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Spinal injuries: Recognition and Therapy. Definition (Stedmans 1998). The Spine : A short sharp process of bone; a spinous process A thorn Columna Vertebralis Really not much help. The Spinal Column. C-Spine (44%). Thoracic Spine (41%). Lumbar Spine. (15%). Sacral Spine.
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Spinal injuries: Recognition and Therapy Ian Scott Feb 6 2002
Definition (Stedmans 1998) • The Spine: • A short sharp process of bone; a spinous process • A thorn • Columna Vertebralis Really not much help Ian Scott Feb 6 2002
The Spinal Column C-Spine (44%) Thoracic Spine (41%) Lumbar Spine (15%) Sacral Spine Ian Scott Feb 6 2002
Cervical Spine The most vulnerable yet most common site of injury. Data from the UK (1993-95) 44% of all spine trauma occurs at the cervical level Ian Scott Feb 6 2002
Incidence of SCI • 20-40 cases per million per year • US data 10 000 cases per year • Of these 10 000 cases • 40% are “complete” • No sensory or motor function below the lesion • 4 000 cases per year of tetra/paraplegia Ian Scott Feb 6 2002
Incidence of SCI cont. • Disease of the young male • 85% male • Age usually between 15-35 years • Mechanisms of injury (UK vs. Can) • MVA 36% / 36% • Sport 20% / 14% • Domestic/Work 37% / 44% • Assault 6.5% / 6% Ian Scott Feb 6 2002
Cost of Spinal Cord Injury • Lifetime direct medical costs range between $325 000 - $1 350 000 • Varies according to age at injury as well as severity of injury • High Tetraplegics account for over 80% of expenditures • $7.7 Billion per year in USA Ian Scott Feb 6 2002
Spinal Injuries • The devastating effects on the patient, as well as the burdensome effect on health care dollars has created an urgency for a cure. • WHAT CAN BE DONE? Ian Scott Feb 6 2002
Spinal Injuries • The patient with potential spine injury. • Injury prevention • Pre-hospital care • Emergency triage • Surgical Management • Medical Management • Rehabilitation Ian Scott Feb 6 2002
Spinal Injuries • The patient with potential spine injury. • Injury prevention • Pre-hospital care • Emergency triage • Surgical Management • Medical Management • Rehabilitation Ian Scott Feb 6 2002
SCI pre-hospital care • We are instructed to maintain potential SCI patients “in a Neutral position” for fear of worsening the initial injury • “Pithing the Frog” • Cervical Hard collar is North American Standard of Care. Ian Scott Feb 6 2002
Identifying the SCI patient • Emergency medical personnel are usually the first on the scene. • Who should be placed in spinal precautions? Ian Scott Feb 6 2002
Who should get spinal precautions? • Stroh & Braude (Ann Emerg Med June 2001) • Retrospective chart review • Fresno County EMS Spine protocol • 861 patients discharged from hospital with SCI from 1990-96 • 504 patients brought by EMS • 495 were in Spinal precautions • What about the 9 patients that weren’t? Ian Scott Feb 6 2002
Fresno County EMS policy #530 • Spinal immobilization • Implement spinal immobilization under following circumstances: • Spinal pain or tenderness, include any neck pain with hx of trauma • Significant Multi trauma • Severe facial/head trauma • Numbness/weakness after trauma • Loss of consciousness caused by trauma • If altered mental status and • No hx available • Found in setting of possible trauma • Near drowning with hx or probability of diving Ian Scott Feb 6 2002
Fresno Protocol • Of the 9 patients not immobilized • 2 refused immobilization AMA • 2 could not be immobilized • The remaining 5 patients however: • 2 patients had criteria BUT were not immobilized • Protocol violation • 3 patients were missed by protocol • This leaves a 499/504 ratio 99% sensitivity Ian Scott Feb 6 2002
Pre-hospital immobilization • An interesting point: • Do ANY patients with suspected SCI need immobilization? (Hauswald Acad Emerg Med Mar 1998) Ian Scott Feb 6 2002
