Respiratory insufficiency

Disease class: Respiration disorders

Also known as

• Respiratory failure

Type 1:  

Failure of oxygenation.

• Hypoxaemia : A low oxygen level in the blood.
• Normocapnia: A normal level of carbon dioxide (P_aCO₂) or hypocapnia: A low level of carbon dioxide (P_aCO₂).

Type 2: 

Failure to ventilate the alveoli. Gas exchange (both O2 and CO2) between the blood and the external atmosphere is impaired.

• Hypoxaemia (PaO2 < 8kPa)
• Hypercapnia (PaCO₂ > 6.0kPa)
• Decrease in pH, potentially causing respiratory acidosis.

Investigations

• Pulse oximetry: to measure peripheral oxygen saturation.
• Arterial blood gas analysis
• Venous blood gas analysis
• Capnography: to measure CO₂ exhalation
• Spirometry
• Ventilation / perfusion scan (V/Q lung scan)