Anesthesia considerations in a case for spinal cord injury.ppt

cme

1. Anesthesia for Patients with
Spinal Cord Injury
Dr. Ashish
Moderator : Dr.R.Tope
www.anaesthesia.co.in [email protected]

4. Blood supply
 Two posterior spinal arteries
Anterior spinal artery – formed by the confluence of
two vertebral arteries
The lower cervical cord is a region of relative
ischemia and is vulnerable for ischemic injury
should the anterior spinal artery be compromised
between the foramen magnum and C
8, the cervical
watershed.

6. Spinal Cord Paralysis Levels
C1-C3
All daily functions must be totally assisted
Breathing is dependant on a ventilator
Motorised wheelchair controlled by sip and puff or
chin movements is required
C4
Same as C1-C3 except breathing can be done
without a ventilator
C5
Good head, neck, shoulder movements, as well as
elbow flexion
Electric wheelchair, or manual for short distances

7. C6
Wrist extension movements are good
Assistance needed for dressing, and transitions from
bed to chair and car may also need assistance
C7-C8
All hand movements
Ability to dress, eat, drive, do transfers, and do upper
body washes
T1-T4 (paraplegia)
Normal communication skills
Help may only be needed for heavy household work
or loading wheelchair into car

8. T5-T9
Manual wheelchair for everyday living
Independent for personal care
T10-L1
Partial paralysis of lower body
L2-S5
Some knee, hip and foot movements with possible slow
difficult walking with assistance or aids
Only heavy home maintenance and hard cleaning will
need assistance

9. Treatment of Spinal Injuries
No Current Effective Treatment
Prevention is Key
–all current medical and surgical treatments aimed
to prevent further injury to the spinal cord.

10. Spinal Cord Injuries
May occur with neck or back trauma
Associated with blunt head trauma,
especially when casualty is unconscious
Can occur with penetrating trauma of
vertebral column
Improper handling may cause further injury

11. Mechanisms of
Spinal Injury
Hyperextension
Hyperflexion
Compression
Rotation
Lateral Stress
Distraction

12. Pathophysiology
Damage – Begins centrally in grey matter and
spreads centrifugally.
Primary insult –B/W Time of injury and initial care
Secondary insult – Delayed swelling
Continued mechanical trauma
Low perfusion
Endogenous factors
Initial segmental loss can be withstood because
only small portion of grey matter neuronal pool is
involved.

13. –ASIA A: Complete: no motor or sensory function is
preserved in the sacral segments S4-S5
–ASIA B: Incomplete: sensory but NOT motor function is
preserved below the neurological level and includes the
sacral segments
–ASIA C: Incomplete: motor function is preserved below the
neurological level and more than half of key muscles below
the neurological level have a muscle grade <3
–ASIA D: Incomplete: motor function is preserved w/
muscle grade > 3
–ASIA E: Normal

14. Diagnosis and management of acute spinal
cord injury
Initial assessment and immobilization
Resuscitation and medical management
Radiological diagnostics
Anaesthesia management
Surgical therapy
Post op critical care management

15. Initial assessment and immobilization
*History
Pain/paresthesias
Transient or persistent motor or
sensory symptoms
*Physical Examination
Abrasions/hematoma
Tenderness
Interspinous process widening

16. Immobilize the casualty’s
head and neck manually
Apply a cervical collar, if
available, or improvise
one
Secure patient to short
spine board if extracting
from a vehicle
Secure head and neck to
spine board for extraction

17. Transfer patient to long
spine board as soon as
feasible
Logroll in unison
Stabilize head and neck
with sandbags or rolled
blankets

18. Secure casualty to long spine board with straps
across forehead, chest, hips, thighs, and lower legs

19. Resuscitation and medical
management ATLS principles
Airway
Breathing
Circulatory
Neurologic Classification
Spinal Imaging
GastroIntestinal System
Genitourinary System
Skin

20. Airway
Risk Associated with Level of Injury
Decision to Intubate
Airway Intervention

21. Risk Associated with
Level of Injury cont’d
Ventilatory Function
–C1 - C7 = accessory muscles
–C3 - C5 = diaphragm
“C3-4-5 keeps the diaphragm alive!
–T1 - T11 = intercostals
–T6 - L1 = abdominals

