If a diver shows cyanosis around his lips and pink froth from his mouth after ascending, what should your initial action be?

When a diver experiences cyanosis around the lips and pink froth from the mouth after ascending, these signs are indicative of serious respiratory distress, possibly related to decompression sickness or pulmonary barotrauma. In such situations, ensuring the airway is clear is critical.

The chosen approach of suctioning the mouth and nose is appropriate because it helps remove any frothy fluid that may inhibit breathing. Following this, applying high-flow oxygen is essential to address the hypoxia suggested by the cyanosis. Monitoring breath sounds is also important, as it provides insight into the effectiveness of your interventions and the condition of the patient’s respiratory status.

This initial action prioritizes airway management and oxygenation, which are vital steps when dealing with a potentially compromised airway and reduced oxygen levels in the body. By addressing these concerns promptly, the chances of stabilizing the diver's condition increase significantly.