CNS ORAL PRESENTATIONS 333 Thoracoabdominal Crush Injury Causes Increased Intracranial Pressure Resulting in Traumatic Brain Injury Detectable With Eye Tracking Technology and Blood-Based Biomarkers Daniel J. Rafter, MD; Uzma Samadani, MD INTRODUCTION: Conventionally traumatic brain injuries (TBIs) have been associated with a clear trauma to the head. However, patients with elevated intrathoracic (ITP) and intra-abdominal pressures (IAP) as a result of crush injuries may potentially also have potentially undiag- nosed TBI due to elevated intracranial pressure (ICP). METHODS: We prospectively recruited 625 trauma subjects and healthy nontrauma controls in whom we analyzed serum samples and performed eyetracking to characterize and classify the nature of their brain injury, if any. Eight subjects were noted to have sustained crush injuries and were subcategorized as isolated thoracoabdominal, thora- coabdominal with blunt head trauma, isolated extremity, and extremity with blunt head trauma. The eye tracking metrics and biomarker concen- trations were then compared to nontrauma control and known TBI subjects. RESULTS: Serum biomarkers and eye tracking metrics in patients with significant isolated throacoabdominal crush injury more closely resembled those found in the CT-scan positive TBI population versus healthy controls. GFAP levels at the time of admission for an isolated thoracoabdominal crush subject and those with crush injury and blunt head trauma were elevated when compared to the control population [4549.6 ± 9951.0] vs [11.5 ± 8.9]. Eye tracking metrics, indicative of elevated ICP, were also found to be altered in both isolated thoracoab- dominal crush subjects. Patients with isolated extremity crush had levels of GFAP and eye tracking similar to healthy nontrauma controls. CONCLUSION: Thoracoabdominal but not extremity crush can lead to elevated ICP resulting in eye tracking and serum biomarker findings consistent with brain injury. Future work may elicit the intra- abdominal pressure and intrathoracic pressure elevation necessary to increase the ICP and produce these demonstrated ocular motility dysfunctions as well as explore the impact of other crush injuries on ICP. 334 Interfacility Neurosurgical Transfers: An Analysis of Nontraumatic Inpatient and Emergency Department Transfers With Implications for Improvements In Care Michael Safaee, MD; Ramin A. Morshed, MD; Jordan Spatz, PhD; Sujatha Sankaran, MD; Mitchel S. Berger, MD; Manish K. Aghi, MD, PhD INTRODUCTION: Interfacility neurosurgical transfers to tertiary care centers are driven by a number of variables including lack of onsite coverage, limited technology, insurance, and patient preference. We sought to assess the timing and necessity of surgery and compare transfers from Emergency Departments (ED) and inpatient units. METHODS: Nontraumatic adult neurosurgical transfers to a single tertiary care center were analyzed over 12 mo. RESULTS: A total of 504 transfer patients were accepted with a mean age 55 yr (range: 19-92) and 53% women. Points of origin were ED in 54% and inpatient hospital unit in 46% with mean distance traveled of 119 miles. Broad diagnosis categories included brain tumors (n = 142; 28%), vascular lesions or intracerebral hemorrhage (n = 143; 28%), spinal lesions (n = 126; 25%), hydrocephalus (n = 45; 9%), wound complications (n = 29; 6%), and others (n = 19; 4%). Inpatient transfers had higher rates surgical intervention (75% vs 57%; P < .001), although ED transfers had higher rates of urgent surgery (20% vs 8%; P < .001) and shorter mean time to surgery (3 vs 5 d; P < .001). Misdiagnosis rates were higher among ED referrals (11% vs 4%; P = .008). Patients under- going elective admission (n = 1986) or admission from our own ED (n = 248) had significantly shorter length of stay (P < .001) and ICU days (P < .001) compared to transfer patients, as well as significantly lower total cost (P < .001). CONCLUSION: In this cohort, 65% of patients required surgery, but rates were higher among inpatient referrals and misdiagnosis rates were higher among ED transfers. These data suggest that admitting nonurgent patients to local hospitals may improve diagnostic accuracy, more precisely identify patients in need of transfer, and reduce costs. Telemedicine and integration of electronic medical records may help guide referring facilities in the pursuit of additional workup and eliminate the need for unnecessary transfer and provide additional cost savings. 335 Predictors of Withdrawal of Care in Patients With Severe Traumatic Brain Injury: A Nationwide Analysis Theresa Williamson, MD; Jihad Abdelgadir, MD, MSc; Jordan Komisarow, MD; Peter A. Ubel, MD; Aladine A. Elsamadicy, BE; Beiyu Liu, PhD; C. Rory Goodwin, MD, PhD; Nandan Lad, MD, PhD INTRODUCTION: There is paucity of research addressing how health care decisions are made in cases of severe traumatic brain injury. This study aims to identify the demographic and clinical factors associated with withdrawal care in the setting of severe traumatic brain injury. METHODS: This is a retrospective study using the Trauma Quality Improvement Program database from 2013 to 2015. Patients with severe traumatic brain injury (GCS 3-8, AIS 2-5) were included. Univariate and multivariate analyses with adjusted P-values were performed for descriptive statistics. A logistic regression analysis was used to identify demographic and clinical factors associated with withdrawal of care. RESULTS: The analysis included 7869 (21%) patients who withdrew and 30 080 (79%) who did not. More than half of those withdrawn were at a University hospital. Patients undergoing withdrawal of care were older (57.6 ± 20.6 vs 42.9 ± 18.8 yr) and 69% were male, 82% were white, 43% were from the Southern United States and 31% had private insurance. Black or other races were less likely to undergo withdrawal of care as compared to white (odds ratio [OR] 0.7, 95% confidence interval [CI] 0.6-0.7 and 0.8, 95% CI 0.8-0.9, respectively). Injury severity score (ISS) was significantly different between those who underwent withdrawal and those who did not, 28.2 ± 12.3 vs 26.1 ± 12.1. The presence of epidural or subdural hematoma was also significantly different between the 2 groups (78% vs 72%). Those who did not have a craniotomy were less likely to undergo withdrawal and those who did not have a hematoma were less likely to undergo withdrawal (OR 0.7, 95% CI 0.7-0.8 and 0.8, 95% CI 0.7-0.9, respectively). The average ICU length of stay and ventilation days were shorter for patients who underwent withdrawal. CONCLUSION: Age, ISS, craniotomy, race (white), and type of insurance (Medicare) were each positive predictors for withdrawal of care. 134 | VOLUME 65 | NUMBER 1 | SEPTEMBER 2018 www.neurosurgery-online.com Downloaded from https://academic.oup.com/neurosurgery/article-abstract/65/CN_suppl_1/134/5074903 by guest on 01 June 2020