Impending respiratory failure

Impending respiratory failure, also known as silent chest, is a life-threatening event due to the inability to breath deeply. It may occur in an asthma attack and is a sign of impending respiratory failure.

Signs and symptoms
In the silent chest, audible wheezes disappear owing to constrained airflow. Other signs of silent chest suggestive of severe bronchospasm comprise use of accessory muscles, cyanosis, agitation[disambiguation needed], and depression. In those with silent chest, exhaustion, altered consciousness, increased carbon dioxide levels in the blood and acidosis also occur frequently.

Those gradually entering silent chest state might just feel so fatigued and lethargic and fail to recognize them as an early sign of respiratory failure, missing the golden hour to respond with emergency care.