What is Pneumonia?
Pneumonia is an infection involving the lungs. It is usually caused by bacterial or viral infections. Patients typically develop a fever, cough, chest pain, difficulty breathing, and fatigue. The disease can be very serious, especially in patients with advanced age, immunocompromised status, or history of chronic lung or heart disease. In some cases, pneumonia can lead to respiratory failure and even death. In fact, it is a common cause of death in the elderly population.
What Causes Pneumonia?
Pneumonia is typically caused by infection of the lungs by viruses or bacteria. Common bacterial pathogens include S. pneumoniae, H. influenza, M. pneumoniae, C. pneumonia, Legionella, gram-negative bacilli, and S. aureus. Viruses may include influenza, parainfluenza, respiratory syncytial virus, adenovirus, coronavirus, and rhinovirus.
Less commonly, fungi may be responsible for pneumonia, including Histoplasma capsulatum and Coccidioides.
How Common is Pneumonia?
Pneumonia is an extremely common infection that leads to a high frequency of primary care and emergency room visits. Severe cases may require consultation with a pulmonary medicine physician.
Community-acquired pneumonia occurs in about 6 cases per 1000 persons per year. The rate of community-acquired pneumonia increases with age. The combination of pneumonia and influenza were the 8th most common cause of death in the United States in 2005. Most cases occur during winter.
Signs and Symptoms
Symptoms of pneumonia often include:
- Productive cough
- Difficulty breathing
- Chest pain
Symptoms typically occur quickly within days. A cough is often productive of yellow or green sputum. Chest pain may occur with deep breathing – this is called pleuritic chest pain. Most patients endorse a history of exposure to sick contacts or recent hospitalization.
It may exacerbate other underlying heart or lung conditions such as congestive heart failure, asthma, and chronic obstructive pulmonary disease (COPD). Elderly patients may not present with classic symptoms such as cough and fever – instead, they may become disoriented or confused.
- Temp > 101, tachypnea (elevated breathing rate), and tachycardia (elevated heart rate)
- Altered mental status - disorientation
- Respiratory distress – use of accessary muscles
- Interrupted speech
- Wheezing and crackles on lung examination
It is diagnosed based on symptoms and physical examination and confirmed with a chest x-ray. The chest x-ray will often show an area of infiltrate or consolidation, which is concerning for an infection. Pneumonia can affect one lobe, multiple lobes, or have a diffuse, interstitial pattern.
If diagnosed on chest-ray, a repeat study should be performed in 4-6 weeks to make sure the consolidation has resolved. If the consolidation has not improved, this could suggest an underlying mass such as lung cancer.
If severe, the doctor will likely order other tests such as blood cultures, sputum culture, and serum and urine serology/PCR for specific bacteria that cause pneumonia. They will also likely obtain a nasopharyngeal swab to test for influenza A and B virus. Other basic tests include a comprehensive metabolic panel (CMP), complete blood cell count (CBC), urinalysis, and lactate level.
Pneumonia Medication and Treatment
The treatment of pneumonia begins with its prevention. Most adult patients should generally receive the annual influenza vaccination – the flu can cause viral pneumonia and increase the risk of bacterial superinfection. Patients with immunosuppression, history of chronic cardiac or lung disease, and the elderly should also receive vaccination for pneumococcal pneumonia with Pneumovax and Prevnar.
The treatment of pneumonia depends on whether or not you are hospitalized. In both these situations, smoking cessation is encouraged if you use tobacco. The outpatient treatment generally involves one or more of the following antibiotics:
- Zithromax (Azithromycin)
- Levaquin (Levofloxacin)
- Avelox (Moxifloxacin)
- Tetracycline (Doxycycline)
- Augmentin (Amoxicillin-Clavulanate)
- Bactrim (Trimethoprim-Sulfamethoxazole)
If you have concomitant influenza virus, you doctor may recommend Tamiflu (Oseltamivir).
Your doctor will usually encourage you to rest and drink plenty of fluids. If you have underlying asthma or COPD exacerbation, they may recommend bronchodilators (e.g., Ventolin, ProAir, Advair) and oral corticosteroids (e.g., Prednisone). Patients with severe symptoms and risk factors for complications such as death should be hospitalized.
Patients hospitalized generally receive intravenous medications, which may include:
- Rocephin (ceftriaxone)
- Vancocin (vancomycin)
- Zosyn (piperacillin-tazobactam)
Hospitalized patients also generally have blood and sputum cultures obtained. Bronchodilators and oxygen are usually necessary. Severe cases accompanied by respiratory failure may require pneumonia assistance with a breathing machine and occasionally respiratory intubation.
Elderly patients hospitalized often become deconditioned. They may require skilled nursing facility placement for physical therapy prior to being discharged home.
- Watkins R, Lemonovich T. Diagnosis and Management of Community-Acquired Pneumonia in Adults. Am Fam Physician. 2011 Jun 1;83(11):1299-1306. - https://www.aafp.org/afp/2011/0601/p1299.html
- Wunderink RG, Waterer GW. Clinical practice. Community-acquired pneumonia. N Engl J Med 2014; 370:543. - https://www.nejm.org/doi/full/10.1056/NEJMcp1214869
The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.