Lise Belanger

Intrathecal pressure monitoring and cerebrospinal fluid drainage in acute spinal cord injury: a prospective randomized trial

OBJECT Ischemia is an important factor in the pathophysiology of secondary damage after traumatic spinal cord injury (SCI) and, in the setting of thoracoabdominal aortic aneurysm repair, can be the primary cause of paralysis. Lowering the intrathecal pressure (ITP) by draining CSF is routinely done in thoracoabdominal aortic aneurysm surgery but has not been evaluated in the setting of acute traumatic SCI. Additionally, while much attention is directed toward maintaining an adequate mean arterial blood pressure (MABP) in the acute postinjury phase, little is known about what is happening to the ITP during this period when spinal cord perfusion pressure (MABP - ITP) is important. The objectives of this study were to: 1) evaluate the safety and feasibility of draining CSF to lower ITP after acute traumatic SCI; 2) evaluate changes in ITP before and after surgical decompression; and 3) measure neurological recovery in relation to the drainage of CSF. METHODS Twenty-two patients seen within 48 hours of injury were prospectively randomized to a drainage or no-drainage treatment group. In all cases a lumbar intrathecal catheter was inserted for 72 hours. Acute complications of headache/nausea/vomiting, meningitis, or neurological deterioration were carefully monitored. Acute Spinal Cord Injury motor scores were documented at baseline and at 6 months postinjury. RESULTS On insertion of the catheter, mean ITP was 13.8 +/- 1.3 mm Hg (+/- SD), and it increased to a mean peak of 21.7 +/- 1.5 mm Hg intraoperatively. The difference between the starting ITP on catheter insertion and the observed peak intrathecal pressure after decompression was, on average, an increase of 7.9 +/- 1.6 mm Hg (p < 0.0001, paired t-test). During the postoperative period, the peak recorded ITP in the patients randomized to the no-drainage group was 30.6 +/- 2.3 mm Hg, which was significantly higher than the peak intraoperative ITP (p = 0.0098). During the same period, the peak recorded ITP in patients randomized to receive drainage was 28.1 +/- 2.8 mm Hg, which was not statistically higher than the peak intraoperative ITP (p = 0.15). CONCLUSIONS The insertion of lumbar intrathecal catheters and the drainage of CSF were not associated with significant adverse events, although the cohort was small and only a limited amount of CSF was drained. Intraoperative decompression of the spinal cord results in an increase in the ITP measured caudal to the injury site. Increases in intrathecal pressure are additionally observed in the postoperative period. These increases in intrathecal pressure result in reduced spinal cord perfusion that will otherwise go undetected when measuring only the MABP. Characteristic changes in the observed intrathecal pressure waveform occur after surgical decompression, reflecting the restoration of CSF flow across the SCI site. As such, the waveform pattern may be used intraoperatively to determine if adequate decompression of the thecal sac has been accomplished.

Early versus late enteral feeding in patients with acute cervical spinal cord injury: a pilot study.

Study Design. A prospective randomized clinical pilot study to compare early versus late enteral feeding in patients with acute cervical spinal cord injury. Objectives. To compare the incidence of infections in patients with acute cervical spinal cord injury who received early versus late enteral feeding. Secondary objectives included assessing nutritional status, feeding tolerance, the number of ventilator hours, and acute-care hospital length of stay. Summary of Background Data. Early nutritional support has been found to be beneficial in critically ill patients. However, the same benefits may not be realized in patients with acute cervical spinal cord injury because of their unique nutritional challenges. Methods. Eligible patients were randomized to early feeding (initiated before 72 hours after injury) and late (initiated more than 120 hours after injury). Patients were stratified on the basis of their neurologic level. Patients were assessed daily for the first 15 days. After that time, infections (according to Center for Disease Control criteria), ventilator hours, and length of acute-care hospital stay were tracked. Results. Twenty-three patients met the eligibility criteria, and 17 patients were included in the analysis. There were 7 patients in the early group and 10 in the late group. The early group had a mean of 2.4 ± 1.5 infections compared with the late group, which had a mean of 1.7 ± 1.1 infections. Secondary outcomes were not substantially different between the two groups. Conclusions. This pilot study failed to detect any differences in the incidence of infection, nutritional status, feeding complications, number of ventilator hours, or length of stay between patients receiving early versus late initiation of enteral feeding. These data will assist in the determination of an adequate sample size for future studies.

