Isolated subdural hematomas in mild traumatic brain injury. Part 2: a preliminary clinical decision support tool for neurosurgical intervention.

OBJECTIVEA paucity of studies have examined neurosurgical interventions in the mild traumatic brain injury (mTBI) population with intracranial hemorrhage (ICH). Furthermore, it is not understood how the dimensions of an ICH relate to the risk of a neurosurgical intervention. These limitations contribute to a lack of treatment guidelines. Isolated subdural hematomas (iSDHs) are the most prevalent ICH in mTBI, carry the highest neurosurgical intervention rate, and account for an overwhelming majority of all neurosurgical interventions. Decision criteria in this population could benefit from understanding the risk of requiring neurosurgical intervention. The aim of this study was to quantify the risk of neurosurgical intervention based on the dimensions of an iSDH in the setting of mTBI.METHODSThis was a 3.5-year, retrospective observational cohort study at a Level I trauma center. All adult (≥ 18 years) trauma patients with mTBI and iSDH were included in the study. Maximum length and thickness (in mm) of acute SDHs, the presence of acute-on-chronic (AOC) SDH, mass effect, and other hemorrhage-related variables were double-data entered; discrepant results were adjudicated after a maximum of 4 reviews. Patients with coagulopathy, skull fractures, no acute hemorrhage, a non-SDH ICH, or who did not undergo imaging on admission were excluded. Tentorial SDHs were not measured. The primary outcome was neurosurgical intervention (craniotomy, burr holes, intracranial pressure monitor placement, shunt, ventriculostomy, or SDH evacuation). Multivariate stepwise logistic regression was used to identify significant covariates, to assess interactions, and to create the scoring system.RESULTSThere were a total of 176 patients included in our study: 28 patients did and 148 did not receive a neurosurgical intervention. There were no significant differences between neurosurgical intervention groups in 11 demographic and 22 comorbid variables. Patients with neurosurgical intervention had significantly longer and thicker SDHs than nonsurgical controls. Logistic regression identified thickness and AOC hemorrhage as being the most important variables in predicting neurosurgical intervention; SDH length was not. Risk of neurosurgical intervention was calculated based on the SDH thickness and presence of an AOC hemorrhage from a multivariable logistic regression model (area under the receiver operating characteristic curve 0.94, 95% CI 0.90-0.97; p < 0.001). With a decision point of 2.35% risk, we predicted neurosurgical intervention with 100% sensitivity, 100% negative predictive value, and 53% specificity.CONCLUSIONSThis is the first study to quantify the risk of neurosurgical intervention based on hemorrhage characteristics in patients with mTBI and iSDH. Once validated in a second population, these data can be used to inform the necessity of interhospital transfers and neurosurgical consultations.

Isolated subdural hematomas in mild traumatic brain injury. Part 1: the association between radiographic characteristics and neurosurgical intervention.

OBJECTIVEIsolated subdural hematomas (iSDHs) are one of the most common intracranial hemorrhage (ICH) types in the population with mild traumatic brain injury (mTBI; Glasgow Coma Scale score 13-15), account for 66%-75% of all neurosurgical procedures, and have one of the highest neurosurgical intervention rates. The objective of this study was to examine how quantitative hemorrhage characteristics of iSDHs in patients with mTBI at admission are associated with subsequent neurosurgical intervention.METHODSThis was a 3.5-year, retrospective observational cohort study at a Level I trauma center. All adult trauma patients with mTBI and iSDHs were included in the study. Maximum length and thickness (in mm) of acute SDHs, the presence of acute-on-chronic SDH, mass effect, and other hemorrhage-related variables were double-data entered; discrepant results were adjudicated after a maximum of 4 reviews. Patients with coagulopathy, skull fractures, no acute hemorrhage, a non-SDH ICH, or who did not undergo imaging on admission were excluded. The primary outcome was neurosurgical intervention (craniotomy, burr hole, catheter drainage of SDH, placement of intracranial pressure monitor, shunt, or ventriculostomy). Multivariate stepwise logistic regression was used to identify significant covariates and to assess interactions.RESULTSA total of 176 patients were included in our study: 28 patients did and 148 patients did not receive a neurosurgical intervention. Increasing head Abbreviated Injury Scale score was significantly associated with neurosurgical interventions. There was a strong correlation between the first 3 reviews on maximum hemorrhage length (R2 = 0.82) and maximum hemorrhage thickness (R2 = 0.80). The neurosurgical intervention group had a mean maximum SDH length and thickness that were 61 mm longer and 13 mm thicker than those of the nonneurosurgical intervention group (p < 0.001 for both). After adjusting for the presence of an acute-on-chronic hemorrhage, for every 1-mm increase in the thickness of an iSDH, the odds of a neurosurgical intervention increase by 32% (95% CI 1.16-1.50). There were no interventions for any SDH with a maximum thickness ≤ 5 mm on initial presenting scan.CONCLUSIONSThis is the first study to quantify the odds of a neurosurgical intervention based on hemorrhage characteristics in patients with an iSDH and mTBI. Once validated in a second population, these data can be used to better inform patients and families of the risk of future neurosurgical intervention, and to evaluate the necessity of interhospital transfers.

