Extreme Medicine Read Online Free PDF Page A

18°C. (64.4°F.) before stopping the heart completely. Then, while the heart and circulation were at a standstill, Dr. Elefteriades performed the complicated repair, racing the clock while his patient lay dying on the operating table.
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    O N THE DAY OF THE OPERATION, I was there to watch this remarkable feat of surgery. Though Dr. Elefteriades is an old hand with the technique of deep hypothermic arrest, every time feels like a leap of faith. Once the circulation has come to a standstill, he has no more than about forty-five minutes to complete the repair before irreversible damage to the patient’s brain occurs. Without the induced hypothermia, he’d have just four.
    Standing in the operating room and marking the moment at which Esmail’s circulation comes to a stop is a sobering experience. At this point, nothing is supporting him: no drugs, no machines, no bypass circuit. Esmail’s physiology is crashing in slow motion. Up until now, the surgery has proceeded in a relaxed fashion. Knife in hand, paring away the tissues around the heart, John has chatted away as if he’s doing nothing more taxing than driving to the supermarket. That demeanor changes at the moment of circulatory arrest. Now there’s no time for small talk.
    The hands of the clock on the wall swing around; the digital timer counts off the minutes and seconds. John lays down the stitches, elegantly and efficiently, making every movement count. He has to cut out the diseased section of aorta, a length of around six inches or so, and then replace it with an artificial graft. To this he must stitch other tributaries supplying the brain and upper body. And all the while Esmail is dying.
    The electrical activity in Esmail’s brain is, at this point, undetectable. He is not breathing and has no pulse. Physically and biochemically he is indistinguishable from someone who is dead. It seems impossible to believe that he might be successfully resuscitated from this state and go on to be the man he was before.
    Yet after thirty-two minutes, the repair is complete and Dr. Elefteriades is ready to reestablish Esmail’s circulation. The team warms his freezing body, and very quickly his heart explodes back into life, pumping beautifully, delivering a fresh supply of oxygen to Esmail’s brain for the first time in over half an hour.
    A day later, I visit Esmail on the intensive-care unit. He is awake and well, even if he’s in a little pain, and his wife stands by his bed, overjoyed to have him back.
    To cure this man, his surgeons had to come close to killing him—using profound hypothermia to buy his survival. Esmail is living proof that physical extremes can cure as well as kill.
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    T HERE IS ANOTHER EXTREME that we have recently begun to explore, defined not by environmental conditions, like Scott’s Antarctica, but by disease and injury. Modern intensive-care medicine hangs ordinary people out at the very limits of endurance, to endure perilous derangements in physiology, with the expectation that they might survive and go on to lead normal lives. Life at the extremes can be lifesaving.
    Evolution did not prepare us for life at the extremes. Only engineering and technology allow us to cheat our environment and our biological fate—and then only temporarily. One of the questions this book will address is whether technology emboldens us before we understand its consequences. Think again of that medical team heating Anna BÃ¥genholm’s chilled blood and pumping it back into her body, with only the slimmest hope that she would survive to lead a normal life. Perhaps we have no business pushing the envelope after all. Perhaps we have finally gone too far.
    But Anna did make a complete recovery. She owes her life to science, technology, and medicine and to an understanding of the biology of deep hypothermia that is as young as she is. So goes the story of our exploration of the extreme tolerances of the