Correspondence / American Journal of Emergency Medicine 35 (2017) 1759–1783 1777

Table 1

Canadian head CT scan rule (Stiell et al. [7]). Risk criteria for clinically important MTBI

Table 2

CT results by provider before and after BPA intervention period.

Pr N

and limitations in the data due to the collection of non-trauma events that we are not able to exclude from the pre-intervention period. Prior studies have supported the use of BPAs as an effective means of decreas- ing variation in clinical practice [7,8] while providing evidence-based Clinical decision support at the point of care. However, future studies should examine whether the use of electronic BPAs are as effective in supporting clinicians in clinical decision-making.

Study authorship

SH conceived the study. TS, SH designed the trial and prepared the study proposal. SH, TS supervised the conduct of the trial and data col- lection. SH, TS, CH, RW, RN, NM undertook recruitment of subjects, DS, TS, SH, RW, RN managed the data, including quality control. DS, TS, SH provided statistical advice on study design, analyzed the data, and interpreted the results. DS, SH, TS, CH drafted the manuscript, and each author contributed substantially to its revision. All authors take re- sponsibility for the paper as a whole.

Donald Szlosek, MPH

University of Southern Maine, Muskie School of Public Service, Portland, ME

04102, United States E-mail address: [email protected]

Samir A. Haydar, DO, MPH

Maine Medical Center, Department of Emergency Medicine, 22 Bramhall

Street, Portland, ME 04102, United States E-mail address: [email protected]

Rachel J. Williams, MD

Wake Forest University, Medical Center Boulevard, Winston-Salem, NC

27157, United States E-mail address: [email protected]

Ryan C. Jackson, MD

York Hospital, 15 Hospital Drive, York, ME 03909, United States

E-mail address: [email protected]

Christine L. Hein, MD Nathan Mick, MD

Tania D. Strout, PhD, RN, MS* Maine Medical Center, Department of Emergency Medicine, Tufts University School of Medicine, 22 Bramhall Street, Portland, ME 04102,

http://dx.doi.org/10.1016/j.ajem.2017.05.023

References

1. Mannix R, O’Brien MJ, Meehan 3rd WP. The epidemiology of outpatient visits for Minor head injury: 2005 to 2009. Neurosurgery 2013;73:129-34 [discussion 134].
2. Faul M, Xu L, Wald MM, Coronado VG. Traumatic brain injury in the United States: emergency department visits, hospitalizations and deaths 2002-2006. National Cen- ter for Injury Prevention and Control; 2010.
3. Stiell IG, Wells GA, Vandemheen K, Clement C, Lesiuk H, Laupacis A, et al. The Cana- dian CT Head rule for patients with minor head injury. Lancet 2001;357:1391-6.
4. Holmes JF, Hendey GW, Oman JA, Norton VC, Lazarenko G, Ross SE, et al. Epidemiol-

   ogy of blunt head injury victims undergoing ED cranial computed tomographic scan- ning. Am J Emerg Med 2006;24:167-73.

   Haydel MJ, Preston CA, Mills TJ, Luber S, Blaudeau E, DeBlieux PMC. Indications for

   computed tomography in patients with minor head injury. N Engl J Med 2000;343: 100-5.

   Stiell IG, Clement CM, Rowe BH, Schull MJ, Brison R, Cass D, et al. Comparison of the Canadian CT head rule and the New Orleans criteria in patients with minor head in- jury. JAMA 2005;294:1511-8.

5. Stiell IG, Wells GA, Vandemheen K, Laupacis A, Brison R, Eisenhauer MA, et al. Varia- tion in ED use of computed tomography for patients with minor head injury. Ann Emerg Med 1997;30:14-22.
6. Papa L, Stiell IG, Clement CM, Pawlowicz A, Wolfram A, Braga C, et al. Performance of the Canadian CT head rule and the New Orleans criteria for predicting any traumatic Intracranial injury on computed tomography in a United States level I trauma center. Acad Emerg Med 2012;19:2-10.

   Referrals for CT scans in mild TBI patients can be aided by the use of a brain electrical

   

   activity biomarker?

   Heightened awareness of the potential short and long-term conse- quences of mild traumatic brain injury (mTBI or concussion) has result- ed in an increase in Emergency Department (ED) visits for Traumatic head injury, even as the volume of overall ED visits has remained stable over the same period of time [1]. While the vast majority (~ 95%) of these head injured patients are mild, N 80% receive CT scans of which

   ~ 91% are found to be negative [2]. The rising number of negative CT findings, cost, radiation exposure, and ED resource utilization, has led to an increased need for reliable predictors of intracranial injury in the mild head injured population [3].

   Several decision rules (such as New Orleans Criteria and Canadian CT Head Trauma Rule) have demonstrated high sensitivity but have ex- tremely poor specificity [4-7] and when strictly applied, are not

   United States

   *Corresponding author.

   E-mail addresses: [email protected] (C.L. Hein)

   [email protected] (N. Mick) [email protected] (T.D. Strout)

   ? Sources of support: The parent study from which this study cohort was derived was funded in part by a research contract from the U.S Army, contract #W81XWH-14-C- 1405. Disclaimer: The views, opinions and/or findings contained in this report are those of the author(s) and should not be construed as an official Department of the Army position, policy or decision unless so designated by other documentation.

   1778 Correspondence / American Journal of Emergency Medicine 35 (2017) 1759–1783

   

   Fig. 1. Population disposition for decision pathway 1. Use of the clinical site practice pathway results in 564 patients referred for CT scanning (age mean 45.2, SD 18.9; 64.4% male). Of these, 156 patients were “true positives” (referred for CT scanning who were later adjudicated to be CT positive) and 408 were “false positives” (referred for CT scanning who were later adjudicated to be CT negative).

   

   Fig. 2. Population disposition for decision pathway 2. Use of the BrainScope One decision pathway would have resulted in 416 patients referred for CT scanning (age mean 50.2, SD 18.4; 65.4% male). Of these, 144 patients were “true positives” and 272 were “false positives”.

   applicable to significant portions of the population [8,9]. A developing literature attests to the utility of quantitative EEG based biomarkers for prediction of the likelihood of intracranial injuries visible on CT scan in the mild head injured population [10,11].

   This retrospective analysis is based on data from an independent val- idation trial¹ using the BrainScope(R) One² EEG-based structural injury algorithm in mildly presenting head injured patients (N = 719, age 18-85, GCS 13-15, evaluated within 3 days of injury). All subjects pro- vided informed consent. The BrainScope One assessment is based on 5-10 min of eyes closed EEG acquired from frontal and frontotemporal regions and selected clinical risk factors [12,13]. In the validation trial, Hanley and colleagues (2017) reported a binary classification sensitivity of 92% for any finding visible on CT scans, with specificity 2-6 times higher than obtained using the decision rules, NPV of 98%, and an area under the curve of 0.82 [14]. The performance of two decision path- ways, measured against an independently adjudicated positive or nega- tive CT finding, is compared in this analysis. The first pathway, representing Clinical Site Practice, follows the clinical judgement of the ED physician at the clinical site for referring patients for a CT scan

   ¹ B-Ahead III validation trial (ClinicalTrials.gov Identifier: NCT02367300) conducted at 11 US Emergency Departments.

   ² BrainScope(R) One device is registered as the Ahead(R) 300 (FDA 510(k) clearance, K161068).

   according to standard of care. The second follows the use of BrainScope One structural injury determination as an input to CT scan referral.

   Clinical site practice (Fig. 1) resulted in the referral of 78.4% of the population (564 patients) for a CT scan. In this group, 156 patients were later adjudicated to be CT positive, i.e., “true positives” and 408 pa- tients were later adjudicated to be CT negative, i.e., “false positives”. The proportion of false positives within the patients referred for CT scanning, i.e., the “false discovery rate”, in this pathway was 72% (=408/564).

   On the other hand, use of the BrainScope One assessment (Fig. 2) as input for CT referral would have resulted in a positive structural injury classification for 57.9% of the population (416 patients). This is a 26% reduction (=(564 – 416) / 564) compared to clinical site practice. In this group, 144 were “true positives” and 272 were “false positives” representing a 33.3% reduction (=(408 – 272) / 408) in the number of false positives. In addition, a significantly lower false discovery rate of 65% (= 272/416) was achieved compared to the clinical site practice (one-sided comparison, p = 0.01). The BrainScope One device can con- tribute to reduced overscanning without compromising the overall clini- cal performance as evidenced by the reduction in the number of false positives by 33%.

   The reduced overscanning and false discovery rates do not take into consideration the existence of a small number of false negatives (7.7%). The corresponding false negative number for the clinical site practice pathway cannot be estimated because for these cases, the CT was not or- dered. However, it is important to note that none of the false negatives required neurosurgery or returned to the hospital for exacerbation of

   Correspondence / American Journal of Emergency Medicine 35 (2017) 1759–1783 1779

   symptoms or additional neuroimaging, all had GCS = 15, and none had any focal neurological signs.

   This retrospective analysis demonstrates that the rapid assessment obtained at the point of care using this easy to use, non-invasive, hand- held BrainScope One technology has the potential to significantly con- tribute to decreasing unnecessary CT scans in the mild head injury population. While not intended to replace a CT scan, the addition of such quantitative, objective information could significantly impact confi- dence of scanning decisions by the evaluating physician, unnecessary ra- diation exposure for the patient, as well as cost to the health care system.

   Disclosure

   Dr. Michelson is on the Medical Advisory Board of BrainScope. Dr. Ghosh Dastidar is an employee of BrainScope. All other authors have nothing to disclose.

   Acknowledgements

   The authors wish to acknowledge the contributions of all Research staff at the Clinical sites for their efforts toward conducting this study.

   J. Stephen Huff

   University of Virginia Health System, Charlottesville, VA, United States

   Rosanne Naunheim

   Washington University Barnes Jewish Medical Center, St. Louis, MO,

   United States

   Samanwoy Ghosh Dastidar

   BrainScope Company, Inc., Bethesda, MD, United States Corresponding author at: BrainScope Company, Inc., 4350 East-West Highway, Suite 1050, Bethesda, MD 20814, United States.

   E-mail address: [email protected]

   Jeffrey Bazarian

   University of Rochester Medical Center, Rochester, NY, United States

   Edward A.Michelson

   Department of Emergency Medicine, Texas Tech Univ. Health Sciences

   Center, El Paso, TX, United States

   http://dx.doi.org/10.1016/j.ajem.2017.05.027

   References

   Marin JR, Weaver MD, Yeaton DM, Mannix RC. Trends in visits for traumatic brain injury to emergency departments in the United States. JAMA 2014;311(5/14): 1917-9.

7. Korley F, Kelen G, Jones C, Diaz-Arrastia R. Emergency department evaluation of traumatic brain injury in the US, 2009-2010. J Head Trauma Rehabil 2016;31(6): 379-87.
8. ACEP. ACEP announces lists of tests as part of choosing wisely campaigns. https:// www.acep.org/Clinical–Practice-Management/ACEP-Announces-List-of-Tests-As- Part-of-Choosing-Wisely-Campaign/; 2013. [accessed 24.04.17].
9. Smits M, Dippel DWJ, de Haan GG, Dekker HM, Vos PE, Kool DR, et al. External val- idation of the Canadian CT head rule and the New Orleans criteria for CT scanning in patients with minor head injury. JAMA 2005;294(12):1519-25.
10. Stiell IG, Wells GA, Vandemheen K, Clement C, Lesiuk H, Laupacis A, et al. The Cana- dian CT head rule for patients with minor head injury. Lancet 2001;357(9266): 1391-6.
11. Haydel MJ, Preston CA, Mills TJ, Luber S, Blaudeau E, DeBlieux PMC. Indications for computed tomography in patients with minor head injury. NEJM 2000;343(2):100-5.
12. Papa L, Stiell IG, Clement CM, Pawlowicz A, Wolfram A, Braga C, et al. Performance of

    the Canadian CT head rule and the New Orleans criteria for predicting any traumatic intracranial injury on computed tomography in a United States level I trauma center. Acad Emerg Med 2012;19(1):2-10.