Epidemiology of Mild Traumatic Brain Injury with Intracranial Hemorrhage: Focusing Predictive Models for Neurosurgical Intervention.

OBJECTIVE: To outline differences in neurosurgical intervention (NI) rates between intracranial hemorrhage (ICH) types in mild traumatic brain injuries and help identify which ICH types are most likely to benefit from creation of predictive models for NI. METHODS: A multicenter retrospective study of adult patients spanning 3 years at 4 U.S. trauma centers was performed. Patients were included if they presented with mild traumatic brain injury (Glasgow Coma Scale score 13-15) with head CT scan positive for ICH. Patients were excluded for skull fractures, "unspecified hemorrhage," or coagulopathy. Primary outcome was NI. Stepwise multivariable logistic regression models were built to analyze the independent association between ICH variables and outcome measures. RESULTS: The study comprised 1876 patients. NI rate was 6.7%. There was a significant difference in rate of NI by ICH type. Subdural hematomas had the highest rate of NI (15.5%) and accounted for 78% of all NIs. Isolated subarachnoid hemorrhages had the lowest, nonzero, NI rate (0.19%). Logistic regression models identified ICH type as the most influential independent variable when examining NI. A model predicting NI for isolated subarachnoid hemorrhages would require 26,928 patients, but a model predicting NI for isolated subdural hematomas would require only 328 patients. CONCLUSIONS: This study highlighted disparate NI rates among ICH types in patients with mild traumatic brain injury and identified mild, isolated subdural hematomas as most appropriate for construction of predictive NI models. Increased health care efficiency will be driven by accurate understanding of risk, which can come only from accurate predictive models.

Aggressive operative neurosurgical management in patients with extra-axial mass lesion and Glasgow Coma Scale of 3 is associated with survival benefit: A propensity matched analysis.

INTRODUCTION: Prognosis in patients with traumatic brain injury (TBI) and Glasgow Coma Scale (GCS) score of 3 is poor, raising concern regarding the utility of aggressive operative neurosurgical management. Our purpose was to describe outcomes in a propensity matched population with TBI and GCS3 treated with operative neurosurgical procedures of craniotomy or craniectomy (CRANI). METHODS: We conducted a five-year, multicenter retrospective cohort study of patients with an ED GCS 3 and a positive head CT identified by ICD-9CM diagnosis codes. Two populations were examined: (1) patients with extra-axial mass lesion (subdural or epidural haematoma), (2) patients without mass lesion (subarachnoid and intraparenchymal haemorrhage including contusion, other intracerebral haemorrhage or intracranial injury including diffuse axonal injury). In patients with extra-axial mass lesion, propensity score techniques were used to match patients 1:1 by CRANI, and the following outcomes were analysed with conditional logistic regression: survival, favourable hospital disposition to home or rehabilitation, and development of complications. RESULTS: There were 541 patients with TBI and GCS3; 19% had a CRANI, 83% were initiated within 4h. In those with mass lesion, 27% (91/338) had a CRANI; after matching, a significant survival benefit was observed with CRANI vs. without CRANI (65% vs. 34% survival, OR: 3.9 (1.6-10.5) p<0.001). There was borderline increased odds of favourable disposition (43% vs. 26%, OR: 2.4 (0.99-6.3, p=0.052) with CRANI vs. without CRANI, and no difference in developing a complication (58% vs. 48%, OR: 1.5 (0.7-3.4), p=0.30). CONCLUSIONS: Survival was achieved in 65% of patients that underwent surgical intervention for subdural and epidural haematoma, despite a presenting GCS of 3. These results demonstrate prompt operative neurosurgical management of mass lesion is warranted for selected patients with a GCS of 3, contributing to a significant 4-fold survival benefit. In the absence of mass lesion the effect of immediate neurosurgery on outcomes is inconclusive.

The effect of age on Glasgow Coma Scale score in patients with traumatic brain injury.

