What is the first step in treating DCS?

Administering 100% oxygen is a critical initial step in treating decompression sickness (DCS). The rationale behind this approach lies in the physics of gas exchange and the physiological effects of increasing the partial pressure of oxygen in the blood. When a diver or airman experiences DCS, nitrogen bubbles form in the body due to the rapid reduction in pressure. Breathing pure oxygen helps to reduce the size of these bubbles and facilitates their reabsorption into the bloodstream, ultimately alleviating the symptoms of DCS.

Additionally, increasing the oxygen concentration in the lungs enhances the transport of oxygen to tissues that may be compromised due to the presence of nitrogen bubbles. This method is often used in the pre-hospital treatment phase and can significantly improve the patient's condition while preparing for more advanced care, such as hyperbaric oxygen therapy.

In contrast, consulting a flight surgeon is important for further care and guidance in managing DCS, but it is not the immediate first step in the acute treatment process. Descending as quickly as possible may help to relieve pressure, but without administering oxygen, the underlying issue of nitrogen bubbles remains unaddressed. Reassessing the flight plan can also be valuable for safety in the future, but it does not provide immediate relief for