✓ Prospectively collected data bases are discussed with particular reference to neurosurgical data. The objectives, design, and collection of data bases are detailed. Statistical issues that relate to the analysis of these data bases are reviewed, with examples from the National Institute of Neurological Disorders and Stroke-supported Traumatic Coma Data Bank. The utility and limitations of data base inferences are considered.
Mary A. Foulkes
Mary A. Foulkes, Howard M. Eisenberg, John A. Jane, Anthony Marmarou, Lawrence F. Marshall and Traumatic Coma Data Bank Research Group
✓ The Traumatic Coma Data Bank is a collaborative project to prospectively collect data on the clinical course and outcome of severely head-injured patients. The objectives were to further define the natural history of traumatic head injury, to identify prognostic factors, and to provide planning data for future studies. A brief historical development and a description of the organizational structure and methods are given. The characteristics of the cohort at baseline for the 1030 patients enrolled between January, 1984, and September, 1987, are presented, including a summary of the patients' demographic profile, mechanisms of injury, and intracranial diagnoses. The utility and limitations of these data are discussed.
Lawrence F. Marshall, Theresa Gautille, Melville R. Klauber, Howard M. Eisenberg, John A. Jane, Thomas G. Luerssen, Anthony Marmarou and Mary A. Foulkes
✓ The outcome of severe head injury was prospectively studied in patients enrolled in the Traumatic Coma Data Bank (TCDB) during the 45-month period from January 1, 1984, through September 30, 1987. Data were collected on 1030 consecutive patients admitted with severe head injury (defined as a Glasgow Coma Scale (GCS) score of 8 or less following nonsurgical resuscitation). Of these, 284 either were brain-dead on admission or had a gunshot wound to the brain. Patients in these two groups were excluded, leaving 746 patients available for this analysis.
The overall mortality rate for the 746 patients was 36%, determined at 6 months postinjury. As expected, the mortality rate progressively decreased from 76% in patients with a postresuscitation GCS score of 3 to approximately 18% for patients with a GCS score of 6, 7, or 8. Among the patients with nonsurgical lesions (overall mortality rate, 31%), the mortality rate was higher in those having an increased likelihood of elevated intracranial pressure as assessed by a new classification of head injury based on the computerized tomography findings. In the 276 patients undergoing craniotomy, the mortality rate was 39%. Half of the patients with acute subdural hematomas died — a substantial improvement over results in previous reports. Outcome differences between the four TCDB centers were small and were, in part, explicable by differences in patient age and the type and severity of injury.
This study describes head injury outcome in four selected head-injury centers. It indicates that a mortality rate of approximately 35% is to be expected in such patients admitted to experienced neurosurgical units.
Jürgen Piek, Randall M. Chesnut, Lawrence F. Marshall, Marjan van Berkum-Clark, Melville R. Klauber, Barbara A. Blunt, Howard M. Eisenberg, John A. Jane, Anthony Marmarou and Mary A. Foulkes
✓ In order to define the role of intracranial and extracranial complications in determining outcome from severe head injury, 734 patients from the Traumatic Coma Data Bank were analyzed. Nine classes of intracranial and 13 classes of extracranial complications occurring within the first 14 days after admission were analyzed, while controlling for age, admission Glasgow Coma Scale motor score, early hypoxia or hypotension, and severe extracranial trauma. Outcome for survivors was based on the last recorded Glasgow Outcome Scale score, obtained a median of 521 days after injury. Intracranial complications did not significantly alter outcome for the study group. Of the extracranial complications, pulmonary, cardiovascular, coagulation, and electrolyte disorders occurred most frequently at 2 to 4 days. Infections developed later, peaking at 5 to 11 days. Gastrointestinal, renal, and hepatic complications followed no specific time course. Electrolyte abnormalities were the most frequent occurrence (59% of patients) but did not alter outcome. Pulmonary infections (41%), shock (29%, systemic blood pressure ≤ 90 mm Hg for 30 minutes or more), coagulopathy (19%), and septicemia (10%) were significant independent predictors of an unfavorable outcome. Backward-elimination, stepwise logistic regression modeling indicated that the estimated reduction of unfavorable outcome was 2.9% for the elimination of pneumonia, 3.1% for coagulation disturbances, 1.5% for septicemia, and 9.3% for shock. These data suggest that extracranial complications are highly influential in determining the outcome from severe head injury and that significant improvements in outcome in a sizeable proportion of patients could be accomplished by improving the ability to prevent or reverse pneumonia, hypotension, coagulopathy, and sepsis.
