Surviving the Extremes: A Doctor's Journey to the Limits of Human Endurance (34 page)

The porter’s feet weren’t frozen. In fact I was astounded to discover they were warmer to the touch than my fingertips. And they weren’t white or blue; they were pink. He had been out in a snowstorm with wet feet, in subzero temperatures, for probably ten hours. Yet his feet were warm. I realized that the Sherpa was benefiting from a primitive yet carefully modulated limb-salvage reflex, called the “hunter reflex,” present in warm-blooded animals but well developed only in those whose limbs habitually contact cold water, like wading birds in the Arctic and fishermen in Nova Scotia. The body’s initial response to cold-water exposure of hands or feet is to constrict their blood flow in an effort to prevent rapid heat loss. If the animal or human can’t, or won’t, remove the body part, and it continues to cool, the blood vessels will dilate again, as if the body had decided that, on balance, losing a little extra heat was better than losing a hand or foot. With further cooling, the vessels begin to alternate periods of dilation and constriction, providing an intermittent blood supply as a compromise between trying to conserve both heat and limb. If the low-temperature conditions persist and the hypothalamus senses that body temperature is at risk, it will signal the vessels to remain constricted,
effectively giving up on the limb and allowing it to freeze.

The feet before me were in the dilation-constriction phase. I needed only to dry them. Once they were out of the cold, the swelling subsided, the toes started moving, and sensation returned. I watched this demonstration of the body’s ability to fend off the cold and reverse the damage, feeling that there was nothing much more a mere mortal could or should do. I offered the man a pair of my wool socks, but his feet had become so sensitive that he was unable to put them on. When the storm abated, he put his thongs back on over his bare feet and departed. He kept my socks, promising to use them next time. For me, wool socks were a necessity. For him, they were a luxury. He had been born and raised in this environment, and his feet, like the rest of his body, were highly resistant to cold. There is no Sherpa gene for cold tolerance (at least none has so far been isolated), and yet the porter was able to walk nearly barefoot over fresh snow because his body had had a lifetime to realize its innate potential to adapt. Any of his ancestors who hadn’t possessed that ability would have been eliminated by natural selection long before the invention of wool socks.

With his feet self-restored, the porter moved down the glacier. Though he was far better adapted to this environment than I, he had no desire to go higher up into it. He was on one of the “big headache” mountains that Sherpas know to stay away from, even if their employers will not. Gods live at the tops of these mountains and they draw out the strength and the breath of animals and humans who approach them. Those still strong enough to enter their higher reaches are warned away with terrible headaches. And if those warnings are ignored, the gods lose their patience. Punishment is swift.

Climbing to 21,000 feet a few days later, tired and breathless, I understood that the gods were annoyed at me. As I approached Camp II, I was hoping they wouldn’t get any angrier. Before I had even reached my tent, I found out from climbers on my team who had arrived at the camp earlier that the gods had already inflicted their wrath on someone else. Rather than being greeted with the usual comments, such as “Glad to see you” and “Nice job,” what I heard was, “Man, are you slow. Go take a look at Ricardo. He looks worse than you.”

Ricardo was a South American climber with another expedition whom I had met years earlier on a mountain in Patagonia. His teammates told me this was his second trip hauling supplies up to Camp II. He had arrived yesterday, feeling fine and planning to move on up to Camp III this morning. But he awoke complaining of a pounding headache. He was given two codeine pills, and when that didn’t work, he was given two more. His headache had eased, but he didn’t feel well enough to come out of his tent.

Still wearing my climbing harness, I crawled in to see him. He was curled up in his sleeping bag, lying sideways. I expected he would remember me, and I knew he spoke English well, so I greeted him with a cheery “Hi, Ricardo, how’ve you been?”

“What do you want?”

His hostility was a bad sign.

“Ricardo, who won the World Cup?” I asked.

“I did,” he replied.

