Morgan, Kimbly M.2020-09-112020-09-112020-09-11http://hdl.handle.net/10222/79847INTRODUCTION: Autogenic drainage (AD) is a breathing pattern comprised of 3 phases of tidal volume (Vt) breathing distinguished by low, mid, and high end-expiratory lung volumes (EELV). AD increases FVC and clears clinically significant amounts of sputum. METHODS: AD was defined by EELV as a percent of functional residual capacity (FRC): ≥30% below FRC Phase 1, ±10% at FRC Phase 2, ≥40% above FRC Phase 3, and Vt ±10% of resting Vt. Thirty-two healthy adolescents were taught AD and assessed using spirometry and plethysmography. RESULTS: The mean EELV was 26%, 16%, and 53% of FRC for Phases 1,2,3 (p<.001). The mean Vt was 87%, 108%, 138% of Vtrest for Phases 1,2,3 (p>.05). All defining criteria were met or were within 1 standard deviation of the defining mean. At least 20% of participants achieved each criterion. CONCLUSION: The AD quantitative definition is achievable in a cohort of healthy adolescents.enAutogenic DrainageAirway Clearance TechniquePlethysmographySpirometryThesis