Pepsin as a marker for pulmonary aspiration.

Abstract

BACKGROUND:

Although assessment for aspiration of small volumes of gastric contents in tube-fed patients receiving mechanical ventilation is important, available methods for this purpose are not wholly satisfactory. A potential method is immunoassay of tracheal secretions for the gastric enzyme pepsin.

OBJECTIVES:

To determine the frequency with which pepsin in suctioned tracheal secretions from acutely ill, tube-fed patients receiving mechanical ventilation could be detected via an immunoassay.

METHODS:

A convenience sample of 136 specimens of suctioned tracheal secretions was collected from 30 acutely ill, tube-fed adults receiving mechanical ventilation. Multiple samples were obtained from 26 of the 30 patients (range, 2-11 per subject). An immunoassay with rooster polyclonal antibodies to purified human pepsin was used to detect pepsin in the secretions.

RESULTS:

Fourteen specimens tested positive for pepsin. Secretions from 5 patients accounted for the 14 pepsin-positive results. A significant relationship was found between the position of the head of the bed and the presence of pepsin in tracheal secretions (P<.001). Of the 14 pepsin-positive specimens, 13 (92.9%) were obtained from subjects in a flat position.

CONCLUSIONS:

A pepsin immunoassay can be used to detect pepsin in human tracheal secretions. If pepsin in tracheal secretions is considered an indicator of aspiration of gastric contents, aspiration occurred in 5 of the 30 subjects. A flat position is strongly associated with the presence of pepsin in tracheal secretions.

• Authors: Norma A Metheny, Yie-Hwa Chang, Jing Song Ye, Sharon J Edwards, Julie Defer, Thomas E Dahms, Barbara J Stewart, Kathleen S Stone, Ray E Clouse
• Journal: American journal of critical care : an official publication, American Association of Critical-Care Nurses (Am J Crit Care) Vol. 11 Issue 2 Pg. 150-4 (Mar 2002) ISSN: 1062-3264 [Print] United States
• PMID: 11888127 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Pepsin A

Topics

• Enteral Nutrition
• Gastric Juice (enzymology)
• Humans
• Immunoassay
• Intubation, Intratracheal
• Pepsin A (analysis)
• Pneumonia, Aspiration (diagnosis, etiology)
• Respiration, Artificial
• Suction
• Trachea (metabolism)