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Completed

NCT Number: NCT02832609

Mechanisms of Orthopnea in Stable Obese Patients

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

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Key information

Conditions

Obesity Body Weight Dyspnea Nutrition Disorders Nutritional and Metabolic Diseases Overnutrition Overweight Pathological Conditions, Signs and Symptoms Respiration Disorders Respiratory Tract Diseases Signs and Symptoms Signs and Symptoms, Respiratory

Age range

20 year–60 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Hospices civils de lyon, Hôpital de la Croix-Rousse - Réanimation, Surveillance Continue Médicales et Assistance Respiratoire

Lyon, 69004, France

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

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

Exclusion criteria

  • other respiratory disorder (COPD)
  • left cardiac insufficiency

Treatment and study plan

supine

Other

measurements after 30 minutes in complete supine position

Primary outcomes

  1. closing volume by nitrogen washout method

    Time frame: 30 minutes after changing position (hour 2)

Secondary outcomes

  1. static lung volumes by plethysmography

    Time frame: 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

  2. expiratory flow limitation by NEP test

    Time frame: 30 minutes after changing position (hour 2)

    NEP test

Sponsors and collaborators

Lead sponsor

Hospices Civils de Lyon

Other

Registry information

Acronym: OBAIRWAY

Important dates

Study start
2010
Primary completion
2013
Study completion
2013
First posted
Jul 14, 2016
Registry last updated
May 28, 2019

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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