Computational Modelling of Cough Function and Airway Penetrant Behavior in Patients with Disorders of Laryngeal Function

Objective/Hypothesis: Patients with laryngeal disorders often exhibit changes to cough function contributing to aspiration episodes. Two primary cough variables (peak cough flow: PCF and compression phase duration: CPD) were examined within a biomechanical model to determine their impact on characteristics that impact airway compromise. Study Design: Computational study. Methods: A Computational Fluid Dynamics (CFD) technique was used to simulate fluid flow within an upper airway model reconstructed from patient CT images. The model utilized a finite-volume numerical scheme to simulate cough-induced airflow, allowing for turbulent particle interaction, collision, and break-up. Liquid penetrants at 8 anatomical release locations were tracked during the simulated cough. Cough flow velocity was computed for a base case and four simulated cases. Airway clearance was evaluated through assessment of the fate of particles in the airway following simulated cough. Results: Peak-expiratory phase resulted in very high airway velocities for all simulated cases modelled. The highest velocity predicted was 49.96 m/s, 88 m/s, and 117 m/s for Cases 1 and 3, Base case, and Cases 2 and 4 respectively. In the base case, 25% of the penetrants cleared the laryngeal airway. The highest percentage (50%) of penetrants clearing the laryngeal airway are observed in Case 2 (with −40% CPD, +40% PCF), while only 12.5% cleared in Case 3 (with +40% CPD, −40% PCF). The proportion that cleared in Cases 1 and 4 was 37.5%. Conclusion: Airway modelling may be beneficial to the study of aspiration in patients with impaired cough function including those with upper airway and neurological diseases. It can be used to enhance understanding of cough flow dynamics within the airway and to inform strategies for treatment with “cough-assist devices” or devices to improve cough strength. Level of Evidence: N/A

UNLV Title III AANAPISI & McNair Scholars Institute Research Journal

Journal articles based on research conducted by undergraduate students in the AANAPISI and McNair Scholars Programs Table of Contents About AANAPISI Biography of Dr. Ronald E. McNair Statements Dr. Len Jessup, UNLV President Dr. Juanita P. Fain, Vice President for Student Affairs Dr. William W. Sullivan, Associate Vice President for Retention and Outreach Mr. Keith Rogers, Deputy Executive Director of the Center for Academic Enrichment and Outreach Title III AANAPISI and McNair Scholars Institute Staff Ms. Terri Bernstein, Director for College Programs Dr. Matthew Della Sala, Assistant Director for Undergraduate Researc

The (In)Significance of Race and Discrimination among Latino Youth: The Case of Depressive Symptoms

Despite the growing population of Latinos in the United States, there is little research that explores how discrimination affects the mental health of Latino youth along racial lines. In this paper we ask two closely related questions. First, do black Latino youth have higher or lower symptoms of depression than nonblack Latinos? Second, is the relationship between race and depression among Latino youth buffered by discrimination stress? Results from the Transitions Study show that black Latino youth have significantly higher symptoms of depression than nonblack Latinos. The relationship between race and depression depends on daily—but not on lifetime—experiences of discrimination. The combined effect of race and discrimination holds in the face of a wide range of measures of stress, including major lifetime events, recent life events, and chronic stressors. These findings encourage future research that considers the mental health effects of racial variation among Latinos