Linda M. Gerber, Ya-Lin Chiu, Nancy Carney, Roger Härtl and Jamshid Ghajar
In spite of evidence that use of the Brain Trauma Foundation Guidelines for the Management of Severe Traumatic Brain Injury (Guidelines) would dramatically reduce morbidity and mortality, adherence to these Guidelines remains variable across trauma centers. The authors analyzed 2-week mortality due to severe traumatic brain injury (TBI) from 2001 through 2009 in New York State and examined the trends in adherence to the Guidelines.
The authors calculated trends in adherence to the Guidelines and age-adjusted 2-week mortality rates between January 1, 2001, and December 31, 2009. Univariate and multivariate logistic regression analyses were performed to evaluate the effect of time period on case-fatality. Intracranial pressure (ICP) monitor insertion was modeled in a 2-level hierarchical model using generalized linear mixed effects to allow for clustering by different centers.
From 2001 to 2009, the case-fatality rate decreased from 22% to 13% (p < 0.0001), a change that remained significant after adjusting for factors that independently predict mortality (adjusted OR 0.52, 95% CI 0.39–0.70; p < 0.0001). Guidelines adherence increased, with the percentage of patients with ICP monitoring increasing from 56% to 75% (p < 0.0001). Adherence to cerebral perfusion pressure treatment thresholds increased from 15% to 48% (p < 0.0001). The proportion of patients having an ICP elevation greater than 25 mm Hg dropped from 42% to 29% (p = 0.0001).
There was a significant reduction in TBI mortality between 2001 and 2009 in New York State. Increase in Guidelines adherence occurred at the same time as the pronounced decrease in 2-week mortality and decreased rate of intracranial hypertension, suggesting a causal relationship between Guidelines adherence and improved outcomes. Our findings warrant future investigation to identify methods for increasing and sustaining adherence to evidence-based Guidelines recommendations.
Roger Härtl, Linda M. Gerber, Quanhong Ni and Jamshid Ghajar
Traumatic brain injury (TBI) remains a serious public health crisis requiring continuous improvement in pre-hospital and inhospital care. This condition results in a hypermetabolic state that increases systemic and cerebral energy requirements, but achieving adequate nutrition to meet this demand has not been a priority in reducing death due to TBI. The effect of timing and quantity of nutrition on death within the first 2 weeks of injury was analyzed in a large prospective database of adult patients with severe TBI in New York State.
The study is based on 797 patients with severe TBI (Glasgow Coma Scale [GCS] score < 9) treated at 22 trauma centers enrolled in a New York State quality improvement program between 2000 and 2006. The inhospital section of the prospectively collected database includes information on age, initial GCS score, weight and height, results of CT scanning, and daily parameters such as pupillary status, arterial hypotension, GCS score, and number of calories fed per day.
Patients who were not fed within 5 and 7 days after TBI had a 2- and 4-fold increased likelihood of death, respectively. The amount of nutrition in the first 5 days was related to death; every 10-kcal/kg decrease in caloric intake was associated with a 30–40% increase in mortality rates. This held up even after controlling for factors known to affect mortality, including arterial hypotension, age, pupillary status, initial GCS score, and CT scan findings.
Nutrition is a significant predictor of death due to TBI. Together with prevention of arterial hypotension, hypoxia, and intracranial hypertension it is one of the few therapeutic interventions that can directly affect TBI outcome.
Arash Farahvar, Linda M. Gerber, Ya-Lin Chiu, Roger Härtl, Matteus Froelich, Nancy Carney and Jamshid Ghajar
The normalization of increased intracranial pressure (ICP) in patients with severe traumatic brain injury (TBI) is assumed to limit secondary brain injury and improve outcome. Despite evidence-based recommendations for monitoring and treatment of elevated ICP, there are few studies that show an association between response to ICP-directed therapeutic regimens and adjusted mortality rate. This study utilizes a large prospective database to examine the effect of response to ICP-lowering therapy on risk of death within the first 2 weeks of injury in patients who sustained TBI and are older than 16 years.
The current study is based on 1426 patients with severe TBI (Glasgow Coma Scale [GCS] score < 9) of whom 388 were treated for elevated ICP (> 25 mm Hg) between 2000 and 2008 at 22 trauma centers enrolled in a New York State quality improvement program. This prospectively collected database also contains information including age, admission GCS score, pupillary status, CT scanning parameters, and hypotension, which are all known early prognostic indicators of death. Treatment of elevated ICP consisted of administration of mannitol, hypertonic saline, barbiturates, and/or drainage of CSF or decompressive craniectomy. The factors predicting ICP response to treatment and predicting death at 2 weeks were evaluated using logistic regression analyses.
Increasing age and fewer hours of elevated ICP on Day 1 were found to be significant predictors (p = 0.001 and 0.0003, respectively) of a positive response to treatment. Response to ICP-lowering therapy (p = 0.03), younger age (p < 0.0001), fewer hours of elevated ICP (p < 0.0001), and absence of arterial hypotension on Day 1 (p = 0.001) significantly predicted reduced risk of death.