Out of Hospital spinal immobilization: its effect on neurologic injury • 5 year retrospective chart review • Effect of emergent immobilization on neurologic outcome, comparing two different University hospitals • University of Malaya, Malaysia • 120 patients • University of New Mexico • 334 patients Ian Scott Feb 6 2002
Malaysia Similar hospital Similar Staff NO SPINAL PRECAUTIONS New Mexico Universal precautions Who Cares? Ian Scott Feb 6 2002
Malaysia Similar hospital Similar Staff NO SPINAL PRECAUTIONS Less neurologic disability in malaysian patients at discharge New Mexico Universal precautions Who Cares? Out of hospital immobilization has little effect on outcome Ian Scott Feb 6 2002
Of course we can’t! • A retrospective study has many significant pitfalls but it suggests a few things • Spinal cord injury is primarily the result of the initial impact. • Secondary damage may be caused by swelling, ischemia etc, but NOT necessarily by unrestricted movement post injury • There may be unrecognized morbidities associated with spinal immobilization. Ian Scott Feb 6 2002
Morbidity associated with Spinal immobilization • Several studies have questioned the wisdom of routine spinal immobilization • Pain and discomfort • Respiratory compromise • Increased intracranial pressure • Actual worsening of symptoms (numerous references) Ian Scott Feb 6 2002
Identifying potential SCI: Clearing the Spines • There is no easy solution. • We must recognize that MANY people will be immobilized in the hopes of preventing further injury to those patients with true spinal injury. • Efforts must be made to “clear” low risk patients quickly and efficiently. Ian Scott Feb 6 2002
Spinal injury • To identify the 10 000 people each year with spinal injury, emergency physicians will screen approximately 800 000 patients with spinal radiography. • Two recent papers address this situation Ian Scott Feb 6 2002
NEXUS: National emergency X-radiography Utilization Study • Hoffman et al NEJM 2000 343:94-99 • Prospective observational study to validate decision rule for low risk patients • Decision instrument as follows: • Absence of tenderness in posterior midline • Absence of neurologic deficit • Normal level of alertness (GCS 15) • No evidence of intoxication • No distracting pain elswhere Ian Scott Feb 6 2002
NEXUS • Patients who fulfilled all five criteria were considered low risk for C-spine injury and therefore do not require C-spine radiography • If patients had any of the 5 criteria, they would have radiographic imaging in the form of 3 views • AP, lateral and odontoid views Ian Scott Feb 6 2002
NEXUS • 34 069 patients enrolled • 818 patients had significant c-spine injury • 810 were identified as potential spinal injury patients by the decision rule • 8 patients were identified as low risk, but in fact had radiographic injury Ian Scott Feb 6 2002
NEXUS • Sensitivity 99% • Negative predictive value 99.8% • Specificity 12.9% • Positive predictive value 2.7% • Radiographic imaging could have been avoided in 4309 patients (12.6%) of the 34 069 patients Ian Scott Feb 6 2002
NEXUS • Several concerns have been raised regarding NEXUS • Screening C-spines with three views may not be sensitive enough to detect all spinal injuries in the study population • Many centres advocate use of bilateral oblique views also (5 views) Ian Scott Feb 6 2002
NEXUS • Many emergency physicians also feel the criteria are too vague and open for interpetation • Distracting injuries • Presence of intoxication • Enter the Canadian C-spine rules.. Ian Scott Feb 6 2002
Canadian C-spine rules (JAMA Oct 17 2001) • Brought to fruition by same group who developed the Ottawa Ankle rules • Prospective cohort study, patients evaluated for 20 standardized clinical findings PRIOR to radiography • Hx of blunt trauma to head/neck, hemodynamically stable, with GCS 15 Ian Scott Feb 6 2002
Canadian C-spine rules • 8924 patients enrolled • 151 patients had important c-spine injury (1.7%) • Derived Decision rule as follows: Ian Scott Feb 6 2002
Canadian Rules… Ian Scott Feb 6 2002
