ASTHMA
Dr Kripesh Ranjan Sarmah
CONSULTANT PULMONOLOGIST
09864152139
Introduction
Asthma is a chronic inflammatory disorder of the airways characterized by increased airway hyper-reactivity (AHR) and variable airflow obstruction. Its importance is underpinned by the recognition that an estimated 300 million people worldwide suffer from asthma and an estimated additional 100 million persons may be expected to develop the disease by 2025.
Asthma is a chronic lung disease associated with inflammation and narrowing of the airways. Asthma causes recurring episodes of wheezing (a whistling sound when breathe), chest tightness, shortness of breath, and coughing. The coughing often occurs at night or early in the morning. Asthma affects people of all ages and it most often starts in childhood. In the United States, more than 22 million people are known to have asthma. Nearly 6 million of these people are children. In Indian prevalence of asthma varies from 2 to 16% in different areas.
People who have asthma have inflammed airways. This makes the airways swollen and very sensitive. They tend to react strongly to many of substances that are breathed in to which a normal person would not react at all. When the airways react, the muscles around them tighten. This causes the airways to narrow and less air flows to the lungs. The swelling of the airways also makes the airways even narrower. Cells in the airways may make more mucus than normal. Mucus is a sticky, thick liquid that can further narrow your airways. This chain reaction can result in asthma symptoms. Symptoms can happen each time the airways are provoked. Sometimes symptoms are mild and go away on their own or after minimal treatment with an asthma medicine. At other times, symptoms continue to get worse. When symptoms get more intense and/or additional symptoms appear, this is an asthma attack. Asthma attacks also are called flare-ups or exacerbations. It's important to treat symptoms when patient first notice them. This will help prevent the symptoms from worsening and causing a severe asthma attack. Severe asthma attacks may require emergency care, and sometimes it can cause death.
Asthma can't be cured it can be controlled. Even when patient feel fine, he or she still continue to have the disease i.e. inflammation and it can flare up at any time. But with today's knowledge and treatments, most asthmatics can lead a normal life.
Causes Asthma
The exact cause of asthma isn't known. Combination of factors, family genes and certain environmental exposures interact to cause asthma to develop, most often in early life. These factors include:
- An inherited tendency to develop allergies, called atopy
- Parents who have asthma
- Certain respiratory infections during childhood
- Exposure to some airborne allergens or exposure to some viral infections in infancy or in early childhood when the immune system is developing
- Obesity
- Exposure to fumes, gases at workplaces
- In-door and outdoor pollution
- Tobacco smoke
If asthma or atopy runs in the family then the airways when exposed to airborne allergens (for example, house dust mites, cockroaches, and possibly cat or dog dander) and irritants (for example, tobacco smoke) will react in an exaggerated manner. the effect of different factors varies from patient to patient.
The "Hygiene Hypothesis"
One theory related to causes of asthma is the "hygiene hypothesis”. Some people believe that Western lifestyle—with its emphasis on hygiene and sanitation—has resulted in changes in living conditions and an overall decline in infections in early childhood. Many young children no longer experience the same types of environmental exposures and infections as children did in the past and it may increase their risk for atopy and asthma.
Factors that can trigger asthma attack
There are number of things can bring about or worsen asthma symptoms when an asthmatics can in contact with then. Triggers may include:
- Allergens found in dust, animal fur, cockroaches, mold, and pollens from trees, grasses, and flowers
- Irritants such as cigarette smoke, air pollution, chemicals or dust, fumes in the workplace, compounds in home décor products, and sprays (such as hairspray)
- Certain medicines such as aspirin or other nonsteroidal anti-inflammatory drugs like ibuprofen and nonselective beta-blockers.
- Viral upper respiratory infections such as colds
- Exercise (physical activity) in cold enverionment
- Tobacco smoke
- Some foods
- Food preservative
- Strong emotions
- Perfume
- Spray-on deodorants
Diagnosis
Diagnosis of asthma primarily based on medical history supported by a physical exam, and laboratory tests. Diagnosis and severity of asthma is determined by pulmonary function test.
