Twenty-Four-Hour Esophageal pH Measurement in Mechanically Ventilated Children: A Prospective Cohort Study*

Objectives: To assess the prevalence of gastroesophageal reflux in mechanically ventilated children using 24-hour esophageal pH-metry and its role as a risk factor for ventilator-associated pneumonia. Design: Prospective cohort study. Setting: PICU of a tertiary care hospital from North India. Patients: Mechanically ventilated children 1-15 years old in PICU from July 2015 to June 2017, excluding those receiving acid suppressants, known cases of gastroesophageal reflux disease, having upper gastrointestinal bleed. Intervention: Demographic details, baseline investigations, diagnosis, treatment details, and Pediatric Risk of Mortality III score were recorded at enrollment. Gastroesophageal reflux was evaluated using 24-hour esophageal pH-metry. Children were followed up for 7 days or 48 hours after extubation for development of ventilator-associated pneumonia using Centers for Disease Control and Prevention criteria. Pathologic acidic gastroesophageal reflux was defined as fall in esophageal pH less than 4 for more than 4% of total time, whereas pathologic alkaline gastroesophageal reflux as rise in esophageal pH greater than 7 for more than 17% of total time. Measurements and Main Results: Sixty-one children (median [interquartile range], age 73 mo [30-132 mo]; 44 boys [72%]) were enrolled. Median Pediatric Risk of Mortality III score was 10.0 (3-16). Median duration of ventilation was 6 days (3-9 d). Pathologic gastroesophageal reflux (acidic or alkaline) was present in 47 children (77%). Twelve children (19.7%) met criteria for pathologic acidic gastroesophageal reflux, whereas 44 children (72.1%) had pathologic alkaline gastroesophageal reflux; nine children (14.7%) had both pathologic acidic and alkaline gastroesophageal reflux. Of the enrolled children, 17 (27.9 %) developed ventilator-associated pneumonia. No patient had both pathologic acidic gastroesophageal reflux and ventilator-associated pneumonia. Of 17 children who developed ventilator-associated pneumonia, 12 (70.5%) had pathologic alkaline gastroesophageal reflux as compared to 32 children (72.7%) among the 44 children who did not develop ventilator-associated pneumonia (p = 0.87). Conclusions: The current study shows high incidence of gastroesophageal reflux on 24-hour esophageal pH-metry in mechanically ventilated children with medical diagnoses. The significance of this finding and its impact on ventilator-associated pneumonia and other ventilator-associated events need to be examined in larger studies.