IMPORTANCE: The Glasgow Coma Scale (GCS) is used frequently to define the extent of neurologic injury in patients with a traumatic brain injury (TBI). Whether age affects the predictive ability of the GCS for severity of TBI (determined by the Abbreviated Injury Scale [AIS] score) remains unknown. OBJECTIVE: To investigate the effect of age on the association between the GCS and anatomic TBI severity. DESIGN, SETTING, AND PARTICIPANTS: We examined all patients with a TBI, defined by diagnostic codes 850 to 854 from the International Classification of Diseases, Ninth Revision, Clinical Modification, who were admitted to 2 level I trauma centers from January 1, 2008, through December 31, 2012. EXPOSURES: We compared elderly (≥65 years) and younger (18-64 years) adults with TBI. MAIN OUTCOMES AND MEASURES: We examined differences by age in GCS category (defined by emergency department GCS as severe [3-8], moderate [9-12], or mild [13-15]) at each level of TBI severity (head AIS score, 1 [minor] to 5 [critical]). Cochran-Armitage χ² trend tests and stepwise multivariate linear and logistic regression models were used. RESULTS: During the study period, 6710 patients had a TBI (aged <65 years, 73.17%). Significant differences in GCS category by age occurred at each AIS score (P ≤ .01 for all). In particular, among patients with an AIS score of 5, most of the elderly patients (56.33%) had a mild neurologic deficit (GCS score, 13-15), whereas most of the younger patients (63.28%) had a severe neurologic deficit (GCS score, 3-8). After adjustment, the younger adults had increased odds of presenting with a severe neurologic deficit (GCS score, 3-8) at each of the following AIS scores: 1, 4.2 (95% CI, 1.0-17.6; P = .05); 2, 2.0 (1.0-3.7; P = .04); 3, 2.0 (1.2-3.5; P = .01); 4, 4.6 (2.8-7.5; P < .001); and 5, 3.1 (2.1-4.6; P < .001). The interaction between age and GCS for anatomic TBI severity remained significant after adjustment (estimate, -0.11; P = .005). CONCLUSIONS AND RELEVANCE: Age affects the relationship between the GCS score and anatomic TBI severity. Elderly TBI patients have better GCS scores than younger TBI patients with similar TBI severity. These findings have implications for TBI outcomes research and for protocols and research selection criteria that use the GCS.

Should the management of isolated traumatic subarachnoid hemorrhage differ from concussion in the setting of mild traumatic brain injury?

BACKGROUND: In the setting of mild traumatic brain injury (TBI), the clinical significance of a traumatic subarachnoid hemorrhage (tSAH) has not been sufficiently studied. We examined the impact of an isolated tSAH on patient outcomes in the mild TBI population. METHODS: We retrospectively identified all mild TBI patients (Glasgow Coma Scale score ≥13) who presented to a Level I trauma center over a 10-year period. We compared isolated tSAH patients with isolated concussion patients. χ(2) and logistic regression analyses were used to compare intensive care unit (ICU) admission, ICU length of stay (LOS), hospital LOS, progression of tSAH, in-hospital mortality, and disposition to rehabilitation. RESULTS: There were 1,144 concussion and 117 tSAH patients included in our study. After adjustment, tSAH patients had increased odds of admission to the ICU (odds ratio, [OR] = 8.87; p < 0.0001), yet their ICU LOS was significantly shorter (OR = 0.29; p = 0.01). The overall hospital LOS and mortality rate were not significantly different between the TBI groups. When stratified by age, only the 40-year to 69-year-old tSAH patients had significantly increased adjusted odds of disposition to rehabilitation compared with concussion patients, independent of ICU admission (OR = 7.96; p = 0.004). None of the patients required any neurosurgical interventions. CONCLUSIONS: We encourage healthcare facilities to consider revising or creating ICU admission criteria for the mild TBI population to help optimize the utilization of their ICUs. We believe clinicians should place more emphasis on variables such as age, comorbidities, and neurologic condition rather than the presence of a small volume of blood in the subarachnoid space when admitting mild isolated TBI patients to the ICU.

Interrupted pharmocologic thromboprophylaxis increases venous thromboembolism in traumatic brain injury.

