Complications of pneumonia that could occur include build-up of fluid in the space between the lung and chest walls (pleural effusion), pockets of pus that accumulate in the space between the lung and chest wall (empyema) or in the lung itself (lung abscess), secondary bacterial lung infection after a viral infection, secondary infection, such as a vaginal infection or infections of the digestive system, because of antibiotic therapy, bacteria in the bloodstream (bacteremia) or throughout the body (septicemia), infection caused by swelling of the covering of the spinal cord (meningitis),infection of a joint caused by spread of bacteria through the bloodstream (septic arthritis), and infection of the heart muscle or the sac surrounding the heart (endocarditis or pericarditis).
Abscesses: Abscesses in lung are thick-walled, pus-filled cavities that are formed when infection has destroyed lung tissue. They, frequently, are a result of aspiration pneumonia if a mixture of organisms is carried into the lung. Abscesses can cause hemorrhage (bleeding) in the lungs if untreated, but antibiotics that target them have significantly reduced their danger. Abscesses are most common with Staphylococcus aureus or Klebsiella pneumoniae, and uncommon with Streptococcus pneumonia.
Respiratory Failure: Respiratory failure is one of the main causes of death in people with pneumococcal pneumonia. ARDS (Acute respiratory distress syndrome) is the specific condition that occurs when the lungs are unable to function and O2 is so severely reduced that the personís life is at risk. Failure could occur if pneumonia leads to mechanical changes in the lungs (called ventilatory failure) or O2 loss in the arteries (called hypoxemic respiratory failure).
Bacteremia: Bacteremia (bacteria in blood) is the most and prevalent complication of pneumococcus infection, although it rarely spreads to others sites. Bacteremia is a frequent-occuring complication of infection from other gram-negative organisms, including Haemophilus influenzae.
Empyema and Pleural Effusions: The pleura are 2 thin membranes:
- Lungs are covered by visceral pleura.
- Chest wall are covered by parietal pleura.
In few cases of pneumonia, the pleura become inflamed, that can result in breathlessness and acute chest ache when breathing.
And, in about 20% of pneumonia cases, there is build-up of the fluid between the pleural membranes that lubricates the lung. (Ordinarily the thin zone between the 2 membranes contains only a small amount of fluid.)
Collapsed Lung: In few cases, air may fill up the space between the pleural membranes, causing the lungs to collapse, a condition called pneumothorax. It can be a complication of pneumonia (specifically Streptococcus pneumoniae) or of some of the invasive procedures used to treat pleural effusion.
Other Complications of Pneumonia: : In unique cases, infection may spread from the lungs to the heart and can even spread throughout the body, sometimes causing abscesses in the brain and other organs. Coughing up blood (severe hemoptysis) is another potentially serious complication of pneumonia, particularly in persons with other lung problems such as cystic fibrosis.