OBJECTIVE:Chordoma and chondrosarcoma are rare malignant bone tumors of the spine and sacrum. While en bloc resection with wide or marginal margins (Enneking appropriate [EA]) is considered the standard of care, the role of radiation therapy (RT) in the management of these traditionally radioresistant tumors remains controversial. This retrospective study aimed to evaluate treatment strategies with a focus on overall survival (OS), disease-free survival (DFS), and local recurrence-free survival (LRFS) patterns and analyze variables associated with these outcomes. METHODS:A retrospective cohort study was conducted at Vancouver General Hospital including patients with chordoma or low-grade chondrosarcoma of the mobile spine or sacrum treated surgically between 2009 and 2023. Patients were categorized into 1 of 4 groups: 1) en bloc EA resection without RT, 2) en bloc Enneking inappropriate (EI) resection with RT, 3) en bloc EI resection without RT, and 4) planned intralesional (IL) resection with or without RT. Primary outcomes were OS, DFS, and LRFS. Multivariable Cox regression was used to identify variables associated with these outcomes. RESULTS:Sixty-two patients had a median follow-up of 5.3 years. The 5-year OS, DFS, and LRFS rates were 78%, 65%, and 73%, respectively. Patients undergoing EA resection or en bloc EI resection with RT had superior OS and LRFS compared to en bloc EI resection without RT (OS 93% vs 88% vs 71%, p < 0.05; LRFS 82% vs 88% vs 52%, p < 0.05). DFS was highest in the en bloc EI resection with RT group (87%) compared to EA resection (74%; p < 0.05) and en bloc EI resection without RT (39%; p < 0.05). On multivariable analysis, age ≥ 65 years and en bloc EI resection without RT were associated with decreased OS, while en bloc EI resection without RT was the only variable independently associated with worse DFS and LRFS. All patients who underwent a planned IL resection died within 5 years. CONCLUSIONS:This study highlights the complexity of achieving EA margins in en bloc resections for spinal chordoma and chondrosarcoma. In cases in which EA resection is not feasible, adjuvant high-dose RT appears to mitigate the negative impact of EI surgery and should be strongly considered. Further studies with longer follow-up durations are warranted to confirm these findings and optimize multimodal treatment strategies.

Longer hospital length of stay (LOS) has been associated with worse outcomes and increased resource utilization. However, diagnostic and patient-level factors associated with LOS have not been well studied on a large scale. The goal was to identify patient, surgical and organizational factors associated with longer patient LOS for adult patients at a high-volume quaternary spinal care center. We performed a retrospective analysis of 13,493 admissions from January 2006 to December 2019. Factors analyzed included age, sex, admission status (emergent vs scheduled), ASIA grade, operative vs non-operative management, mean blood loss, operative time, and adverse events. Specific adverse events included surgical site infection (SSI), other infection (systemic or UTI), neuropathic pain, delirium, dural tear, pneumonia, and dysphagia. Diagnostic categories included trauma, oncology, deformity, degenerative, and “other”. A multivariable linear regression model was fit to log-transformed LOS to determine independent factors associated with patient LOS, with effects expressed as multipliers on mean LOS. Mean LOS for the population (SD) was 15.8 (34.0) days. Factors significantly (p < 0.05) associated with longer LOS were advanced patient age [multiplier on mean LOS 1.011/year (95

BACKGROUND:Surgery for degenerative spine pathologies is typically performed on a scheduled basis; however, worsening symptoms may warrant emergency surgery. An increasing number of patients requiring emergency surgery has been observed (22.6% in 2006 to 34.8% in 2019). We sought to compare the outcomes of patients who received scheduled surgery and those who required emergency surgery. METHODS:All patients treated between Jan. 1, 2006, and Dec. 31, 2019, were included. Retrospective comparisons were made between patients who were scheduled (elective) for surgery and those requiring emergency surgery, patients who were scheduled for surgery and those who decompensated while on the surgical waitlist and patients who presented as de novo emergencies and those who decompensated while on the surgical waitlist. RESULTS:Among the 6217 patients with degenerative pathologies, 4654 (74.9%) patients were scheduled (elective) for surgery and 1563 (25.1%) were patients requiring emergency surgery. Compared with patients who were scheduled, patients requiring emergency surgery had a longer length of stay (LOS) in hospital (5.1 d, interquartile range [IQR] 2.7-11.2 v. 3.6 d, IQR 1.3-6.4, p < 0.001) and lower rate of home discharge (78.6% v. 94.2%, p < 0.001). Patients requiring emergency surgery were 1.34 times more likely to have any adverse events (95% confidence interval [CI] 1.06-1.68, p = 0.01). When compared with patients who were scheduled for surgery, those who decompensated while on the surgical waitlist had longer LOS (7.0 d, IQR 3.3-15.0 v. 3.6 d, IQR 1.3-6.4, p < 0.001), less home discharge (77.6% v. 94.2%, p < 0.001) and were 2.5 times more likely to have any adverse events (95% CI 1.5-4.1, p < 0.001). Patients who decompensated had a 2.1 times higher risk of having any adverse events than patients who presented as de novo emergencies (95% CI 1.2-3.6, p < 0.001). CONCLUSION:We observed worse perioperative outcomes for patients requiring emergency surgery for degenerative spinal conditions than for patients who were scheduled for surgery. Patients who decompensated while on the surgical waitlist had the worst outcomes.

Efforts to safely reduce hospital LOS while maintaining quality outcomes and patient satisfaction are paramount. The primary goal of this study was to assess trends in LOS at a high-volume quaternary care spine center. Secondary goals were to assess trends in factors most associated with prolonged LOS. This is a prospective study of all consecutive patients admitted from January 2006 to December 2019. Data included demographics, diagnostic category (degenerative, oncology, deformity, trauma, other), LOS (mean, median, interquartile range, standard deviation, defined as days from admission to discharge), and in-hospital adverse events. A total of 13,493 patients were included. Overall LOS has not changed over time with an overall median of 6.3 days (p = 0.451). Median LOS significantly increased for patients treated for degenerative pathology from 2.2 days in 2006 to 3.2 days in 2019 (p = 0.019). LOS has not changed for patients treated for deformity (overall median 6.8 days, p = 0.411), oncology (overall median 11.0 days, p = 0.051), or trauma (overall median 11.8 days, p = 0.582). Emergency admissions increased 3.2%/year for degenerative pathologies (p =  < 0.001). Mean age has increased from 48.4 years in 2006 to 58.1 years in 2019 (p =  < 0.001). This trend was observed in the deformity, degenerative and trauma group, not for patients treated for oncological disease. More adverse events were significantly associated with increasing age. This is the first North American study to comprehensively analyze trends in LOS for spinal surgery overtime in an academic center. Overall, LOS has not changed from 2006–2019. Various factors that influence LOS appear to have balanced each other. It may also be explained by the changing epidemiology of both elective and emergency surgeries. These findings provide opportunities for intervention and improvement, targeted at the geriatric population, to reduce length of hospitalization.

Background: Length of stay (LOS) is a surrogate for care complexity and a determinant of occupancy and service provision. Our primary goal was to assess changes in and determinants of LOS at a quaternary spinal care center. Secondary goals included identifying opportunities for improvement and determinants of future service planning. Methods: This is a prospective study of patients admitted from 2006 to 2019. Data included demographics, diagnostic category (degenerative, oncology, deformity, trauma, other), LOS (mean, median, interquartile range, standard deviation) and in-hospital adverse events (AEs). Results: 13,493 admissions were included. Mean age has increased from 48.4 (2006) to 58.1 years (2019) (p=<0.001). Mean age increased overtime for patients treated for deformity (p=<0.001), degenerative pathology (p=<0.001) and trauma (p=<0.001), but not oncology (p=0.702). Overall LOS has not changed over time (p=0.451). LOS increased in patients with degenerative pathology (p=0.019) but not deformity (p=0.411), oncology (p=0.051) or trauma (p=0.582). Emergency admissions increased overtime for degenerative pathologies (p=<0.001). AEs and SSIs have decreased temporally (p=<0.001). Conclusions: This is the first North American study to analyze temporal trends in LOS for spine surgery in an academic center. Understanding temporal trends in LOS and patient epidemiology can provide opportunities for intervention, targeted at the geriatric populations, to reduce LOS.

