Respiratory failure is a life-threatening impairment of oxygenation or CO₂ elimination. Respiratory failure may occur because of impaired gas exchange, decreased ventilation, or both. Common manifestations include dyspnea, use of accessory muscles of respiration, tachypnea, tachycardia, diaphoresis, cyanosis, altered consciousness, and, without treatment, eventually obtundation, respiratory arrest, and death. Diagnosis is clinical, supplemented by ABGs and chest x-ray. Treatment is usually in an ICU and involves correction of the underlying cause, supplemental O₂, control of secretions, and ventilatory assistance if needed.

The respiratory system oxygenates and eliminates CO₂ from venous blood. Thus, a useful classification of respiratory failure is whether the principal abnormality is inadequate oxygenation or inadequate CO₂ elimination (which means inadequate ventilation), although many disorders affect both. Although temporizing measures exist, respiratory failure frequently necessitates mechanical ventilation.

Last full review/revision August 2007 by Brian K. Gehlbach, MD; Jesse B. Hall, MD

Content last modified February 2012