Author(s)
Ahmad F. Mahmoud MD
Erica R. Thaler MD
Affiliation(s)
University of Pennsylvania
Abstract:
Educational Objective: At the conclusion of this presentation, the participants should be able to 1) compare partial, complete, and no airway collapse using pressure tracing; 2) demonstrate understanding of Bernoulli's principle as a predictor of airway obstruction; and 3) explain how aerodynamic analysis may be applied to the human airway. Objectives: To characterize pressure waveform characteristics that reliably identify partial airway collapse as opposed to complete or no airway collapse in patients with obstructive sleep apnea (OSA). Study Design: Single institution diagnostic study. Methods: Patients with OSA underwent airway evaluation with drug induced sleep endoscopy in conjunction with a fluid dynamic pressure transducer. Aerodynamic and soft tissue pressure data were obtained from the retropalatal region and oropharynx during three degrees of retropalatal obstruction: complete, partial, and no retropalatal collapse. Pressure waveforms variables were analyzed using ANOVA testing between these three conditions, variables included negative and positive pressure deflections as well as pressure differentials. Results: Seventeen patients contributing 52 samples are included in this study. As measured in the retropalatal region, negative pressure deflections were noted to be significantly different between the three degrees of retropalatal collapse; these were -3.51 ± 0.32 mmHg for complete, -3.25 ± 0.32 for partial, and -1.35 ± 0.15 for no collapse (p = 0.000). Positive pressure differential was also noted to be significantly different between the three conditions of retropalatal collapse (p = 0.028). As measured in the oropharynx, negative pressure deflections were noted to be significantly different between the three degrees of retropalatal collapse; -8.05 ± 0.41 for complete, -4.16 ± 0.43 for partial, and -2.16 ± 0.49 no collapse, (p = 0.000). Positive pressure differential was also noted to be significantly different between the three conditions of retropalatal collapse (p = 0.002). Conclusions: Aerodynamic pressure waveform analysis may distinguish between various obstructive conditions and can identify partial retropalatal collapse.