HeRO monitoring in the NICU : sepsis detection and beyond

Heart rate patterns offer a ‘window’ into autonomic nervous system function: when they become abnormal they signal an underlying pathology. Preterm infants in the neonatal intensive care unit (NICU) are extremely vulnerable to sepsis, which is often associated with decreased heart rate variability (HRV) and transient heart rate decelerations. A monitor was developed – the HeRO monitor – to analyse these abnormal heart rate characteristics (HRC) and display to clinicians a score, which indicates the risk of an infant deteriorating from sepsis in the next day. Display of this HeRO score resulted in a 22% relative reduction in mortality in a large randomised clinical trial (RCT) of very low birthweight (VLBW) NICU patients. New research has elucidated various pathological conditions that can cause worsening of HRC and a rise in the HeRO score. To assist clinicians in appropriate use of the HeRO monitor for the benefit of NICU patients, this article will review: ■ The physiological basis of abnormal HRC in sepsis ■ Development and validation of the HeRO algorithm ■ Results of the RCT of HeRO monitoring ■ Answers to frequently asked questions about the monitor ■ Clinical conditions associated with a high HeRO score ■ Current research aimed at developing even more sophisticated and effective predictive monitoring algorithms to improve outcomes of patients in the NICU and elsewhere in the hospital.