22. Decision to Intubate:
Need for Artificial Airway is Usually Related to Resp
Compromise e.g.
–Loss of innervation of the diaphragm
(C 3-4-5 keep the diaphragm alive)
–Fatigue of innervated resp muscles
–Hypoventilation – SaO2 <60, PaCO2 >45
–V/Q mismatch – PaO2/FiO2 <250
–Secretion retention
–Atelectasis

23. Decision to Intubate
Related to Neurological Level
Occiput - C3 Injuries
(ASIA A & B)
–Require immediate intubation
and ventilation due to loss of innervation of
diaphragm

24. Decision to Intubate
Related to Neurological Level
cont’d
C4-C6 Injuries (ASIA A & B)
–Serious consideration for prophylactic
intubation and ventilation if:
Ascending injury (requires serial M/S
assessment by a trained clinician)
Fatigue of unassisted diaphragm
Inability to clear secretions

25. Airway Intervention
Maintaining Spinal Precautions
–Supine position
Maintain neutral C-spine
–Remove rigid collar and sandbags
–Manually stabilize C-spine
2 person technique:
–1st person to provide manual
in-line stabilization (not traction) of C-spine
–2nd person intubates

27. Complications of cervical spine
immobilization
Airway:delayed tracheostomy-poor oral hygeine
Breathing: prolonged mechanical ventillation-VAP
Circulation:difficult central line insertion and access,
increased thromboembolism
Neurological: increased ICP
Gut: gastrostasis,reflux and aspiration;delayed
enteral nutrition
Skin: pressure sores around collar
Staffing: minimum 4 for log rolling; cross infection

28. Breathing
Cough Function
C1-C3 = absent
C4 = non-functional
C5-T1 = non-functional
T2-T4 = weak
T5-T10 = poor
T11 & below = normal

29. Breathing cont’d
Vital Capacity (acute phase)
C1-C3 = 0 - 5% of normal
C4 = 10-15% of normal
C5-T1 = 30-40% of normal
T2-T4 = 40-50% of normal
T5-T10 = 75-100% of normal
T11 and below = normal

30. Breathing cont’d
SCI Respiratory Sequale
–Atelectasis
–Ventilatory failure
(PaCO
2 > 50mmHg and pH < 7.30)
–Increased secretions
–Pneumonia
–Pulmonary emboli
–Pulmonary edema (Autonomic)

31. Breathing cont’d
Intervention
–O
2 therapy
–Assisted ventilation
–Medications (bronchodilators)

32. Circulatory
Spinal Shock
Temporary suppression
of all reflex activity
below the level of injury
Occurs immediately
after injury
Intensity & duration
vary with the level &
degree of injury
Neurogenic Shock
The body’s response to the
sudden loss of sympathetic
control
Distributive shock
Occurs in people who have
SCI above T6 (> 50% loss of
sympathetic innervation)

33. Hemodynamic Instability: Intervention
First Line:
Volume |Resuscitation (1-2 L)
Second line:
Vasopressors- (dopamine/norepinephrine) to
counter loss of sympathetic tone and provide
chronotropic support to the heart

34. Hemodynamics and Cord Perfusion
Options:
–Avoid hypotension
–Maintain MAP 85-90mmHg for first 7 days
if possible

35. Bradycardia: Intervention
Prevention:
–Avoid vagal stimulation
–Hyperventilate and hyperoxygenate prior to
suctioning
–Pre-medicate patients with known hypersensitivity
to vagal stimuli
Treatment of Symptomatic Bradycardia:
–Atropine 0.5 - 1.0 mg IV

36. Neurological Classification
–Motor and sensory assessment
–ASIA Impairment Scale (A-E)
–Clinical Syndromes (patterns of incomplete injury)

37. Spinal Shock
An immediate loss of reflex function, called areflexia,
below the level of injury
Signs:
–Slow heart rate
–Low blood pressure
–Flaccid paralysis of skeletal muscles
–Loss of somatic sensations
–Urinary bladder dysfunction
Spinal shock may begin within an hour after injury
and last from several minutes to several months,
after which reflex activity gradually returns

