![]() ![]() ![]() Once the trauma surgeon has control of bleeding, a heart-lung machine restarts blood flow and the patient is given a blood transfusion. Through these tubes, they infuse cold saline to reduce core body temperature and replace lost blood. In one experimental therapy, surgeons insert a cardiopulmonary bypass cannula through the chest and into the aorta, or through the groin and into the femoral artery. In emergency situations, anesthetists can insert a cannula-a slim tube-into the nose that feeds cooling nitrogen gas directly to the base of the brain. The babies are treated with cooling caps for 72 hours, which lower their metabolism just enough to reduce tissue oxygen requirements and allow the brain and other vital organs to recover.īy the same token, surgeons apply cooling and metabolic suppression to patients who’ve suffered various physical traumas: heart attack, stroke, gunshot wounds, profuse bleeding, or head injuries resulting in brain swelling. Today, physicians use moderate hypothermia (roughly 89 degrees) as a staple of care for some newborns in medical distress, such as those born premature or suffering from fetal oxygen deprivation (hypoxia). ![]() Babies were placed in cooling blankets or packed in ice and even snow banks to slow circulation and reduce oxygen requirements before heart surgery. Experimental procedures with cooling started as early as the 1960s, mostly in cardiac and neonatal cases. Therapeutic hypothermia has become a part of surgical practice. The colder, the longer the brain can tolerate not having blood flow.” “The key is cooling the brain either before blood flow stops or as soon as possible after blood flow stops. Cases like this are “exactly why we think that very deep hypothermia can allow our patients to survive,” writes Samuel Tisherman, Professor of Surgery at the University of Maryland School of Medicine, in an email. His doctors believed the icy lake had rapidly cooled his body to a state of protective metabolic torpor, preserving all vital organs and tissues while reducing the need for blood oxygen-in effect, saving the boy’s life. The boy made a full recovery and was discharged two weeks later. ![]() Ten minutes after that, his heart resumed normal sinus rhythm. Twenty minutes later, as doctors worked to warm the boy’s chest cavity, the ventricles of his heart started contracting. Upon admission to the hospital, his core body temperature was 67.6 degrees Fahrenheit, a sign of severe hypothermia. His pupils were fixed and dilated, and he remained in cardiac arrest a full 88 minutes. A rescue team pulled him out but could not resuscitate him in the field. A four-year-old boy fell through the ice of a frozen lake in Hanover, Germany. This interest is due in part to advances in low-temperature surgery, but also to an increased understanding of cases like one documented in 1995 in the journal Prehospital and Disaster Medicine. Scientists call this phenomenon “torpor-induced hibernation.” Once considered outlandish, torpor induction-the old term was “suspended animation”-is under serious study for long-duration spaceflight. More likely, though, astronauts and space colonists will learn a few tricks from dehydrated snails, which survive for a year or more ingesting nothing giant pandas subsisting on low-calorie bamboo leeches that survive a liquid nitrogen bath children who have been submerged in frozen ponds yet can still be resuscitated or skiers buried in an avalanche and brought back to life ever so slowly, reborn from a super-cooled, dreamless state. Perhaps they’ll sleep in white coffin-like pods, as the cryo-preserved astronauts in futuristic fantasies like 2001: A Space Odyssey, Alien, and Avatar did. They’ll hibernate like bears as they hurtle through space for months at a time. Some day, astronauts packed into rocketing tin cans bound for other planets may be protected from radiation and space sickness by having their metabolisms depressed to a fraction of their typical rate. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |