1 Spinal injuries: Recognition and TherapyIan Scott Feb

2 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

3 The Spinal Column C-Spine (44%) Thoracic Spine (41%) Lumbar Spine(15%) Sacral Spine Ian Scott Feb

4 Cervical Spine The most vulnerable yet most common site of injury.Data from the UK ( ) 44% of all spine trauma occurs at the cervical level Ian Scott Feb

5 Incidence of SCI 20-40 cases per million per yearUS data cases per year Of these cases 40% are “complete” No sensory or motor function below the lesion 4 000 cases per year of tetra/paraplegia Ian Scott Feb

6 Incidence of SCI cont. Disease of the young maleAge usually between years Mechanisms of injury (UK vs. Can) MVA 36% / 36% Sport 20% / 14% Domestic/Work 37% / 44% Assault 6.5% / 6% Ian Scott Feb

7 Cost of Spinal Cord InjuryLifetime direct medical costs range between $ $ 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

8 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

9 Spinal Injuries The patient with potential spine injury.Injury prevention Pre-hospital care Emergency triage Surgical Management Medical Management Rehabilitation Ian Scott Feb

10 Spinal Injuries The patient with potential spine injury.Injury prevention Pre-hospital care Emergency triage Surgical Management Medical Management Rehabilitation Ian Scott Feb

11 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

12 Identifying the SCI patientEmergency medical personnel are usually the first on the scene. Who should be placed in spinal precautions? Ian Scott Feb

13 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 504 patients brought by EMS 495 were in Spinal precautions What about the 9 patients that weren’t? Ian Scott Feb

14 Fresno County EMS policy #530Spinal 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

15 Fresno Protocol Of the 9 patients not immobilized2 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

16 Pre-hospital immobilizationAn interesting point: Do ANY patients with suspected SCI need immobilization? (Hauswald Acad Emerg Med Mar 1998) Ian Scott Feb

17 Out of Hospital spinal immobilization: its effect on neurologic injury5 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

18 Who Cares? Malaysia New Mexico Similar hospital Similar StaffNO SPINAL PRECAUTIONS New Mexico Universal precautions Ian Scott Feb

19 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 Ian Scott Feb

20 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

21 Morbidity associated with Spinal immobilizationSeveral 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

22 Identifying potential SCI: Clearing the SpinesThere 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

23 Spinal injury To identify the people each year with spinal injury, emergency physicians will screen approximately patients with spinal radiography. Two recent papers address this situation Ian Scott Feb

24 NEXUS: National emergency X-radiography Utilization StudyHoffman et al NEJM :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

25 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

26 NEXUS 34 069 patients enrolled818 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

27 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 patients Ian Scott Feb

28 Ian Scott Feb

29 NEXUS Several concerns have been raised regarding NEXUSScreening 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

30 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

31 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

32 Canadian C-spine rules8924 patients enrolled 151 patients had important c-spine injury (1.7%) Derived Decision rule as follows: Ian Scott Feb

33 Canadian Rules… Ian Scott Feb

34 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

35 Canadian C-spine rules100% sensitivity 42.5% specificity Potential radiography order rate 58.2% Unfortunately, these rules do not apply to the usual ICU patients Ian Scott Feb

36 Spinal Radiography in critically illNo 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

37 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

38 Lateral c-spine view Lateral views have a sensitivity of approx 80% to identify c-spine fractures Ian Scott Feb

39 Disruption of all spinal lines with obvious anterior dislocationIan Scott Feb

40 Vertebral Burst fracturesIan Scott Feb

41 SCIWORET worth a mentionSCIWORET 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

42 Pathophysiology of Spinal Cord injuryPrimary mechanisms Initial crush, shear impingement of cord with the inciting trauma. Secondary mechanisms Vascular insults/insufficiency Edema Cell toxicity Apoptosis Ian Scott Feb

43 Secondary Injury Electrolytes Cell toxicity Vascular CELL DEATHDecreased energy (ATP) Edema Apoptosis Ian Scott Feb

44 Secondary Mechanisms Ian Scott Feb

45 Secondary Mechanisms Electrolytes Cell toxicity Apoptosis VascularCalcium release Cell toxicity Glutamate release, arachidonic acid metabolites, free radical generation Apoptosis Programmed cell death Vascular Disautoregulation, hypotension, neurogenic shock Ian Scott Feb

46 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

47 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

48 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

49 The Controversy Unfortunately, the degree of “statistically significant benefit” has no clinical relevance Motor score improvements were 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

50 Important Papers NASCIS II NASCIS III Revisiting NASCIS II & IIINEJM : NASCIS III JAMA : Revisiting NASCIS II & III J. Trauma : Methylprednisolone for acute spinal injury…. J. Neurosurg (Spine 1) 2000:93:1-7 Ian Scott Feb

51 Future Directions Glutamate receptor inhibitionPeripheral nerve transplants Glial cell regeneration Axon growth, guidance and synaptogenesis Ian Scott Feb

52 Ian Scott Feb