Aetiology, Signs and Symptoms of Asthma

This assignment will explore in detail the chronic inflammatory lung disease known as asthma. It will identify the aetiology of the condition and explain how the causes contribute to the disease. It will present the signs and symptoms associated with asthma incorporating clinical signs whilst linking with the underlying pathophysiology. It will include the main investigations undertaken in order to aid the diagnosis of asthma and identify one common drug group used in the treatment and management of the condition. Psychological and sociological effects of the condition will also be explored.

Asthma is a common respiratory condition often chronic; it is characterized by attacks of spasm in the bronchi of the lungs, causing breathing difficulty. According to Asthma UK, currently in Northern Ireland 182,000 people (1 in 10) are currently receiving treatment for asthma. This includes 36,000 children and 146,000 adults. The National Health Service (NHS) spends around one billion pounds a year treating and caring for people with asthma attributing to 77,124 UK hospital admissions in 2016/17 (Asthma UK, 2019).

Asthma is caused when inflammation occurs in the bronchioles, these are small airways which transport air from the larger bronchial tubes to the microscopic alveoli. However, in asthma the bronchial smooth muscle wall narrows therefore making breathing extremely difficult. Plugs containing a mixture of sticky mucus form, serum proteins and cell debris production increases, which may entirely block the airway creating an airway obstruction. Certain triggers may cause hyper-responsiveness of the airways leading to bronchospasm and chronic inflammation often occurs when something that irritates the lungs enters, allergens such as animal fur, pollen, mould, cigarette smoke, air pollution, exercise and contracting an upper respiratory tract infection may also trigger asthma. (Aldington and Beasley 2007)

An exacerbation is a deterioration in the level of control experienced by a person with asthma. Recurring episodes of inflammation can lead to an obstructed airway which is a life-threatening medical emergency. It is vital a nurse takes note of the level and duration of deterioration as well as obtaining a full detailed history from the patient. Current UK guidelines advise that once an adequate history has been taken, the following parameters should be checked, respiratory rate; pulse rate; pulse oximetry; peak expiratory flow (PEF) and record and document any treatment a patient may have self-administered before presentation. After this initial assessment the patient can then be categorized as moderate, severe or life threatening based on criteria and a management plan implemented.

It can be very difficult to say for certain why some people contract asthma, although it is known that an individual is more likely to develop it if there is a family history of the condition. Researchers in Oxford have found that the gene responsible for asthma, hay fever and other allergy-type illnesses is only active when inherited from the mother. If inherited from the father, the offspring is less likely to suffer from these illnesses. (Tanday, 2015)

Asthma may develop at any age; atopic asthma generally begins in childhood or adolescence and is associated with identifiable triggers that provoke wheezing. There are several factors can increase a person's risk of developing asthma such as exposure to tobacco smoke as a child or a mother smoking whilst pregnant (Gilliland FD, 2001). In many cases, asthma is an allergic disorder and when an allergen is inhaled into the airway it triggers the release of the hormone histamine from the mast cells, the chemicals generate an inflammatory response leading to swelling and an increased production of viscous mucus from the epithelial lining. Histamine can also act as a bronchoconstrictor and is partly responsible for airway hyper-reactivity and increased secretions. All these effects shrink the lumen of the airway and restrict airflow entering or leaving the alveoli, fresh supplies of oxygen can no longer enter, and therefore the concentration of oxygen in the alveoli will fall. As a result, blood flowing through the pulmonary circulation is no longer fully oxygenated, which can lead to hypoxaemia. Oxygen saturations will drop, and all body tissues will become hypoxic. (Cambell, 2011)

Asthma can also be drug induced, amongst the common causes are acetylsalicylic acid (ASA; aspirin) and other non-steroidal anti-inflammatory drugs (NSAIDs), which have been known to trigger asthma attacks in 4-28% of asthmatic patients. Early exposure of the drug acetaminophen (paracetamol) has also been linked to asthma. (Gonzalez-Barcala et al., 2013)

Frequency and severity of attacks varies with each person; however, the most common signs and symptoms of asthma are dyspnoea (difficulty breathing), patients may experience a tightening sensation of the chest, coughing and wheezing. A cough may be worse at night and in the early mornings. The basic underlying pathology in asthma is reversible and causes diffuse airway inflammation (Porth 2011). Asthma can also get worse for a short time – this is known as an asthma attack and can happen suddenly, or gradually over several days. It is vital for a nurse to be able to recognise the signs and symptoms of a severe asthma attack, for effective relief and treatment. This is especially important when a patient presents to an emergency department (A&E) experiencing severe symptoms as there is thought to be a link between deaths in some cases (Camargo, Rachelefsky and Schatz, 2009). Such patients have a respiratory rate of over 25 breaths per minute, a tachycardia of 110 beats per minute or more, and a peak expiratory flow rate of 33-50% of their normal volume. This happens because the lungs become hugely hyperinflated as the patient cannot breathe out effectively. Other signs may include being too breathless to eat, sleep or even speak, hypertension, cyanosis, fainting, drowsiness, dizziness, exhaustion and confusion. (Campbell, 2011).

Asthma can be difficult to diagnose however there are several investigative tools used to assist doctors diagnose asthma, whilst also taking into consideration the patients' symptoms and detailed past medical history. The main tests used to help diagnosis are the FeNO test, this requires the patient to breathe into a machine that measures the nitric oxide levels on the breath which can be a sign of lung inflammation. A similar test is the peak flow test, this is handheld device that will measure expiration rate and may be repeated several times over a few weeks to determine if it changes over time. Serum immunoglobulin (Ig) E levels may increase from an allergic reaction and taking a complete blood count (CBC) may reveal increased eosinophil count. Studies have shown that patients with asthma and blood eosinophil counts greater than 400 cells per μL experience more severe exacerbations and have poorer asthma control. (Price et al., 2019). Peak flow expiratory flow rate usually morning and evening measurements can be useful in long term assessment of asthma; a characteristic morning dipping pattern is seen in poorly controlled asthma. Chest x-rays can diagnose or monitor asthmas progression and may flag up hyperinflation with areas of atelectasis. It is important to consider that patients with asthma their pulse oximetry (Sao2) may be reduced and rates of <90% should be treated as life threatening and emergency treatment given immediately (Ww2.health.wa.gov.au, 2019).

