早上听BBC Reith Lecture，Doctor Atul Gawande提到一个紧急救治的案例：奥地利一个三岁的小女孩在跟父母散步的时候跑到结冰的池塘上，然后落入开裂的冰面了。父母紧跟过去，但是也只是在30分钟之后才找到她。把她打捞上来时她已经完全失去知觉了——体温非常低，没有呼吸，没有心跳，瞳孔散开，对光线没有反应。
Consider a case report in The Annals of Thoracic Surgery of a three-year-old girl who fell into an icy fishpond in a small Austrian town in the Alps. She was lost beneath the surface for thirty minutes before her parents found her on the pond bottom and pulled her up. Following instructions from an emergency physician on the phone, they began cardiopulmonary resuscitation. A rescue team arrived eight minutes later. The girl had a body temperature of sixty-six degrees, and no pulse. Her pupils were dilated and did not react to light, indicating that her brain was no longer working.
但是救助团队坚持继续救治：
But the emergency technicians continued CPR anyway. A helicopter took her to a nearby hospital, where she was wheeled directly to an operating room. A surgical team put her on a heart-lung bypass machine. Between the transport time and the time it took to plug the inflow and outflow lines into the femoral vessels of her right leg, she had been lifeless for an hour and a half. By the two-hour mark, however, her body temperature had risen almost ten degrees, and her heart began to beat. It was her first organ to come back.
After six hours, her core temperature reached 98.6 degrees. The team tried to put her on a breathing machine, but the pond water had damaged her lungs too severely for oxygen to reach her blood. So they switched her to an artificial-lung system known as ECMO—extracorporeal membrane oxygenation. The surgeons opened her chest down the middle with a power saw and sewed lines to and from the ECMO unit into her aorta and her beating heart. The team moved the girl into intensive care, with her chest still open and covered with plastic foil. A day later, her lungs had recovered sufficiently for the team to switch her from ECMO to a mechanical ventilator and close her chest. Over the next two days, all her organs recovered except her brain. A CT scan showed global brain swelling, which is a sign of diffuse damage, but no actual dead zones. So the team drilled a hole into the girl’s skull, threaded in a probe to monitor her cerebral pressure, and kept that pressure tightly controlled by constantly adjusting her fluids and medications. For more than a week, she lay comatose. Then, slowly, she came back to life.
First, her pupils started to react to light. Next, she began to breathe on her own. And, one day, she simply awoke. Two weeks after her accident, she went home. Her right leg and left arm were partially paralyzed. Her speech was thick and slurry. But by age five, after extensive outpatient therapy, she had recovered her faculties completely. She was like any little girl again.
from: http://www.newyorker.com/magazine/2007/12/10/the-checklist
我就搜索了一下，这样的案例还不止一例，还有更有名的：
http://en.wikipedia.org/wiki/Anna_B%C3%A5genholm
大概看了一下，有几个要点：
- 坚持CPR非常重要
- 体温低，这使得各脏器，尤其是大脑不必消耗太多氧气，这样即使呼吸停止，脏器和大脑也不会被破坏；
- 救治过程首先上体外循环机，逐步升高体温（体温升高太快会破坏红细胞）。心脏恢复搏动则循环系统恢复；
- 然后上人工肺和呼吸机，确保氧能够进入循环系统；
- 心肺都恢复之后可以恢复其他脏器；
- 大脑没有因为缺氧而坏死，恢复的希望也很大，只是需要时间。
所以，其实冬天落水比夏天落水存活概率更高。只是不知道这次“东方之星”的救助能不能从中得到启发。。。