Predicting the Outlook for Coma Patients
New guidelines help to gauge a poor prognosis
WEDNESDAY, July 26, 2006 (HealthDay News) -- An international team of physicians has drafted a new set of guidelines to help neurologists better predict the long-range outlook for heart-attack patients who lapse into a coma after receiving cardiopulmonary resuscitation.
"What we tried to do is establish a guideline for physicians that would give them far more clarity in determining whether patients would have a poor outcome once in a coma," said study author Dr. Eelco F.M. Wijdicks, chairman of the division of critical care neurology at the Mayo Clinic College of Medicine, in Rochester, Minn.
Wijdicks and his colleagues from Canada, the Netherlands and Switzerland based their guidelines on a review of 40 years of coma research. The guidelines highlight clinical tools that the researchers say offer 100 percent accuracy in predicting an unfavorable outlook.
The doctors defined unfavorable outlook as death, unconsciousness one month after the onset of the coma, or unconsciousness or severe disability six months out.
"Neurologists do not have the tools to determine a good outcome but are very good in assessing poor outcome," Wijdicks explained. "So, this will help in determining futility of care."
By boosting the ability of neurologists to accurately predict a poor prognosis, the guideline authors hoped to help family members of coma patients make more informed and timely decisions about long-term care.
Families of coma patients must wrestle with such decisions as life-support care, resuscitation orders, and the administration of pain medications. According to the National Institute of Neurological Disorders and Stroke, comas can last two to four weeks, while a prolonged persistent vegetative state can endure for years, even decades.
The guidelines, published in the July 25 issue of Neurology, were based on a review of English, German, Italian and French research done between 1966 and 2006. The 391 studies all involved patients aged 17 or older who had entered into a coma following cardiac arrest and CPR.
The researchers found that many pieces of a patient's story do not help predict a poor outlook. Those pieces include the cause of cardiac arrest, length of time CPR is administered, circumstances surrounding the administration of CPR, and the amount of time between the onset of a heart attack and CPR administration.
But Wijdicks and his team were able to identify a list of clinical exams and lab tests that did help to predict a poor coma outlook. Those indicators include:
- The absence of a normal pupil reaction when the eye is exposed to light, known as a pupillary reflex;
- The absence of blinking when the corneal part of the eye is touched, known as a corneal reflex;
- The lack of body movement in response to pain -- known as an absent motor response -- three days after a heart attack;
- The spontaneous or pain-provoked presence of movement involving the straightening of arms or legs -- known as extensor motor response -- also three days following a heart attack.
The authors noted that these indicators can sometimes be thrown off by the use of sedative medications, organ failure, or patient shock. And they called for more research to determine if additional tools -- including perhaps MRIs -- could be harnessed to aid in coma outcome prediction.
In the meantime, they suggested that the guidelines could help the doctor, the patient, and the patient's loved ones in a time of distress and anxiety.
"If we can predict with a high degree of certainty that the patient would remain in a vegetative state or be severely disabled and dependant on others, then I think that is important information for the family who wants to decide what kind of care they want the patient to receive," Wijdicks said.
"Of course, the guidelines remain guidelines," he added. "It's not mandatory to use them. But we think they will provide clarity."
Dr. Kester Nedd, head of the division of neurological rehabilitation at the University of Miami School of Medicine, said he believes the effort to establish a simple, diagnostic approach has merit.
"As physicians, we are in a very difficult position to help families understand what's going on," he said. "So, anything that helps in putting all the facts together for them is very important."
However, he cautioned that a coma guideline would need to be used carefully to ensure that patients are always assessed on an individual basis.
For more on comas, visit the Brain Injury Association of America.