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Respiratory failure

Last updated: August 30, 2021

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Respiratory failure is the acute or chronic inability of the respiratory system to maintain gas exchange (PaO2 of < 60 mmHg, PaCO2 > 50 mmHg). Causes can be extrapulmonary (e.g., CNS depression due to narcotic overdose) as well as pulmonary (e.g., acute exacerbation of COPD). Respiratory failure can be classified as hypoxemic (type 1) or hypercapnic (type 2). Clinical features of hypoxemia include respiratory distress, cyanosis, tachycardia, and altered mental status. Clinical features of hypercapnia include hypoventilation, headache, warm extremities, and asterixis. Diagnostics include arterial blood gas analysis and possibly chest imaging to detect the underlying disease. Treatment includes supportive measures (oxygen delivery and/or ventilator support) and treatment of the underlying condition. Complications may arise due to prolonged hypoxemia and can affect various organs (e.g., renal/heart failure, brain damage).

Respiratory failure is the acute or chronic inability of the respiratory system to maintain gas exchange. This leads to: [1]

  • Failure to oxygenate the body: defined as a PaO2 of < 60 mmHg (8 kPa)
  • Failure to eliminate carbon dioxide: defined as a PaCO2 of > 50 mmHg (6.5 kPa)
Types of respiratory failure [1]
Type 1 (hypoxemic respiratory failure) Type 2 (hypercapnic respiratory failure)
Definition
PaO2
  • ↓ (< 60 mmHg)
  • Normal or ↓ (< 80 mm Hg)
PaCO2
  • Normal or ↓ (< 33 mm Hg)
  • ↑ (> 50 mmHg)

Supportive measures [1]

Treatment of underlying conditions

We list the most important complications. The selection is not exhaustive.

  1. Shebl E, Burns B. Respiratory Failure. StatPearls. 2021 .