There is no known cure for asthma. However, successful asthma management will achieve both control of symptoms and prevention of acute attacks. To achieve this, preventative measures including the use of medication to prevent symptoms to treat acute attacks is necessary. Avoiding triggers where possible is just as important. Drugs used in the management of asthma can be classified into two categories, preventers and relievers. The most effective forms are those delivered via inhalation directly into the lungs, this achieves high drug concentrations in the airways, the risk of adverse effects is minimal. (Douglass and Holgate, 2010)

In accordance to (Rees 2019) it is important to follow The British Thoracic Society (BTS) and Scottish Intercollegiate Guidelines Networtk (SIGN) stepwise approach to help in the diagnosis and management of asthma, it also helps guide the practitioner when prescribing treatment. For the purpose of this assignment only one drug will be focused on, due to it typically being used for acute exacerbations and exercised induced asthma. It is often the first line of treatment, the inhalation drug named Salbutomol. Salbutomol is a reliever medication (often a rescue drug) it is a short-acting bronchodilator with a rapid onset of action. β2-agonists target β2-adrenergic receptors binding to them, mimicking the effects of adrenaline, inducing relaxation of the smooth muscle in the airway, increasing airflow and reduces hypoxemia providing rapid relief of acute symptoms. Common side effects of salbutamol can include, tremors, arrythmias; dizziness; headache and hypokalameia (Excellence, 2019).

Asthma can have many psychological and sociological effects as well as physiological, as with lots of illnesses, psychological variables may influence outcome in asthma via their effects on treatment adherence and symptom reporting. Emerging evidence suggests that the relation between asthma and psychological factors may be more complex than that, however. Central cognitive processes may influence not only the interpretation of asthma symptoms but also the manifestation of measurable changes in immune and physiologic markers of asthma.

Asthma and major depressive disorders share several risk factors and have similar patterns of dysregulation in key biologic systems, including the neuroendocrine stress response, cytokines, and neuropeptides. Despite the evidence that depression is common in people with asthma and exerts a negative impact on outcome, few treatment studies have examined whether improving symptoms of depression do, in fact, result in better control of asthma symptoms or improved quality of life in patients with suffer with asthma. (Van Lieshout and MacQueen, 2008). In addition, people with asthma can feel socially isolated due to having to restrict their participation in social events, limiting their working and playing and have higher tendencies to take time off work due to the illness, which may lead to financial difficulty. (NATHELL et al., 2000) Some people with asthma tend to display avoidance behaviour leading to strained relationships with friends, family and work colleagues. A study has shown asthma control is related to treatment effectiveness and patient disease behaviour, an example of which would be, avoidant or passive coping strategies (tendency to avoid, ignore, deny, or minimize the seriousness of a problem) are associated with less perceived control by patients, attendance at emergency departments, hospital admissions, symptoms and worsening pulmonary function and poor adherence. (Braido etal., 2012)

Effects during an asthma attack can be life threatening and patients can experience extreme feelings of anxiety and fear including thoughts that they may die due to the feeling of being unable to breathe. Asthma’s discomfort and stress may make a person more aggressive, lose control of their lives, leading to diminished self-care in general. According to (Asthma UK, 2017) it may also be said that a person with asthma can feel embarrassment at times whether due to coughing and spluttering during attacks or taking medication in front of others. An Australian study showed children and adolescents living with asthma suffer from lower self-esteem, behavioral problems, and poorer physical and mental health than those without asthma. (Ogundele, 2018)

As previously stated, asthma can affect persons of any age or background, but where someone lives, how much money someone has and how old they are can disproportionately affect the care an individual may receive. Asthma UK’s report On the Edge: How inequality affects people with asthma outlines the impact of health inequality on people with asthma and outlines a possible solution to help reduce this unfair burden. Some key insights noticed were asthma is more prevalent within more deprived communities, and those living in more deprived areas of England are more likely to go to hospital for their asthma. People from disadvantaged socio-economic backgrounds are more likely to be exposed to the causes and triggers of asthma, such as air pollution and cigarette smoke. There is significant variation in access to basic asthma care across geography, ethnicity and age group. Asthma requires a person to manage their own illness, self-management is difficult to embed in groups with lower health literacy. In order to reduce health inequality in asthma and enable people to better adhere to self-managed treatment, there must be preventative action on the causes of asthma and its triggers, improved access to basic care, and digital innovation to improve engagement in healthcare and health literacy (Cumella and Haque, 2018). Due to the absence of a cure and a need for asthma management, health care professionals can play a very important role in order to educate an individual around the signs and symptoms of asthma including its triggers to lessen and prevent an asthma attack occurring.

Asthma is an important chronic disease which can result in clinically significant morbidity, many missed days for people off work and school and has a substantial impact upon the NHS through rising costs, emergency care and 77,124 admissions to UK hospitals for asthma in the last year alone, 1’700 of which were Northern Ireland hospital admissions. (Asthma UK, 2019) This makes it essential for one to understand the development, causes and diagnosis of asthma, it is clear more research would be beneficial to those that suffer with asthma as health practitioners do not know what causes the disease, therefore making it difficult to treat, alongside variant symptoms from patient to patient.