Canada Rules • 1) Any High risk factor that mandates radiography? • Age>65, dangerous mechanism, paresthesias • 2) Any low risk factors that allow safe assessment of range of motion • Simple rear end MVC, sitting position in ER, Ambulatory at any time, delayed onset of neck pain, absence of midline tenderness • 3) Able to rotate neck? • 45 degrees left and right Ian Scott Feb 6 2002
Canadian C-spine rules • 100% sensitivity • 42.5% specificity • Potential radiography order rate 58.2% Unfortunately, these rules do not apply to the usual ICU patients Ian Scott Feb 6 2002
Spinal Radiography in critically ill • No clear consensus. • Full agreement that patients with trauma and decreased LOC must be assumed to have spinal fracture until cleared clinically and/or radiographically Ian Scott Feb 6 2002
C-spine radiography • Bare Minimum: • Cross table lateral • Anteroposterior view • Open mouth odontiod • If adequate views NOT attainable, patient requires CT scan reconstructions of disputed areas Ian Scott Feb 6 2002
Lateral c-spine view Lateral views have a sensitivity of approx 80% to identify c-spine fractures Ian Scott Feb 6 2002
Disruption of all spinal lines with obvious anterior dislocation Ian Scott Feb 6 2002
Vertebral Burst fractures Ian Scott Feb 6 2002
SCIWORET worth a mention • SCIWORET is Spinal cord injury without radiographic evidence of trauma • First described in pediatric population (SCIWORA) • In adults, tends to affect the elderly • Much more prevalent in cervical spine as opposed to the thoracolumbar area. • Related to the degenerative changes in the c-spine Ian Scott Feb 6 2002
Pathophysiology of Spinal Cord injury • Primary mechanisms • Initial crush, shear impingement of cord with the inciting trauma. • Secondary mechanisms • Vascular insults/insufficiency • Edema • Cell toxicity • Apoptosis Ian Scott Feb 6 2002
Secondary Injury Electrolytes Cell toxicity Vascular CELL DEATH Decreased energy (ATP) Edema Apoptosis Ian Scott Feb 6 2002
Secondary Mechanisms Ian Scott Feb 6 2002
Secondary Mechanisms • Electrolytes • Calcium release • Cell toxicity • Glutamate release, arachidonic acid metabolites, free radical generation • Apoptosis • Programmed cell death • Vascular • Disautoregulation, hypotension, neurogenic shock Ian Scott Feb 6 2002
Secondary mechanisms • Numerous mediators of spinal cord damage have been identified experimentally. • The hope is that through simple pharmacologic interventions, the secondary damage can be limited, or even potentially reversed. • Unfortunately very little clinical progress has been made to date. Ian Scott Feb 6 2002
Steroids • Several studies have reported success with high dose steroid infusions, limiting progression of spinal cord damage in trauma. • NASCIS II and III (NEJM 1990, JAMA 1997) • Two highly publicized studies demonstrating small but clinically significant improvement with neurologic recovery following administration of high dose methyl-prednisolone • NASCIS II placebo controlled • NASCIS III dose varied. Not placebo controlled Ian Scott Feb 6 2002
NASCIS II • Steroid bolus 30mg/kg over 15min in 1st hour, then 5.4mg/kg/hr for 23 hours • An average 70Kg patient would receive 23 GRAMS of steroid over 24 hours • NASCIS II was in fact a negative study. • Only on post hoc sub group analysis did steroid yield a “benefit” • Only patients who received steroid in the first 8 hours post injury demonstrated a benefit • What degree of benefit however? Ian Scott Feb 6 2002
The Controversy • Unfortunately, the degree of “statistically significant benefit” has no clinical relevance • Motor score improvements were 17 .2 and 12.0 for steroid and placebo groups respectively (out of a total possible score of 70), which gives a difference of 5.2. • A difference of 5.2 simply put could be gained if a patient regained the ability to shrug his shoulders. Ian Scott Feb 6 2002
Important Papers • NASCIS II • NEJM 1990 322:1405-11 • NASCIS III • JAMA 1997 277:1597-1604 • Revisiting NASCIS II & III • J. Trauma 1998 45:6 1088-93 • Methylprednisolone for acute spinal injury…. • J. Neurosurg (Spine 1) 2000:93:1-7 Ian Scott Feb 6 2002