Modeling the Patient Journey from Injury to Community Reintegration for Persons with Acute Traumatic Spinal Cord Injury in a Canadian Centre

Background A patient’s journey through the health care system is influenced by clinical and system processes across the continuum of care. Methods To inform optimized access to care and patient flow for individuals with traumatic spinal cord injury (tSCI), we developed a simulation model that can examine the full impact of therapeutic or systems interventions across the care continuum for patients with traumatic spinal cord injuries. The objective of this paper is to describe the detailed development of this simulation model for a major trauma and a rehabilitation centre in British Columbia (BC), Canada, as part of the Access to Care and Timing (ACT) project and is referred to as the BC ACT Model V1.0. Findings To demonstrate the utility of the simulation model in clinical and administrative decision-making we present three typical scenarios that illustrate how an investigator can track the indirect impact(s) of medical and administrative interventions, both upstream and downstream along the continuum of care. For example, the model was used to estimate the theoretical impact of a practice that reduced the incidence of pressure ulcers by 70%. This led to a decrease in acute and rehabilitation length of stay of 4 and 2 days, respectively and a decrease in bed utilization of 9% and 3% in acute and rehabilitation. Conclusion The scenario analysis using the BC ACT Model V1.0 demonstrates the flexibility and value of the simulation model as a decision-making tool by providing estimates of the effects of different interventions and allowing them to be objectively compared. Future work will involve developing a generalizable national Canadian ACT Model to examine differences in care delivery and identify the ideal attributes of SCI care delivery.

Development and Assessment of a Community Follow-Up Questionnaire for the Rick Hansen Spinal Cord Injury Registry

OBJECTIVE To develop a comprehensive community follow-up questionnaire for participants enrolled in the Rick Hansen Spinal Cord Injury Registry (RHSCIR). DESIGN Development and preliminary assessment of measurement properties (reliability and validity) of instruments used during a community follow-up and aligned with the International Classification of Functioning, Disability and Health (ICF). SETTING General community setting. PARTICIPANTS People with spinal cord injury (N=50) living in the community. INTERVENTION Not applicable. MAIN OUTCOME MEASURES A comprehensive follow-up questionnaire, referred to as the RHSCIR Community Follow-up Questionnaire Version 2.0 (CFQ-V2.0), includes 8 instruments. Four new instruments were developed, 2 existing instruments were modified, and 2 previously published instruments were included. RESULTS Intra- and interrater reliability statistics (Gwets AC1) support the measurement properties of the new and modified instruments. Correlations between new and existing instruments and between groups based on the severity of injury support the construct validity of the secondary complications and person-perceived participation instruments. CONCLUSIONS The RHSCIR CFQ-V2.0 is a comprehensive community follow-up questionnaire that aligns to the ICF. Initial study results suggest that it covers all relevant aspects of community living, and the measurement properties are promising.

Cerebrospinal Fluid Biomarkers To Stratify Injury Severity and Predict Outcome in Human Traumatic Spinal Cord Injury

Neurologic impairment after spinal cord injury (SCI) is currently measured and classified by functional examination. Biological markers that objectively classify injury severity and predict outcome would greatly facilitate efforts to evaluate acute SCI therapies. The purpose of this study was to determine how well inflammatory and structural proteins within the cerebrospinal fluid (CSF) of acute traumatic SCI patients predicted American Spinal Injury Association Impairment Scale (AIS) grade conversion and motor score improvement over 6 months. Fifty acute SCI patients (29 AIS A, 9 AIS B, 12 AIS C; 32 cervical, 18 thoracic) were enrolled and CSF obtained through lumbar intrathecal catheters to analyze interleukin (IL)-6, IL-8, monocyte chemotactic protein (MCP)-1, tau, S100β, and glial fibrillary acidic protein (GFAP) at 24 h post-injury. The levels of IL-6, tau, S100β, and GFAP were significantly different between patients with baseline AIS grades of A, B, or C. The levels of all proteins (IL-6, IL-8, MCP-1, tau, S100β, and GFAP) were significantly different between those who improved an AIS grade over 6 months and those who did not improve. Linear discriminant analysis modeling was 83% accurate in predicting AIS conversion. For AIS A patients, the concentrations of proteins such as IL-6 and S100β correlated with conversion to AIS B or C. Motor score improvement also was strongly correlated with the 24-h post-injury CSF levels of all six biomarkers. The analysis of CSF can provide valuable biological information about injury severity and recovery potential after acute SCI. Such biological markers may be valuable tools for stratifying individuals in acute clinical trials where variability in spontaneous recovery requires large recruitment cohorts for sufficient power.

The Validity of Administrative Data To Classify Patients with Spinal Column and Cord Injuries

International Classification of Diseases (ICD) codes are used to document patient morbidity in administrative databases. Although administrative data are used for research purposes, the validity of the data to accurately describe clinical diagnostic information is uncertain. We compared the clinical diagnoses for spinal cord and column injuries from a longitudinal patient registry, the Rick Hansen Spinal Cord Injury Registry (RHSCIR), to the ICD-10 spinal injury codes from the Discharge Abstract Database (DAD) at one institution. There were 603 RHSCIR participants with data describing the spinal cord injury, and 341 had data on the spinal column injury. The validity of DAD data to describe spinal injuries was evaluated using the sensitivity and positive predictive values of specific ICD-10 codes; 5.3% of the spinal column injuries and 10.9% of the spinal cord injuries documented in RHSCIR were missed in data from the DAD using ICD-10 codes. The most problematic spinal column ICD-10 code was the dislocation of the cervical vertebra (S13.1); only 14.0% of the dislocations of the cervical vertebrae in RHSCIR were correctly coded in the DAD. The most problematic spinal cord injury ICD-10 code was the incomplete lesion of the lumbar spinal cord (S34.1X); 66.7% of incomplete lesions of the lumbar spinal cord in RHSCIR were correctly coded in the DAD. The validity of DAD data to code spinal injuries is variable, and cannot be reliably used to classify all types of spinal injuries. Patient registries, such as RHSCIR, should be used if accurate detailed diagnostic data are required.

