title: Heart rate characteristics: novel physiomarkers to predict neonatal infection and death.
abstract: OBJECTIVE
  Monitoring of regulated physiologic processes using physiomarkers such as heart rate variability may be important in the early diagnosis of subacute, potentially catastrophic illness. Early in the course of neonatal sepsis, there are physiomarkers of reduced heart rate variability and transient decelerations similar to fetal distress. The goal of this study was to determine the degree of increased risk for sepsis, urinary tract infection (UTI), and death when these abnormal heart rate characteristics (HRC) were observed.
  
  
  METHODS
  We monitored 1022 infants at 2 tertiary care NICUs, 458 of whom were very low birth weight. We calculated an HRC index from validated regression models relating mathematical features of heart rate time series and histograms to episodes of illness. We calculated the risks for adverse events of sepsis, UTI, and death for infants stratified by HRC measurements.
  
  
  RESULTS
  Compared with infants with low-risk HRC measurements, infants with high-risk HRC measurements had 5- to 6-fold increased risk for an adverse event in the next day and 3-fold increased risk in the next week. Laboratory tests that were relevant to infection added information to HRC measurements. Infants with both high-risk HRC and abnormal laboratory tests had 6- to 7-fold increased risk for an adverse event in the next day compared with infants who had neither.
  
  
  CONCLUSIONS
  HRC are noninvasively monitored physiomarkers that identify infants in the NICU who are at high risk for sepsis, UTI, and death.
authors.affiliation: Department of Pediatrics, University of Virginia Health System, Charlottesville, Virginia, USA.
authors.forename: M Pamela
authors.initials: MP
authors.lastname: Griffin
authors.forename: Douglas E
authors.initials: DE
authors.lastname: Lake
authors.forename: Eric A
authors.initials: EA
authors.lastname: Bissonette
authors.forename: Frank E
authors.initials: FE
authors.lastname: Harrell
authors.forename: T Michael
authors.initials: TM
authors.lastname: O'Shea
authors.forename: J Randall
authors.initials: JR
authors.lastname: Moorman
mesh_terms: D005865:Gestational Age; D006339:Heart Rate; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000175:diagnosis* / Q000401:mortality; D019102:Infant, Very Low Birth Weight; D008991:Monitoring, Physiologic; D018805:Sepsis / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology; D015996:Survival Rate; D014552:Urinary Tract Infections / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology