Hypotension, hypoxia, and head injury: frequency, duration, and consequences.

BACKGROUND: Retrospective studies have suggested an association between systemic hypotension and hypoxia and worsened outcome from traumatic brain injury. Little is known, however, about the frequency and duration of these potentially preventable causes of secondary brain injury. HYPOTHESIS: Early episodes of hypoxia and hypotension occurring during initial resuscitation will have a significant impact on outcome following traumatic brain injury. DESIGN: Prospective cohort study. SETTING: Urban level I trauma center. PATIENTS: Patients with a traumatic brain injury who had a Glasgow Coma Score of 12 or less within the first 24 hours of admission to the hospital and computed tomographic scan results demonstrating intracranial pathologic features. Patients who died in the emergency department were excluded from the study. MAIN OUTCOME MEASURES: Automated blood pressure and pulse oximetry readings were collected prospectively from the time of arrival through initial resuscitation. The number and duration of hypotensive (systolic blood pressure, < or =90 mm Hg) and hypoxic (oxygen saturation, < or =92%) events were analyzed for their association with mortality and neurological outcome. RESULTS: One hundred seven patients met the enrollment criteria (median Glasgow Coma Score, 7). Overall mortality was 43%. Twenty-six patients (24%) had hypotension while in the emergency department, with an average of 1.5 episodes per patient (mean duration, 9.1 minutes). Of these 26 patients with hypotension, 17 (65%) died (P =.01). When the number of hypotensive episodes increased from 1 to 2 or more, the odds ratio for death increased from 2.1 to 8.1. Forty-one patients (38%) had hypoxia, with an average of 2.1 episodes per patient (mean duration, 8.7 minutes). Of these 41 patients with hypoxia, 18 (44%) died (P =.68). CONCLUSIONS: Hypotension, but not hypoxia, occurring in the initial phase of resuscitation is significantly (P =.009) associated with increased mortality following brain injury, even when episodes are relatively short. These prospective data reinforce the need for early continuous monitoring and improved treatment of hypotension in brain-injured patients.

Improving oral hygiene for the seriously ill patient: implementing research-based practice.

A research-based policy and procedure to improve the oral hygiene care of intubated and other seriously ill patients was developed, implemented, and evaluated. The project resulted in (a) improved oral hygiene for patients, (b) standardization and simplification of nursing practice, and (c) a reduction in supply costs. The project has implications for nursing practice and evidence-based practice protocol development.

Outcome after severe head injury: an analysis of prediction based upon comparison of neural network versus logistic regression analysis.

More reliable prediction of outcome would be helpful for clinicians who treat severely head-injured patients. To determine if neural network modeling would improve outcome prediction compared with standard logistic regression analysis and to determine if data available 24 h after severe head injury allows better prediction than data obtained within 6 h, we tested the ability of both techniques at these two times to predict outcome (dead versus alive) at 6 months. One thousand sixty-six consecutive patients with Glasgow Coma Scale scores of 8 or less during the first 24 h after injury were randomly divided into two groups. Data from the first group (n = 799) were used to develop the models; data from the second group (n = 267) were used to test the accuracy, sensitivity, and specificity of the models by comparing predicted and actual outcomes. The 6-month mortality rate was 63.5%. Our findings confirm the importance of age, Glasgow Coma Scale scores, and hypotension in predicting outcome. Using data available at 24 h improved the predictive power of both models compared with admission data; at both time points, however, the differences in the results obtained with the two models were negligible. We conclude that outcome (dead versus alive) at 6 months after severe head injury can be predicted with logistic regression or neural network models based on data available at 24 h. Critical therapeutic decisions, such as cessation of therapy, should be based on the patient's status 1 day after injury and only rarely on admission status alone.

Predicting survival from head trauma 24 hours after injury: a practical method with therapeutic implications.

OBJECTIVE: To develop a method to predict long-term outcome after head injury and determine if outcome can be accurately predicted 24 hours after injury. DESIGN: A retrospective review was performed on a study cohort of 672 head-injured patients admitted in coma (Glascow Coma Scale score < or = 8) who remained comatose for at least 6 hours, survived more than 24 hours, and had 6-month outcome data available. Stepwise logistic regression analysis was used to determine which clinical variables predicted 6-month outcome. Statistically significant clinical predictors were combined into a single examination variable (MPX score), which reflected a rank-ordering of examinations from worst to best, which was then further weighted by patient age. The relation between 6-month outcome and MPX score at admission and 24 hours was plotted and analyzed. MEASUREMENT AND MAIN RESULTS: Age, best motor score, and pupillary reactivity at admission and 24 hours were significant predictors of outcome; extraocular motility was predictive at 24 hours only. Age was the most important independent predictor, followed by best motor score, pupillary reactivity, and extraocular motility. Combining these predictors into MPX score resulted in a set of graphs that reliably predicted long-term outcome. The 24-hour MPX data were better predictors of 6-month outcome and were more specific in predicting negative outcomes than admission data. CONCLUSIONS: The method is simple to use, relying on bedside neurologic examination and a single graph, but appears to predict long-term outcome accurately as early as 24 hours after head injury. If validated on other large series of patients, this method could provide an objective and practical basis for terminating care in patients unlikely to survive a head injury.

Severity and outcome of intracranial lesions in pedestrians injured by motor vehicles.

To evaluate the type and severity of intracranial lesions and the prognosis after closed head trauma in pedestrians injured by motor vehicles, we reviewed the cases of 225 consecutive patients who suffered major head injuries in collisions with motor vehicles. Patients in this series were comatose, had intracranial hematomas requiring surgical removal, or both. The initial Glasgow Coma Scale (GCS) score was 9-15 in 24% of patients, 6-8 in 32%, and 3-5 in 43%. Intracranial hypertension occurred in 40%. Diagnostic studies showed subdural hematomas in 45% of patients, epidural hematomas in 8%, intracerebral hematomas in 10%, and cerebral contusions in 9%. Clinically significant mass lesions were evacuated, and intracranial pressure was monitored and treated aggressively if elevated. After 6 months, 51% of the patients had died, 13% were vegetative or severely disabled, and 35% had a good outcome or moderate disability. These major head injuries in pedestrians struck by motor vehicles were usually severe, included a high incidence of intracranial hematomas and increased intracranial pressure, and frequently had poor outcomes.