Spinal injuries: Recognition and Therapy

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Spinal injuries Recognition and Therapy
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Definition (Stedmans 1998)

• The Spine
• A short sharp process of bone a spinous process
• A thorn
• Columna Vertebralis
• Really not much help

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The Spinal Column
C-Spine (44)
Thoracic Spine (41)
Lumbar Spine
(15)
Sacral Spine
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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
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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

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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

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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

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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?

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Spinal Injuries

• The patient with potential spine injury.
• Injury prevention
• Pre-hospital care
• Emergency triage
• Surgical Management
• Medical Management
• Rehabilitation

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Spinal Injuries

• The patient with potential spine injury.
• Injury prevention
• Pre-hospital care
• Emergency triage
• Surgical Management
• Medical Management
• Rehabilitation

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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.

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Identifying the SCI patient

• Emergency medical personnel are usually the first
  on the scene.
• Who should be placed in spinal precautions?

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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 werent?

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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

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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

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Pre-hospital immobilization

• An interesting point
• Do ANY patients with suspected SCI need
  immobilization?
• (Hauswald Acad Emerg Med Mar 1998)

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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

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Who Cares?

• Malaysia
• Similar hospital
• Similar Staff
• NO SPINAL PRECAUTIONS

• New Mexico
• Universal precautions

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Who Cares?

• Malaysia
• Similar hospital
• Similar Staff
• NO SPINAL PRECAUTIONS
• Less neurologic disability in malaysian patients
  at discharge

• New Mexico
• Universal precautions

Out of hospital immobilization has little effect
on outcome
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Of course we cant!

• 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.

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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)

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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.

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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

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NEXUS National emergency X-radiography
Utilization Study

• Hoffman et al NEJM 2000 34394-99
• 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

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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

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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

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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

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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)

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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..

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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

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Canadian C-spine rules

• 8924 patients enrolled
• 151 patients had important c-spine injury (1.7)
• Derived Decision rule as follows

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Canadian Rules
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Canada Rules

• 1) Any High risk factor that mandates
  radiography?
• Agegt65, 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

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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

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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

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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

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Lateral c-spine view
Lateral views have a sensitivity of approx 80 to
identify c-spine fractures
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• Disruption of all spinal lines with obvious
  anterior dislocation

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Vertebral Burst fractures
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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

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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

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Secondary Injury
Electrolytes
Cell toxicity
Vascular
CELL DEATH
Decreased energy (ATP)
Edema
Apoptosis
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Secondary Mechanisms
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Secondary Mechanisms

• Electrolytes
• Calcium release
• Cell toxicity
• Glutamate release, arachidonic acid metabolites,
  free radical generation
• Apoptosis
• Programmed cell death
• Vascular
• Disautoregulation, hypotension, neurogenic shock

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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.

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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

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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?

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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.

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Important Papers

• NASCIS II
• NEJM 1990 3221405-11
• NASCIS III
• JAMA 1997 2771597-1604
• Revisiting NASCIS II III
• J. Trauma 1998 456 1088-93
• Methylprednisolone for acute spinal injury.
• J. Neurosurg (Spine 1) 2000931-7

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Future Directions

• Glutamate receptor inhibition
• Peripheral nerve transplants
• Glial cell regeneration
• Axon growth, guidance and synaptogenesis

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