When it comes to decompression emergencies, administering oxygen is by far the number one way to prevent or reduce long term damage to the diver. By creating a positive pressure gradient against nitrogen in the bloodstream, the body can flush out nitrogen bubbles quicker than it could without oxygen treatment (This is an answer to a question on many instructor and divemaster exams, so write that one down. You're welcome). No dive operation should be without a proper oxygen kit, and DAN produces some of the best in the industry. Remember to keep your kit up-to-date and filled regularly.