Background: Prolonged length of stay (LOS) is associated with increased resource utilization and worse outcomes. The goal of this study is identifying patient, surgical and systemic factors associated with prolonged LOS overall and per diagnostic category for adults admitted to a quaternary spinal care center. Methods: We performed a retrospective analysis on 13,493 admissions from 2006 to 2019. Factors analyzed included patient age, sex, emergency vs elective admission, diagnostic category (degenerative, deformity, oncology, trauma), presence of neurological deficits in trauma patients, ASIA score, operative management and duration, blood loss, and adverse events (AEs). Univariate and multivariate analyses determined factors associated with prolonged LOS. Results: Overall mean LOS (±SD) was 15.80 (±34.03) days. Through multivariate analyses, predictors of prolonged LOS were advanced age (p<0.001), emergency admission (p<0.001), advanced ASIA score (p<0.001), operative management (p=0.043), and presence of AEs (p<0.001), including SSI (p=0.001), other infections (systemic and UTI) (p<0.001), delirium (p=0.006), and pneumonia (p<0.001). The effects of age, emergency admission, and AEs on LOS differed by diagnostic category. Conclusions: Understanding patient and disease factors that affect LOS provides opportunities for QI intervention and allows for an informed preoperative discussion with patients. Future interventions can be targeted to maximize patient outcomes, optimize care quality, and decrease costs.

STUDY DESIGN:Qualitative study.OBJECTIVES:The purpose of this study is to understand the patient perspective after diagnosis of an acute traumatic spinal cord injury (tSCI). Discussing the diagnosis and prognosis of a tSCI with a patient can be a challenging experience for both the patient and the physician. As such, this paper attempts to better understand the patient experience to improve communication when discussing this life-altering injury.SETTING:Vancouver General Hospital, Vancouver, British Columbia, Canada.METHODS:This study is a qualitative study utilizing grounded theory and semi-structured interviews. The interview transcripts were manually coded using manifest and latent content analysis. Major and minor codes were identified and discussed.RESULTS:In total, 17 interviews were conducted, fifteen individuals with tSCI who received acute care at Vancouver General Hospital (VGH) and eleven family members were interviewed. Patient participants were interviewed individually or in a paired interview with a participating family member. Patient participants had varying spinal cord injuries from AIS A-D. Two major themes were identified from the interviews. The first major theme was physician demeanor (general approach and attitude towards patients) and the second major theme was delivery of information (content, timing, and source).CONCLUSIONS:This study summarizes the preferences of patients who sustained a tSCI discussions regarding their diagnosis and prognosis in the acute care setting. The goal of this study is to help guide physician interactions at this difficult and vulnerable time for patients with hopes to improve patient care through effective communication.

Background: Mean arterial pressure augmentation is one current established practice for management of patients with SCI. We present the first data investigating the effectiveness of Intrathecal Pressure (ITP) reduction through CSF drainage (CSFD) in managing patients with acute traumatic SCI at a large academic center. Methods: Data from 6 patients with acute traumatic SCI were included. A lumbar intrathecal catheter was used to monitor ITP and volume of CSFD. CSFD was performed and recorded hourly. ITP recordings were collected hourly and the change in ITP was calculated (hour after minus before CSFD). 369 data points were collected and change in ITP was plotted against volume of CSFD. Results: Data across all patients showed variability in the ITP over time without a significant trend (slope=0.016). We found no significant change in ITP with varying amounts of CSFD (slope=0.007, r2=0.00, p=0.88). Changes in ITP were not significantly different across groups of CSFD but the variation in the data decreased with increasing levels of CSFD. Conclusions: We present the first known data on changes in ITP with varying degrees of CSFD in patients with acute traumatic SCI. These results may provide insight into the complexity of ITP changes in patients post-injury and help inform future SCI management.

