Community Acquired Pneumonia

Introduction

Have you ever ached all over, coughed continuously, and felt like you were burning up one second, but really cold the very next. You might have thought you had a common cold or maybe even a touch of the flu; however, at the doctor's office, you were informed that you have community acquired pneumonia. Read on to learn more about this common infection.

What is it?

Community acquired pneumonia (CAP) refers to an inflammation of the lungs usually caused by an infection that is acquired outside of a hospital or long term care facility. When this infection is acquired, the air sacs in your lungs fill with pus or other liquid, making it difficult for oxygen to penetrate through your lungs to reach your bloodstream. If CAP is not treated properly with antibiotics or spreads throughout your body, it can result in death, especially in the elderly or in people with weakened immune systems.

What causes it?

Your body has many mechanisms in place to fight off infection. If fact, you are frequently exposed to organisms that can cause pneumonia, but your body normally protects against them through its various defense mechanisms. Occasionally however, these invaders can pass your defense mechanisms and make their way to your lungs and airways causing pneumonia.

CAP is spread by close person-to-person contact, usually when an infected person coughs or sneezes on another person.

CAP can be caused by several different organisms, including bacteria, viruses, and fungi. The most common organism responsible for CAP is the bacterium known as Streptococcus pneumoniae, however there are many other 'bugs' that can have the same effect. Many times, a doctor will try to get a sputum sample from your cough to help determine the exact 'bug' that is causing the infection; however, this is often unsuccessful and an the exact cause of the infection may go unidentified.

Who has it?

In the United States, CAP (combined with influenza or "the flu") is the eighth leading cause of death and the number one cause of death from infectious diseases. It is estimated that approximately 5.6 million cases of CAP occur annually and of these 1.1 million require hospitalization. Anyone can be susceptible to CAP, but it more commonly occurs and is more severe in very young children and the elderly. CAP is also more common in the chronically ill such as patients who have cancer, kidney disease, organ transplants, immune system disorders, chronic obstructive pulmonary disease (COPD), etc. Smokers are also more likely to acquire pneumonia.

What are the risk factors?

Risk factors are characteristics that may increase the chance for developing a condition. The more risk factors present, the more likely you are to develop the condition. You are at an increased risk for developing CAP if:

  • You are 65 years or older
  • You have other medical conditions or a combination of conditions such as:
    1. chronic obstructive lung disease (COPD) or other chronic lung disorders
    2. diabetes mellitus
    3. chronic kidney disease
    4. heart failure
    5. coronary artery disease
    6. cancer
    7. chronic liver disease
    8. cystic fibrosis
  • You are a smoker
  • You are exposed to certain chemicals or pollutants such as those used for agriculture, construction, or industrial chemicals. Exposure to these pollutants can sometimes cause damage to the lungs and contribute to lung inflammation?thus leaving the lungs more susceptible to infection.
  • You suffer from alcoholism
  • You have a weakened immune system

What are the symptoms?

CAP sometimes presents after a cold, the flu, or any condition that damages the defenses of the airways that would allow bacteria, viruses, and bacteria to infect them. The symptoms of CAP can vary and generally overlap with other symptoms of the common cold or flu. This variability makes it sometimes difficult to recognize pneumonia. Many people attribute it to a cold that just won't go away. However, CAP can be life-threatening if it is not properly treated.

Some symptoms that you may notice with community acquired pneumonia include, but are not limited to:

  • shaking and chills
  • fever
  • a cough that produces sputum which is usually rust colored (or burnt orange)
  • shortness of breath
  • chest pain worsened by deep breathing or coughing
  • night sweats
  • confusion or delirium is very common in the elderly
  • fast heart rate
  • feeling tired or weak
  • diarrhea
  • nausea and vomiting

How is it treated?

