Acute respiratory failure is a life-threatening impairment of oxygenation, carbon dioxide elimination, or both. 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 measurements of arterial or venous blood gases (ABGs or VBGs) and chest x-ray. Treatment is usually in an intensive care unit and involves correction of the underlying disorder, supplemental oxygen, and ventilatory assistance if needed.
The respiratory system oxygenates and eliminates carbon dioxide from venous blood. Thus, a useful classification of respiratory failure is whether the principal abnormality is
Inadequate carbon dioxide elimination (which means inadequate ventilation)
Many disorders affect both. Although temporizing measures exist, respiratory failure frequently necessitates invasive or noninvasive mechanical ventilation.