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

External Validation of a Tool to Identify Low-Risk Patients With Isolated Subdural Hematoma and Preserved Consciousness

STUDY OBJECTIVE

The SafeSDH Tool was derived to identify patients with isolated (no other type of intracranial hemorrhage) subdural hematoma who are at very low risk of neurologic deterioration, neurosurgical intervention, or death. Patients are low risk by the tool if they have none of the following: use of anticoagulant or nonaspirin antiplatelet agent, Glasgow Coma Score (GCS) <14, more than 1 discrete hematoma, hematoma thickness >5 mm, or midline shift. We attempted to externally validate the SafeSDH Tool.

METHODS

We performed a retrospective chart review of patients aged ≥16 with a GCS ≥13 and isolated subdural hematoma who presented to 1 of 6 academic and community hospitals from 2005 to 2018. The primary outcome, a composite of neurologic deterioration (seizure, altered mental status, or symptoms requiring repeat imaging), neurosurgical intervention, discharge on hospice, and death, was abstracted from discharge summaries. Hematoma thickness, number of hematomas, and midline shift were abstracted from head imaging reports. Anticoagulant use, antiplatelet use, and GCS were gathered from the admission record.

RESULTS

The validation data set included 753 patients with isolated subdural hematoma. Mortality during the index admission was 2.1%; 26% of patients underwent neurosurgical intervention. For the composite outcome, sensitivity was 99% (95% confidence interval [CI] 97 to 100), and specificity was 31% (95% CI 27 to 35). The tool identified 162 (21.5%) patients as low risk. Negative likelihood ratio was 0.03 (95% CI 0.01 to 0.11).

CONCLUSION

The SafeSDH Tool identified patients with isolated subdural hematoma who are at low risk for poor outcomes with high sensitivity. With prospective validation, these low-risk patients could be safe for management in less intensive settings.

Neuroworsening in the Emergency Department Is a Predictor of Traumatic Brain Injury Intervention and Outcome: A TRACK-TBI Pilot Study

INTRODUCTION

Neuroworsening may be a sign of progressive brain injury and is a factor for treatment of traumatic brain injury (TBI) in intensive care settings. The implications of neuroworsening for clinical management and long-term sequelae of TBI in the emergency department (ED) require characterization.

METHODS

Adult TBI subjects from the prospective Transforming Research and Clinical Knowledge in Traumatic Brain Injury Pilot Study with ED admission and disposition Glasgow Coma Scale (GCS) scores were extracted. All patients received head computed tomography (CT) scan <24 h post-injury. Neuroworsening was defined as a decline in motor GCS at ED disposition (vs. ED admission). Clinical and CT characteristics, neurosurgical intervention, in-hospital mortality, and 3- and 6-month Glasgow Outcome Scale-Extended (GOS-E) scores were compared by neuroworsening status. Multivariable regressions were performed for neurosurgical intervention and unfavorable outcome (GOS-E ≤ 3). Multivariable odds ratios (mOR) with [95% confidence intervals] were reported.

RESULTS

In 481 subjects, 91.1% had ED admission GCS 13-15 and 3.3% had neuroworsening. All neuroworsening subjects were admitted to intensive care unit (vs. non-neuroworsening: 26.2%) and were CT-positive for structural injury (vs. 45.4%). Neuroworsening was associated with subdural (75.0%/22.2%), subarachnoid (81.3%/31.2%), and intraventricular hemorrhage (18.8%/2.2%), contusion (68.8%/20.4%), midline shift (50.0%/2.6%), cisternal compression (56.3%/5.6%), and cerebral edema (68.8%/12.3%; all p < 0.001). Neuroworsening subjects had higher likelihoods of cranial surgery (56.3%/3.5%), intracranial pressure (ICP) monitoring (62.5%/2.6%), in-hospital mortality (37.5%/0.6%), and unfavorable 3- and 6-month outcome (58.3%/4.9%; 53.8%/6.2%; all p < 0.001). On multivariable analysis, neuroworsening predicted surgery (mOR = 4.65 [1.02-21.19]), ICP monitoring (mOR = 15.48 [2.92-81.85], and unfavorable 3- and 6-month outcome (mOR = 5.36 [1.13-25.36]; mOR = 5.68 [1.18-27.35]).

CONCLUSIONS

Neuroworsening in the ED is an early indicator of TBI severity, and a predictor of neurosurgical intervention and unfavorable outcome. Clinicians must be vigilant in detecting neuroworsening, as affected patients are at increased risk for poor outcomes and may benefit from immediate therapeutic interventions.

Characterizing Interhospital Variability in Neurosurgical Interventions for Patients with Mild Traumatic Brain Injury and Intracranial Hemorrhage

The objective of this study was to quantify nation-wide interhospital variation in neurosurgical intervention risk by intracranial hemorrhage (ICH) type in the setting of mild traumatic brain injury (mTBI). This was a retrospective cohort study of adult (≥18 years) trauma patients included in the National Trauma Data Bank from 2007 to 2019 with an emergency department Glasgow Coma Scale score 13-15, diagnosed ICH, no skull fracture. The primary outcome was neurosurgical intervention. Interhospital variation was assessed by examining the best linear unbiased predictors (BLUPs) obtained from mixed-effects logistic regression with random slopes and intercepts for hospitals and covariates for time and 14 demographic, injury, and hospital characteristics; one model per ICH type. Intercept BLUPs are estimates of how different each hospital is from the average hospital (after covariate adjustment). The study population included 49,220 (7%) neurosurgical interventions among 666,842 patients in 1060 hospitals. In 2019, after adjusting for patient case-mix and hospital characteristics, the percentage of hospitals with hemorrhage-specific neurosurgical intervention risk significantly different from the average hospital was as follows: isolated unspecified hemorrhage (0% of 995 hospitals); isolated contusion/laceration (0.54% of 929); isolated epidural hemorrhage (0.39% of 778); isolated subarachnoid hemorrhage (0.10% of 1002); multiple hemorrhages (2.49% of 963); and isolated subdural hemorrhage (16.25% of 1028). In the setting of mTBI, isolated subdural hemorrhages were the only ICH type to have considerable interhospital variability. Causes for this significant variation should be elucidated and might include changing hemorrhage characteristics and practice patterns over time.

