Tuesday, December 16, 2008

Asthma

Definition
Asthma is inflammation and narrowing of the airways (called the bronchial tubes).
Inflamed Bronchus in the Lungs

Causes
The cause of asthma is not known. It does seem to run in some families. Possible triggers of an asthma attack in a person with asthma include:
• Exercise
• Cold weather
• Viral illness
• Sinusitis
• Gastroesophageal reflux disease (GERD)
• Sulfites used in dried fruits and wine
• Medications, such as aspirin, ibuprofen, and beta-blockers
• Exposure to irritants or allergens, including:
o Cigarette smoke, smoke from a wood-burning stove
o Pet dander
o Dust
o Chemicals
o Mold and mildew
o Pollen
o Smog or air pollution
o Perfumed products
Risk Factors
A risk factor is something that increases your chance of getting a disease or condition.
• Living in a large urban area
• Regularly breathing in cigarette smoke (including second-hand smoke)
• Regularly breathing in industrial or agricultural chemicals
• A parent who has asthma
• History of multiple respiratory infections during childhood
• Low birth weight
• Being overweight
• GERD
Symptoms
Symptoms include:
• Wheezing
• Tightness in the chest
• Trouble breathing
• Shortness of breath
• Cough
• Chest pain
Diagnosis
The doctor will ask about your symptoms and medical history and perform a physical exam:
Tests may include:
Peak Flow Examination – blowing quickly and forcefully into a special instrument that measures your output of air
Pulmonary Function Tests (PFTs) – breathing into a machine that records information about the function of your lungs
Methacholine Provocation Test – lung function tests performed after taking a small dose of methacholine, which causes narrowing of the airways in susceptible people; helps confirm asthma in unclear cases
Allergy Tests – usually skin or sometimes blood tests to find out if allergies are causing your symptoms
Treatment
Asthma is treated with medication. Often, you'll need to take more than one type of medication.
Asthma medications include:
Quick-acting Beta Agonists (such as inhaled albuterol and xopenex) – relaxes your airways so that they become wider again. These are used to stop an acute episode of asthma, or "asthma attack." (also called a rescue inhaler)
Long-acting Beta Agonists (such as inhaled salmeterol) – used daily to prevent asthma attacks. This inhaler should not be used to try to stop an asthma attack in progress. A recent study showed that long-acting inhalers, like salmeterol, may increase the risk of a life-threatening asthma attack and asthma-related death if taken for more than three months * If you have any concerns, be sure discuss them with your doctor.
Inhaled Steroid – used daily to reduce inflammation in your airways. These types of inhalers should not be used to try to stop an asthma attack in progress.
Cromolyn Sodium or Nedocromil Sodium Inhaler – used daily to prevent asthma flare-ups. These may also be used just before exercise, if you have exercise-induced asthma. These types of inhalers should not be used to try to stop an asthma attack in progress.
Zafirlukast, Zileuton, and Montelukast – pills taken daily to help prevent asthma attacks
Corticosteroids – pills, injections, or intravenous (IV) medications given to treat an acute flare-up of symptoms. You may also take corticosteroid pills for a longer period of time if you have severe asthma that isn't responding to other treatments.
Theophylline – pills taken daily to help prevent asthma attacks
Epinephrine – a shot given to stop an asthma attack
Prevention
There are no guidelines for preventing asthma because the cause is not known. However, you can help prevent asthma attacks by avoiding substances that trigger asthma attacks. Some general guidelines include:
• Keep windows closed.
• Consider getting HEPA filters for your heating/cooling system and your vacuum cleaner.
• Keep the humidity down in your house.
• Avoid strenuous outdoor exercise during days with high air pollution, a high pollen count (if you’re allergic to pollens), or a high ozone level.
• Get a yearly flu shot.
• Treat allergies and sinusitis.
• Don't smoke.
• Avoid breathing in chemicals or second-hand smoke.
• Don't use a wood-burning stove regularly.
• Consider getting allergy shots, if allergies trigger your asthma attacks.
• Talk to your doctor about an appropriate level of exercise for you.
• Talk to your doctor about how to track your asthma, so you can identify and treat flare-ups immediately