NEW YORK (Reuters Health) – Heart rate characteristics (HRC) monitoring can improve survival rates in very low birth weight infants, according to a randomized study.

Bedside HRC monitoring “can spot problems very early, and gets doctors and nurses to the right bedside at the right time,” lead investigator Dr. Joseph Randall Moorman, of the University of Virginia in Charlottesville, told Reuters Health.

Dr. Moorman is Chief Medical Officer of Medical Predictive Science Corporation, which makes the HeRO monitoring system used in the study. The company co-funded the study with the National Institutes of Health.

”HRC monitoring is predicated on the idea that neonatal sepsis is preceded by subclinical reduced variability and transient decelerations of heart rate,” he and colleagues explain in a paper in the Journal of Pediatrics, available online now.

In previous work, the researchers developed and validated a HRC index and showed that it provides added information to laboratory tests and clinical signs. The index is computed in real time and displayed continuously at the bedside using the HeRO monitoring system.

In their latest study, they tested the system in randomized controlled trial involving 3,003 very low birth weight infants in nine neonatal intensive care units (NICU). In one group, HRC monitoring was displayed; in the other, it was masked.

Infants whose HRC were displayed had an average of 2.3 more days alive and off the ventilator (the composite primary outcome) than those whose HRC were masked; the difference was not significant (P = 0.08).

However, there was a clinically significant 22% relative reduction in the mortality rate in infants whose HRC monitoring results were displayed (P = 0.04), from 10.2% to 8.1%.

“Just turning the monitor display on so that doctors and nurses could see it saved the life of 1 in 48 very low birth weight babies (< 1500 grams) and 1 in 23 extremely low birth weight babies (< 1000 grams),” Dr. Moorman told Reuters Health.

There were no significant differences in the number of days spent in the intensive care unit or on antibiotics.

Dr. Moorman believes HRC monitoring in very low birth weight infants “should be standard of care.”

Dr. Karen Fairchild, a neonatologist at the University of Virginia, who was not involved in the study and has no financial ties to the company, agrees.

“I’ve personally seen a number of cases where the HeRO score went up and the baby ‘looked fine’ but turned out to have a serious bloodstream infection,” she told Reuters Health. “The benefit of this monitor is that it takes complex heart rate patterns associated with impending illness (patterns that clinicians cannot see by looking at a standard monitor) and turns them into a score,” Dr. Fairchild said.

“If the score goes up, the nurses and doctors are alerted to look very closely at the baby for signs of infection, and consider whether to start antibiotics,” she added.

“I think now that the HeRO study has been published showing a 20% reduction in mortality, this monitor will become standard of care for NICUs caring for very low birth weight premature infants,” Dr. Fairchild said.

Dr. Judy Aschner, of Vanderbilt University School of Medicine and director of the division of neonatology at Monroe Carell Jr. Children’s Hospital, Nashville, has also seen the benefit of HRC monitoring firsthand. Dr. Aschner is a co-author on the current study but has no ties to the company.

“I learned the value of the HeRO score for predicting neonatal sepsis as a faculty member at Wake Forest University several years before I moved to Vanderbilt University,” she told Reuters Health.

“The HeRO score is now hard wired into our daily practice. It is recorded like other vital signs (respiratory rate, blood pressure, oxygen saturation) by the nursing staff twice daily in the electronic medical record and presented by the residents and nurse practitioners on morning patient care rounds with the attending neonatologist,” Dr. Aschner explained.

“I document the HeRO on every baby in the NICU every day in my notes; it has become the standard of care in our 83 bed NICU,” added Dr. Aschner.

Reference:
Mortality Reduction by Heart Rate Characteristic Monitoring in Very Low Birth Weight Neonates: A Randomized Trial.
J Pediatr 2011. Published online August 10, 2011.