Significant National Declines in Neurosurgical Intervention for Mild Traumatic Brain Injury with Intracranial Hemorrhage: A 13-Year Review of the National Trauma Data Bank

There have been large changes over the past several decades to patient demographics in those presenting with mild traumatic brain injury (mTBI) with intracranial hemorrhage (ICH; complicated mTBI) with the potential to affect the use of neurosurgical interventions. The objective of this study was to characterize long-term trends of neurosurgical interventions in patients with complicated mTBI using 13 years of the National Trauma Data Bank (NTDB). This was a retrospective cohort study of adult (≥18 years) trauma patients included in the NTDB from 2007 to 2019 who had an emergency department Glasgow Coma Scale score 13-15, an intracranial hemorrhage (ICH), and no skull fracture. Neurosurgical intervention time trends were quantified for each ICH type using mixed-effects logistic regression with random slopes and intercepts for hospitals, as well as covariates for time and 14 demographic, injury, and hospital characteristics. In total, 666,842 ICH patients across 1060 hospitals were included. The four most common hemorrhages were isolated subdural hemorrhage (36%), isolated subarachnoid hemorrhage (24%), multiple hemorrhage types (24%), and isolated unspecified hemorrhages (9%). Overall, 49,220 (7%) patients received a neurosurgical intervention. After adjustment, the odds of neurosurgical intervention significantly decreased every 10 years by the following odds ratios (odds ratio [95% confidence interval]): 0.85 [0.78, 0.93] for isolated subdural, 0.63 [0.51, 0.77] for isolated subarachnoid, 0.50 [0.41, 0.62] for isolated unspecified, and 0.79 [0.73, 0.86] for multiple hemorrhages. There were no significant temporal trends in neurosurgical intervention odds for isolated epidural hemorrhages (0.87 [0.68, 1.12]) or isolated contusions/lacerations (1.03 [0.75, 1.41]). In the setting of complicated mTBI, the four most common ICH types were associated with significant declines in the odds of neurosurgical intervention over the past decade. It remains unclear whether changing hemorrhage characteristics or practice patterns drove these trends.

A natural language processing algorithm to extract characteristics of subdural hematoma from head CT reports

PURPOSE

Subdural hematoma (SDH) is the most common form of traumatic intracranial hemorrhage, and radiographic characteristics of SDH are predictive of complications and patient outcomes. We created a natural language processing (NLP) algorithm to extract structured data from cranial computed tomography (CT) scan reports for patients with SDH.

METHODS

CT scan reports from patients with SDH were collected from a single center. All reports were based on cranial CT scan interpretations by board-certified attending radiologists. Reports were then coded by a pair of physicians for four variables: number of SDH, size of midline shift, thickness of largest SDH, and side of largest SDH. Inter-rater reliability was assessed. The annotated reports were divided into training (80%) and test (20%) datasets. Relevant information was extracted from text using a pattern-matching approach, due to the lack of a mention-level gold-standard corpus. Then, the NLP pipeline components were integrated using the Apache Unstructured Information Management Architecture. Output performance was measured as algorithm accuracy compared to the data coded by the two ED physicians.

RESULTS

A total of 643 scans were extracted. The NLP algorithm accuracy was high: 0.84 for side of largest SDH, 0.88 for thickness of largest SDH, and 0.92 for size of midline shift.

CONCLUSION

A NLP algorithm can structure key data from non-contrast head CT reports with high accuracy. The NLP is a potential tool to detect important radiographic findings from electronic health records, and, potentially, add decision support capabilities.

Importance of effusion of blood under the dura mater in forensic medicine: A STROBE - compliant retrospective study

Subdural hemorrhage is commonly associated with mechanical brain injury and has a correspondingly high mortality rate. Subdural hematomas may immediately provoke symptoms or may be initially asymptomatic, with further symptoms evolving rapidly and fatally.The data regarding forensic autopsy of victims were obtained from The State Forensic Medicine Service of Lithuania between the years 2013 and 2016. A retrospective study was performed including 110 patients, whose cause of death was subdural hemorrhage. 95% confidence intervals were calculated.It was calculated, that in cases of sudden death, after subdural hemorrhage was diagnosed, a higher concentration of ethyl alcohol in blood (mean 2.22 ± 1.3%) demanded a smaller amount of blood under the dura matter (mean 81.6 ± 60.5 g) in order for the patient to die. It was also noted that hospitalized patients with subdural hemorrhage had a smaller concentration of blood ethyl alcohol (mean 1.33 ± 1%) and a larger amount of blood under the dura (mean 135.6 ± 82.9 g).Due to the toxic effect of ethyl alcohol, even a small amount (81.6 ± 60.5 g) of blood under the dura matter can determine a sudden death.