Background context Frailty and sarcopenia variably predict adverse events (AEs) in a number of surgical populations. Purpose The aim of this study was to investigate the ability of frailty and sarcopenia to independently predict early mortality and AEs following urgent surgery for metastatic disease of the spine. Study Design A single institution, retrospective cohort study. Patient Sample One hundred eight patients undergoing urgent surgery for spinal metastases from 2009 to 2015. Outcome Measures The incidence of AEs including 1- and 3-month mortality. Methods Sarcopenia was defined using the L3 Total Psoas Area/Vertebral body Area (L3-TPA/VB) technique on CT. The modified Frailty Index (mFI), Metastatic Frailty Index (MSTFI) and the Bollen prognostic scales were calculated for each patient. Additional data included demographics, tumor type and burden, neurological status, the extent of surgical treatment and the use of radiation-therapy. Spearman correlation test, logistic regression and Kaplan-Meier were used to study the relation between the outcomes measures and potential predictors (L3-TPA/VB, MSTFI, mFI, and the Bollen prognostic scales). Results Eighty-five percent of patients had at least one acute AE. Sarcopenia predicted the occurrence of at least one postop AE (L3-TPA/VB, 1.07±0.40 vs. 1.25±0.52; p=.031). Sarcopenia (L3-TPA/VB) and the degree of neurological impairment were predictive of postoperative AE but MFI or MSTFI were not. Sarcopenia predicted 3-month mortality, independent of primary tumor type (L3-TPA/VB: 0.86±0.27 vs. 1.12±0.41; p<.001). Kaplan-Meyer analysis showed L3-TPA/VB and the Bollen Scale to significantly discriminate patient survival. Conclusions Sarcopenia, easily measured by the L3-TPA/VB on conventional CT, predicts both early postoperative mortality and adverse events in patients undergoing urgent surgery for spinal metastasis, thus providing a practical tool for timely therapeutic decision-making in this complex patient population.

OBJECTIVE Surgical treatment of primary bone tumors of the spine and en bloc resection for isolated metastases are complex and challenging. Operative care is fraught with complications, though the true incidence and predictors of adverse events (AEs), length of stay (LOS), and mortality in this population remain poorly understood. The primary objective of this study was to describe the incidence and predictors of perioperative AEs in these patients. Secondary objectives included the determination of the incidence and predictors of admission to the intensive care unit (ICU), unanticipated reoperation during the same admission, hospital LOS, and mortality. METHODS In this retrospective analysis of prospectively collected data, the authors included consecutive patients at a single quaternary care referral center (January 1, 2009, to September 30, 2018) who underwent either surgery for a primary bone tumor of the spine or an en bloc resection for an isolated spinal metastasis. Information on perioperative AEs, demographic data, primary tumor histology, neurological status, surgical variables, pathological margins, Enneking appropriateness, LOS, ICU stay, reoperation during the same admission period, and in-hospital mortality was collected prospectively in the institutional database. The modified frailty score was extracted retrospectively. RESULTS One hundred thirteen patients met the inclusion criteria: 98 with primary bone tumors and 15 with isolated metastases. The cohort was 59% male, and the mean age was 49 years (SD 19 years). Overall, 79% of the patients experienced at least 1 AE. The median number of AEs per patient was 2 (IQR 0-4 AEs), and the median LOS was 16 days (IQR 9-32 days). No in-hospital deaths occurred in the cohort. Thirty-two patients (28%) required an ICU stay and 19% underwent an unanticipated second surgery during their admission. A longer surgical duration was associated with a higher likelihood of AEs (OR 1.21/hour, 95% CI 1.06-1.37, p = 0.005), longer ICU stay (OR 1.35/hour, 95% CI 1 1.20-1.52, p < 0.001), and reoperation (OR 1.001/hour, 95% CI 1.0003-1.003, p = 0.012). Longer hospital LOS was independently predicted by older age, female sex, upper cervical and sacral location of the tumor, surgical duration, preoperative neurological deficit, presence of AEs, and higher modified frailty index score. CONCLUSIONS Surgeries for primary bone tumors and en bloc resection for metastatic tumors are associated with a high incidence of perioperative AEs. Surgical duration predicts complications, reoperation, LOS, and ICU stay.

