Respiratory failure and arrest

Last updated: October 17, 2022

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Respiratory failure is the acute or chronic inability of the respiratory system to maintain gas exchange (PaO2 < 60 mm Hg, PaCO2 > 50 mm Hg). 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).

By gas exchange abnormality

Types of respiratory failure [1]
Type 1 (hypoxemic respiratory failure) Type 2 (hypercapnic respiratory failure)
  • ↓ (< 60 mm Hg)
  • Normal or ↓ (< 80 mm Hg)
  • Normal or ↓ (< 33 mm Hg)
  • ↑ (> 50 mm Hg)

Patients may present with mixed hypoxemic and hypercapnic respiratory failure.

By duration [3]

In patients with hypercapnia, a normal pH suggests chronic CO2 retention while a low pH raises concern for acute or acute-on-chronic CO2 retention, which requires immediate intervention (see also “Respiratory acidosis.”)

This section lists causes of respiratory failure and respiratory arrest by type and mechanism. See “Etiology of dyspnea” for a system-based approach.

Respiratory failure and respiratory arrest share the same causes and patients with respiratory failure can quickly decompensate into respiratory arrest.

Causes of hypoxemia [4]

Causes of hypercapnia [4]

Hypercapnia may be caused by decreased ventilation (hypoventilation) resulting from any of the following:

Increased O2 consumption and/or CO2 production (e.g., due to severe sepsis, toxic shock syndrome, cardiogenic shock, multiorgan dysfunction) may contribute to respiratory failure.

By affected system

By underlying process

Recognize signs of imminent or ongoing respiratory arrest (e.g., gasping, inspiratory stridor, decreased respiratory rate, cyanosis, absent chest rise, or acute oxygen desaturation) and treat it immediately if present.

This section outlines the management of acute respiratory failure. For the management of chronic respiratory failure, see articles on specific causes, e.g., “COPD” and “Interstitial lung disease.”

Approach [5]

Respiratory support

Treatment of rapidly reversible causes of respiratory failure

Respiratory failure and respiratory arrest are clinical diagnoses. ABG analysis, rapid laboratory studies, and bedside imaging can help identify the type of respiratory failure and guide treatment of the underlying cause.

Respiratory failure and arrest require immediate management, i.e., prior to diagnostic confirmation.

Initial investigations [5]

ABG analysis is key to diagnosing and classifying respiratory failure.

Bedside imaging [5]

POCUS may help to quickly identify pneumothorax, pulmonary edema, pleural effusions, heart failure, cardiac tamponade, or the presence of DVT and/or signs of acute right heart strain suggesting pulmonary embolism.

Advanced diagnostic testing [5]

Treatment of the underlying cause of respiratory failure

The following is a nonexhaustive list of common causes of respiratory failure. See also “Rapidly reversible causes of respiratory failure.”

Common causes of respiratory failure and their management
Suggestive features Cause-specific management
Upper airway causes of respiratory failure
Pulmonary causes of respiratory failure
Cardiac causes of respiratory failure
Toxic and metabolic causes of respiratory failure
CNS causes of respiratory failure

Monitoring and disposition [5]

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

None of the individuals in control of the content for this article reported relevant financial relationships with commercial interests. For details, please review our full conflict of interest (COI) policy.

  1. Walls R, Hockberger R, Gausche-Hill M. Rosen's Emergency Medicine. Elsevier Health Sciences ; 2018
  2. Roberts JR. Roberts and Hedges' Clinical Procedures in Emergency Medicine and Acute Care. Elsevier ; 2018
  3. Schneider J, Sweberg T. Acute Respiratory Failure. Crit Care Clin. 2013; 29 (2): p.167-183. doi: 10.1016/j.ccc.2012.12.004 . | Open in Read by QxMD
  4. Shebl E, Burns B. Respiratory Failure. StatPearls. 2021 .
  5. Kleinman ME, Brennan EE, Goldberger ZD, et al. Part 5: Adult Basic Life Support and Cardiopulmonary Resuscitation Quality. Circulation. 2015; 132 (18 suppl 2): p.S414-S435. doi: 10.1161/cir.0000000000000259 . | Open in Read by QxMD
  6. Kasper DL, Fauci AS, Hauser SL, Longo DL, Lameson JL, Loscalzo J. Harrison's Principles of Internal Medicine. McGraw-Hill Education ; 2015

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