The Impact of Mean Arterial Pressure on Functional Outcome Post-Acute Spinal Cord Injury: A Scoping Systematic Review of Animal Models

Bioethical, Reproducibility, and Translational Challenges of Animal Models

There is no prescribed stage or standardized point at which an animal model protocol is reviewed for reproducibility and translatability. The method of review for a reproducible and translatable study is not consistently documented in peer literature, and this is a major challenge for those working with animal models of human diseases. If the study is ill designed, it is impossible to perform an accurate harm/benefit analysis. In addition, there may be an ethical challenge if the work is not reproducible and translatable. Animal welfare regulations and other documents of control clearly state the role of the Institutional Animal Care and Use Committees are to look at science justification within the context of animal welfare. This article, concentrating on models not governed by regulations, outlines issues and offers recommendations for refining animal model review with a goal to improve study reproducibility and translatability.

Early Management of Spinal Cord Injury: WFNS Spine Committee Recommendations

Scientific knowledge today is being generated more rapidly than we can assimilate thus requiring continuous review of gold-standards for diagnosis and treatment of specific pathologies. The aim of this paper is to provide an update on the best early management of spinal cord injury (SCI), in order to produce acceptable worldwide recommendations to standardize clinical practice as much as possible.The WFNS Spine Committee voted recommendations regarding management of SCI based on literature review of the last 10 years. The committee stated 9 recommendations on 3 main topics: (1) clinical assessment and classification of SCI; (2) emergency care and early management; (3) cardiopulmonary management. American Spinal Injury Association impairment scale, Spinal Cord Independence Measure, and International Spinal Cord Injury Basic Pain Data Set are considered the most useful and feasible in emergency evaluation and follow-up in case of SCI. Magnetic resonance imaging is the most indicated examination to evaluate patients with symptomatic SCI. In early phase, correction of hypotension (systolic blood pressure < 90 mmHg), and bradycardia are strongly recommended. Surgical decompression should be performed as soon as possible with the ideal surgical time being within 8 hours for both complete and incomplete lesions.

Exploration of surgical blood pressure management and expected motor recovery in individuals with traumatic spinal cord injury

STUDY DESIGN

Retrospective analysis.

OBJECTIVE

To assess the impact of mean arterial blood pressure (MAP) during surgical intervention for spinal cord injury (SCI) on motor recovery.

SETTING

Level-one Trauma Hospital and Acute Rehabilitation Hospital in San Jose, CA, USA.

METHODS

Twenty-five individuals with traumatic SCI who received surgical and acute rehabilitation care at a level-one trauma center were included in this study. The Surgical Information System captured intraoperative MAPs on a minute-by-minute basis and exposure was quantified at sequential thresholds from 50 to 104 mmHg. Change in International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) motor score was calculated based on physiatry evaluations at the earliest postoperative time and at discharge from acute rehabilitation. Linear regression models were used to estimate the rate of recovery across the entire MAP range.

RESULTS

An exploratory analysis revealed that increased time within an intraoperative MAP range (70-94 mmHg) was associated with ISNCSCI motor score improvement. A significant regression equation was found for the MAP range 70-94 mmHg (F[1, 23] = 5.07, r² = 0.181, p = 0.034). ISNCSCI motor scores increased 0.039 for each minute of exposure to the MAP range 70-94 mmHg during the operative procedure; this represents a significant correlation between intraoperative time with MAP 70-94 and subsequent motor recovery. Blood pressure exposures above or below this range did not display a positive association with motor recovery.

CONCLUSIONS

Hypertension as well as hypotension during surgery may impact the trajectory of recovery in individuals with SCI, and there may be a direct relationship between intraoperative MAP and motor recovery.

Heterogeneous emergency department management of published recommendation defined hypotension in patients with acute traumatic spinal cord injury: A multi-centre overview

OBJECTIVE

Evidence-based management for patients with acute traumatic spinal cord injury (TSCI) in the ED has a critical impact on long-term outcomes. Acute hypotension post-injury may compromise spinal cord perfusion and extend neurological damage. Published guidelines recommend mean arterial blood pressure (BP) maintenance between 85 and 90 mmHg for 7 days post-injury; the extent to which this is followed in Australia is unknown.

METHODS

Prospective observational study of patients ≥16 years with TSCI, treated at 48 hospitals across two Australian states. Mean arterial BPs were recorded in the Ambulance, and ED arrival and discharge. Patients' medical records documented treatment provided (intravenous fluids, vasopressors or both) for BP augmentation. Hypotension was defined as mean arterial BP <85 mmHg, per the American Association of Neurological Surgeons guidelines.

RESULTS

The 208 patients with TSCI in the present study were more likely to receive BP augmentation if they experienced direct transport to a Spinal Cord Service hospital (OR 5.57, 95% CI 2.32-10.11), had a cervical level injury (OR 2.32, 95% CI 1.01-5.5) or were hypotensive on ED arrival (OR 2.42, 95% CI 1.34-4.39). Of the 112 patients who were hypotensive, 71 (63.4%) received treatment for this; however, the majority (76%) remained hypotensive on discharge.

CONCLUSION

Hypotensive patients' post-TSCI experienced heterogeneous ED care discordant with published guidelines; varying by hospital type. Specialist care and more severe injury increased likelihood of guideline adherence. Lack of adherence may influence patient outcomes. Level 1 evidence is needed along with consistent guideline implementation and clinician training to likely improve TSCI management and outcomes.

Emergency and acute care management of traumatic spinal cord injury: a survey of current practice among senior clinicians across Australia

Background

To describe pre-hospital, emergency department and acute care assessment and management practices of senior clinicians for patients with acute traumatic spinal cord injury (TSCI) across Australia; and to describe clinical practice variation.

Methods

We used a descriptive, cross-sectional study design to survey senior clinicians (greater than 10 years practice in this field) caring for patients with acute TSCI. The assessment, management and referral practices of prehospital, emergency department/trauma and surgical expert clinicians, across prehospital, early hospital care, diagnostic imaging and haemodynamic management were surveyed.

Results

We invited 95 eligible senior clinicians; the response rate was 75%. Survey findings demonstrated overall lack of awareness or consistent use of evidence based published guidelines; many clinicians following ‘locally written’ or ‘no particular’ guideline. Practitioners were conflicted across multiple areas including patient assessment and diagnosis, treatment and transport decisions. Reported spinal immobilisation practices differed substantially, as did target setting for blood pressure; the majority of clinicians actively monitored risk of respiratory deterioration. Specialist care consult and specialist service bed availability was reported as problematic by more than one third of clinicians.

Conclusions

Unwarranted clinical practice variation is known to contribute to different health outcomes for patients with similar etiologies. Clinical practice guidelines offer evidence based, best practice standards, however are only effective if adopted throughout the healthcare system. Wide variability in acute care practices, pathways and timing to specialist centres for TSCI was evidenced by this survey despite seniority among clinicians. This devastating injury requires prompt, consistent, evidence based care from the moment of first responder. Improved outcomes for patients with TSCI would be more likely with standardised care across pre-hospital, emergency and acute care phases of care.

Keywords

Spinal Cord Injuries, Multiple Trauma, Practice Guideline, Treatment Outcome, Surveys and Questionnaires, Expert Testimony