COMMUNITY-ACQUIRED PNEUMONIA (CAP)

BACKGROUND

Community-acquired pneumonia (CAP) develops in people with limited or no contact with medical institutions or settings. The most commonly identified pathogens are Streptococcus pneumoniae, Haemophilus influenzae, atypical bacteria (i.e. Chlamydia pneumoniae, Mycoplasma pneumoniae, Legionella sp), and viruses.

DISEASE OCCURRENCE IN POPULATION:

The number of annual community-acquired pneumonia (CAP) cases is difficult to estimate. One study, in which 46,237 elderly patients were monitored over a 3-year period, showed the rate of CAP among those aged 65-69 years to be 18.2 cases per 1000 person-years.

A study from Pakistan reported an 11% crude mortality rate on 329 patients hospitalised with CAP.

RISK FACTORS:

Several risk factors for CAP are recognized, including

• Age >65 years
• Smoking
• Alcoholism
• Immunosuppressive conditions
• Conditions such as COPD
• Cardiovascular disease
• Cerebrovascular disease
• Chronic liver or renal disease
• Diabetes mellitus
• Dementia

SIGN AND SYMPTOMS:

• Cough (with some pneumonias you may cough up greenish or yellow mucous, or even bloody mucus)
• Fever, which may be mild or high
• Shaking chills
• Shortness of breath (may only occur when you climb stairs or exert yourself)

DIAGNOSTIC TEST:

The health care provider will listen for crackles or abnormal breath sounds when listening to your chest with a stethoscope. Tapping on your chest wall (percussion) helps the provider listen and feel for abnormal sounds in your chest.

If pneumonia is suspected, the provider will likely order a chest x-ray.

Other tests that may be ordered include:

• Arterial blood gasesto see if enough oxygen is getting into your blood from the lungs.
• Bloodand sputum cultures to look for the germ that may be causing the pneumonia.
• Complete Blood Count (CBC)to check white blood cell count.
• CT scan of the chest.
• Bronchoscopy. A flexible tube with a lighted camera on the end passed down to your lungs, in selected cases.
• Thoracentesis. Removing fluid from the space between the outside lining of the lungs and the chest wall.

TREATMENT OPTIONS:

Your doctor must first decide whether you need to be in the hospital. If you are treated in the hospital, you will receive:

• Fluids and antibiotics through your veins
• Oxygen therapy
• Breathing treatments (possibly)

If you are diagnosed with a bacterial form of pneumonia, it is important that you are started on antibiotics very soon after you are admitted. If you have viral pneumonia, you will not receive antibiotics. This is because antibiotics do not kill viruses. You may receive other medicines, such as antivirals, if you have the flu.

You are more likely to be admitted to the hospital if you:

• Have another serious medical problem
• Have severe symptoms
• Are unable to care for yourself at home, or are unable to eat or drink
• Are older than 65
• Have been taking antibiotics at home and are not getting better

Many people can be treated at home. If so, your doctor may tell you to take medicines such as antibiotics.

When taking antibiotics:

• DO NOT miss any doses. Take the medicine until it is gone, even when you start to feel better.
• DO NOT take cough medicine or cold medicine unless your doctor says it is ok. Coughing helps your body get rid of mucus from your lungs.

Breathing warm, moist (wet) air helps loosen the sticky mucus that may make you feel like you are choking. These things may help:

• Place a warm, wet washcloth loosely over your nose and mouth.
• Fill a humidifier with warm water and breathe in the warm mist.
• Take a couple of deep breaths 2 or 3 times every hour. Deep breaths will help open up your lungs.
• Tap your chest gently a few times a day while lying with your head lower than your chest. This helps bring up mucus from the lungs so that you can cough it out.

Drink plenty of liquids, as long as your provider says it is ok.

• Drink water, juice, or weak tea
• Drink at least 6 to 10 cups (1.5 to 2.5 liters) a day
• DO NOT drink alcohol

Get plenty of rest when you go home. If you have trouble sleeping at night, take naps during the day.

PRECAUTIONS:

Wash your hands often, especially:

• Before preparing and eating food
• After blowing your nose
• After going to the bathroom
• After changing a baby's diaper
• After coming in contact with people who are sick

DO NOT smoke. Tobacco damages your lung's ability to fight infection.

Vaccines may help prevent some types of pneumonia. Be sure to get the following vaccines:

• Flu vaccine can help prevent pneumonia caused by the flu virus.
• Pneumococcal vaccine lowers your chances of getting pneumonia from Streptococcus pneumoniae.

Vaccines are even more important for older adults and people with diabetes, asthma, emphysema, HIV, cancer, people with organ transplants, or other long-term conditions.

REFERENCES:

• https://medlineplus.gov/ency/article/000145.htm
• Irfan M, Hussain SF, Mapara K, Memon S, Mogri M, Bana M, et al. Community acquired pneumonia: risk factors associated with mortality in a tertiary care hospitalized patients. J Pak Med Assoc 2009; 59: 448-52.
• http://www.mayoclinic.org/diseases-conditions/pneumonia/symptoms-causes/dxc-20204678
• https://www.uptodate.com/contents/pneumonia-in-adults-the-basics?source=see_link