Acidity of Enteral Feeding Tube Aspirate in Neonates: Do pH Values Meet the Cutoff for Predicting Gastric Placement?

BACKGROUND: Enteral feeding tubes (EFTs) are commonly used in neonatal practice, but complications from tube misplacement remain a concern. Measuring the pH of EFT aspirate is a recommended method to evaluate EFT placement. A pH value of ≤5.5 is considered predictive of gastric placement. Using this method in infants has been questioned. It is unclear whether infants can produce adequate gastric acid to achieve a pH 5 or less and whether feedings and medications influence pH.

PURPOSE: To report EFT aspirate pH values in infants and to evaluate factors potentially influencing pH values.

METHODS: A retrospective descriptive study was conducted with 1024 infants with 6979 pH values. Demographic and clinical data were collected including type of EFT, pH of gastric aspirate, feeding method, time of last feeding, and administration of acid suppression medications. The frequency of measured pH values of 5 or less was calculated for each covariate.

FINDINGS/RESULTS: The majority (97.51%) of pH values were 5 or less. Orogastric tubes, continuous feeding, a 4-hour or more feeding interval, exposure to medications (proton pump inhibitor, histamine-2 receptor antagonist, or multiple medications) were associated with an increased likelihood of pH values of more than 5. However, with each study variable the majority of pH values were 5 or less.

IMPLICATIONS FOR PRACTICE: These findings suggest EFT pH, a recommended method to evaluate the likelihood of gastric placement, can be successfully used in the neonatal population.

IMPLICATIONS FOR RESEARCH: Future research should prospectively evaluate EFT pH in infants when compared with clinically indicated radiographs. Other factors that might influence pH should be explored including severity of illness, feeding type, and other medications.