Differentiating esophageal sensitivity phenotypes using pH–impedance in intensive care unit infants referred for gastroesophageal reflux symptoms

Abstract

OBJECTIVE: To identify esophageal sensitivity phenotypes relative to acid (S Acid ), bolus (SBolus), acid and bolus (S Acid+Bolus ), and none (S None ) exposures in infants suspected with gastroesophageal reflux disease (GERD). METHODS: Symptomatic infants (N=279) were evaluated for GERD at 42(40–45) weeks postmenstrual age using 24-hour pH-impedance. Symptom associated probability (SAP) for acid and bolus components defined esophageal sensitivity: 1) S Acid as SAP≥95% for acid (pH<4), 2) S Bolus as SAP≥95% for bolus, 3) S Acid+Bolus as SAP≥95% for acid and bolus, or 4) S None as SAP<95% for acid and bolus. RESULTS: Esophageal sensitivity prevalence (S Acid , SBolus, SAcid+Bolus, S None ) was 28(10%), 94(34%), 65(23%), and 92(33%) respectively. Emesis occured more in SBolus and S Acid+Bolus vs S None (p<0.05). Magnitude (#/day) of cough and emesis events increased with S Bolus and S Acid+Bolu s vs S None (p<0.05). S Acid+Bolus had increased acid exposure vs S None (p<0.05). Distributions of feeding and breathing methods were distinct in infants with S Bolus vs S None (both, p<0.05). Multivariate analysis revealed that arching and irritability events/day were lesser at higher PMAs (p<0.001), greater for infants on NCPAP (p<0.01), with S Bolus and S Acid+Bolu s (p<0.05). Coughs/day was greater at higher PMAs (p<0.001), for infants with gavage and transitional feeding methods (p<0.02), with S Bolu s and S Acid+Bolus (p<0.05) but lesser with Trach (p<0.001). Number of emesis events/day were greater with SBolus and SAcid+Bolus (p<0.001). Sneezes/day decreased for infants on Trach (p=0.02). CONCLUSIONS: Feeding and breathing methods can influence the frequency and type of aerodigestive symptoms. We differentiated esophageal sensitivity phenotypes in NICU infants referred for GERD symptoms using pH-Impedance. Acid sensitivity alone was rare, which may explain poor response to acid suppressives; aerodigestive symptoms were predominantly linked with bolus spread. Magnitude of esophageal acid exposure and esophageal sensitivity to bolus spread may explain the pathophysiological basis for symptoms.

Impact of esophageal mucosal permeability markers on provocation‐induced esophageal reflexes in high‐risk infants

“…Infants underwent 24‐h pH‐impedance testing via a disposable pH‐impedance probe with six impedance channels and one distal pH sensor (Greenfield MMS‐Z1‐I or ZandorpH MMS‐Z1‐P‐7R, Laborie Medical Technologies) connected to a recording device (MMS Ohmega, Laborie Medical Technologies) (Jadcherla et al, 2019 ; Jadcherla, Sultana, et al, 2020 ). The probe was calibrated with buffer solutions of pH 4.0 and pH 7.0 before placement.…”

Proton pump inhibitor therapy may alter the sensory motor characteristics of pharyngoesophageal motility in infants with suspected GERD

“…To categorize an infant as having ARI 3%-7% or ARI >7%, 24-h pH-impedance testing was performed using previously published methods. [21][22][23][24] A disposable pH-impedance probe with six impedance sensors and one distal pH sensor (Greenfield MMS-Z1-I or ZandorpH MMS-Z1-P-7R, Laborie Medical Technologies, Mississauga, ON, Canada) was attached to a recording device (MMS Ohmega, Laborie Medical Technologies, Mississauga, ON, Canada). The probe was placed so that the pH sensor was between the T7 and T8 vertebrae and verified by chest x-ray.…”

“…Acid (pH sensor) and bolus (impedance sensors) components were analyzed. [21][22][23][26][27][28] Acid characteristics included: (a) ARI, %, defined as the percentage of time the esophagus was exposed to acid, 2,23,24,26 (b) number of reflux events, #, 29 (c) longest reflux event, seconds, 30,31 and (d) number of symptoms. 21,22,24,26,27 Impedance characteristics included: (e) distal baseline impedance (DBI), ohms, categorized by severity (<900, 900-2000, or >2000) 23,32 and f) bolus clearance time (BCT) at Z3 and Z6, seconds, defined as the time duration of the impedance channel to drop by 50% and return to baseline.…”

Comparison of direct effects of rice‐thickened formula vs routine feeds on symptoms and gastroesophageal reflux indices: A crossover cohort study

“…Gastroesophageal reflux disease (GERD) is a frequently attributed diagnosis in infants with feeding difficulties and aerodigestive symptoms among convalescing infants in the neonatal intensive care unit (NICU) 1–3 . Many troublesome symptoms are ubiquitous, such as choking, gagging, arching, irritability, regurgitation, refusal to feed, and poor weight gain; these symptoms are nonspecific to GERD 4 . Objective measurements using 24‐h pH‐impedance testing, such as percentage of esophageal acid exposure (acid reflux index [ARI]) and symptom correlation for bolus events, can offer more precision with diagnosis and therapeutic strategies 5,6 .…”

“…[1][2][3] Many troublesome symptoms are ubiquitous, such as choking, gagging, arching, irritability, regurgitation, refusal to feed, and poor weight gain; these symptoms are nonspecific to GERD. 4 Objective measurements using 24-h pH-impedance testing, such as percentage of esophageal acid exposure (acid reflux index [ARI]) and symptom correlation for bolus events, can offer more precision with diagnosis and therapeutic strategies. 5,6 However, ambiguity still exists regarding abnormal ARI threshold values for infants.…”