OBJECTIVE The study aimed to determine if the intraoperative segmental lordosis (as calculated on a cross-table lateral radiograph following a single-level transforaminal lumbar interbody fusion [TLIF] for degenerative spondylolisthesis/low-grade isthmic spondylolisthesis) is maintained at discharge and at 6 months postsurgery. METHODS The authors reviewed images and medical records of patients ≥ 16 years of age with a diagnosis of an isolated single-level, low-grade spondylolisthesis (degenerative or isthmic) with symptomatic spinal stenosis treated between January 2008 and April 2014. Age, sex, surgical level, surgical approach, and facetectomy (unilateral vs bilateral) were recorded. Upright standardized preoperative, early, and 6-month postoperative radiographs, as well as intraoperative lateral radiographs, were analyzed for the pelvic incidence, segmental lumbar lordosis (SLL) at the TILF level, and total LL (TLL). In addition, the anteroposterior position of the cage in the disc space was documented. Data are presented as the mean ± SD; a p value < 0.05 was considered significant. RESULTS Eighty-four patients were included in the study. The mean age of patients was 56.8 ± 13.7 years, and 46 patients (55%) were men. The mean pelvic incidence was 59.7° ± 11.9°, and a posterior midline approach was used in 47 cases (56%). All TLIF procedures were single level using a bullet-shaped cage. A bilateral facetectomy was performed in 17 patients (20.2%), and 89.3% of procedures were done at the L4-5 and L5-S1 segments. SLL significantly improved intraoperatively from 15.8° ± 7.5° to 20.9° ± 7.7°, but the correction was lost after ambulation. Compared with preoperative values, at 6 months the change in SLL was modest at 1.8° ± 6.7° (p = 0.025), whereas TLL increased by 4.3° ± 9.6° (p < 0.001). The anteroposterior position of the cage, approach, level of surgery, and use of a bilateral facetectomy did not significantly affect postoperative LL. CONCLUSIONS Following a single-level TLIF procedure using a bullet-shaped cage, the intraoperative improvement in SLL is largely lost after ambulation. The improvement in TLL over time is probably due to the decompression part of the procedure. The approach, level of surgery, bilateral facetectomy, and position of the cage do not seem to have a significant effect on LL achieved postoperatively.

BACKGROUND CONTEXT: Sarcopenia measured by normalized total psoas area (NTPA) has been shown to predict mortality and adverse events (AEs) in numerous surgical populations. The relationship between sarcopenia and postoperative outcomes after surgery for degenerative spine disease (DSD) has not been investigated. PURPOSE: This study aimed to determine the relationships between sarcopenia, frailty, and postoperative AEs in the elderly DSD population. Secondary objectives were to describe the distribution and predictors of NTPA and to determine the relationship between sarcopenia, frailty, and length of stay, discharge to a facility, and in-hospital mortality. STUDY DESIGN: This is an ambispective study from a quaternary care academic center. PATIENT SAMPLE: A total of 102 patients over 65 years old who underwent elective thoracolumbar surgery for DSD between 2009 and 2013 were included in this study. OUTCOME MEASURES: The primary outcome was a composite of perioperative AEs; the secondary outcomes were length of stay, discharge disposition, and in-hospital mortality. METHODS: Total psoas area (TPA) at mid-L3 level on preoperative computed tomography scan adjusted for height (NTPA) defined sarcopenia. The modified frailty index (mFl) of 11 clinical variables defined frailty. The distribution and predictors of sarcopenia (NTPA) were determined. The association of NTPA with AEs, length of stay, discharge disposition to care facility, and mortality was analyzed, including adjusting for known and suspected confounders using multivariate regression. RESULTS: Median Spine Surgical Invasiveness Index was 8 (interquartile range 2-10), and mean NTPA was 674 mm(2)/m(2) (293.21-1636.25). Using the mFI, 20.6% were pre-frail and 19.6% were frail. Inter- and intraobserver reliability for determining NTPA were near perfect with kappa 0.95-0.97 and 0.94-1.00, respectively. The NTPA was independently associated with patient gender and body mass index (BMI) but not frailty (mFI). Age, BMI, mFI, and American Anesthesiologists' Society score were not associated with incidence of postoperative AEs. The NTPA did not predict the occurrence of AE (odds ratio [OR] 1.06 per 100 mm(2)/m(2), 95% confidence interval [CI] 0.91-1.23, p=.45). Similarly, NTPA was not predictive of length of stay (rho=-0.04, p=.67), discharge home (OR 0.95 (95% CI 0.76-1.20) per 100 mm(2)/m(2), p=.70), or death (OR 1.12 (95% CI 0.83-1.53) per 100 mm(2)/m(2), p=.47). In contrast, increasing mFI was associated with increased risk of mortality (OR 3.12 (95% CI 1.21-8.03) per 0.1 increase in frailty score, p=.006). CONCLUSIONS: In contrast to other surgical groups, sarcopenia (NTPA) or frailty (mFI) did not predict acute care complications in a selected population of elderly patients undergoing simple lumbar spine surgery for DSD. Although NTPA can be reliably measured in this population, it may be an inappropriate surrogate for sarcopenia given its anatomical relationship to spinal function. Copyright (C) 2017 Published by Elsevier Inc. All rights reserved.

