Respiratory failure

The inability of the respiratory system to maintain adequate gas exchange such that arterial oxygenation and/or carbon dioxide elimination are insufficient to meet normal metabolic demands without ventilatory support.

• Type 1 Hypoxemic respiratory failure: Arterial hypoxemia (PaO₂ <8.0 kPa)

• Type 2 Hypercapnic respiratory failure: Arterial hypercapnia (PaCO₂ >6.0 kPa) with respiratory acidosis (pH <7.35)

Causes

• Airway and lung diseases

  • Chronic obstructive pulmonary disease (COPD)

  • Acute respiratory distress syndrome (ARDS)

  • Pneumonia

  • Asthma

  • Upper airway obstruction

  • Foreign body aspiration

  • Lung trauma

  • Toxic inhalation (fumes, smoke)

  • Water aspiration (drowning)

  • Pulmonary edema

  • Pulmonary embolism

• Cardiovascular causes

  • Heart failure

  • Myocardial infarction

• Systemic causes

  • Sepsis

  • Anaphylaxis

  • Acute pancreatitis

  • Blood transfusion-related lung injury

  • Neuromuscular disorders causing ventilatory failure

  • Central nervous system depression (e.g., opioids, sedatives)

  • Obesity hypoventilation syndrome