compared with 93.6 in control subjects, P = .08). The mortality benefit was concentrated in infants with a birth weight <1000 g (hazard ratio, 0.74; 95% CI, 0.57-0.95; P = .02; number needed to monitor = 23). There were no significant differences in the other outcomes.

Conclusion: HRC monitoring can reduce the mortality rate in very low birth weight infants.

Trial registration: ClinicalTrials.gov NCT00307333.

Copyright © 2011 Mosby, Inc. All rights reserved.

Figures

Figure 1

CONSORT diagram

Figure 2

Screen display of the monitor as used in the study.

Figure 3

A, Survival of very low birth weight infants as a function of time in the infants whose heart rate characteristics monitoring results were displayed (top) and conventional monitoring-only group (bottom). B, Predictiveness curve of the HRC index as a risk model and classifier for neonatal sepsis. The solid line represents 2M HRC index values normalized by the average risk of 0.62% and plotted from lowest to highest with units of fold-increase in risk. The open circles are the proportion of infants per decile with proven sepsis in the next 24 hours.

Figure 3

A, Survival of very low birth weight infants as a function of time in the infants whose heart rate characteristics monitoring results were displayed (top) and conventional monitoring-only group (bottom). B, Predictiveness curve of the HRC index as a risk model and classifier for neonatal sepsis. The solid line represents 2M HRC index values normalized by the average risk of 0.62% and plotted from lowest to highest with units of fold-increase in risk. The open circles are the proportion of infants per decile with proven sepsis in the next 24 hours.