P&E PROFICIENCY Hypoxia knockout Down for the count B Y D AV E H I R S C H M A N VIDEO EXTRA View the video. BRUCE LANDSBERG (left) and Dave Hirschman don altitude masks at the Nastar training chamber in Philadelphia. TWO FELT WOOZY; one became flush; another had a headache; one got silly; and I passed out. Six general aviation pilots who live near sea level had strikingly different reactions to hypoxia when exposed to the rarefied air at the AirDocs high-altitude training chamber at Western Michigan University. My journey to oblivion began when Dr. Gregory Pinnell, a retired U.S. Air Force flight surgeon, asked AOPA colleague Alyssa Miller and I to remove our masks at a simulated altitude of 30,000 feet. Pulse oximeters showed a steady drop in Miller's oxygen-saturation level from 98 percent at the beginning to 82 percent two minutes later-and then all the way down to an alarming 78 percent. My own oxygen level started in the 90s and stayed there. After two minutes, I felt a vague but persistent sense that something was not quite right. Then my blood-oxygen level plummeted to 80 percent, and I felt a tingling in my fingers and light ringing in my ears. We were about to start a simple task-putting nuts and washers on a bolt to test our fine motor skills at altitude-but I thought it wise to take a few breaths of oxygen from my mask first. I told Pinnell that I was going strap on my oxygen mask momentarily. A few hits of regular air would bring me back to near full strength, but that's the last thing I recall. Miller said I became pale and my head fell to my right shoulder while my unseeing eyes stared into the distance. Pinnell sprang into action, first securing my mask tightly around my face and squeezing the air bag to force more air into my lungs. When that didn't bring me back right away, he swapped masks and put me on a separate system with 100-percent oxygen. Then I'm told I involuntarily straightened out in my seat, and clenched my fists for 30 seconds or so. www.aopa.org/pilot AOPA PILOT | 83http://www.aopa.org/pilot