Treatment for CAP varies according to the organism responsible for the infection. If the cause is bacterial, then the goal of treatment is to cure the infection with antibiotics, which can typically be taken orally at home if the infection is not severe. However, if the infection is severe, the person is having a lot of difficulty breathing, or has other chronic medical conditions, then antibiotics should be given intravenously (into a vein) at a health facility such as a hospital. If the infection is caused by a virus, then treatment with antibiotics would not be effective because antibiotics only help eliminate bacteria,. In this type of situation, supportive care should be administered which might include using acetaminophen to reduce fever or provide oxygen therapy to help with breathing.

Because several treatment guidelines are available, the specific drug(s) that your doctor may use to treat your CAP may vary. Clinical expertise/preference and antibiotic drug resistance in a particular setting are two factors that may affect a doctor?s drug of choice for treating CAP.

At the initial visit to the doctor, he or she will question you about your past medical history and perform a physical examination. It may be necessary to perform a chest X-ray. Next, your doctor will determine how much your infection places your life at risk. Your doctor may need to send samples of your sputum, blood or urine to the laboratory to confirm your CAP diagnosis. Due to that fact that identifying the exact cause of your infection may take several days, doctors will prescribe "empiric therapy" by using their clinical expertise. This kind of treatment is based on the most likely cause of the infection (bacteria, virus, or fungi) and allows for treatment to begin as soon as possible. Once the organism is identified, therapy can be tailored to treat that specific organism. The following chart describes the guidelines from the Infectious Diseases Society of America and American Thoracic Society for patients that do not require hospitalization.


Patient Variables

Treatment Options

Healthy Patients who HAVE NOT had recent antibiotic therapy taken within the last 3 months

  • A macrolide, such as azithromycin (Zithromax), clarithromycin (Biaxin) or erythromycin, or doxycycline.
     

Patients with other health problems (eg. COPD, diabetes, heart failure, or cancer) or who HAVE had recent antibiotic therapy taken within the last 3 months*

  • A respiratory fluoroquinolone, such as levofloxacin (Levaquin), gemifloxacin (Factive), moxifloxacin (Avelox)

  • A macrolide or doxycycline plus high-dose amoxicillin (e.g., 1000mg three times daily), high-dose amoxicillin-clavulanate (Augmentin), ceftriaxone (Rocephin), cefpodoxime (Vantin), cefdinir (Omnicef), or cefuroxime (Ceftin)
*For patients who HAVE had recent antibiotic therapy within the last 3 months, an alternative antibiotic from a different class should be selected. For example, if a fluoroquinolone such as levofloxacin was taken within the last 3 months, a combination of a macrolide or doxycyline plus high-dose amoxicillin, amoxicillin clavulanate, ceftriaxone, cefpodoxime, or cefuroxime should be used to treat the current pneumonia.

When CAP patients require hospitalization, IV antibiotics will generally be initiated along with oxygen therapy to help breathing. Studies have shown that bacterial CAP can effectively be treated with 5 to 14 days of antibiotics. However, this duration of therapy may be longer if the cause of the infection is found to be from specific bacterial organisms such as Legionella or Pseudomonas, fungal organisms, or if you have other medical conditions that may compromise your recovery. Regardless of the drug chosen, it is important to remember to take the entire antibiotic prescribed by your physician. Many people take their medication only until they feel better. This can contribute to antibiotic resistance and allow an infection to recur with even greater severity in the near future. Development of resistance can also have the potential to prevent a given antibiotic from working well to treat other patients with the same infection in your family or community.

Helping Yourself

You can help lessen your chances of contracting CAP by using the practices recommended below.

  • Immunization-- Pneumonia vaccines are available. The Centers for Disease Control and Prevention (CDC) recommends vaccination with pneumococcal conjugate vaccine (PCV) for children at 2, 4, 6, and 12-15 months. The pneumococcal polysaccharide vaccine (PPV) should be administered to adults 65 years of age and older, and persons 2 years of age and older with normal immune systems who have chronic illnesses such as heart or lung disorders or diabetes, and those who are immunocompromised (weakened immune system). A single revaccination dose is recommended 5 years after the initial dose of the PPV for some. You should speak with your physician to discuss whether a booster dose is necessary. The pneumococcal vaccination can be given at any time of the year, however it is most commonly given with flu vaccines in the late fall or early winter months.