38. Central Cord Syndrome
Usually involves a cervical lesion
May result from cervical hyperextension causing
ischemic injury to the central part of the cord
Motor weakness is more present in the upper limbs
then the lower limbs
Patient is more likely to lose pain and temperature
sensation than proprioception
Patient may complain of a burning feeling in the
upper limbs
More commonly seen in older patients with cervical
arthritis or narrowing of the spinal cord

39. Brown-Sequard Syndrome
Results from an injury to only half of the
spinal cord and is most noticed in the
cervical region
Often caused by spinal cord tumours,
trauma, or inflammation
Motor loss is evident on the same side as
the injury to the spinal cord
Sensory loss is evident on the opposite
side of the injury location (pain and
temperature loss)
Bowel and bladder functions are usually
normal
Person is normally able to walk although
some bracing or stability devices may be
required

40. Anterior Spinal Cord Syndrome
Usually results from compression of the artery that
runs along the front of the spinal cord
Compression of SC may be from bone fragments or
a large disc herniation
Patients with anterior spinal cord syndrome have a
variable amount of motor function below the level of
injury
Sensation to pain and temperature are lost while
sensitivity to vibration and proprioception are
preserved

41. Cauda Equina Syndrome:
Injury to the lumbosacral nerve roots w/ in
the neurocanal resulting in areflexive
bladder, bowel and lower limbs

42. Spine Imaging
the Asymptomatic Patient
–Option - Xray not needed in alert, sober, compliant
patient without neck pain and tenderness or major
distracting injuries
Symptomatic Patient
–Standard – Ap lat and odontoid view
–Option – discontinue protection after….
 normal and adequate dynamic radiography, or
 normal MRI within 48hrs of injury, or
 at the discretion of treating MD

43. CT myelogram – Bony detail of fracture site,
and anatomic relation of segment to spinal
cord.
MRI – anterior discs, ligamentum flava & cord
contusion.

44. GI System
Risk of aspiration is high d/t:
–cervical immobilization
–local cervical soft tissue swelling
–delayed gastric emptying
Parasympathetic reflex activity is altered, resulting in:
–decreased gut motility and
–often prolonged paralytic ileus

45. GI Intervention- Nasogastric tube
IV H2 blockers
GU Intervention – Catheterisation
Skin Intervention –
*Remove spine board
*Turn or reposition individuals with SCI initially
every 2 hours in the acute phase if the medical
condition allows.

46. Pharmacologic Therapy
Methylprednisolone-controversial
–30mg/kg IV loading dose + 5.4 mg/kg/hr (over
23hrs) effective if administered within 8 hours of
injury
–If initiated < 3hrs continue for 24 hrs, if 3-8 hrs
after injury, continue for 48hrs (morbidity higher -
increased sepsis and pneumonia)
Thromboprophylaxis - LMWH, discontinued at
3months

47. Secondary Interventions
Without mechanical compression on CT
myelogram – External stabilisation
Mean arterial pressures are kept b/w 80-90
mmHg and CO kept ( N/ high N )
Dopamine infusion may be necessary

48. Anaesthesia Management
Pre op assessment
Medical history
Premedication and pt. Education
Airway management
Positioning
Fluid requirements
Special intraop requirements(wake up test)
Post op pain and pulmonary toilet

50. Airway evaluation
MP classification and range of neck mobility and elicitation of
pain/ neurological symptom
Pulmonary evaluation
During spinal shock (3 days – 6 wks)
ABG- assess adequacy of ventilation, intubation if
hypoxemia or hypercapnia (on O2 mask)
Chronic stage
PFT and Chest X ray – Restrictive pattern (FEV1&FVC)

51. Severity of functional impairment related to –
Angle of scoliosis, No of vertebrae,
cephalad location of curve and loss of normal
kyphosis.
Respiratory function should be optimised –
Treating infection
Bronchodilation
Chest physiotherapy

52. Cardiac evaluation
ECG – myocardial ischemia
Cardiovascular instability evidenced by hypotension,
hypertension, brady & arry. – assessment of cardiac
reserve and to optimise circulatory volume according
to cardiac function and peri. Vas. Tone.
Pacemaker – persistently bardycardic.
High spinal cord injury – initially spinal shock,autonomic
dys,impaired LVF and later autonomic dysreflexia.

