Lung Compliance: Difference between revisions
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|+'''Factors which Affect Respiratory Compliance''' | |+'''Factors which Affect Respiratory Compliance''' | ||
|Lung compliance | |'''Lung compliance''' | ||
|Chest wall compliance | |'''Chest wall compliance''' | ||
|- | |- | ||
|Increased lung compliance | |'''Increased lung compliance''' | ||
* Lung surfactant | * Lung surfactant | ||
* Lung volume: compliance is at its highest at FRC | * Lung volume: compliance is at its highest at FRC | ||
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* Loss of lung conective tissue associated with age | * Loss of lung conective tissue associated with age | ||
* Emphysema | * Emphysema | ||
|Increased chest wall | |'''Increased chest wall compliance''' | ||
* Ehler-Dahlos syndrome and other connective tissue diseases | * Ehler-Dahlos syndrome and other connective tissue diseases | ||
* Rib resection | * Rib resection | ||
* Cachexia | * Cachexia | ||
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* Open chest (eg clamshell) | * Open chest (eg clamshell) | ||
|- | |- | ||
|Decreased static lung compliance | |'''Decreased static lung compliance''' | ||
* Loss of surfactant (eg. ARDS) | * Loss of surfactant (eg. ARDS) | ||
* Decreased lung elasticity | * Decreased lung elasticity | ||
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* Alveolar derecruitment | * Alveolar derecruitment | ||
* Alveolar overdistension | * Alveolar overdistension | ||
Decreased dynamic lung compliance | '''Decreased dynamic lung compliance''' | ||
* Increased airway resistance (eg. asthma) | * Increased airway resistance (eg. asthma) | ||
* Increased air flow (increased resp rate) | * Increased air flow (increased resp rate) | ||
|Decreased chest wall compliance | |||
|'''Decreased chest wall compliance''' | |||
* Structural abnormalities | * Structural abnormalities | ||
** Kyphosis / scoliosis | ** Kyphosis / scoliosis |
Revision as of 19:22, 19 September 2020
Original Editor - User Name
Top Contributors - Kapil Narale, Shalini Varadhan, Lucinda hampton, Kim Jackson, Uchechukwu Chukwuemeka and Mohit Chand
Introduction[edit | edit source]
The extent to which the lungs will expand for each unit increase in trans pulmonary pressure is called Lung Compliance.
Normal Range: The total compliance of both lungs together in normal adult human being average is about 200 millilitres of air per centimetre of water trans-pulmonary pressure. That is every time the trans pulmonary pressure increases one centimetre of water the lung volume after 10 to 20 seconds will expand 200 milliliteres.
Compliance Diagram[edit | edit source]
The diagram relates the lung volume changes to changes in the trans pulmonary pressure. It differs for inspiration and expiration.
Compliance Curve[edit | edit source]
The two compliance curves are:
- Inspiratory Compliance curve
- Expiratory Compliance curve
Types of Compliance[edit | edit source]
Dynamic Compliance : This describes the compliance measured during breathing which involves a combination of Lung compliance and air resistance.
Static Compliance : This describes the pulmonary compliance when there is no air flow like an inspiratory pass
Important Factors[edit | edit source]
The two important factors of Lung compliance :
Elastic Fibers : More fibers in the tissue lead to ease in expand-ability and there for compliance.
Surface tension : It is decrease due to the production of surfactant to prevent collapse.
Hysteresis[edit | edit source]
Hysteresis is the term used to describe the difference between inspiratory and expiratory compliance. Lung volume at any given pressure during inhalation is less than the lung volume at any given pressure during exhalation.
Hysteresis is present in both static and dynamic lung compliance curves
Hysteresis develops due to:
- The effect of surfactant
- Relaxation of lung tissue
- Recruitment and derecruitment of alveoli
- Gas absrption during measurement
- Differences in expiratory and inspiratory air flow (for dynamic compliance)
Factors which affect compliance can be divided into chest wall factors and lung factors:
Lung compliance | Chest wall compliance |
Increased lung compliance
|
Increased chest wall compliance
|
Decreased static lung compliance
Decreased dynamic lung compliance
|
Decreased chest wall compliance
|
Resources[edit | edit source]
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or
- numbered list
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