Lawrence F. Marshall, Sharon Bowers Marshall, Melville R. Klauber, Marjan van Berkum Clark, Howard M. Eisenberg, John A. Jane, Thomas G. Luerssen, Anthony Marmarou and Mary A. Foulkes
✓ A new classification of head injury based primarily on information gleaned from the initial computerized tomography (CT) scan is described. It utilizes the status of the mesencephalic cisterns, the degree of midline shift in millimeters, and the presence or absence of one or more surgical masses. The term “diffuse head injury” is divided into four subgroups, defined as follows: Diffuse Injury I includes all diffuse head injuries where there is no visible pathology; Diffuse Injury II includes all diffuse injuries in which the cisterns are present, the midline shift is less than 5 mm, and/or there is no high- or mixed-density lesion of more than 25 cc; Diffuse Injury III includes diffuse injuries with swelling where the cisterns are compressed or absent and the midline shift is 0 to 5 mm with no high- or mixed-density lesion of more than 25 cc; and Diffuse Injury IV includes diffuse injuries with a midline shift of more than 5 mm and with no high- or mixed-density lesion of more than 25 cc. There is a direct relationship between these four diagnostic categories and the mortality rate. Patients suffering diffuse injury with no visible pathology (Diffuse Injury I) have the lowest mortality rate (10%), while the mortality rate in patients suffering diffuse injury with a midline shift (Diffuse Injury IV) is greater than 50%. When used in conjunction with the traditional division of intracranial hemorrhages (extradural, subdural, or intracerebral), this categorization allows a much better assessment of the risk of intracranial hypertension and of a fatal or nonfatal outcome. This more accurate categorization of diffuse head injury, based primarily on the result of the initial CT scan, permits specific subsets of patients to be targeted for specific types of therapy. Patients who would appear to be at low risk based on a clinical examination, but who are known from the CT scan diagnosis to be at high risk, can now be identified.
A report from the NIH Traumatic Coma Data Bank
E. Francois Aldrich, Howard M. Eisenberg, Christy Saydjari, Thomas G. Luerssen, Mary A. Foulkes, John A. Jane, Lawrence F. Marshall, Anthony Marmarou and Harold F. Young
✓ In this study, data were prospectively collected from 753 patients (111 children and 642 adults) with severe head injury and examined for evidence of diffuse brain swelling and its association with outcome. Diffuse brain swelling occurred approximately twice as often in children (aged 16 years or younger) as in adults. A high mortality rate (53%) was found in these children, which was three times that of the children without diffuse brain swelling (16%). Adults with diffuse brain swelling had a mortality rate (46%) similar to that of children, but only slightly higher than that for adults without diffuse brain swelling (39%). When the diagnosis of diffuse brain swelling was expanded to include patients with diffuse brain swelling plus small parenchymal hemorrhages (< 15 cu cm), these mortality rates were virtually unchanged.
A report from the NIH Traumatic Coma Data Bank
Howard M. Eisenberg, Howard E. Gary Jr., E. Francois Aldrich, Christy Saydjari, Barbara Turner, Mary A. Foulkes, John A. Jane, Anthony Marmarou, Lawrence F. Marshall and Harold F. Young
✓ In this prospective multicenter study, the authors have examined data derived from the initial computerized tomography (CT) scans of 753 patients with severe head injury. When the CT findings were related to abnormal intracranial pressure and to death, the most important characteristics of the scans were: midline shift; compression or obliteration of the mesencephalic cisterns; and the presence of subarachnoid blood. Diffuse hemispheric swelling was also found to be associated with an early episode of either hypoxia or hypotension.
