In an acutely deteriorating patient, what is the first priority?

• A. Circulation and perfusion
• B. Airway and breathing assessment and support
• C. Disability assessment
• D. Exposure and environment control

Answer: (B)

The key idea is that airway and breathing come first because oxygen delivery to the body's tissues depends on a patent airway and effective ventilation. In an acutely deteriorating patient, the immediate threat is hypoxia from airway obstruction or inadequate ventilation. If oxygen cannot reach the lungs and be circulated, even a strong heart cannot sustain tissue oxygenation, so stabilizing breathing and securing the airway takes priority before addressing circulation, neurologic status, or exposure.

Once the airway is open and breathing is supported—using measures such as clearing obstructions, giving supplemental oxygen, or initiating ventilation as needed—the focus can then shift to improving circulation, assessing neurologic status, and managing exposure. The other aspects remain important but are not the earliest action because without adequate ventilation, tissue oxygenation cannot be achieved regardless of heart rate or blood pressure.