Prevalence

More than 300 million people worldwide are affected by asthma, with over 8 million people in the UK diagnosed with the condition, accounting for approximately 12% of the population.

In the UK, asthma is responsible for 2-3% of primary care consultations and results in 60,000 hospital admissions per year.

The treatment of asthma in adults, both in routine and emergency settings, can be challenging due to the varying degree of bronchitis, particularly in smokers.

Prognosis

The pattern of asthma during childhood tends to predict outcome in later adult life.

In the UK, approximately 2000 individuals die each year due to asthma, with those who have severe asthma and one or more of the risk factors listed below being at a higher risk of death.

Risk Factors 

Asthma Exacerbation Pathophysiology

Chronic inflammation of the bronchi, which results in their narrowing, is the underlying cause of asthma. Exacerbations are characterised by the irritation and contraction of muscles surrounding the bronchi, leading to the increase of acute asthma symptoms. Inflammation also stimulates the excessive production of sputum by the mucus glands, leading to further blockage of the airway.

The narrowing and obstruction of small airways is typically caused by:

• Bronchial mucosal swelling
• Bronchial muscle spasm and constriction
• Increased bronchial mucus and secretions.

On inspiration, as the process involved the bronchial muscles, the obstructions of the airway is overcome. However, on expiration, the bronchial muscles become relaxed and air flow is further delayed by the narrowing of the airway, causing the classic expiratory wheeze.

Respiratory viruses are the most common cause of acute exacerbations, but they can also be triggered by bacterial infections, allergens, pollutants, and occupational exposure.

Assessment

Exacerbation of asthma varies between patients and the severity of acute exacerbation can be categorised in to mild, moderate, severe, and life-threatening. Assessing the standard <C>ABCD algorithm along with the severity of the asthma attack will dictate the management plan.

More information on the DR<C>ABCDE algorithm can be found here. Once an initial DR<C>ABCDE assessment has been carried out, identify the severity of the exacerbation.

Below shows how you may determine the severity of the asthma attack.

To assess the severity of the asthma attack, a set of basic observations is needed along with a respiratory examination. In addition, a peak expiratory flow rate (PEFR) should be carried out. See how to conduct a PEFR test here —>.

However, in severe and life-threatening severity it could further distress the patient and cause deterioration so should be carried out based on clinical judgment.

Management

Any time-critical features???

If any of the following time-critical features are present, undertake a time-critical transfer to the nearest hospital whilst continuing patient management enroute. Time-critical features include:

• Major <C>ABCD problems,
• Extreme difficulty in breathing or assisted ventilations needed,
• Life-threatening asthma.

Treatment of asthma varies based on severity levels. Initial management includes moving to a calm, quiet environment and in mild causes encouraging the PT to use their own inhaler with spacer, ensuring the correct technique is adopted.

In more moderate/severe cases, administer high levels of supplementary oxygen. In addition, administer nebulised salbutamol. If no improvement, administer ipratropium bromide.

If further treatment is needed, with no response to the above, steroids, magnesium and adrenaline may be administered. The below algorithm taken from the JRCALC allows constant reassessment after each initial treatment considering the patient’s overall response using the arrows and transfer as indicated.

Asthma Exacerbation Medications

High-Level Oxygen

As the pathophysiology section suggests, exacerbation of asthma causes the bronchi to inflame leading to the narrowing of the airways. Oxygen will provide adequate tissue oxygenation and assists in reversing the hypoxia, however, will only improve if respiratory effort or ventilation is adequate.

Salbuatmol

As a beta-2 adrenoreceptor stimulant drug it allows the smooth muscle in the airways to relax, which tend to be in spasm in asthma attacks. More Info here…

Ipratropium Bromide

An antimuscarinic bronchodilator drug can provide short-term relief in asthma exacerbation. More info here…

Hydrocortisone

The glucocorticoid drug allows a suppression of the inflammation and immune response, helping to restore blood pressure, blood sugar and cardiac volume and synchronicity.

Prednisolone

Like hydrocortisone, prednisolone, a glucocorticoid, reduced inflammation and swelling in addition to suppressing part of the immune system.

Magnesium Sulphate

It allows the bronchial muscles to relax. Magnesium is a relatively new drug to the prehospital environment so may not be available.

Adrenaline

It stimulates the alpha and beta-adrenergic receptors which can relieve bronchospasm in severe asthma attacks. This can only be administered IM.

Differential Diagnoses

Symptoms present in asthma can also been seen in many other diseases so differentials that are important to consider include:

Respiratory related – Pulmonary Embolism, Bronchiectasis, COPD, Infection.

Cardiac: Heart Failure.

Gastrointestinal: Gastro-oesophageal Reflux.

Other: Foreign body inhalation, allergic rhinitis.

Key Points

• Prompt recognition: Early recognition of asthma symptoms and signs is crucial to initiate timely intervention.
• Oxygen administration: Provide supplemental oxygen to maintain adequate oxygen saturation levels.
• Bronchodilator therapy: Administer bronchodilators, such as short-acting beta-agonists (e.g., Salbutamol), to relieve bronchospasm and improve airflow.
• Corticosteroid administration: Consider administering systemic corticosteroids (e.g., Ipratropium Bromide) to reduce airway inflammation and prevent future exacerbations.
• Reassess and adjust treatment: Regularly reassess the patient’s response to treatment and adjust interventions accordingly.
• Transport decision: Determine the need for transport based on the patient’s condition, response to treatment, and available resources.