Association of enteral feeding with microaspiration in critically ill adults

Abstract

Aim: This study explored relationships between enteral feeding and tracheal pepsin A.

Background: Mechanically ventilated (MV) patients receiving enteral feeding are at risk for microaspiration. Tracheal pepsin A, an enzyme specific to gastric cells, was a proxy for microaspiration of gastric secretions.

Methods: Secondary analysis of RCT data from critically ill, MV adults was conducted. Microaspiration prevention included elevated head of bed, endotracheal tube cuff pressure management, and regular oral care. Tracheal secretions for pepsin A were collected every 12 h. Microaspiration was defined as pepsin A ≥ 6.25 ng/mL. Positive pepsin A in >30 % of individual tracheal samples was defined as abundant microaspiration (frequent aspirator). Chi-squared, Fisher's Exact test, and generalized linear model (GLM) were used.

Results: Tracheal pepsin A was present in 111/283 (39 %) mechanically ventilated patients and 48 (17 %) had abundant microaspiration. Enteral feeding was associated with tracheal pepsin A, which occurred within 24 h of enteral feeding. Of the patients who aspirated, the majority received some enteral feeding 96/111 (86 %), compared to only 15/111 (14 %) who received no feeding. A greater number of positive pepsin A events occurred with post-pyloric feeding tube location (55.6 %) vs. gastric (48.6 %), although significant only at the event-level. Frequent aspirators (abundant pepsin A) had higher pepsin A levels compared to infrequent aspirators.

Conclusions: Our findings confirmed the stomach as the microaspiration source. Contrary to other studies, distal feeding tube location did not mitigate microaspiration. Timing for first positive pepsin A should be studied for possible association with enteral feeding intolerance.

Trial registration: ClinicalTrials.gov NCT02284178.

Keywords: Critical care; Enteral feeding; Mechanical ventilation; Microaspiration; Pepsin A.

Conflict of interest statement

Declaration of competing interest None identified.

Copyright © 2022 Elsevier Inc. All rights reserved.

Figures

Fig. 1.

Pepsin A measures by patient. Note: Abundant pepsin was calculated as individual patients with positive pepsin A in >30 % of their tracheal samples.

Fig. 2.

Pepsin A status by any enteral feeding. Note: Abundant pepsin was calculated as individual patients with positive pepsin A in >30 % of their tracheal samples.

Fig. 3.

Pepsin A levels of abundant (frequent) vs. infrequent aspirators. Median, upper and lower quartiles, of individual positive tracheal pepsin A samples (6.25 ng/mL) are displayed by patient aspiration status. Infrequent aspirators are patients who had positive pepsin A in fewer than 30 % of their individual tracheal samples and frequent aspirators (abundant) had positive pepsin A in >30 % of their individual tracheal samples. All data points were included in the analysis; however, several data points (200–400 ng/mL) in the frequent aspirator group were removed to create this figure. The total number of positive pepsin A events included in the analysis were infrequent aspirators (n = 120) and frequent aspirators (n = 187).