By Ceci Connolly
Washington Post Staff Writer
Monday, March 13, 2006
When a doctor utters the word "coma," the prognosis is usually bleak. Yet every day, physicians intentionally put patients into comas.
Despite great advances in modern medicine, there are still few options for treating severe brain injuries such as those caused by a blow to the head, a stroke or constant seizures. Physicians can try draining fluid or raising the head of the patient's bed to alleviate potentially fatal swelling. But if those efforts fail, they sometimes decide to push patients to the precipice, as close to brain death as humanly possible.
The procedure, called medically induced coma, slows brain activity almost to a stop by pumping huge doses of barbiturates into the patient. The goal is to give the injured brain a rest in the hope it will heal itself.
"It's a leap of faith," said Julian Bailes, neurosurgery chairman at West Virginia University School of Medicine. "It's a last-ditch measure when we feel we're at the end of the game. Although it has been very effective for some patients."
Though drug-induced comas have been in use for three decades, the procedure has made headlines in recent months with famous patients such as Israeli Prime Minister Ariel Sharon and the sole survivor of the Sago Mine explosion in West Virginia.
The brain is an energy glutton, controlling all body activity from basic reflexes to deep intellectual thoughts. It rouses sleepy muscles in the morning, controls breathing and heart rates, inspires creative flights of fancy and sparks emotional outbursts. Even when the rest of the body is sleeping, the busy brain is working, generating dreams.
Fueled by oxygen and glucose, the brain operates like a faucet, opening capillaries when it needs to draw in more nutrient-packed blood to keep working. In some situations, such as when a patient has a blood clot, the delivery pipe from heart to brain becomes blocked, causing one type of stroke. In many injuries, the brain is bruised and too much blood pours in. To deal with a trauma, or "insult," the brain works harder, sucking in more nutrients and swelling up to accept them. But because it is encased in the skull, there is little room for it to expand.
"It literally suffocates inside the armor," said Lee Schwamm, associate director of the stroke center at Massachusetts General Hospital. If the "intracranial" pressure is not relieved, the patient will probably die in a matter of days.
To measure the pressure, doctors insert a small fiber-optic tube into the patient's head. The wire acts like an air gauge, monitoring the balance of blood flow. One way to reduce the pressure is essentially to "turn off the brain" so it does not need as much fuel, said Marc Mayberg, executive director of the Seattle Neuroscience Institute. The drug-induced coma, which Mayberg compared to a motor slowed to idle, "enables the brain to recover while it's under this state of reduced metabolism."
Some medical experts, however, say drug-induced coma is an experimental treatment with little data behind it.
"We're clear about what is therapy and we're clear about what counts as research, but experimentation falls in between the two," said Ronald Carson, an ethicist at the University of Texas Medical Branch at Galveston. "There are risks involved in doing something, as well as risks involved in doing nothing. We don't know what the person is going to be like at the other end."
Comas come in varying degrees, often measured on a scale created by a pair of professors at the University of Glasgow in Scotland in 1974. Patients are assigned a numerical score based on how well they respond to verbal commands and external stimuli such as pinching: the lower the score, the deeper the coma. A patient put into a medically induced coma rates a 3, the lowest score on the scale.
In many surgeries, patients are put into a temporary coma with anesthesia. Even when patients are already comatose, physicians often use high doses of medicine to push them into a deeper coma that enables the physicians to administer other treatments, such a uncomfortable breathing tubes, or simply to lower the brain's workload.
"The challenge here is to let the brain rest during a time when you can hopefully correct the underlying problem," Schwamm said. "There's a tradeoff. You're trying to save the healthy brain; you're not really doing anything for the brain that's already damaged."
After his stroke and three surgeries, Sharon was put into a very deep coma for a few days. As he was gradually weaned off the barbiturates, he emerged minimally improved, breathing spontaneously and moving one arm and leg slightly, his surgeon said. But it was impossible to assess the impact of the drug-induced coma because Sharon's underlying damage was so great.
"The still-unanswered question is: Do we improve the patient's outcome?" said Jack Wilberger, neurology chairman at Allegheny General Hospital in Pittsburgh. The patient's life is saved, but the person "may end up in a vegetative state. That, to some extent, becomes a value judgment."
Initially, ABC News President David Westin reported that anchor Bob Woodruff had been placed in a coma after sustaining life-threatening injuries in an attack in Iraq. A network spokeswoman later said Westin was mistaken; Woodruff was only heavily sedated, she said.
Even physicians can have different interpretations of what constitutes a drug-induced coma. Take Randal McCloy, the West Virginia coal miner rescued in January. When he was first sent to Allegheny General Hospital, McCloy was "receiving very significant doses of medications that were specifically designed to render him motionless, in what we would call a drug-induced coma," said Richard P. Shannon, chairman of the hospital's department of medicine.
But Bailes, who now oversees McCloy's care in West Virginia, said the young man was never in a medically induced coma, just heavily sedated.
"It's a bit of semantic silliness," said Stephen Mernoff, co-chief of the neurology division at Roger Williams Medical Center in Providence, R.I. "Coma is defined as a state of unconsciousness that is not sleep. A medically induced coma is one type."
Increasingly, neurologists are testing two alternative treatments for brain trauma: hypothermia, lowering the patient's body temperature; and a craniectomy, removing part of the skull to give the swollen brain room. At the National Naval Medical Center in Bethesda, it's not uncommon to see patients patrolling the halls with a portion of their skulls missing, said neurosurgery chief Lisa Mulligan. That, she said, "has decreased the need for the barbiturate coma."