Postural effect on the fluid retention in upper airways of healthy men

• Grant number: 14/03649-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2014
• End date: June 30, 2015
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Geraldo Lorenzi Filho
• Grantee: Amanda Araújo dos Reis Botega
• Host Institution: Instituto do Coração Professor Euryclides de Jesus Zerbini (INCOR). Hospital das Clínicas da Faculdade de Medicina da USP (HCFMUSP). Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil

Abstract

Obstructive sleep apnea (OSA) is a very prevalent disease and can lead to serious consequences. However, the pathophysiology of upper airway obstruction is not completely elucidated. A current hypothesis suggests that a fluid retention in the neck in the supine position could contribute to the collapse of the upper airway in subjects with OSA and in healthy subjects. This research aims to test the hypothesis that the supine position favors the retention of fluid in the airways resulting in reduction of its lumen and increased collapsibility. The objective is to compare the amount of accumulated fluid in the cervical region and lower limbs as well as lumen and collapsibility variations of superior airway during an hour in the sitting and supine positions . Fifteen healthy adults with no OSA syndrome (assessed by questionnaires and sleep polygraphy) will be evaluated. Volunteers will be evaluated by anthropometric measurements (neck, abdominal and calves circumference), Segmental bioimpedance (InBody S10), Cervical Electrical Impedance Tomography (equipment under development in the laboratory, able to infer the amount of liquid and upper airway patency), Negative Expiratory Pressure (NEP , assesses airway collapsibility). The present work will contribute to the understanding of the dynamics of fluid displacement and its influence on upper airway patency and collapsibility under physiological conditions.