Which of the following is a life-threatening sign of asthma in adults?

• A. Cyanosis.
• B. Respiratory rate < 8 per minute.
• C. Bradycardia (heart rate < 50 per minute).
• D. Exhaustion, confusion, decreased conscious level.

Answer: (D)

In a severe asthma situation, the most dangerous development is when the patient can no longer maintain adequate breathing. Exhaustion, confusion, or a decreased level of consciousness signals that ventilation is failing and the brain is not getting enough oxygen or is being affected by high CO2. This change in mental status is a clear warning that respiratory failure is imminent, requiring urgent escalation of care.

Cyanosis can accompany severe hypoxaemia, but it may appear later or be absent early, so it’s not as reliable an immediate marker of danger as a decline in consciousness. A very low respiratory rate is unusual in an asthma attack because the body typically works hard to breathe, and a rate under eight per minute suggests a late, failing respiratory drive but is less commonly the first clear life-threatening sign. Bradycardia is not typical in acute asthma and would prompt consideration of other problems.