What are the distinguishing signs and symptoms between a mild to moderate asthma exacerbation and a life-threatening asthma attack, according to the Australian guidelines for Asthma (Chronic Obstructive Airway Disease)?

From the Guidelines

Asthma attacks can be classified as mild/moderate or life-threatening based on specific signs and symptoms, with life-threatening attacks requiring immediate medical attention to prevent respiratory failure and potential death. According to the most recent and relevant guidelines, in mild to moderate asthma attacks, patients typically present with mild to moderate breathlessness that affects activities but not speech, and they can speak in full sentences 1. They may have an increased respiratory rate but without significant distress, a pulse rate of 100-120 beats per minute, oxygen saturation levels above 94%, and peak expiratory flow (PEF) readings at 50-75% of their personal best.

Key Features of Life-Threatening Asthma Attacks

Life-threatening asthma attacks, however, present with more severe symptoms, including:

• Marked breathlessness that affects the ability to speak, with patients only able to speak in words or short phrases
• Obvious respiratory distress with accessory muscle use
• Tachypnea (respiratory rate often exceeding 30 breaths per minute)
• Tachycardia (pulse rate exceeding 120 beats per minute)
• Oxygen saturation below 90% in adults or 92% in children
• PEF readings less than 50% of personal best or predicted Additional life-threatening features include:
• Drowsiness
• Confusion
• Silent chest (reduced or absent breath sounds)
• Cyanosis
• Poor respiratory effort
• Hypotension
• Exhaustion ### Treatment of Life-Threatening Asthma Attacks Immediate medical attention is required for life-threatening attacks, with administration of:
• High-flow oxygen
• Frequent or continuous salbutamol via nebulizer or spacer
• Ipratropium bromide
• Systemic corticosteroids
• Consideration of intravenous magnesium sulfate or aminophylline in hospital settings 2, 3. Early recognition of these differences is crucial as life-threatening asthma requires urgent, aggressive treatment to prevent respiratory failure and potential death.

From the Research

Distinguishing Signs and Symptoms

The distinguishing signs and symptoms between a mild to moderate asthma exacerbation and a life-threatening asthma attack are crucial for proper management. According to the available evidence:

• A mild to moderate asthma exacerbation may present with symptoms such as wheezing, dyspnea, and cough, with a peak expiratory flow rate (PEFR) between 50-80% of the predicted value 4.
• A life-threatening asthma attack, on the other hand, is characterized by severe symptoms, including marked wheezing, dyspnea, and cough, with a PEFR less than 50% of the predicted value 5, 6.
• It is essential to note that wheeze is an unreliable indicator of the severity of an asthma attack, and may be absent in severe asthma 4.

Management of Asthma Exacerbations

The management of asthma exacerbations involves the use of oxygen, inhaled beta 2 agonists, and systemic steroids. According to the evidence:

• Inhaled beta 2 agonists, such as salbutamol, are effective in relieving acute symptoms of asthma 5, 4, 6.
• The addition of ipratropium bromide to salbutamol may provide greater bronchodilatation and improve lung function in acute severe asthma 5, 6, 7.
• Systemic steroids, such as prednisolone, are important in the management of acute asthma exacerbations, particularly in severe cases 4, 7.

Assessment of Severity

The assessment of severity is vital in the management of asthma exacerbations. According to the evidence:

• A brief history and rapid physical examination can help assess the severity of an asthma attack 4.
• Peak expiratory flow rate (PEFR) is an essential tool in assessing the severity of an asthma exacerbation, with values less than 50% of the predicted value indicating a life-threatening attack 5, 6.