Description
An in-depth report on the causes, diagnosis, treatment, and prevention of pneumonia.
Highlights
Introduction
- Pneumonia is inflammation of the air sacs in the lungs
- It can be defined according to its location in the lung (lobar pneumonia or bronchopneumonia)
- It can be defined according to the setting of infection (community- or hospital-based pneumonia)
Causes
- Bacteria are the most common causes of pneumonia
- Pneumonia can also be caused by viruses, fungi, and other agents
- The Gram-positive bacterium Streptococcus (S.) pneumonia, also called pneumococcus, is the most common cause of pneumonia
- Opportunistic pneumonias, caused by organisms that are usually harmless, can arise in patients with impaired immunity
Symptoms
- Symptoms vary among children, adults, and the elderly
- Symptoms may include: shaking chills, fever, chest pain, cough, night sweats, nausea, vomiting, muscle aches, rapid breathing and heartbeat, shortness of breath, and weight loss
Prognosis
- The majority of pneumonia patients respond well to treatment
- The mortality rate is well below 5% in outpatients
- The mortality rate is much higher for hospitalized patients
- Elderly patients have lower survival rates than younger adult patients
- Small children who develop pneumonia and survive are at risk for developing lung problems in adulthood
- Prognosis varies according to the type of infecting organism
Risk Factors
- For hospital-acquired pneumonia, risk factors include: being very young or elderly, undergoing surgery, having a chronic illness, being in the intensive-care unit, receiving sedation, receiving antibiotics
- For community-acquired pneumonia, risk factors include: being very young or elderly, having a chronic lung disease, having a compromised immune system, having a swallowing disorder, staying in dormitory conditions, exposure to smoke or pollutants, abusing drugs or alcohol
Diagnosis
- It is important to identify the infecting organisms, because they require different treatments
- Diagnosis may include one or more of the following: patient history, physical examination, laboratory tests, and imaging
- In some case, such as if standard diagnostic procedures yield no definitive results, invasive techniques may be employed
Treatment
- Treatment generally involves determining the need for: hospitalization, antibiotics, supportive care, and follow-up care
- Most adult patients do not need to be hospitalized for pneumonia
- Home-care involves: drinking fluids, monitoring body temperature, allowing the cough reflex to clear the lung (no cough suppression), pain relief (if needed), finishing the entire course of antibiotics (if applicable), and not smoking
- If hospitalization is needed, the standard treatment is intravenous antibiotics
Pharmacologic Intervention
- Pneumonia patients need an antibiotic that is effective against the organism causing the disease
- Antibiotic treatment is determined by several factors, including: the type of organism present, the patient's history of antibiotic therapy, the patient's immune status, the presence of co-existing diseases, and whether hospitalization is needed
- Treatment can include a single drug or a combination of drugs
Drug Classes
- Beta-lactam antibiotics (such as penicillins) interfere with bacterial cell walls
- Fluoroquinolones interfere with bacteria's genetic material to prevent them from reproducing
- Macrolides also affect the genetic material of bacteria and are effective against atypical bacteria
- Tetracyclines inhibit the growth of bacteria
- For very serious bacterial infections, an injection of aminoglycosides may be used
- Lincosamides prevent bacteria from reproducing
- Glycopeptides are used for S. aureus infections that have become resistant to standard antibiotics
- Linezolid is the first antibacterial drug in a new class of man-made antibiotics called oxazolidinones. It has been shown to work against certain aerobic Gram-positive bacteria
Surgery
- Although most patients with pneumonia do not need invasive therapy, it may be necessary in patients with abscesses, empyema, or certain other complications
- Chest tubes are used to drain infected fluid
Prevention
- The best way to prevent serious respiratory infections such as pneumonia is to avoid sick people (if possible), and to practice good hygiene
- Health care facilities are changing many of their practices to reduce the likelihood of transmitting bacteria
- Vaccines are a safe and effective way to prevent some infections