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Pepsin A in Tracheal Secretions From Patients Receiving Mechanical Ventilation
Steven Talbert1, Annette M Bourgault2, Kimberly Paige Rathbun3
1Steven Talbert is interim director of the nursing PhD program and a clinical assistant professor, University of Central Florida College of Nursing, Orlando, Florida.
Insights
Microaspiration of gastric contents, indicated by tracheal pepsin A, is common in mechanically ventilated patients. This condition is linked to longer mechanical ventilation and intensive care unit (ICU) stays.
Area of Science:
- Critical Care Medicine
- Pulmonary Medicine
- Gastroenterology
Background:
- Aspiration of gastric contents in mechanically ventilated patients can cause adverse outcomes.
- Pepsin in pulmonary secretions serves as a biomarker for gastric microaspiration.
Purpose of the Study:
- To investigate the association between tracheal pepsin A levels and clinical outcomes in patients requiring mechanical ventilation.
Main Methods:
- Pepsin A was measured in tracheal aspirates from 297 intensive care unit (ICU) patients on mechanical ventilation.
- A pepsin A concentration of ≥6.25 ng/mL was considered positive; abundant microaspiration was defined as positive in ≥30% of samples.
- Statistical analyses included ANOVA, ANCOVA, and chi-squared tests.
Main Results:
- Microaspiration was detected in 43.8% of patients, with 17.5% having abundant microaspiration.
- Patients with tracheal pepsin A showed significantly longer mechanical ventilation duration (155 vs 104 hours) and ICU stays (9.9 vs 8.2 days) after controlling for acuity.
- No significant difference in overall hospital stay was observed.
Conclusions:
- Gastric microaspiration, identified by tracheal pepsin A, affects nearly half of mechanically ventilated patients.
- Microaspiration is associated with prolonged mechanical ventilation and ICU admission, suggesting a need for enhanced preventative strategies.
- Further research is needed to optimize the timing of pepsin measurements for capturing microaspiration events.
Background:
In patients in the intensive care unit (ICU) receiving mechanical ventilation, aspiration of gastric contents may lead to ventilator-associated events and other adverse outcomes. Pepsin in pulmonary secretions is a biomarker of microaspiration of gastric contents.
Objectives:
To evaluate the association between tracheal pepsin A and clinical outcomes related to ventilator use.
Methods:
A subset of 297 patients from a larger clinical trial on aspiration of oral secretions in adults receiving mechanical ventilation consented to have pepsin A measured in their tracheal aspirate samples. A concentration ≥6.25 ng/mL indicated a positive result. Abundant microaspiration was defined as pepsin A in ≥30% of samples. Statistical analyses included analysis of variance, analysis of covariance, and χ2 tests.
Results:
Most patients were White men, mean age 59.7 (SD, 18.8) years. Microaspiration was found in 43.8% of patients (n = 130), with abundant microaspiration detected in 17.5% (n = 52). After acuity was controlled for, patients with tracheal pepsin A had a longer mechanical ventilation duration (155 vs 104 hours, P < .001) and ICU stay (9.9 vs 8.2 days, P = .04), but not a longer hospital stay.
Conclusions:
Microaspiration of gastric contents occurred in nearly half of patients and was associated with a longer duration of mechanical ventilation and a longer stay in the ICU. Additional preventative interventions beyond backrest elevation, oropharyngeal suctioning, and management of endotracheal tube cuff pressure may be needed. Also, the timing of pepsin measurements to capture all microaspiration events requires additional exploration.
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