Respiratory compliance

Lung compliance Chest wall compliance
Increased lung compliance

- Lung surfactant
- Lung volume: compliance is at its highest at FRC
- Posture (supine, upright)
- Loss of lung conective tissue associated with age
- Emphysema
Increased chest wall complance

- Ehler-Dahlos syndrome and other connective tissue diseases associated with increased connective tissue elasticity
- Rib resection
- Cachexia
- Flail segment rib fractures
- Open chest (eg clamshell)
Decreased static lung compliance
- Loss of surfactant (eg. ARDS)
- Decreased lung elasticity
- Pulmonary fibrosis
- Pulmonary oedema
- Decreased functional lung volume
- Pneumonectomy or lobectomy
- Pneumonia
- Atelectasis
- Small stature
- Alveolar derecruitment
- Alveolar overdistension

Decreased dynamic lung compliance
- Increased airway resistance (eg. asthma)
- Increased air flow (increased resp rate)
Decreased chest wall compliance

- Structural abnormalities
- Kyphosis / scoliosis
- Pectus excavatum
- Circumferential burns
- Surgical rib fixation
- Functional abnormalities
- Muscle spasm, eg. seizure or tetanus
- Extrathoracic influences on chest/diaphragmatic excursion
- Obesity
- Abdominal compartment syndrome
- Prone position

TODO: measurement