    Stiell IG, Clement CM, Rowe BH, Schull MJ, Brison R, Cass D, et al. Comparison of the Canadian CT head rule and the New Orleans criteria in patients with minor head injury. JAMA 2005;294(12):1511-8.

13. Smits M, Dippel DW, Steyerberg EW, de Haan GG, Dekker HM, Vos PE, et al. Predicting intracranial traumatic findings on computed tomography in patients with minor head injury: the CHIP prediction rule. Ann Intern Med 2007;146(6):397-405.
14. Hanley D, Chabot R, Mould WA, Morgan T, Naunheim R, Sheth K, et al. Use of brain electrical activity for the identification of hematomas in mild traumatic brain injury. J Neurotrauma 2013;30(24):2051-6.
15. Prichep LS, Naunheim R, Bazarian J, Mould WA, Hanley D. Identification of hemato- mas in mild traumatic brain injury using an index of quantitative brain electrical activity. J Neurotrauma 2015;32(1):17-22.
16. Prichep LS, Jacquin A, Filipenko J, Ghosh Dastidar S, Zabele S, Vodencarevic A, et al. Classification of traumatic brain injury severity using informed data reduction in a series of binary classification algorithms. IEEE Trans Neural Syst Rehabil Eng 2012; 20:806-22.
17. Prichep LS, Ghosh Dastidar S, Jacquin A, Koppes W, Miller J, Radman T, et al. Classi- fication algorithms for the identification of structural injury in TBI using brain elec- trical activity. Comput Biol Med 2014;53:125-33.
18. Hanley D, Prichep L, Bazarian J, Huff J, Naunheim R, Garrett J, et al. Emergency de- partment triage of traumatic head injury aided by using a brain electrical activity marker: a multisite prospective observational validation trial. Acad Emerg Med 2017. http://dx.doi.org/10.1111/acem.13175 (Online Ahead of Print).

    Acute Liver failure and emergency consideration for liver transplant

    

    Acute liver failure (ALF) is a Serious disease characterized by a life threatening, rapidly progressing liver deterioration, following a major liver injury [1]. While the exact definition of ALF has varied, most liter- ature defines ALF as the rapid deterioration of liver function in a patient who has no preexisting cirrhosis, with features of both (i) impaired syn- thetic function, defined as an INR >= 1.5, and (ii) impaired neurological function with any degree of Hepatic encephalopathy [2,3]. Patients with ALF can also develop fatal clinical symptoms of cerebral edema, renal failure, metabolic disturbances, hemodynamic instability, and in- creased susceptibility to infection and sepsis [1]. ALF has numerous causes, including drug-induced, viral infection, metabolic disturbances, excessive alcohol consumption, or pregnancy. In the United States, Acetaminophen toxicity is the most common cause of ALF, whereas worldwide, the most common cause is viral hepatitis [1]. Previously, survival rates for ALF were low–just four decades ago, survival rates were reportedly as low as 17%. Since then, improvements in detection, medical treatment, and, importantly, the introduction of liver transplan- tation as a treatment option have dramatically increased survival rates to around 80%, with some studies showing up to a 92% survival rate in patients post liver transplant [3,4]. Choosing the right candidates and appropriate time for transplantation is crucial in improving likelihood of survival, however such a decision is challenging because of the vari- ous factors that a physician must consider.

    There are multiple etiologies of ALF (Table 1), and deducing the rel-

    evant cause is essential given that the etiology of ALF will determine a patient’s treatment and predict prognosis. For example, ALF induced by acetaminophen, pregnancy, ischemia or hepatitis A, have trans- plant-free survival rates of N 50%, while ALF caused by Wilson’s disease, Budd-Chiari, or idiosyncratic drug reactions have transplant-free surviv- al rates of b 25% [5]. Additionally, patients with poor prognosis in ALF may fail medical management and require emergent liver transplantation.

    Although having a thorough history and physical exam may help identify the cause of ALF, patients with severe impairment due to hepat- ic encephalopathy may provide limited or unavailable histories and nonspecific Physical exam findings. In such instances, laboratory find- ings can help identify patients with ALF [6]. Typically, patients with