Airway Pepsin Levels in Otherwise Healthy Surgical Patients Receiving General Anesthesia With Endotracheal Intubation

Detecting laryngopharyngeal reflux in patients with upper airways symptoms: Symptoms, signs or salivary pepsin?

“…Pepsin has previously been found in the saliva of asymptomatic control subjects that is occurring as a result of physiological reflux [23,27] but not in the lower airways [28]. Such reflux becomes pathological when it starts to cause inflammation and injury producing symptoms.…”

Aspiration Following Elective Intubation

“…In our original publication, we reported a 0% rate of aspiration using the enzymatic assay for pepsin A. 1 However, using the more sensitive ELISA on the same airway samples, we have detected a 4% rate of aspiration. Th e ELISA is more sensitive than the enzymatic assay, likely due to its ability to detect partially degraded pepsin A. Th us, it appears that although the rate of gastric-to-pulmonary aspiration is very low (4% in adults without risk factors for aspiration undergoing elective intubation), it is higher than previously reported using the enzymatic assay for pepsin A.…”

“…Since publication, our group has validated an enzyme-linked immunosorbant assay (ELISA) for pepsin A, which we subsequently used to analyze the same airway samples collected in our previous study. 1 Briefl y, pepsin A was detected by incubating with biotin-conjugated polyclonal antibody against porcine pepsin A (Abcam plc) that recognizes human pepsin A. Th e bound biotin-polyclonal antibody was detected by adding HRP-streptavidin (Abcam plc). Th e ELISA sensitivity threshold is 0.1 ng/mL compared with the sensitivity threshold of 25 ng/mL for the pepsin A enzymatic assay.…”

Characteristics and Outcomes of Patients Hospitalized Following Pulmonary Aspiration

“…In particular, our fi ndings are confi ned to "gross" or macroaspiration, and not microaspiration. Although there is renewed interest in biomarkers to more objectively diagnose and quantify aspiration (eg, pepsin), [14][15][16] none has been validated, and the clinical impact of unwitnessed aspiration or microaspiration events remains uncertain. 17 Despite the diffi culties in the diagnosis, the fi ndings of this study suggest that the simple defi nition for aspiration, used in this and prior ARDS epidemiologic studies, 7,8 is highly clinically relevant.…”