BACKGROUND: Pharmacologic thromboprophylaxis (PTP) is frequently withheld, begun late, or interrupted in patients with traumatic brain injury (TBI). The purpose of this study was to analyze whether late or interrupted PTP increases the risk of venous thromboembolism (VTE) after TBI. METHODS: We retrospectively studied patients with blunt TBI and stable head computed tomography (CT) scans who were admitted to two Level I trauma centers. PTP use was analyzed as an independent risk factor for VTE using separate logistic regression models for each definition of PTP use: (1) administration of PTP; (2) timing of PTP (early [<72 hours] vs. late [≥72 hours]); and (3) continuous versus interrupted use of PTP. RESULTS: Four hundred eighty patients with TBI were identified. VTE occurred in 15 patients (3.13%). VTE developed in six patients despite early PTP (5.56%), four patients with late PTP (2.72%), and five with no PTP (2.22%). Neither administration of PTP nor timing of PTP was independent predictor of developing a VTE (PTP vs. none: odds ratio [OR]=0.36, p=0.18; early PTP vs. late PTP: OR=2.00, p=0.41). PTP was administered continuously in 188 patients (73.7%). Patients with interrupted PTP had a significant increased odds of developing VTE compared with patients with continuous PTP (OR=7.07, p=0.04). Walking before discharge significantly decreased the odds of developing a VTE (OR=0.19, p=0.02). CONCLUSIONS: Interrupted administration of PTP in patients with TBI is associated with significantly increased risk of VTE. These findings underscore the importance of continuous PTP administration, and every effort should be made to avoid interruption if possible.

Plasma oxidation-reduction potential and protein oxidation in traumatic brain injury.

The amount of oxidative stress in patients with an isolated traumatic brain injury (ITBI) can be estimated by measuring several biochemical parameters, such as total antioxidants, lipid peroxidation, protein oxidation, and others. Unfortunately, measuring these parameters is time-consuming, impractical in a clinical setting, and may miss important factors contributing to the overall redox balance. Here we suggest that the overall oxidative status in ITBI patients can be assessed by measuring plasma oxidation-reduction potential (ORP). Daily whole blood samples were obtained from severe ITBI patients (abbreviated injury score [AIS] >or=3, n = 32), and demographically similar non-head injury traumatized patients (n = 26) until discharge. Whole blood was also collected from patients with minor to moderate ITBI (AIS

Helmets for skiers and snowboarders: an injury prevention program.

The authors' Level I trauma center has advocated the use of ski helmets for several years and in 1998, undertook a social-marketing campaign and a helmet loaner program to increase helmet use among skiers and snowboarders. The loaner program's effect on helmet acceptance was measured by comparing helmet acceptance in participating rental stores with acceptance in nonparticipating stores during 3 years. For the 1998-1999 season, 13.8% of renters in the participating stores accepted a helmet compared to 1.38% in the nonparticipating stores (p < .01); for 2000-2001, 33.5% to 3.93% (p < .01); and for 2001-2002, 30.3% to 4.48% (p < .01). The authors believe that efforts to increase helmet use--by increasing education and public awareness and decreasing barriers, such as through helmet loaner programs or routinely including helmets in rental packages--have significant potential to decrease the incidence and severity of brain injuries from skiing and/or snowboarding accidents in Colorado.

An analysis of head injuries among skiers and snowboarders.

BACKGROUND: Head injury is the leading cause of death and critical injury in skiing and snowboarding accidents. METHODS: Data relating to head injuries occurring on the ski slopes were collected from the trauma registry of a Level I trauma center located near a number of ski resorts. RESULTS: From 1982 to 1998, 350 skiers and snowboarders with head injuries were admitted to our Level I trauma center. Most of the injuries were mild, with Glasgow Coma Scale (GCS) scores of 13 to 15 in 81% and simple concussion in 69%. However, 14% of patients had severe brain injuries, with GCS scores of 3 to 8, and the overall mortality rate was 4%. Collision with a tree or other stationary object (skier-tree) was the mechanism of injury in 47% of patients; simple falls in 37%; collision with another skier (skier-skier) in 13%; and major falls in 3%. Skier-tree collision and major falls resulted in a higher percentage of severe injuries, with GCS scores of 3 to 8 in 24% and 20%, respectively, and mean Injury Severity Scores of 14 and 17, respectively. Mortality from skier-tree collision was 7.2%, compared with 1.6% in simple falls and no deaths from skier-skier collision or major falls. The risk of sustaining a head injury was 2.23 times greater for male subjects compared with female subjects, 2.81 times higher for skiers/boarders < or = 35 years of age compared with those > 35 years, and 3.04 times higher for snowboarders compared with skiers. CONCLUSION: Skier-tree collision was the most common mechanism for head injuries in patients admitted to our Level I trauma center, and resulted in the most severe injuries and the highest mortality rate. Because most traumatic brain injuries treated at our facility resulted from a direct impact mechanism, we believe that the use of helmets can reduce the incidence and severity of head injuries occurring on the ski slopes.