Acute Asthma

Question 1

Definition

Answer 1

An acute or subacute episode of progressive worsening of symptoms of asthma, including shortness of breath, wheezing, cough, and chest tightness. Exacerbations are marked by decreases from baseline in objective measures of pulmonary function, such as peak expiratory flow rate.

Question 2

Pathophysiology

Answer 2

Triggered by airway inflammation from allergens, infections, or irritants. The inflammatory cascade leads to bronchospasm, airway swelling, and mucus plugging, causing significant airflow obstruction.

Question 3

Epidemiology

Answer 3

Asthma affects 300 million people worldwide, with exacerbations responsible for significant morbidity and mortality. Exacerbations contribute to 60,000 hospital admissions annually in the UK.

Question 4

Risk Factors

Answer 4

Uncontrolled asthma, poor adherence to treatment, high use of short-acting beta-agonists, viral infections (e.g., rhinovirus), smoking, air pollution, obesity, and allergen exposure.

Question 5

History

Answer 5

Worsening symptoms of wheezing, breathlessness, chest tightness, and cough. Ask about poor treatment adherence, prior exacerbations, and exposure to known triggers.

Question 6

Examination

Answer 6

Key findings include wheezing, tachypnea, tachycardia, accessory muscle use, and decreased oxygen saturation. Severe cases may present with silent chest or altered mental status.

Question 7

Investigations - Bedside

Answer 7

Peak expiratory flow (PEF) measurements assess severity. Pulse oximetry determines oxygen saturation.

Question 8

Investigations - Bloods

Answer 8

Arterial blood gases for severe cases to assess oxygenation and hypercapnia. Full blood count may show eosinophilia or infection.

Question 9

Investigations - Imaging

Answer 9

Chest X-ray to rule out complications like pneumothorax or pneumonia in severe cases.

Question 10

Investigations - Special Tests

Answer 10

Spirometry is not typically performed during acute exacerbations. Allergy testing and FeNO levels may guide long-term management.

Question 11

Management - Conservative

Answer 11

Avoidance of triggers, patient education, and use of a written asthma action plan.

Question 12

Management - Medical

Answer 12

First-line treatment includes high-dose inhaled beta-agonists (e.g., salbutamol), oxygen to maintain saturation >92%, and systemic corticosteroids (e.g., oral prednisolone). Consider nebulized ipratropium and intravenous magnesium sulfate for severe cases.

Question 13

Management - Surgical

Answer 13

Not applicable for acute asthma exacerbations.

Question 14

Risks of Treatments

Answer 14

Beta-agonists can cause tremors and tachycardia. Systemic steroids increase the risk of hyperglycemia and infections.

Question 15

Benefits of Treatments

Answer 15

Relief of airflow obstruction, reduction of inflammation, and prevention of life-threatening complications.

Question 16

Medical and Laboratory Sciences

Answer 16

Arterial blood gas and peak flow measurement provide critical information for assessing severity and guiding treatment.

Question 17

Prognosis

Answer 17

Good with prompt and appropriate treatment. Severe cases with delayed treatment can lead to respiratory failure or death.

Question 18

Complications

Answer 18

Respiratory failure, pneumothorax, pneumomediastinum, and infections. Chronic poor control increases the risk of airway remodeling.

Question 19

Differentials

Answer 19

Include COPD exacerbation, pulmonary embolism, pneumothorax, and heart failure. History and objective measurements like PEF help differentiate.

Question 20

Cheat Sheet/Buzz Words

Answer 20

Wheezing, PEF <50%, silent chest, salbutamol, corticosteroids, accessory muscle use, magnesium sulfate.