Medical History
Symptoms of Asthma
Common asthma symptoms include:
- Coughing. Usually worse at night or early in the morning, making it hard to sleep.
- Wheezing. Wheezing is a whistling or squeaky sound that occurs over chest while breathing.
- Chest tightness. This may feel like something is squeezing or sitting on chest.
- Shortness of breath. Patient often feel as if he or she can't get air out of the lungs.
Finding during examination
Some patient may have normal examination while others may have extensive signs of airflow limitation. Usually patient have wheezing on auscultation. During severe attack patient may have hyperinflated chest, cyanosis, drowsiness, difficulty in speaking, tachycardia, use of accessory muscles, intercostal recession etc
Diagnostic Tests
Pulmonary function test
The function of the lung is measured with an equipment/instrument called spirometer. A series of tests are done with the help of spirometer and these are together called Pulmonary Function Test. As we measure one’s degree of temperature in fever with the help of a clinical thermometer, spirometry helps us to measure degree and extent of airway obstruction. With the help of spirometry the severity of asthma can be detected.
Peak Flow Meter
This device can be used both in clinic and home. This small, hand-held device shows how well air moves out of the lungs. Patient blow into the device and it gives a score, or peak flow number. Score shows how well lungs are working at the time of the test. Measuring peak flow regularly can help whether asthma is getting worse. This device is useful for self monitoring of asthma.
Other Tests
Other tests are required if needed for more information or to exclude other diagnosis. Other tests may include:
- Allergy testing to find out which particular allergens affect patient’s asthma symptoms,
- Bronchoprovocation test. Using spirometry, this test repeatedly measures lung function during physical activity or after patient receive increasing doses of cold air or a special chemical to breathe in. This test measure airway hyperreactivity.
- A chest x ray or an EKG (electrocardiogram). These tests will help find out whether a foreign object or other disease may be causing asthma like symptoms.
Diagnosing Asthma in Young Children
Most children who have asthma develop their first symptoms before 5 years of age. However, asthma in young children (aged 0 to 5 years) can be hard to diagnose. Sometimes it can be difficult to tell whether a child has asthma or another childhood condition because the symptoms of both conditions can be similar.
Also, many young children who have wheezing episodes when they get colds or respiratory infections don't go on to have asthma after they're 6 years old. These symptoms may be due to the fact that infants have smaller airways that can narrow even further when they get a cold or respiratory infection. The airways grow as a child grows older, so wheezing no longer occurs when the child gets a cold.
A young child who has frequent wheezing with colds or respiratory infections is more likely to have asthma if:
- One or both parents have asthma
- The child has signs of allergies, including the allergic skin condition eczema
- The child has allergic reactions to pollens or other airborne allergens
- The child wheezes even when he or she doesn't have a cold or other infection
Asthma Treatment and Control
Asthma is a long-term disease that can't be cured. The goal of asthma treatment is to control the disease. Good asthma control will:
- Prevent chronic and troublesome symptoms such as coughing and shortness of breath
- Reduce need of quick-relief medicines
- Maintain good lung function
- Maintain normal activity levels and sleep throughout the night
- Prevent asthma attacks that could result in emergency room visit or being admitted to the hospital for treatment
The steps in asthma management includes
· Development of Patient/Doctor Partnership
· Identify and reduce exposure to risk factors
· Assess, Treat and Monitor Asthma
· Manage asthma exacerbations
· Special considerations
Patient doctor partnership/Asthma action plan
Patient doctor partnership help to attain guided self asthma management. The essential component include
• Education
• Joint setting of goals
• Self-monitoring. The person with asthma is taught to combine assessment of asthma control with educated interpretation of key symptoms
• Regular review of asthma control, treatment, and skills by a health care professional
• Written action plan. An asthma action plan gives guidance on taking medicines properly, avoiding factors that worsen asthma, tracking level of asthma control, responding to worsening asthma, and seeking emergency care when needed.
Avoid Things That Can Worsen Your Asthma
A number of things (sometimes called asthma triggers) can often set off or worsen asthma symptoms. Asthma patients should avoid these triggers as far as possible.
Several health conditions can make asthma more difficult to manage. These conditions include runny nose, sinus infections, reflux disease, psychological stress, and sleep apnea. These conditions also need to be treated along side of asthma.
