Chronic Spinal Cord Injury

Patients undergo a number of physiological changes following a spinal cord injury:

Covers management of spinal cord injuries after the first few weeks following injury. Acute spinal cord injuries are covered under Spinal Cord Injury.

Epidemiology and Risk Factors

Pathophysiology

Degree of deficit depends on the level of the lesion.

Respiratory:

Patients with cervical spine injury ventilate better in the supine position as:

  • Abdominal paralysis pushes abdominal contents cephalad
    Can be replicated with an abdominal binder in the erect position.
  • This ↓ FRC but ↑ excursion of the diaphragm, providing mechanical advantage
  • ↓ VC
    • Intercostal muscle paralysis
    • Diaphragm paralysis
      Requires permanent mechanical ventilation.
  • ↓ Respiratory compliance
    • Intercostal muscle spasticity
    • ↓ FRC
      • Atelectasis
      • Altered surfactant
  • ↓ Abdominal compliance
    • Abdominal muscle paralysis
  • ↑ Bronchial tone
  • ↑ Bronchial secretions
  • Impaired cough
    • ↓ VC
    • Abdominal muscle paralysis
    • Intercostal muslce paralysis
  • Sleep disordered breathing

Cardiovascular:

  • ↓ Sympathetic tone
    • Due to:
      • Loss of sympathetic outflow
      • Unopposed vagal tone
    • ↓ HR
    • Vasodilatation
    • Hypotension

Clinical Manifestations

Management

Specific therapy:

  • Physical
    • Assisted ventilation

Supportive care:

Anaesthetic Considerations

  • A
    • Fusion may impair airway management
  • B
    • Reduced TLC, FRC
      Rapid desaturation with anaesthetic induction.
  • C
    • Consider induction with vasopressor infusion
    • Arterial line
    • MAP within 20% of baseline
    • Pulmonary oedema with overfilling
      Heart reliant on the Starling mechanism to ↑ cardiac output.
    • Autonomic dysreflexia
  • D
    • Anaesthetic technique
      Consider autonomic dysreflexia.
    • Sensitivity to sedatives
  • E
    • Avoid suxamethonium

Autonomic dysreflexia is covered under Autonomic Dysreflexia.

Marginal and Ineffective Therapies

Complications

Presence and severity depends on height of injury.

  • B
    • Pneumonia
      Impaired expectoration.
  • C
    • Coronary artery disease
      3-10× ↑ prevalence, due to ↑ risk factors.
    • Atypical ischaemic symptoms
    • Hypovolaemia
    • Bradycardia
      Resting heart rate ~50-60.
  • D
    • Chronic pain
      Present in ~60%. Evidence for:
      • Gabapentinoids
      • TCA
  • E
    • Pressure area care
      Decubitus injury occurs in 30-50%:
      • Loss of sensation
      • Paralysis
  • F
    • Urinary retention
      Due to combined sphincter and detrusor overactivity.
      • Leads to:
        • Vesicoureteric reflux
        • Overflow incontinence
        • ↑ Risk UTI
      • May require:
        • Suprapubic catheter
        • Anticholinergics
        • Intra-detruser botulinum toxin
    • Renal stones
      Due to altered calcium homeostasis.
  • G
    • Gastric ulceration
    • Gastroparesis
    • Constipation
      Regular stool softeners required.
  • H
    • Anaemia
      Prevalent in ~50%
    • VTE
      100% risk without VTE prophylaxis.

Prognosis

Key Studies

References

  1. Bersten, A. D., & Handy, J. M. (2018). Oh’s Intensive Care Manual. Elsevier Gezondheidszorg.