Experience of the Traumatic Coma Data Bank
Harvey S. Levin, Howard E. Gary Jr., Howard M. Eisenberg, Ronald M. Ruff, Jeffrey T. Barth, Jeffrey Kreutzer, Walter M. High Jr., Sandra Portman, Mary A. Foulkes, John A. Jane, Anthony Marmarou and Lawrence F. Marshall
✓ The outcome 1 year after they had sustained a severe head injury was investigated in patients who were admitted to the neurosurgery service at one of four centers participating in the Traumatic Coma Data Bank (TCDB). Of 300 eligible survivors, the quality of recovery 1 year after injury was assessed by at least the Glasgow Outcome Scale (GOS) in 263 patients (87%), whereas complete neuropsychological assessment was performed in 127 (42%) of the eligible survivors. The capacity of the patients to undergo neuropsychological testing 1 year after injury was a criterion of recovery as reflected by a significant relationship to neurological indices of acute injury and the GOS score at the time of hospital discharge. The neurobehavioral data at 1 year after injury were generally comparable across the four samples of patients and characterized by impairment of memory and slowed information processing. In contrast, language and visuospatial ability recovered to within the normal range. The lowest postresuscitation Glasgow Coma Scale (GCS) score and pupillary reactivity were predictive of the 1-year GOS score and neuropsychological performance. The lowest GCS score was especially predictive of neuropsychological performance 1 year postinjury in patients who had at least one nonreactive pupil following resuscitation. Notwithstanding limitations related to the scope of the TCDB and attrition in follow-up material, the results indicate a characteristic pattern of neurobehavioral recovery from severe head injury and encourage the use of neurobehavioral outcome measurements in clinical trials to evaluate interventions for head-injured patients.
Anthony Marmarou, Randy L. Anderson, John D. Ward, Sung C. Choi, Harold F. Young, Howard M. Eisenberg, Mary A. Foulkes, Lawrence F. Marshall and John A. Jane
✓ This study describes the relationship between raised intracranial pressure (ICP), hypotension, and outcome from severe head injury. The study is based on information derived from the Traumatic Coma Data Bank where ICP records from a relatively large number of patients were available to help delineate the major factors influencing outcome. From the total data base of 1030 patients, 428 met minimum monitoring duration criteria for inclusion in the present analysis. Outcome was classified according to the Glasgow Outcome Scale score determined at 6 months postinjury. Arrays of comparably defined summary measures describing the patient's course were considered for ICP, blood pressure (BP), central perfusion pressure, and therapy intensity level. For instance, the array of ICP summary descriptors included the proportion of ICP readings greater than x, for x = 0 to 80 mm Hg by increments of 5 mm Hg. A total of 187 candidate summary descriptors were considered. A stepwise ordinal logistic regression was used to select the subset of candidate summary descriptors that best explained the 6-month outcome.
As established previously, age, admission motor score, and abnormal pupils were each highly significant in explaining outcome. Beyond these factors, the proportion of hourly ICP readings greater than 20 mm Hg was next selected and was also highly significant in explaining outcome (p < 0.0001). In addition to the ICP factor, the cutoff point of 20 mm Hg was selected by the procedure as most indicative of outcome. With these four factors modeled, the next selected factor was the proportion of hourly BP readings less than 80 mm Hg. Again, the BP factor was highly significant in explaining outcome (p < 0.0001). As with the ICP factor, the BP cutoff point of 80 mm Hg was objectively selected as most indicative of outcome. In summary, the incidence of mortality and morbidity resulting from severe head trauma is strongly related to raised ICP and hypotension measured during the course of ICP management. Moreover, these ICP and BP factors provide a better indication of outcome than the similarly defined factors of central perfusion pressure or therapy intensity level.
Dennis G. Vollmer, James C. Torner, John A. Jane, Barbara Sadovnic, Deborah Charlebois, Howard M. Eisenberg, Mary A. Foulkes, Anthony Marmarou and Lawrence F. Marshall
✓ To better understand the relationship between patient age and clinical outcome following traumatic coma, the data for 661 patients, aged 15 years or older at the time of receiving a nonpenetrating head injury, were analyzed. All patients were prospectively followed and the information was entered into the Traumatic Coma Data Bank. This information was statistically analyzed to determine trends and interactions between patient age and other prognostic indicators. Older patients had higher rates of mortality overall; vegetative survival was seen in 4.8% to 8.0% of patients and did not exhibit a trend related to age. Injury severity, as assessed by motor score or Glasgow Coma Scale score, did not significantly differ according to age. The injury mechanism was age-related, with a greater frequency of falls and pedestrian accidents in older patients. Multiple injury was less frequent in older patients. Medical complications and systemic trauma were considered to be the primary cause of death in less than 25% of patients, with the exception of those between 45 and 55 years of age. When the data were studied in univariate fashion, no factor was identified that accounts for the adverse effect of age on head-injury outcome.
Multivariate logistic regression, performed to assess the combined effect of multiple variables on outcome, failed to eliminate patient age as an independent predictor. Based upon this analysis, it is likely that the effect of age on outcome following head injury is dependent upon an alteration in the pathophysiological response of the aging central nervous system to severe trauma and not an increased incidence of non-neurological complications or other clinical parameters.