Medicines
Asthma is treated with two types of medicines: long-term control and quick-relief medicines. Long-term control medicines help reduce airway inflammation and prevent asthma symptoms. Quick-relief, or "rescue," medicines relieve asthma symptoms that may flare up.
Initial asthma treatment will depend on how severe the disease is. Follow-up asthma treatment will depend on how well asthma action plan is working to control ones symptoms and prevent patient from having asthma attacks. The level of asthma control can vary over time and with changes in home, school, or work environments that alter how often patient is exposed to the factors that can make asthma worse. Medicines are prescribed in a stepwise approach. Asthma medicines can be taken by mouth or by inhaled form. An inhaler allows the medicine to go right to the lungs. Medication by inhaler devices act fast, less medication is required hence side effect are less.
Drug delivery devices
Inhalers dispense either a fluid or a powdered mist. It is very important to understand how to take inhalers, because if not taken properly, over 95% of inhaled medication may never reach the lungs. By inhalation small amount of drugs delivered into the lung with no systemic side effect but with desired clinical response. Different types of inhaler devices like metered dose inhaler (MDI), dry powder inhaler (DPI), nebulizer etc. are available.
Basic steps of taking inhaler are:
1. Remove the cap and hold the inhaler upright.
2. Shake the canister.
3. Tilt head back and breathe out.
4. Put the inhaler in mouth. Or, if patient is using a spacer, put the end of it in mouth and seal your lips around it. (A spacer is a tube that attach to your inhaler. It makes using an inhaler easier.)
5. Press down on the inhaler to release the medicine as patient slowly breathe in for 3 to 5 seconds. (If patient use inhaled dry powder capsules, close mouth tightly around the mouthpiece of the inhaler and inhale rapidly.)
6. Hold breath for 10 seconds so as to allow the medicine to get into lungs.
7. Repeat as many times as doctor suggests. Wait 1 minute between puffs.
Long-Term Control Medicines
Long term control medicines reduces airway inflammation and most asthma patients are required to take long-term control medicines daily to help prevent symptoms.
Inhaled corticosteroids. Inhaled corticosteroids are the preferred medicines for long-term control of asthma. These medicines are the most effective long-term control medicine to relieve airway inflammation and swelling that makes the airways sensitive to certain substances that are breathed in. Reducing inflammation helps prevent the chain reaction that causes asthma symptoms. Most people who take these medicines daily find they greatly reduce how severe symptoms are and how often they occur. Inhaled corticosteroids are generally safe when taken as prescribed. They're very different from the illegal anabolic steroids taken by some athletes. Inhaled corticosteroids aren't habit-forming, even if patient take them every day for many years.
But, like many other medicines, inhaled corticosteroids can have side effects. However benefits of taking inhaled corticosteroids and preventing asthma attacks far outweigh the risks of side effects. One common side effect from inhaled corticosteroids is a mouth infection called thrush. Patient can use a spacer or holding chamber to avoid thrush. A spacer or holding chamber is attached to the inhaler when taking medicine to keep the medicine from landing in mouth or on the back of throat. Rinsing of mouth with water after taking inhaled corticosteroids also can lower the risk of thrush formation.
In case of severe asthma, systemic corticosteroid in the form of injectable or pills for short periods is required to get asthma under control. If taken for long periods, these medicines raise the risk for cataracts and osteoporosis.
Other long-term control medicines. Other long-term control medicines include:
- Systemic corticosteroids
- Inhaled long-acting beta2-agonists. These medicines open the airways and may be added to low-dose inhaled corticosteroids to improve asthma control. An inhaled long-acting beta2-agonist shouldn't be used alone.
- Leukotriene modifiers. These medicines are taken by mouth.
- Cromolyn and nedocromil. These inhaled medicines also help prevent inflammation and can be used to treat asthma of mild severity.
- Theophylline. This medicine is taken by mouth and helps open the airways.
- Anti-IgE
Quick-Relief Medicines
Asthmatics need a quick-relief medicine to help relieve asthma symptoms that may flare up. Inhaled short-acting beta2-agonists are the first choice for quick relief. Other medications are inhaled anticholinergics, short-acting theophylline, and short-acting oral beta2-agonists.