Patients who responded to ICP-lowering treatment had a 64% lower risk of death at 2 weeks than those who did not respond after adjusting for factors that independently predict risk of death.
Arash Farahvar, Linda M. Gerber, Ya-Lin Chiu, Roger Härtl, Mateus Froelich, Nancy Carney and Jamshid Ghajar
Arash Farahvar, Linda M. Gerber, Ya-Lin Chiu, Nancy Carney, Roger Härtl and Jamshid Ghajar
Evidence-based guidelines recommend intracranial pressure (ICP) monitoring for patients with severe traumatic brain injury (TBI), but there is limited evidence that monitoring and treating intracranial hypertension reduces mortality. This study uses a large, prospectively collected database to examine the effect on 2-week mortality of ICP reduction therapies administered to patients with severe TBI treated either with or without an ICP monitor.
From a population of 2134 patients with severe TBI (Glasgow Coma Scale [GCS] Score <9), 1446 patients were treated with ICP-lowering therapies. Of those, 1202 had an ICP monitor inserted and 244 were treated without monitoring. Patients were admitted to one of 20 Level I and two Level II trauma centers, part of a New York State quality improvement program administered by the Brain Trauma Foundation between 2000 and 2009. This database also contains information on known independent early prognostic indicators of mortality, including age, admission GCS score, pupillary status, CT scanning findings, and hypotension.
Age, initial GCS score, hypotension, and CT scan findings were associated with 2-week mortality. In addition, patients of all ages treated with an ICP monitor in place had lower mortality at 2 weeks (p = 0.02) than those treated without an ICP monitor, after adjusting for parameters that independently affect mortality.
In patients with severe TBI treated for intracranial hypertension, the use of an ICP monitor is associated with significantly lower mortality when compared with patients treated without an ICP monitor. Based on these findings, the authors conclude that ICP-directed therapy in patients with severe TBI should be guided by ICP monitoring.
Halinder S. Mangat, Ya-Lin Chiu, Linda M. Gerber, Marjan Alimi, Jamshid Ghajar and Roger Härtl
Increased intracranial pressure (ICP) in patients with traumatic brain injury (TBI) is associated with a higher mortality rate and poor outcome. Mannitol and hypertonic saline (HTS) have both been used to treat high ICP, but it is unclear which one is more effective. Here, the authors compare the effect of mannitol versus HTS on lowering the cumulative and daily ICP burdens after severe TBI.
The Brain Trauma Foundation TBI-trac New York State database was used for this retrospective study. Patients with severe TBI and intracranial hypertension who received only 1 type of hyperosmotic agent, mannitol or HTS, were included. Patients in the 2 groups were individually matched for Glasgow Coma Scale score (GCS), pupillary reactivity, craniotomy, occurrence of hypotension on Day 1, and the day of ICP monitor insertion. Patients with missing or erroneous data were excluded. Cumulative and daily ICP burdens were used as primary outcome measures. The cumulative ICP burden was defined as the total number of days with an ICP of > 25 mm Hg, expressed as a percentage of the total number of days of ICP monitoring. The daily ICP burden was calculated as the mean daily duration of an ICP of > 25 mm Hg, expressed as the number of hours per day. The numbers of intensive care unit (ICU) days, numbers of days with ICP monitoring, and 2-week mortality rates were also compared between the groups. A 2-sample t-test or chi-square test was used to compare independent samples. The Wilcoxon signed-rank or Cochran-Mantel-Haenszel test was used for comparing matched samples.
A total of 35 patients who received only HTS and 477 who received only mannitol after severe TBI were identified. Eight patients in the HTS group were excluded because of erroneous or missing data, and 2 other patients did not have matches in the mannitol group. The remaining 25 patients were matched 1:1. Twenty-four patients received 3% HTS, and 1 received 23.4% HTS as bolus therapy. All 25 patients in the mannitol group received 20% mannitol. The mean cumulative ICP burden (15.52% [HTS] vs 36.5% [mannitol]; p = 0.003) and the mean (± SD) daily ICP burden (0.3 ± 0.6 hours/day [HTS] vs 1.3 ± 1.3 hours/day [mannitol]; p = 0.001) were significantly lower in the HTS group. The mean (± SD) number of ICU days was significantly lower in the HTS group than in the mannitol group (8.5 ± 2.1 vs 9.8 ± 0.6, respectively; p = 0.004), whereas there was no difference in the numbers of days of ICP monitoring (p = 0.09). There were no significant differences between the cumulative median doses of HTS and mannitol (p = 0.19). The 2-week mortality rate was lower in the HTS group, but the difference was not statistically significant (p = 0.56).
HTS given as bolus therapy was more effective than mannitol in lowering the cumulative and daily ICP burdens after severe TBI. Patients in the HTS group had significantly lower number of ICU days. The 2-week mortality rates were not statistically different between the 2 groups.