A prospective evaluation of hemodynamic management in acute spinal cord injury patients

Study design:Prospective observational study of acute spinal cord-injured (SCI) patients.Objectives:To determine how effectively mean arterial blood pressure (MAP) and spinal cord perfusion pressure (SCPP) are maintained at target levels in acute SCI patients.Setting:Single-institution study at a Canadian level-one trauma center.Methods:Twenty-one individuals with cervical or thoracic SCI were enrolled within 48 h of injury. A lumbar intrathecal drain was inserted for monitoring intrathecal cerebrospinal fluid pressure (ITP). The MAP was monitored concurrently with ITP, and the SCPP was calculated. Data was recorded hourly from the time of first assessment until at least the end of the 5th day post injury.Results:All subjects had at least one recorded episode with a MAP below 80 mm Hg, and 81% had at least one episode with a MAP below 70 mm Hg. On average, subjects with cervical injuries had 18.4% of their pressure recordings below 80 mm Hg. Subjects with thoracic cord injuries had on average 35.9% of their MAP recordings <80 mm Hg.Conclusion:It is common practice to establish MAP targets for optimizing cord perfusion in acute SCI. This study suggests that even in an acute SCI referral center, when prospectively scrutinized, the actual MAP may frequently fall below the intended targets. Such results raise awareness of the vigilance that must be kept in the hemodynamic management of these patients, and the potential discrepancy between routinely setting target MAP according to ‘practice guidelines’ and actually achieving them.

Spinal cord perfusion pressure predicts neurologic recovery in acute spinal cord injury

Objective: To determine whether spinal cord perfusion pressure (SCPP) as measured with a lumbar intrathecal catheter is a more predictive measure of neurologic outcome than the conventionally measured mean arterial pressure (MAP). Methods: A total of 92 individuals with acute spinal cord injury were enrolled in this multicenter prospective observational clinical trial. MAP and CSF pressure (CSFP) were monitored during the first week postinjury. Neurologic impairment was assessed at baseline and at 6 months postinjury. We used logistic regression, systematic iterations of relative risk, and Cox proportional hazard models to examine hemodynamic patterns commensurate with neurologic outcome. Results: We found that SCPP (odds ratio 1.039, p = 0.002) is independently associated with positive neurologic recovery. The relative risk for not recovering neurologic function continually increased as individuals were exposed to SCPP below 50 mm Hg. Individuals who improved in neurologic grade dropped below SCPP of 50 mm Hg fewer times than those who did not improve (p = 0.012). This effect was not observed for MAP or CSFP. Those who were exposed to SCPP below 50 mm Hg were less likely to improve from their baseline neurologic impairment grade (p = 0.0056). Conclusions: We demonstrate that maintaining SCPP above 50 mm Hg is a strong predictor of improved neurologic recovery following spinal cord injury. This suggests that SCPP (the difference between MAP and CSFP) can provide useful information to guide the hemodynamic management of patients with acute spinal cord injury.

The differential effects of norepinephrine and dopamine on cerebrospinal fluid pressure and spinal cord perfusion pressure after acute human spinal cord injury

Study design:Prospective vasopressor cross-over interventional studyObjectives: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.

Evaluation of a Clinical Protocol to Assess and Diagnose Neuropathic Pain During Acute Hospital Admission: Results From Traumatic Spinal Cord Injury

Objectives: A clinical protocol was developed for clinicians to routinely assess and initiate treatment for patients with neuropathic pain (NP) in an acute care setting. The objectives of this study were to: (1) determine the incidence and onset of NP in patients with traumatic spinal cord injury during acute care and (2) describe how the implementation of a clinical protocol impacts the assessment and diagnosis of NP. Materials and Methods: The study was a cohort analysis with a pre-post-test utilizing a historical control. Data were retrospectively collected from a patient registry and charts. Participants were randomly selected in cohort 1 (control) and cohort 2 (NP clinical protocol). Results: The incidence of NP was 56% without significant difference between the cohorts (P=0.3). Onset of NP was 8 days (SD=14) across the study and >85% of the participants with NP were diagnosed within 2 weeks. Participants with incomplete injuries had a significant earlier onset than participants with complete injuries (6.2±12.8, 10.9±15.8 d; P=0.003). The mean number of days from hospital admission to initial assessment decreased with use of the NP clinical protocol (3.7±5.7 d; P=0.02). Discussion: This study demonstrates a high incidence and early onset of NP in traumatic spinal cord injury during acute hospital care, with an earlier emergence in participants with incomplete injury. The NP clinical protocol ensured continuous assessment and documentation of NP while decreasing the time to an initial screen, but did not impact diagnosis.