Is repeat head CT necessary in patients with mild traumatic intracranial hemorrhage.

BACKGROUND: Patients with traumatic intracranial hemorrhage (TIH) frequently receive repeat head CT scans (RHCT) to assess for progression of TIH. The utility of this practice has been brought into question, with some studies suggesting that in the absence of progressive neurologic symptoms, the RHCT does not lead to clinical interventions. METHODS: This was a retrospective review of consecutive patients with CT-documented TIH and GCS ≥ 13 presenting to an academic emergency department from 2009 to 2013. Demographic, historical, and physical exam variables, number of CT scans during admission were collected with primary outcomes of: neurological decline, worsening findings on repeat CT scan, and the need for neurosurgical intervention. RESULTS: Of these 1126 patients with mild traumatic intracranial hemorrhage, 975 had RHCT. Of these, 54 (5.5% (4.2-7.2 95 CI) had neurological decline, 73 (7.5% 5.9-9.3 95 CI) had hemorrhage progression on repeat CT scan, and 58 (5.9% 4.5-7.6 95 CI) required neurosurgical intervention. Only 3 patients (0.3% 0.1-0.9% 95 CI) underwent neurosurgical intervention due to hemorrhage progression on repeat CT scan without neurological decline. In this scenario, the number of RHCT scans needed to be performed to identify this one patient is 305. CONCLUSIONS: RHCT after initial findings of TIH and GCS ≥ 13 leading to a change to operative management in the absence of neurologic progression is a rare event. A protocol that includes selective RHCT including larger subdural hematomas or patients with coagulopathy (vitamin K inhibitors and anti-platelet agents) may be a topic for further study.

Seizure frequency in patients with isolated subdural hematoma and preserved consciousness.

Background: Seizures are a complication of subdural hematoma (SDH), and there is substantial variability in the use of seizure prophylaxis for patients with SDH. However, the incidence of seizures in patients with SDH without severe neurotrauma is not clear. The objective of this study was to assess the frequency of and factors associated with seizures in patients with isolated SDH (iSDH) without severe neurotrauma. Methods: In this retrospective, observational study, we identified adults with Glasgow Coma Score (GCS) ≥13 and computed tomography (CT)-documented iSDH. The primary outcome was clinical seizure frequency. Seizure medication use was also assessed. Fisher's exact test and logistic regression were used to assess association. Results: Of 643 patients with iSDH, 14 (2.2%) had seizures during hospitalization. Of 630 patients (98%) not receiving seizure medication prior to SDH, 522 (82.9%) received levetiracetam. Of the patients who received a seizure medication, 12 (2.3%) had a seizure, while of the 121 patients who did not receive seizure medications, 2 (1.9%) had a seizure (p = .49). In multivariable regression, the only variable significantly associated with seizure was thickness of subdural hematoma (OR 1.16, p = .005). Conclusion: In patients with iSDH and preserved consciousness, in-hospital seizures were rare regardless of seizure medications use.

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.

Rapid Discharge After Interfacility Transfer for Mild Traumatic Intracranial Hemorrhage: Frequency and Associated Factors.

INTRODUCTION: Traumatic intracranial hemorrhage (TIH), brain injury with radiographic hemorrhage, is a common emergency department (ED) presentation, and encompasses a wide range of clinical syndromes. Patients with moderate and severe neurotrauma (Glasgow Coma Scale [GCS] < 13) with intracranial hemorrhage require care at a trauma center with neurosurgical capabilities. However, many patients with mild traumatic intracranial hemorrhage (mTIH), defined as radiographic bleeding and GCS ≥ 13, do not require operative intervention or intensive care unit monitoring, but are still routinely transferred to tertiary care centers. We hypothesized that a significant proportion of patients are managed non-operatively and are discharged within 24 hours of admission. METHODS: This was a retrospective, observational study of consecutive patients age ≥ 16 years, GCS ≥ 13 who were transferred to an urban, medical school-affiliated, 100,000 annual visit ED over a seven-year period with blunt isolated mTIH. The primary outcome was discharge within 24 hours of admission. We measured rates of neurosurgical intervention, computed tomography hemorrhage progression, and neurologic deterioration as well as other demographic and clinical variables. RESULTS: There were 1079 transferred patients with isolated mTIH. Of these, 92.4% were treated non-operatively and 35.8% were discharged within 24 hours of presentation to the tertiary ED. Patient characteristics associated with rapid discharge after transfer include a GCS of 15 (odds ratio [OR] 2.9, 95% confidence interval [CI], 1.9 - 4.4), subdural hematoma ≤ 6mm (OR 3.1, 95% CI, 2.2 - 4.5) or the presence of an isolated subarachnoid hemorrhage (OR 1.7, 95% CI, 1.3 - 2.4). Of patients with length of stay < 24 hours, 79.8% were discharged directly from the ED or ED observation unit. CONCLUSION: Patients transferred to tertiary care centers are frequently discharged after brief observation without intervention. Risk can be predicted by clinical and radiographic data. Further prospective research is required to determine a safe cohort of patients who could be managed at community sites.

Crystal structure of the membrane fusion protein CusB from Escherichia coli.

Gram-negative bacteria, such as Escherichia coli, frequently utilize tripartite efflux complexes belonging to the resistance-nodulation-division family to expel diverse toxic compounds from the cell. These systems contain a periplasmic membrane fusion protein (MFP) that is critical for substrate transport. We here present the x-ray structures of the CusB MFP from the copper/silver efflux system of E. coli. This is the first structure of any MFPs associated with heavy-metal efflux transporters. CusB bridges the inner-membrane efflux pump CusA and outer-membrane channel CusC to mediate resistance to Cu(+) and Ag(+) ions. Two distinct structures of the elongated molecules of CusB were found in the asymmetric unit of a single crystal, which suggests the flexible nature of this protein. Each protomer of CusB can be divided into four different domains, whereby the first three domains are mostly beta-strands and the last domain adopts an entirely helical architecture. Unlike other known structures of MFPs, the alpha-helical domain of CusB is folded into a three-helix bundle. This three-helix bundle presumably interacts with the periplasmic domain of CusC. The N- and C-termini of CusB form the first beta-strand domain, which is found to interact with the periplasmic domain of the CusA efflux pump. Atomic details of how this efflux protein binds Cu(+) and Ag(+) were revealed by the crystals of the CusB-Cu(I) and CusB-Ag(I) complexes. The structures indicate that CusB consists of multiple binding sites for these metal ions. These findings reveal novel structural features of an MFP in the resistance-nodulation-division efflux system and provide direct evidence that this protein specifically interacts with transported substrates.