Pressure was building inside Ricardo’s brain. Memory and reasoning were impaired, as was control over primitive instincts like aggression. These functions are contained within the cerebral cortex—the outer, convoluted layer of the brain that fills the top, front, and sides of the skull. The cerebral cortex was the last brain part to evolve and is responsible for all the higher thought processes. Extremely sensitive to oxygen deprivation, it’s the first part to suffer when the brain swells enough to impede its own blood flow. When it malfunctions, people behave like Ricardo.

Cerebral edema, swelling of the brain, is the worst punishment the mountain gods can inflict. As humans approach the gods’ abode, organs react to the steadily dropping air pressure by dilating the vessels that feed them. This is both to encourage more blood to enter and to slow the flow so that there will be more time for the oxygen to be absorbed. The brain, being the body’s priority organ, becomes the most engorged. It’s also the only organ enclosed in a hard case.

Like a suit of armor, the skull protects against blows from the outside, but like a fortress, it blocks escape when the attack comes from within. As vessels fill with blood, an incompressible liquid, they push against the soft brain tissue, expanding it outward. The additional
blood doesn’t contain enough oxygen to satisfy the brain, so the swelling continues. The cerebrospinal fluid, a liquid bumper between the brain and skull that acts as an impact attenuator, absorbs some expansion. The fluid displaced by the swollen brain flows down into the spinal column, but soon there is no more room to expand, and the cerebral cortex gets pushed against the rigid, unyielding skull. As pressure builds, brain tissue is compressed, vessels are squeezed, and fluid begins to leak out into the surrounding space. Besides adding to the volume and pressure, the fluid creates a barrier between the vessels and the brain cells, depriving them of what little oxygen remains. Cell membranes break down and fluid enters, swelling the individual cells and adding still more volume and pressure within the brain case. At sea level, vessel dilation is a survival adaptation. When man ventures too high, it becomes the enemy within.

Besides attacking the outer cortex and disrupting thought, cerebral edema attacks the cerebellum, the part of the brain at the back of the skull that controls motor function. Fluid leakage and pressure buildup in the cerebellum cause a loss of balance and coordinated movement. At the base of the skull is the medulla, the most primitive part of the brain, containing the limbic system and the hypothalamus. The medulla connects to the spinal cord, processing raw sensory input and maintaining body functions. When pressure reaches down to this level, hallucinations begin and the body’s most basic systems become deregulated. If this process is not rapidly reversed, death is certain.

We had to get Ricardo down.

“Get out of this tent,” I commanded him.

He fumbled with the zipper of his sleeping bag, unable to open it. “I’m not leaving without my girlfriend,” he said.

Ricardo’s girlfriend was in South America. We had to get him down now.

Far too much time had been lost treating Ricardo’s “headache.” Descent is the only truly effective treatment for cerebral edema. Getting him to base camp would mean traveling through the treacherous icefall in the dark. Spending the night here, however, would be fatal. While Ricardo’s teammates converted a ladder into a litter, my teammates brought me the fishing-tackle box filled with emergency medical
supplies that I kept at Camp II. I gave Ricardo an injection of dexamethasone, a powerful steroid that reduces inflammation of tissues. It would shrink his brain for a few hours, temporarily relieving some of the pressure and, I hoped, improving his condition. His rescuers could inject him again en route to tide him over the rest of the way. The expedition had its own doctor at base camp; he could take the relay once they arrived.

We had no oxygen stored at Camp II, but we had the next best thing—a Gamoff bag, a portable hyperbaric chamber that weighs 11 pounds. When folded up, the canvas bag can be carried like a backpack. When inflated by a foot pedal, it opens to become a body-sized cylinder. We put Ricardo inside and, with constant pumping, raised the air pressure around him so that his body would think it was 2,000 feet lower than it really was. We kept up the treatment until his rescuers were ready to leave. There was nothing more we could do for him. With rapid descent, the cause is removed and the symptoms usually ease.

Our expedition continued up to Camp III the following morning to position some supplies. It was three days before we got back to base camp. Before I could even ask, I was told that Ricardo had died. I went directly to the South American camp and found their doctor in the mess tent.

“He didn’t die of cerebral edema, you know.” The doctor poured me some tea and explained. “He didn’t look too bad when he got here, and I thought he would make it, but the next day he had a heart attack. Before he went up, I measured his hematocrit. It was seventy. I warned him not to climb, but he didn’t listen to me.”

