What should be administered to a DCS Type 1 patient after contacting UMO?

Administering 100% oxygen by mask is a crucial step in the management of a Type 1 decompression sickness (DCS) patient after contacting a Undersea Medical Officer (UMO). The primary goal of this intervention is to reduce the size of nitrogen bubbles that form during DCS. By providing pure oxygen, it enhances the elimination of dissolved nitrogen from the body. This process occurs through increased alveolar ventilation and improved diffusion gradients, facilitating the movement of nitrogen from tissues into the bloodstream and then out of the body through respiration.

Additionally, 100% oxygen serves to also counteract hypoxia by delivering a higher concentration of oxygen to tissues, which may be compromised by gas bubbles. Ensuring that the patient breathes 100% oxygen is critical while further medical evaluation and treatment take place, as it can help alleviate symptoms and stabilize the patient until they receive more definitive care, typically recompression in a hyperbaric chamber.

The other interventions, such as intravenous fluids or antibiotics, may play supportive roles in the overall management of the patient but do not directly address the acute pathophysiological processes of DCS as effectively as administering 100% oxygen. Muscle relaxants also do not have a direct role in treating DCS and