Impact of Intraventricular Hemorrhage on Gastroesophageal Reflux Characteristics Using pH-multi-channel Impedance Methods in Premature Infants

Background: Prematurely born infants are at increased risk for acute and chronic neuropathology from intraventricular hemorrhage (IVH) and related consequences. Convalescing infants often manifest with immaturity or maladaptation of peristaltic reflexes and aerodigestive protective mechanisms that result in oral and enteral feeding difficulties. These troublesome airway-, digestive- and somatic symptoms may masquerade as gastroesophageal reflux (GER) or GER disease (GERD), and empiric treatment with acid-suppression, thickened feeds and gastrostomy with fundoplication are implemented. Understanding the relationship between neuropathology and GERD is important to provide accurate diagnoses and guide targeted therapies.

Objectives: 1) To characterize the frequency and types of GER events, and their relationship with symptom-types among enterally fed symptomatic prematurely born infants in the neonatal ICU. 2) To compare pH-impedance patterns and symptom characteristics in infants with varying severities of IVH.

Design/Methods: A total of 156 neonates (27.1 (23.3 – 36.7) weeks gestation) with 4 different IVH grades were evaluated for troublesome GER symptoms using 24-hour pH-impedance at 41.6 ± 0.36 weeks postmenstrual age. List of variables analyzed are shown in Table 1. Frequency of overall and individual symptoms, and symptom association probability (SAP) were also analyzed. Analysis of Variance (ANOVA) was used to compare characteristics across the 4 IVH severity grades. Bonferroni adjustment was used for post-hoc comparison.

Results: Comparison of pH-impedance and symptom characteristics are shown in Table 1. Infants with Grade 4 IVH had greater number of acid reflux periods, acid only events, acid reflux events, total symptoms and individual symptoms of arching/irritability, and emesis when compared to Grade 1 IVH. Infants with Grade 2 IVH had more arching/irritability compared with Grade 1. No significant differences were noted in pH-impedance characteristics between the remaining IVH severity grades.

Conclusions: Grade 4 IVH in premature infants is associated with abnormal pH-impedance patterns, suggesting an underlying aerodigestive pathophysiology. Severe IVH may affect vagal nerve mediated sensory motor aspects of esophageal peristalsis, sphincteric functions, and aerodigestive reflexes, leading to troublesome symptoms. Therefore, infants with severe neuropathology are at increased risk of GERD and may benefit from specialized assessment to guide targeted therapies.