  • Washing hands-- It is important that you frequently wash your hands with soap and water, especially after blowing your nose, going to the bathroom, changing diapers, and before eating or preparing food. This can help cut down on the spread of organisms that cause CAP.

  • Quit smoking-- The damage from smoking cigarettes and cigars decreases your lungs ability to fight off infection.

  • Cover your mouth-- It is important that you cover your mouth when you cough or sneeze to prevent the spread of CAP. This will help to prevent any airborne transmission of infecting organisms.

If you already have pneumonia, you may want to take the following measures to ensure a more speedy recovery or decrease your risk of complications associated with the infection.

  • Drink plenty of fluids
  • Get lots of rest
  • Try over-the-counter products to decrease your cough and cold symptoms:
    1. aspirin, acetaminophen, or ibuprofen for fever and pain
    2. decongestants to open clogged nasal passageways and sinuses
    3. cough syrups and drops to control coughing
  • Take the entire course of any prescribed medications for your infection

What is on the horizon?

Research is continually being conducted to optimize therapies currently used to treat pneumonia. Antibiotic resistance is becoming more and more problematic; therefore studies are being conducted to develop newer drugs that will combat drug resistance. Studies are also being performed to effectively treat patients and shorten length of hospital stay. Because CAP is one of the leading causes of death in very young children, studies are being conducted to compare the efficacy of drugs that have formerly been considered unsafe in children but have proven efficacious in adults with CAP.

References

  1. American Lung Association. Pneumonia. Available at: http://www.lungusa.org/site/pp.asp?c=dvLUK9O0E&b=35691.
    Updated April 2006. Accessed March 2007 and February 2008.

  2. File TM. Community-acquired pneumonia. The Lancet 2003; 362: 1991-1998.

  3. Glover ML and Reed MD. Lower Respiratory Tract Infections. In: DiPiro JT, Talbert RL, Yee GC, Matzke GR, Well BG, Posey LM, editors. Pharmacotherapy A Pathophysiologic Approach. 6th ed. McGraw-Hill 2005. pg. 1943-1962.

  4. Mandell LA, Wunderink RG, Anzueto A, Bartlett JG, Campbell GD, Dean NC, Dowell SF, File TM, Musher DM, Niederman MS, Torres A, and Whitney CG. Infectious Diseases Society of America/American Thoracic Society Consensus Guidelines on the Management of Community-Acquired Pneumonia in Adults. Clinical Infectious Diseases. Available at: http://www.guidelines.gov/summary/summary.aspx?
    doc_id=10560&nbr=005516&string=community+AND+acquired+AND+pneumonia. Accessed February 2008

  5. MayoClinic.com. Pneumonia. Available at: http://www.mayoclinic.com/health/pneumonia/DS00135. Accessed March 2007 and February 2008.

  6. Medlineplus Medical Encyclopedia. Pneumonia. Available at: http://www.nlm.nih.gov/medlineplus/ency/article/000145.htm. Accessed March 2007 and February 2008.

  7. Merck Manual. Community-Acquired Pneumonia. Available at: http://www.merck.com/mrkshared/mmanual_home2/sec04/
    ch042/ch042b.jsp. Accessed March 2007 and February 2008.

  8. Schmitt SK. Community-Acquired Pneumonia. The Cleveland Clinic. Available at: http://www.clevelandclinicmeded.com/diseasemanagement/infectiousdisease/
    communitypneumonia/communitypneumonia.htm. Accessed March 2007 and February 2008.

  9. Thibodeau KP and Viera AJ. Atypical pathogens and challenges in community-acquired pneumonia. American Family Physician 2004; 69:1699-706.

    Community Acquired Pneumonia Health Condition Last Updated: February 2008

    Note: The above information is intended to supplement, not substitute for, the expertise and judgment of your physician, pharmacist, or other healthcare professional. It is not intended to diagnose a health condition, but it can be used as a guide to help you decide if you should seek professional treatment or to help you learn more about your condition once it has been diagnosed.

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