The Irritable Infant in the Neonatal Intensive Care Unit: Risk Factors and Biomarkers of Gastroesophageal Reflux Disease

Abstract

To determine risk factors for arching/irritability in high-risk infants and examine the significance of comorbidity and gastroesophageal reflux (GER) characteristics. Retrospective analysis of 24-hour pH-impedance studies of symptomatic infants in a neonatal intensive care unit (ICU) (n=516, 30.1±4.5weeks of gestation, evaluated at 41.7±3.2weeks postmenstrual age) was conducted. Comparisons were made between infants with >72 vs ≤72 arching/irritability events per day. We characterized risk factors for arching/irritability along with clinical, pH-impedance, and outcome correlates. Of 39 973 arching/irritability events and 42 155 GER events, the averages per day were 77.6±41.0 and 81.7±48.2, respectively. Acid reflux and impedance bolus characteristics were not significantly different between infants with >72 and≤72 arching/irritability events (P≥.05). The odds ratios (ORs) and 95% confidence intervals (CIs) adjusted for postmenstrual age and weight at evaluation were significant for risk factors of preterm birth (2.3 [1.2-4.4]), moderate or severe neuropathology (2.0 [1.1-3.6]), and presence of oral feeding at testing (1.57 [1.07-2.30]). Acid GER disease is unlikely the primary cause of arching/irritability and empiric treatment should not be used when arching/irritability is present. Prematurity and neurologic impairment may be more likely the cause of the arching/irritability. Arching/irritability may not be a concern in orally fed infants.