53. Neurological evaluation
Document preexisting deficits
Neurological dys may dictate intubation
tech,monitoring and choice of agents.
Pharmacology
Altered P/K because of muscle wasting,inc volume
of distribution,dec serum albumin

54. Preop preparation
Hb, Hct, WBC and urinalysis
Other tests indicated by history
SE, BUN, Creatinine, PT,aPTT, Platelet count, ECG,
Chest radiograph, ABG and PFT.
Echo – to assess LV function pulmonary artery
pressures and stress echo in sedentary patients

55. Premedication
If anxious IV midazolam Under supervision
Atropine if HR < 70 – Dose 0.04mg/kg
H2 receptor blocker/ PPI
Induction
Unnecessary/ contraindicated for unconscious,
recently injured patients with spinal cord trauma /
those with severe shock.

56. Technique of intubation
Elective - fiberoptic intubation
Emergency – MILS with rapid sequence
Maintenance
Nitrous oxide, inhalation agent

57. Positioning
Goals
Adequate surgical exposure
Anatomic position of extremities & head
Avoid abdominal pressure
Adequate padding
Various positions
a) Prone
b) Supine
c) Sitting (obsolete

58. PRONE POSITION
MOST COMMONLY USED
EYES:
Corneal abrasion
Optic neuropathy
Retinal artery occlusion
HEAD & NECK
Venous and lymphatic
obstuction
ABDOMEN
Impaired ventilation
Decreased CO

59. Monitoring
Neurological
Wake up test
SSEP
Transcutaneus MEP
Physiological
Pulse oximetry
Continuous ECG
monitoring
EtCo2
CVP
Temperature
Urine output
Invasive BP
Swan Ganz catheter?

60. Post operative pain relief
•NSAIDS (IM,IV,P/R)
•IV opiods (Intermitent / continuous infusion )
•PCA

61. Post op critical care management
Indications for post op ventilation –
Preexisting NM disorder
Severe restrictive – VC <35%
Obesity / RVF
Prolonged surgery
Surgical invasion of thoracic cavity
Blood loss > 30ml/kg

62. post op contd
Prepare for weaning
Adequate nutrition and metabolic state
Infection – May be masked(Poikilothermia)
Optimal fluid management
Treat mechanical impairment to breathing like
abd distention, tight halo cast, position
Psychological preperation

63. Post op contd
Chest Physiotherapy – Postural drainage,
chest wall percussion and vibration, tracheal
suctioning and breathing exercises.
Cough – Glossopharyngeal breathing and
huffing.
Breathing exercises

64. Perioperative complications of spine surgery
a)Airway obstruction : edema, hematoma,recurrent laryngeal
nerve palsy.
b)Respiratory: motor paralysis and infection (pneumonia).
c)Cardiovascular: hypotension, bradycardia, arrhythmias,
hypertension ( spinal cord injury, carotid sinus stimulation).
d)Neurological:
Injury to nerve roots – as a result of direct surgical
manipulation
Injury to lower cranial nerves – VII, IX, X, XII
Injury to peripheral nerves - as a result of positioning
Injury to spinal cord .

65. e) Vessel injury – vertebral and carotid artery during
dissection
f) Tracheal and oesophageal injury
g) CSF leaks - due to tear of dural and arachnoid
membranes can lead to meningitis, pseudomeningocoele,
permanent CSF fistula
h) DVT – seen in 30% of neurosurgical patients, especially
those who had been paraplegic. Pulmonary embolism may
occur

66. Outcome
Acute spinal injury who survive
>24hrs,85%alive at 10years
Most common causes of death-pneumonia,
non-ischemic heart disease (occult
autonomic dysfn), suicide (lifelong impact of
injury)


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