Most of the deaths in patients who sustain severe traumatic brain injury result from withdrawal of life support, usually within the first 3 days of ICU admission, according to a retrospective, multicenter, cohort study published online Aug. 29 in the Canadian Medical Association Journal.
This finding is concerning because the ability to accurately determine prognosis after TBI is so limited. "In some instances, this may be too early for accurate neuroprognostication," Dr. Alexis F. Turgeon of the Centre de Recherche du Centre Hospitalier, Universitaire de Québec-Hôpital de L’Enfant-Jésus, Quebec City, and his associates wrote (Can. Med. Assoc. J. 2011 Aug. 29 [doi: 10.1503/cmaj.101786]).
In addition, their study of TBI mortality in six Canadian trauma centers showed that the rate of withdrawal of life-sustaining therapy varies dramatically from one hospital to another. Such variation "raises the concern that differences in mortality between centers may be partly due to [differences] in physicians’ perceptions of long-term prognosis and physicians’ practice patterns," the researchers wrote.
"Our study highlights the need for high-quality research to better inform decisions to stop life-sustaining treatments for these patients," they noted.
Dr. Turgeon and his colleagues retrospectively assessed outcomes after TBI at six level-one trauma centers in three Canadian provinces over a 2-year period. They randomly selected 60 cases per year at each center to assess for this study, for a total sample size of 720 patients aged 16 years and older.
A total of 77% of the patients were male, and the mean age was 42 years. The most common causes of TBI were motor vehicle crashes (56%), falls (30%), and assaults (8%).
Overall mortality was 32%. More than 70% of the patient deaths stemmed directly from withdrawal of life-sustaining therapy, including 64% of patients who died within 3 days of admission to an ICU.
The rate of withdrawal varied greatly among the centers, ranging from 45% to 87%.
An analysis of numerous factors that might contribute to mortality risk – including patient sex, age, pupillary reactivity at baseline, and Glasgow coma score – showed that they did not account for the variation in the rate of life-support withdrawal. In contrast, the center to which the patient was admitted did account for most of the variation.
Half of the patient deaths occurred within the first 3 days of admission to an ICU. Again, this proportion varied greatly among the medical centers – from a low of 30% to a high of 93%.
This is of particular clinical relevance "when one considers that people who acquire a severe TBI are often young and have few or no comorbidities," Dr. Turgeon and his associates noted.
The most common reasons given for withdrawing life-sustaining therapy were the medical team’s opinion that chance of survival was poor (54% of cases), the next of kin’s opinion that the prognosis was incompatible with the patient’s wishes (34%), and the medical team’s opinion that long-term neurologic prognosis was poor (29%).
The investigators noted that they did not include information on patients’ ethnicity, religious faith, spiritual beliefs, or other factors not written in medical records, "which may have had an impact on decisions surrounding withdrawal of life-sustaining therapy and consequent mortality."
They added that they did not publicly identify the six medical centers "to avoid the potential for drawing spurious inferences about the quality of care."
In a commentary accompanying Dr. Turgeon’s report, Dr. David H. Livingston and Dr. Anne C. Mosenthal wrote, "Although we attribute the variability in withdrawal of life-sustaining therapy to differences in patient preferences, the article by Turgeon and colleagues adds to the growing body of literature that physician practice and the culture of medical centers may play an equally strong role."
The way in which physicians manage the uncertainty in predicting recovery from TBI in their discussions with families "may account for a large proportion of variability in outcomes," they noted (Can. Med. Assoc. J. 2011 Aug. 29 [doi:10.1503/cmaj.110974]).
A lot of the uncertainty arises from the "poor discriminatory power of the tools available to measure the extent of brain injury and the lack of outcome data," they said.
Although the report by Dr. Turgeon and coauthors of variable but often early withdrawal "raises the concern of not only hastening death but increasing mortality for patients who might recover with more time," it should be considered at the same time that "allowing patients to linger when death is inevitable is associated with prolonged suffering for both patients and families," said Dr. Livingston and Dr. Mosenthal, who are with the department of surgery at the University of Medicine and Dentistry of New Jersey, Newark.