Air trapping
Encyclopedia
Air trapping, also called gas trapping, is an abnormal retention of air in the lungs where it is difficult to exhale completely. It is observed in obstructive lung disease
s such as asthma
, bronchiolitis obliterans syndrome and chronic obstructive pulmonary disease
s such as emphysema
and bronchiectasis.
Air trapping is not a diagnosis but is a presentation of an illness and can be used to find an appropriate diagnosis.
, leading to an elevated residual volume and a measurement of forced expiratory volume. Air trapping is often incidentally diagnosed on computed tomography
(CT) scanning. On expiratory films, retained hyperlucent gas will be visualised in cases of air trapping.
Air trapping represents poorly aerated lung, but on its own is clinically benign. It is a common problem for smokers who dive. On diving the lung volume collapses and pushes air into the poorly aerated regions. On arising from a deep depth, these air-trapped areas of lung expand. This places great pressure on the lung tissue which can rupture.
Obstructive lung disease
Obstructive lung disease is a category of respiratory disease characterized by airway obstruction. It is generally characterized by inflamed and easily collapsible airways, obstruction to airflow, and frequent office visits and hospitalizations. Types of obstructive lung disease include; Asthma,...
s such as asthma
Asthma
Asthma is the common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. Symptoms include wheezing, coughing, chest tightness, and shortness of breath...
, bronchiolitis obliterans syndrome and chronic obstructive pulmonary disease
Chronic obstructive pulmonary disease
Chronic obstructive pulmonary disease , also known as chronic obstructive lung disease , chronic obstructive airway disease , chronic airflow limitation and chronic obstructive respiratory disease , is the co-occurrence of chronic bronchitis and emphysema, a pair of commonly co-existing diseases...
s such as emphysema
Emphysema
Emphysema is a long-term, progressive disease of the lungs that primarily causes shortness of breath. In people with emphysema, the tissues necessary to support the physical shape and function of the lungs are destroyed. It is included in a group of diseases called chronic obstructive pulmonary...
and bronchiectasis.
Air trapping is not a diagnosis but is a presentation of an illness and can be used to find an appropriate diagnosis.
Measurement and Function
Exhaled volumes are measured by a pulmonary function test or simple spirometrySpirometry
Spirometry is the most common of the pulmonary function tests , measuring lung function, specifically the measurement of the amount and/or speed of air that can be inhaled and exhaled...
, leading to an elevated residual volume and a measurement of forced expiratory volume. Air trapping is often incidentally diagnosed on computed tomography
Computed tomography
X-ray computed tomography or Computer tomography , is a medical imaging method employing tomography created by computer processing...
(CT) scanning. On expiratory films, retained hyperlucent gas will be visualised in cases of air trapping.
Air trapping represents poorly aerated lung, but on its own is clinically benign. It is a common problem for smokers who dive. On diving the lung volume collapses and pushes air into the poorly aerated regions. On arising from a deep depth, these air-trapped areas of lung expand. This places great pressure on the lung tissue which can rupture.