Which mask is recommended when a breathing injured diver cannot activate the demand inhalator valve?

The recommended mask for a breathing injured diver who cannot activate the demand inhalator valve is the nonrebreather mask. This type of mask is designed to deliver high concentrations of oxygen to the patient. It features one-way valves that prevent exhaled air from re-entering the mask, allowing for an efficient oxygen supply that can significantly improve the oxygen saturation in a diver who is experiencing respiratory distress.

In emergency situations, such as when a diver cannot engage with the demand inhalator valve, the nonrebreather mask can be quickly applied and effectively delivers oxygen without requiring active participation from the diver. This is critical for maintaining oxygen levels and managing potential hypoxia while additional medical assistance is on the way.

The other options, while useful in different scenarios, may not provide the same level of oxygen concentration or effectiveness for an injured diver unable to aid their own breathing. For example, an oronasal resuscitation mask is typically used for mouth-to-mask ventilation but doesn’t provide a high oxygen concentration without a supplemental oxygen source. The bag valve mask allows for manual positive pressure ventilation but requires someone to operate it effectively. A nasal cannula does deliver oxygen but is limited in the amount and concentration it can provide, making it less suitable for a