These medicines act quickly to relax small muscles around airways. This allows the airways to open up so air can flow through them.
Patient should take quick-relief medicine when he or she first notice asthma symptoms. If patient need to use this medicine more than 2 days a week, patient may need to visit doctor to get better control of symptoms.
Anti-IgE
Anti-IgE (omalizumab) is a treatment option limited to patients with elevated serum levels of IgE. Its current indication is for patients with severe allergic asthma who are uncontrolled on inhaled glucocorticosteroids.
Allergen-specific immunotherapy.
The role of specific immunotherapy in adult asthma is limited. Appropriate immunotherapy requires the identification and use of a single well-defined clinically relevant allergen. The later is administered in progressively higher doses in order to induce tolerance. Specific immunotherapy should be considered only after strict environmental avoidance and pharmacologic intervention, including inhaled glucocorticosteroids, have failed to control a patient’s asthma.
Control of asthma
patient can record asthma symptoms in a diary to see how well treatments are controlling patient’s asthma.
Asthma is "well controlled" if:
- Patients have symptoms no more than 2 days a week and they don't have night time symptoms
- Patients can carry out all normal activities.
- Patients take quick-relief medicines no more than 2 days a week.
- Patients have no history of asthma attack that requires to take corticosteroids by mouth or emergency visit.
- Patients’ peak flow doesn't drop below 80 percent of personal best number or have normal or near normal lung function.
If asthma isn't well controlled, patient need to contact doctor. He or she may need to change asthma action plan.
Emergency Care
Most people who have asthma, including many children, can safely manage their symptoms by following the steps for worsening asthma provided in the asthma action plan. However, patient may need medical attention. Visit doctor for advice if:
- Medicines don't relieve an asthma attack.
- Peak flow is less than half of your personal best peak flow number.
Pregnant Women with asthma
Pregnant women who have asthma need to control the disease to ensure a good supply of oxygen to their babies. Poor asthma control raises the chance that a baby will be born early and have a low birth weight. Poor asthma control can even risk the baby's life. Studies show that it's safer to take asthma medicines during pregnant than to risk having an asthma attack. Patient need to inform doctor if she have asthma and are pregnant or planning to get pregnant. Level of asthma control may get better or it may get worse while pregnant.
Exercise induced asthma (People Whose Asthma Symptoms Occur With Physical Activity)
Physical activity is an important part of a healthy lifestyle. Adults need physical activity to maintain good health. Children need it for growth and development.
In many people, however, physical activity may set off asthma symptoms. If this happens patient need to talk to doctor about the best ways to control asthma so patient can stay active.
The following medicines may help to prevent asthma symptoms due to physical activity:
- Short-acting beta2-agonists (quick-relief medicine) taken shortly before physical activity can last 2 to 3 hours and prevent exercise-related symptoms in most people who take them.
- Long-acting beta2-agonists can be protective up to 12 hours. However, with daily use, they will no longer give up to 12 hours of protection. Also, frequent use for physical activity may be a sign that asthma is poorly controlled.
- Leukotriene modifiers. These pills are taken several hours before physical activity. They help relieve asthma symptoms brought on by physical activity in up to half of the people who take them.
- Cromolyn or nedocromil. These medicines are taken shortly before physical activity to help control asthma symptoms.
- Long-term control medicines. Frequent or severe symptoms due to physical activity may indicate poorly controlled asthma and the need to either start or increase long-term control medicines that reduce inflammation. This will help prevent exercise-related symptoms.
Easing into physical activity with a warm-up period may be helpful.
Summery
bronchial asthma is a chronic inflammatory disease of the airways and is characterized by episodic attack of respiratory distress, cough wheezing, chest tightness etc. Patient must have regular asthma checkups with doctor so that he or she can assess level of asthma control and adjust treatment if needed. The main goal of asthma treatment is to achieve the best control of asthma using the least amount of medicine. This may require frequent adjustments to treatments. It is a treatable condition and with proper treatment reasonable control can be achieved.