# Experiences in implementing the EOS radiographic system and SterEOS three-dimensional module {#article-title-2} The American Academy of Orthopaedic Surgeons, Scoliosis Research Society, Pediatric Orthopaedic Society of North America and American Academy of Pediatrics believe that the principles

The treatment of postoperative deep spinal wound infection involves debridement and intravenous antibiotics. Authors have previously reported success in a small series of patients treated with vacuum-assisted closure (VAC) therapy, but its use over exposed dura is controversial and the outcome has not been reported in large series.

The optimization and maintenance of mean arterial blood pressure (MAP) and the general avoidance of systemic hypotension for the first 5-7 days following acute traumatic spinal cord injury (tSCI) is considered to be important for minimizing secondary spinal cord ischemic damage. The characterization of hemodynamic parameters in the immediate post-injury stage prior to admission to a specialized spine unit has not been previously reported. Here we describe the blood pressure management of 40 acute tSCI patients in the early post-injury phases of care prior to their arrival in a specialized spinal injury high dependency unit (HDU), intensive care unit (ICU), or operating room (OR). This study found that a significant proportion of these patients experience periods of relative hypotension prior to their admission to a specialized spinal unit. In particular, the mean calculated MAP was 78.8 mm Hg, with 52% of MAP measurements <80 mm Hg at primary receiving hospitals. Despite having a mean calculated MAP of 83.3 mm Hg in the emergency room of the tertiary hospital, 40% of the MAP measurements were <80 mm Hg. Although stringent monitoring and management of MAP may be facilitated and adhered to in a spinal HDU, ICU, or OR, it is important to recognize that acute traumatic SCI patients may experience many periods of relative hypotension prior to their arrival in such specialized units. This study highlights the need for education and awareness to optimize the hemodynamic management of acute SCI patients during the immediate post-injury period.

Background: Pre-operative spine level localization by palpation of anatomical landmarks (ribs, spinous processes) in posterior approaches for surgeries from T4 to L2 is often inaccurate. This can lead to ineffective utilization of procedural time, increased radiation dose, potentially longer skin incision and wrong level surgery. Factors affecting topographical accuracy includes body mass index (BMI) of the patient, congenital or acquired deformity and knowledge of topographical anatomy. Methods: All patients had the presumed location of their pathology marked on the skin using anatomical landmarks prior to application of the Target Tape ® (Vancouver, BC, Canada) and verification using an anterior-posterior radiograph. Potential factors predictive of accurate pre-operative spine level localization such as age, gender, BMI, palpable deformity, pathology related interspinous distance (ISPD) and pathology related skin to spinous process distance were evaluated. Results: A prospective study was performed with 30 consecutive patients undergoing posterior spine surgery (T4 to L2). Accuracy of pathology related spine level localization using anatomical landmarks was only 40%. Pathology related ISPDs of more than 10 mm and palpable deformity was significantly correlated with successful determination of spine levels using anatomical landmarks. Conclusions: This study showed that poor spine level localization using anatomical landmarks was associated with pathology related ISPDs of less than 10 mm. Conversely, patients with palpable spinal deformity have their levels easily localized.