What the doctor was telling me was that Ricardo’s blood contained nearly twice the normal concentration of red blood cells. High altitude had stimulated their production while blunting his sensation of thirst. Hard work in dry cold air had caused him to lose large amounts of water through exhaled vapor. With more cells and less fluid in which to dilute them, his blood was two-thirds solid, and flowing like tar. Fresh blood leaves the heart through the aorta, an aqueduct that divides, subdivides, and branches off to every organ in the body. Right as the blood starts out, some gets siphoned off from
the aorta and diverted into the coronary arteries—three vessels that return blood to feed the heart muscles themselves. The vessels are narrow and are too often made dangerously narrower when tightened by stress or clogged by cholesterol. Heart attacks occur when blood flow through these vessels is suddenly and totally blocked, usually due to severe spasm or deposition of an errant plaque of fat. At altitudes like this, however, where extreme medicine is the rule, heart attacks happen to young, healthy climbers because their blood has literally become too thick to fit through their arteries.

The cause of death on a high mountain can be as subtle as an overabundance of red blood cells or as brutal as a 2,000-foot fall. My team and I were methodically climbing a sheer ice slope below Camp III, perhaps two days away from Everest’s summit. Kami, one of our support Sherpas, who had moved on ahead of us to drop supplies, had already reached the camp and was just starting his descent. Above me, I heard a sudden rumbling noise but my view was obscured by overhanging ice. For a long second, the noise grew louder and then a body flew over my head. We watched in horror as Kami bounced off the ice below us, tumbling and skidding down the slick slope before being catapulted over a crevasse and then landing, motionless, in the snow.

Kami had made a simple mistake. To save time on the descent, he had decided not to hook his harness into the safety line. Then he slipped, and his error in judgment cost him his life. Brains chronically low on oxygen function slowly. The result is fuzzy thinking. It can be overcome by intense concentration, but without enough oxygen, the extra brain power is hard to muster. Poor judgment comes naturally at high altitudes.

Deeply shaken, we pulled back to base camp to regroup and to do some painful soul searching. No measurements are worth a human life, but we had all assessed and accepted the risks and rewards of adventure. Stopping now wouldn’t bring Kami back, and there was still valuable work to be done. Deploying the equipment
National Geographic
had given us would be an important step toward understanding the geology of the Asian continental plate. We decided to resume the expedition, pledging to be more careful than we had ever been before.

The reascent of the mountain took five days. We worked our way
through the icefall to Camp I, then over the crevasses to Camp II. We reclimbed the ice slope to Camp III, passing the spot where Kami fell, then traversed to Camp IV at the South Col, the last camp before the top.

As we set out toward the summit—and toward that critical moment of decision—we had high hopes and willing muscles, but our strength and even our thoughts were dependent on the fuel in our bodies and the oxygen on our backs. Because the deep snow had slowed our progress throughout the night and into the morning, we had begun to run low on both. At an altitude of 28,100 feet, we had to make that critical decision whether to continue upward or to turn around. Poised on the precipitous edge of the southeast ridge, our lives quite possibly were hanging in the balance. The summit, 900 vertical feet above us, was tantalizingly close. Nonetheless, at our rate of progress, reaching it would probably take another five hours. And while we had enough daylight to do it, it would mean descending in the dark. We had enough oxygen to reach the top, but there would be none left for the return. Descending requires much less energy than going up, but we would be exhausted; fatal accidents are eight times more common on descents than on ascents. Ask Kami.

Thoughts were swirling through our heads. At a saner altitude, the decision would have been easy, but without enough oxygen, higher cortical centers weaken their control and obvious conclusions can be hard to reach. Mount Everest is a powerful lure. So close to the top, we could feel its upward pull. Nine hundred feet. Three football fields. The distance around a New York City block. The chance of a lifetime. Nine hundred feet.

Finally: clarity. Our oxygen supply was too depleted to reach the top safely, but not so depleted that we weren’t able to realize that. We turned around.