Asthma Flashcards
What is asthma?
Asthma is a chronic reactive airway disorder that presents as acute attack causing the airway to over-react to a variety of stimuli resulting in narrowing of the airway due to bronchospasm, oedema and increased mucus production (Scott, 2012)
What is the epidemiology of asthma?
Asthma is the most common chronic illness of childhood and the most common respiratory complaint encountered by ambulance technicians. The earlier the diagnosis the better. Most children diagnosed before 2 years of age grow out of it during primary school age ( British thoracic Society, 2011). According to Asthma UK , 2013 5.4 million people were receiving treatment for asthma, 1.1 million children (1 in 11) and 4.3 million adults (1 in 12). In Scotland, 368,000 people (1 in 14) are currently receiving treatment for asthma. This includes 72,000 children and 296,000. There are roughly 1200 deaths a year of which 90 % are thought to be preventable. There were 1,143 deaths from asthma in the UK in 2010 (16 of these were children aged 14 and under).
Prior to the age of ten, twice as many boys as girls are affected. Between 10 and 30 years old the numbers balance out between sexes. About one third of sufferers share the disease with at least one immediate family member (Scott, 2012).
What are the symptoms of asthma?
Typically the symptoms will develop over a number of hours (>6 hours) (JRCALC, 2013). Wheezing, coughing, shortness of breath, chest tightness/pain (Scott, 2012).
What is the aetiology of asthma?
The over-reactive response that occurs with asthma can be caused by genetic or environmental factors. Genetically induced asthma is triggered by external factors such as pollen, animal dander, smoke, house dust, food additives. The sensitivity to external factors develops during childhood and is commonly accompanied by other hereditary allergies such as eczema and allergic rhinitis.
With environmentally induced asthma the symptoms are triggered by internal, non-allergenic factors, most episodes occurring after a severe infection of the airway. The internal factors that can trigger an asthma attack include emotional stress, fatigue, temperature and humidity variations and exposure to noxious fumes such as nitrogen dioxide from smoking.
Many asthmatics, especially children have both types.
What is the pathophysiology of asthma?
Once an asthma attack has been triggered three mechanism can occur that result in a restricted airway. Bronchospasm - This is the constriction of the smooth muscle that surrounds the larger bronchi, reducing the diameter of the airway, creating a turbulent and restricted airflow. Bronchial oedema- This is the inflammation/swelling of the bronchioles leading to further restriction of the airway. Increased mucus production - Increased production by goblet cells can create thick mucus plugs which can obstruct the airway. The blockages and restrictions caused by the above, can result in severely restricted airflow and air-trapping, and can quickly develop into life-threatening breathing difficulties. The turbulent airflow created by the restrictions causes the characteristic wheeze (Caroline, 2013). Inspiration is an active process that can overcome the constriction of the airways. However, expiration is usually brought about by relaxing the respiratory muscles and so expiration can be severely delayed (JRCALC, 2013).
What is the treatment for asthma?
Mild/moderate - remove to a calm environment, encourage use of own inhalers. If the severity of the symptoms increases, administer high flow oxygen and nebulised salbutamol. If no improvement administer ipratropium bromide. In the case of life-threatening asthma 1:1000 adrenaline given as an intramuscular injection at 5 minute intervals should be given 500 microgrammes for an adult. Time critical transport with pre-alert if necessary. In severe or life threatening cases where transport to hospital exceeds 30 mins - hydrocortisone (JRCALC, 2013).