# 0107: Nationwide quality assessment of the Canadian Spine Outcomes Research Network (CSORN) {#article-title-2} The Canadian Spine Outcomes and Research Network (CSORN) is an emergent, rapidly growing national spine registry. The utility of a medical database is dependent on the quality of the

Efforts to validate novel therapies in acute clinical trials for spinal cord injury (SCI) are impeded by the lack of objective quantitative measures that reflect injury severity and accurately predict neurological recovery. Therefore, a strong rationale exists for establishing neurochemical biomarkers that objectively quantify injury severity and predict outcome. Here, we conducted a targeted proteomics analysis of cerebrospinal fluid (CSF) samples derived from 29 acute SCI patients (American Spinal Injury Association Impairment Scale [AIS] A, B, or C) acquired at 24, 48, and 72h post-injury. From a total of 165 proteins, we identified 27 potential biomarkers of injury severity (baseline AIS A, B, or C), with triosephosphate isomerase having the strongest relationship to AIS grade. The majority of affected proteins (24 of 27) were more abundant in samples from AIS A patients than in those from AIS C patients, suggesting that for the most part, these proteins are released into the CSF more readily with more severe trauma to the spinal cord. We then analyzed the relationship between CSF protein abundance and neurological recovery. For AIS grade improvement over 6 months, we identified 34 proteins that were associated with AIS grade conversion (p<0.05); however, these associations were not statistically significant after adjusting for multiple comparisons. For total motor score (TMS) recovery over 6 months, after adjusting for baseline neurological injury level, we identified 46 proteins with a statistically significant association with TMS recovery. Twenty-two of these proteins were among the 27 proteins that were related to baseline AIS grade, consistent with the notion that protein markers that reflect a more severe injury also appropriately predict a poorer recovery of motor function. In summary, this study provides a description of the CSF proteome changes that occur after acute human SCI, and reveals a number of protein candidates for further validation as potential biomarkers of injury severity.

Study design: Prospective vasopressor cross-over interventional study Objectives: To examine how two vasopressors used in acute traumatic spinal cord injury (SCI) affect intrathecal cerebrospinal fluid pressure and the corresponding spinal cord perfusion pressure (SCPP). Setting: Vancouver, British Columbia, Canada. Methods: Acute SCI patients over the age of 17 with cervical or thoracic ASIA Impairment Scale (AIS). A, B or C injuries were enrolled in this study. Two vasopressors, norepinephrine and dopamine, were evaluated in a ‘crossover procedure’ to directly compare their effect on the intrathecal pressure (ITP). The vasopressor cross-over procedures were performed in the intensive care unit where ITP, mean arterial pressure (MAP) and heart rate were being continuously measured. The SCPP was calculated as the difference between MAP and ITP. Results: A total of 11 patients were enrolled and included in our analysis. There were 6 patients with AIS A, 3 with AIS B and 2 with AIS C injuries at baseline. We performed 24 cross-over interventions in these 11 patients. There was no difference in MAP with the use of norepinephrine versus dopamine (84±1 mm Hg for both; P =0.33). Conversely, ITP was significantly lower with the use of norepinephrine than with dopamine (17±1 mm Hg vs 20±1 mm Hg, respectively, P <0.001). This decrease in ITP with norepinephrine resulted in an increased SCPP during the norepinephrine infusion when compared with dopamine (67±1 mm Hg vs 65±1 mm Hg respectively, P =0.0049). Conclusion: Norepinephrine was able to maintain MAP with a lower ITP and a correspondingly higher SCPP as compared with dopamine in this study. These results suggest that norepinephrine may be preferable to dopamine if vasopressor support is required post SCI to maintain elevated MAPs in accordance with published guidelines.