Training to Survive Hypoxia Without Actually Getting It

The Office of Naval Research has funded a successful program to help train naval aviators to recognize the early effects of hypoxia-oxygen starvation. When the brain is starved of oxygen, it starts to shut down by stages-slowed reactions, impaired judgment, disorientation, loss of consciousness, and eventually death. Hypoxia can affect aviators when they fly too high without supplemental oxygen. The emergency oxygen masks flight attendants show airline passengers how to use at the start of every flight are there to prevent hypoxia should the cabin lose pressure at high altitude.

Learning to recognize the onset of hypoxia is vital to the safety of naval aviators-if you pass out, you can't fly the airplane-and so it's an important training point at Pensacoloa and in aviation units. In the past, aviators have been given hypoxia familiarization by being put into a pressure chamber that simulates the low atmospheric pressure they would encounter at high altitudes. This approach isn't free of risk: it's possible in some cases to suffer from decompression sickness (like the "bends" divers can get) or pressure trauma (burst eardrums, toothaches, etc.) when undergoing this training. The pressure chambers are also expensive to build and operate.

The Naval Aerospace Medical Research Laboratory (NAMRL) with ONR funding has come up with a better way. Captain Charles Vacchiano, a NAMRL researcher, has developed a safer, more cost-effective training tool that induces symptoms of hypoxia in a normal room at normal air pressures. The Reduced Oxygen-Breathing (ROB) device, an aviation mask attached to a computer-controller gas reservoir, adds nitrogen to the air a student breathes, thereby providing the amount of oxygen one would get during a climb to 25,000 feet.

The ROB will probably see most of its use in the periodic hypoxia familiarization training Naval aviators must undergo during their careers.