How induced coma can save lives
Seven time world champion and F-1 racing legend Michael Schumacher came within a blink of dying a shattering death as his head slammed into a rock after he crashed headlong down a snowy run at the Meribel Ski Resort in the French Alps on Monday. "We put him on induced coma to give him his best chance to live," said Dr. Jean-Francois Payen, an anesthesiologist at the Grenoble University Hospital Center where the racing superstar is fighting for his life.
In layman's language a drug-induced coma allows the body to switch off and focus on the healing process. It quite literally puts the brain to sleep, reducing the huge amounts of energy it requires to fuel its hectic electrical activity:Nearly two-thirds of all the blood pumped out by the heart is required to keep the brain functioning normally.
By inducing coma and lowering the temperature of the body (also called therapeutic hypothermia) doctors at the Grenoble hospital are attempting to reduce the energy requirements of the brain, which in turn reduces blood flow and pressure, and allows it to rest. Like any other part of the body, the brain swells when it meets with traumatic injury; however, because the brain is trapped inside your skull it has no room to expand. This increases pressure inside the organ, damages tissues all around the injured site and restricts critical functions, such as blood supply, which in turn causes death.
Injury to the brain quickly spirals into a life-threatening crisis because the skull is a closed space. As the brain starts to expand the only place it can go is down, pushing and thrusting its way into the brain stem, causing morbidity. Along the way, a swelling brain can inflict a great deal of tissue damage. Induced coma and thereauputic hypothermia are like cooling the engine down and allowing the healing process to unwind slowly at its own pace. It also hopefullyhelps decrease the swelling and ease intracranial pressure.
When the head is hit hard, the brain jerks back and forth within the skull, causing stretching injury and damage. This is followed by the release of a wave of chemicals toxic to the brain such as calcium, which can cause cell death and swelling. Either a cell dies instantly or may be so injured that it essentially kills itself--a phenomenon called apoptosis.The goal in management is to try to reduce or slow these processes down so you can save as many of the brain cells as possible.
Schumacher's body temperature is being kept below 18 degrees Celsius (64.4 degrees Fahrenheit), and he is being given anesthetics. Lowering body temperature is generally effective at keeping down intracranial pressure, but it does not always and necessarily improve the outcomes in the end. The biggest part of the brain's inflammatory response to injury peaks after 48 to 72 hours, so doctors usually keep the body cool for up to three to five days.
It is difficult to manage induced coma as it involves walking the tight rope between ensuring that enough blood and nutrients reach the brain to promote healing on the one hand and keeping its energy needs down to the minimum on the other. Specifically, Schumacher is being maintained in the coma in order to keep his body temperature between 12 and 18 degrees Celsius. The brain requires much more energy than usual when it's healing, so doctors try to minimize the amount of metabolic activity by medically-inducing comas and decreasing body temperatures in order to reduce inflammation.
Since, the operation is extremely complex and tough to manage requiring intensive care of the highest order, it is resorted to only in exceptional cases and if the inflammation and swelling does not recede despite the induced coma then doctors must consider other measures to relieve inter-cranial pressure and help the brain to recover. They can, for example, remove a part of the scull and "store it in the abdomen" creating space for the brain to swell outwards without harming other tissues and impeding critical functions. The skull can be reconstructed once the swelling recedes.