Asthma is primarily a disorder of the airways of the lungs. People with asthma experience difficulty breathing as a result of constriction in their airways. Often people with asthma have very sensitive airways that narrow in response to certain “triggers”. The narrowing of the airway is due to inflammation and swelling of the airway lining, the production of excess mucus and the tightening of the airway muscles. Overall these reduced airflow capacity in and out of the lungs.
Asthma is the highly prevalent within our society and is the most widespread chronic health issue in Australia at present. It affects nearly 2 million people throughout Australia with approximately 1 in 7 primary school-aged children, 1 in 8 teenagers and 1 in 9 adults.
Sign and Symptoms
People experiencing an asthma episode experience inflamed airways and a narrowing of the air passages which lead to the following symptoms:
·         wheezing
·         pain or a tight feeling in the chest
·         shortness of breath
·         cough which is usually worse particularly at night and in the early hours of the morning
·         flaring of the nostrils when breathing in usually more common in children
·         interrupted talking
·         agitation
·         hyperinflation in which one appears hunching forward and often prefer not to lie down
According to symptoms asthma is often categorised into four levels of severity, including:
  • Mild intermittent: In this category the episodes of asthma come and go, with symptoms occurring twice a week or less. The person is often bothered by symptoms at night twice a month or less. Between episodes there are no symptoms and lung function is normal.
  • Mild persistent: In this category the symptoms occur more than twice a week, but less than twice in a single day. At night the symptoms present about twice a month. The asthma attacks may begin to affect the person’s activity.
  • Moderate persistent: In this category the symptoms are presenting daily and nighttime symptoms occurring more than once a week. Asthma attacks are usually disturbing the person’s level of activity.
  • Severe persistent: In this category symptoms are experienced daily on most days, with night time symptoms occurring just are frequently. Physical activity is also likely to be limited.
To date the precise cause of asthma is uncertain. However it is believed that there are two main contributing factors, firstly inflammation of the airway passages and secondly, hyperreactive bronchi.
There are identifiable triggers which cause mediators, chemical substances to be released which in turn lead to inflammation of the airways. This inflammation causes the airway passages to swell, the cells lining the passages to produce excess mucus, and the airway opening to narrow.
Hyperreactive bronchi occur in response to over exposure to stimulus and constrict the airways muscle. This results in the person finding it difficult to breathe.
Identifiable triggers which reported to induce an asthma attack are:
  • allergens such as animal dander, dust, food, mold or pollens
  • odors in the household, such as household cleaners, perfumes, paints, varnishes, fabric softeners, laundry detergents and cooking fumes
  • irritants in the air, such as dirt, cigarette smoke and air pollution or fumes and vapors
  • Preservatives found in dried fruits, fruit juices, beer and wine
  • respiratory infections, such as colds, flu, sore throat and bronchitis
  • emotional stress such as excessive fear or excitement
  • weather conditions – very cold, windy or sudden changes in the weather
  • medications, such as aspirin
  • menstrual cycle
  • night time
  • overexertion
Diagnosis of asthma is made following a collaboration of information including presenting symptoms, medical history, a physical examination, and laboratory tests. During the assessment, the doctor is assessing for signs that the patient’s airflow is obstructed and that the obstruction is at least partially reversible. From reported case history the doctor may determine which factors are trigger symptoms such as cold air, exercise and exposure to an allergen. Often however the contributing factors may not be clearly identified.
To determine and evaluate reversible airway obstruction the patient is often required to undertake physiologic testing. This testing generally is recommended to confirm the diagnosis. During an asthma attack, wheezing can be heard by listening to the chest with a stethoscope. The airway obstruction is considered reversible if the wheezing disappears in response to treatment, or when the suspected triggering factor is removed or resolved.
This isa test that records the volume of air entering and leaving the lungs. It is the most reliable way to determine reversible airway obstruction. It is a non-invasive procedure and often performed within the consulting room.
Spirometry is performed using a measuring device called a spirometer. It is a piece of equipment comprised of a flexible tube that is connected to a disposable cardboard mouthpiece. The patient breathes in and out deeply, once the patient has closed their mouth around the mouthpiece they expire forcefully and for as long as possible until all the air is exhaled from their lungs.
The spirometer provides a measure of the amount of exhaled air and the duration of time taken to complete it. Ideally, the patient should exhale for at least 6 seconds. The amount of air exhaled in the first second, expressed as “FEV1,” is measured and compared to the total amount exhaled. A patient is considered to have an obstruction if the amount exhaled in 1 second is disproportionately low to the total exhaled.
A bronchodilator is administered to the patient to test for reversibility. Once the patient inhales a bronchodilator, the spirometry is repeated. The obstruction is believed reversible if the values of the test performed after administration of the bronchodilator are significantly better than prior values.
Peak Expiratory Flow
Given the nature of fluctuating and intermittent asthma symptoms, it is not unusual for a patient to have normal spirometry. In such cases further investigation may be undertaken such as peak expiratory flow (PEF) rate monitoring. A peak flow meter is a portable device that can be carried by the patient. It involves the use of a small tube with a gauge that measures the maximum force with which one can blow air through the tube.
Testing with the peak flow meter is undertaken twice a day for a fortnight and the patient records the results for review in a follow up appointment. The first test should be performed upon waking in the morning and prior to administering bronchodilator medications. The patient should perform the peak expiratory flow procedure three times and record the highest measurement. The second test should be performed in the afternoon or early evening following administration of a bronchodilator. Peak flows vary during the day and the early morning peak is lower than the evening peak. Variability between morning and evening results greater than 20% is indicative of reversible airway obstruction.
Bronchial Provocation
Sometimes, a patient with a suspected asthma associated airway obstruction results in spirometry or peak flow monitoring do not support the diagnosis. In these circumstance, the diagnosis of airway obstruction may be proven by bronchial provocation.
Bronchial provocation aims to detect and categorize hyperresponsive airways by having the patient inhale an aerosolized chemical, called a broncho-spastic agonist, which will trigger a hyperresponsive reaction.
Asthma episodes can develop into a number of serious respiratory problems including:
  • Infection in the lungs
  • Collapse of the lungs
  • Asphyxia.
  • Cardiac arrest.
  • Permanent changes in the function of the lungs.
  • Pneumothorax.
  • Pectus carinatum.
  • Chest hyperinflation.
  • Death.
At present no cure for asthma exists, but it can be controlled with proper asthma management.
The first issue often addressed for controlling asthma are the environmental factors. By changing their environment, people with asthma may lessen or control its impact on their health.
Some examples of how to change the environment to reduce the likely occurrence of an asthma attack are outlined below:
  • Wear a mask while cleaning the house
  • Avoid exposure to pets with fur or feathers
  • Wash the bedding frequently in hot water
  • Use dust proof covers over bedding
  • Use synthetic bedding materials
  • Aim to have a low humidity in the house
  • Consider materials in living areas with preference for leather and hard floors.
The second step undertaken to control asthma involves monitoring lung function. To achieve this asthmatics use a peak flow meter to gauge their lung function. Lung function is often observed to decrease before symptoms of an asthma attack, typically about two to three days prior. If the meter records a reduction in peak flow by 20 percent or greater than from best effort, an asthma attack may be developing.
The third and final step undertaken in the management of asthma involves the use of medications. Medication used to assist in controlling asthma fall into two major groups, anti-inflammatories and bronchodilators.
Anti-inflammatories work by reducing the amount of inflammatory cells in the airways and stop blood vessels from seeping fluid into the airway tissues. Through the reduction in airway inflammation the airway muscles spontaneous spasm eases. Anti-inflammatories are often used as a preventive step to reduce the chance of acute asthma episodes.
Bronchodilators are designed to increase the diameter of the airway passages and facilitate the smooth and effortless flow of gases to and from the lungs.
A small percentage of people cannot control asthma symptoms by avoiding the triggers or using medication. For these people, immunotherapy allergy injections may be considered and provide assistance. Immunotherapy involves the injection of allergen extracts to “desensitize” the person.
Alternative therapies
There are many facets of alternative medicine which can help alleviate
the multiple symptoms experienced by people with asthma. These areas include prayer, herbal teas, vitamins, supplements, and massage. Other popular treatments include the antioxidants vitamins C and E, selenium, and zinc.