Mechanisms of Orthopnea in Stable Obese Patients

Not Applicable

Completed

• Conditions: Obesity
• Interventions: Other: Supine

• Registration Number: NCT02832609
• Lead Sponsor: Hospices Civils de Lyon

Brief Summary

The purpose of this study is to study the role of closing volume as a determinant of orthopnea in stable obese subjects. The investigators hypothesized that: (1) increase in closing volume in supine position would be greater in orthopneic than in non-orthopneic subjects, and (2) the relationship of change in closing volume to change in dyspnea with position would be dependent on expiratory flow limitation in the sitting position.

In stable obese subjects, in sitting and supine positions, the investigators measured Borg dyspnea score, static lung volumes, expiratory flow limitation, and single-breath nitrogen expiration test, from which the investigators determined closing volume and closing capacity, slope of phase III, and opening capacity.

Orthopnea was defined as any increase in the Borg score in the supine position from its value in the sitting position

Detailed Description

Not available

Study Timeline

• Study Start: 2010-03
• Primary Completion: 2013-10
• Study Completion: 2013-10
• Status Verified: 2016-07
• Study First Submitted: 2016-07-07
• Study First Submitted QC: 2016-07-13
• Study First Posted: 2016-07-14
• Last Update Submitted: 2019-05-23
• Last Update Posted: 2019-05-28

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 30

Inclusion Criteria

• obese (BMI ≥ 30)
• stable condition
• 20 < Age < 60 years

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Exclusion Criteria

• other respiratory disorder (COPD)
• left cardiac insufficiency

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
supine position	Supine	measurement in the sitting position

Primary Outcome Measures

Name	Time	Method
closing volume by nitrogen washout method	30 minutes after changing position (hour 2)

Secondary Outcome Measures

Name	Time	Method
static lung volumes by plethysmography	30 minutes after changing position (hour 2)	static lung volumes are composed of vital capacity, FEV1, inspiratory capacity, and reserve expiratory volume and are measured by plethysmography
expiratory flow limitation by NEP test	30 minutes after changing position (hour 2)	NEP test

Trial Locations

Locations (1)

Hospices civils de lyon, Hôpital de la Croix-Rousse - Réanimation, Surveillance Continue Médicales et Assistance Respiratoire; 🇫🇷 Lyon, France