Lung Compliance: Difference between revisions
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== Introduction == | == Introduction == | ||
Pulmonary compliance, a measure of the expansion of the [[Lung Anatomy|lung]], is critical to the proper function of the [[Respiratory System|respiratory]] system. Lung compliance can be calculated by dividing volume by pressure. | |||
== | Factors affecting lung compliance include elasticity from the elastin in connective tissue and surface tension, which is decreased by surfactant production. | ||
Lung compliance participates in the lung-chest wall system by opposing the outward pull of chest wall compliance. | |||
The net compliance (lung-chest wall system) allows the lungs to achieve appropriate functional residual capacity, the volume remaining after passive expiration<ref>Edwards Z, Annamaraju P. Physiology, Lung Compliance.2020 Available from:https://www.statpearls.com/articlelibrary/viewarticle/24496/ (accessed 17.4.2021)</ref>. | |||
== Function == | |||
Compliance of the respiratory system describes the expandability of the lungs and chest wall. There are two types of compliance: dynamic and static. | |||
# Dynamic compliance describes the compliance measured during breathing, which involves a combination of lung compliance and airway resistance. Defined as the change in lung volume per unit change in pressure in the presence of flow. | |||
# Static compliance describes pulmonary compliance when there is no airflow, like an inspiratory pause. Defined as the change in lung volume per unit change in pressure in the absence of flow. | |||
Pressure-volume curves are common schemes to express the relationship of dynamic and static compliance where the slope is compliance. | |||
C = V/P | |||
C: Compliance (ml/mmHg) | |||
V: Volume (mL) | |||
P: Pressure (mm Hg) | |||
== Sub Heading 3 == | == Sub Heading 3 == |
Revision as of 07:14, 17 April 2021
Original Editor - Shalini Varadhan
Top Contributors - Kapil Narale, Shalini Varadhan, Lucinda hampton, Kim Jackson, Uchechukwu Chukwuemeka and Mohit Chand
Introduction[edit | edit source]
Pulmonary compliance, a measure of the expansion of the lung, is critical to the proper function of the respiratory system. Lung compliance can be calculated by dividing volume by pressure.
Factors affecting lung compliance include elasticity from the elastin in connective tissue and surface tension, which is decreased by surfactant production.
Lung compliance participates in the lung-chest wall system by opposing the outward pull of chest wall compliance.
The net compliance (lung-chest wall system) allows the lungs to achieve appropriate functional residual capacity, the volume remaining after passive expiration[1].
Function[edit | edit source]
Compliance of the respiratory system describes the expandability of the lungs and chest wall. There are two types of compliance: dynamic and static.
- Dynamic compliance describes the compliance measured during breathing, which involves a combination of lung compliance and airway resistance. Defined as the change in lung volume per unit change in pressure in the presence of flow.
- Static compliance describes pulmonary compliance when there is no airflow, like an inspiratory pause. Defined as the change in lung volume per unit change in pressure in the absence of flow.
Pressure-volume curves are common schemes to express the relationship of dynamic and static compliance where the slope is compliance.
C = V/P
C: Compliance (ml/mmHg)
V: Volume (mL)
P: Pressure (mm Hg)
Sub Heading 3[edit | edit source]
Resources[edit | edit source]
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References[edit | edit source]
- ↑ Edwards Z, Annamaraju P. Physiology, Lung Compliance.2020 Available from:https://www.statpearls.com/articlelibrary/viewarticle/24496/ (accessed 17.4.2021)
Introduction[edit | edit source]
Lung Compliance is defined as the change in lung volume produced by a unit change in transpulmonary pressure. It is represented by the gradient of the pressure–volume curve.1
Normal Range: The total compliance of both lungs together in normal adult human being average is about 200 milliliters of air per centimeter of water trans-pulmonary pressure. when trans pulmonary pressure increases one centimeter of water the lung volume after 10 to 20 seconds will expand 200 milliliteres.4
Compliance Diagram[edit | edit source]
The diagram relates the lung volume differs 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 :is defined as the change in lung volume per unit change in pressure in the presence of flow.
Static Compliance : is defined as the change in lung volume per unit change in pressure in the absence of flow.
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.4
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.3
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
|
Related articles[edit | edit source]
Lung volumes-physiopedia
Lung compliance
References[edit | edit source]
- Iotti, G., & Braschi, A. (1999). Measurements of respiratory mechanics during mechanical ventilation. Rhäzüns, Switzerland: Hamilton Medical Scientific Library.
- Harris, R. Scott. "Pressure-volume curves of the respiratory system." Respiratory care 50.1 (2005): 78-99.
- Rahn, Hermann, et al. "The pressure-volume diagram of the thorax and lung." American Journal of Physiology-Legacy Content 146.2 (1946): 161-178.
- https://www.us.elsevierhealth.com/guyton-and-hall-textbook-of-medical-physiology-9781455770052.html
- https://www.ncbi.nlm.nih.gov/books/NBK554517/
- https://med.libretexts.org/Bookshelves/Anatomy_and_Physiology/Book%3A_Anatomy_and_Physiology_(Boundless)/21%3A_Respiratory_System/21.6%3A_Factors_Affecting_Pulmonary_Ventilation/21.6B%3A_Factors_Affecting_Pulmonary_Ventilation%3A_Compliance_of_the_Lungs
- http://rc.rcjournal.com/content/respcare/50/1/78.full.pdf