section_path: Prognosis/Respiratory and circulatory failure
section_name: Respiratory and circulatory failure
paragraph_text: Respiratory and circulatory failure
  
  Pneumonia can cause respiratory failure by triggering acute respiratory distress syndrome (ARDS), which results from a combination of infection and inflammatory response. The lungs quickly fill with fluid and become stiff. This stiffness, combined with severe difficulties extracting oxygen due to the alveolar fluid, may require long periods of mechanical ventilation for survival. Other causes of circulatory failure are hypoxemia, inflammation, and increased coagulability.
  
  Sepsis is a potential complication of pneumonia but usually occurs in people with poor immunity or hyposplenism. The organisms most commonly involved are Streptococcus pneumoniae, Haemophilus influenzae, and Klebsiella pneumoniae. Other causes of the symptoms should be considered such as a myocardial infarction or a pulmonary embolism.