Why is 100% oxygen considered the most important first aid for a dive accident?

The reason that 100% oxygen is considered the most important first aid for a dive accident relates to the physiological effects it has following a dive-related injury, such as decompression sickness or arterial gas embolism. When a diver experiences such an incident, the presence of nitrogen bubbles in the bloodstream and tissues can cause significant physiological damage.

Administering 100% oxygen provides several benefits. It creates a pressure gradient that helps to drive the nitrogen bubbles out of the tissues and blood into the lungs, where they can be exhaled. This process, known as off-gassing, is critical for addressing the effects of decompression sickness. The increased availability of oxygen also reduces tissue damage by improving the overall oxygenation of affected tissues, helping to mitigate hypoxia (a deficiency in the amount of oxygen reaching the tissues). Furthermore, the hyperoxygenation can assist in promoting the healing and recovery processes.

These combined effects make 100% oxygen a crucial component in minimizing the consequences of a dive accident, significantly improving outcomes in both immediate first aid and subsequent treatment in a hyperbaric chamber.