A pilot study of quantitative aspiration in patients with symptoms of obstructive sleep apnea: comparison to a...

It has been shown that many healthy people aspirate secretions at night. Patients with obstructive sleep apnea (OSA) have frequent episodes of gasping at night that may predispose them to aspiration. The purpose of this study was to determine whether patients with symptoms of OSA are predisposed to pharyngeal aspiration.

A prospective study in which patients with symptoms of OSA were compared with a historic group of normal controls by using the same methodology.

The study was offered to patients with symptoms of OSA undergoing a sleep study. The radiotracer Technicium was infused through a plastic tube placed in the nasopharynx after the patient achieved stage II sleep. A chest radionuclide scan determined the amount of material aspirated. The Wilcoxon-rank sum test was used to compare the mean amount aspirated between the experimental and historic control groups.

Fourteen patients successfully completed the study. One normal volunteer in our study aspirated a quantity similar to the historic normal control group. The amount of aspirated material in the study group ranged from 0.152 to 3.648 mL, with a mean of 1.24 mL +/- 0.905 (SD). When compared with the historic normal control group, the patients with symptoms of OSA aspirated significantly more radio-tracer (P <.01). There was a lack of association between respiratory disturbance index and amount aspirated.

The results suggest there is an apparent risk of increased pharyngeal aspiration in patients with symptoms of OSA.