Pneumonia is an inflammation of the lungs caused by infection. Bacteria, viruses, fungi or parasites can cause pneumonia. The elderly (> 65 years old) and very young patients who are immunocompromised (e.g., those with AIDS or cancer) tend to develop pneumonia due to unusual organisms like tuberculosis, fungi, or viruses. Viral pneumonia usually occurs in situations of epidemics, e.g., SARS and H1N1. Pneumonia can range in severity from mild to life-threatening.
Symptoms include difficulty in breathing, cough, headache, chest pain, fatigue, and fever. A physical examination, history taking, chest x-rays, and blood tests can help determine if one has pneumonia.
Treatment
The treatment prescribed by the doctor will depend on the cause of pneumonia. If bacteria is suspected, antibiotics will be prescribed. About 50% of patients with pneumonia have an unknown etiology. The tests to determine the microbiology usually turn out negative. Treatment of pneumonia usually involves antibiotics. As antibiotic resistance is becoming a growing challenge due to the widespread misuse of antibiotics, it is important that all patients be assessed case-by-case.
Patients can be managed and treated as an outpatient or inpatient, depending on the level of severity. In patients who are immuno-compromised, the key is to try to identify the offending pathogen using bronchoscopy or other tests.
Prevention
The most common cause of bacterial pneumonia is Streptococcus Pneumoniae (causing about 40% of all bacterial pneumonia). Pneumococcal vaccination is available and is generally recommended for the very elderly and the young.
Complications
Most patients with pneumonia respond well to treatment. However, pneumonia is more likely to cause complications in those with weaker immune systems, such as the elderly and very young children, smokers and people with heart failure or lung disease, such as chronic obstructive pulmonary disease (COPD). Due to this weakened immune system, some individuals with lung cancer may also develop pneumonia.
Pneumonia complications can arise from:
- Bacteria entering the bloodstream (bacteremia)
- Septic shock where normal circulation fails, resulting in end organ failure (e.g., clotting abnormalities and kidney failure).
- Fluid accumulation and infection around your lungs causing sharp pain, cough and breathing limitations (pleural effusion and empyema). In such situations, thoracocentesis and drainage may be needed.
- Lung abscess (a cavity containing pus)
- Acute respiratory distress syndrome (ARDS). When pneumonia involves most areas of both lungs, breathing is difficult and the gas exchange mechanism fails.
Early diagnosis and management of pneumonia is key to preventing complications and possible life-threatening consequences.
