Management of acute high spinal injury

Priority

Issues

Caveats and complicating features

Airway

Decision regarding intubation

• Anybody with a fracture around C4-5 needs early intubation
• About 1/3rd of patients will require intubation within the first 24 hours after their injury.
• It is therefore better to perform a controlled "semi-elective" intubation rather than a panic-driven emergency intubation.

Intubation as appropriate

• May be made difficult by inline stabilisation
• In later stages (after 4 or so days) suxamethonium is contraindicated.

Tracheostomy

• This may be an inevitable consequence of high C-spine injury: in one retrospective review, "all patients with complete injuries at the C5 level and above required a definitive airway and tracheostomy"

Respiratory

Support of spontaneous breathing

• If the diaphragm is working, that does not mean the respiratory function is normal. Mechanics will be disturbed by failure of the other muscles of respiration.
• Paradoxically, sitting the patient upright will actually make the situation worse - their lungs perform better when supine.
• NIV is apparently an option in the early stages. Shallow mechanically impaired breaths lead to atelectasis, and NIV can reverse this process to some degree
• High-flow nasal prongs may provide some protection.
• As spasticity of the chest wall muscles progresses, the chest wall becomes rigid and respiratory mechanics improve; maximum inspiratory effort may recover to about 60% of predicted pre-injury levels.

Mechanical ventilation

• Dependence on this may last until after discharge. The family should be aware of this.
• A fair proportion of patients with injuries below C4 can eventually be weaned, but it may take up to 2 weeks before this process can begin.
• Denervation of most of the body's muscles will likely decrease the total CO₂ production; the demand on ventilation will reflect this.

Secretion control

• Pneumonia is a leading cause of death in the spinal cord injury population; VAP is very common
• Poor secretion clearance due to poor cough is the main problem.

Circulatory

Vasodilated shock

• This is due to sympathetic tone failure (neurogenic shock)
• One typically manages this with fluids, at least intially
• Unfortunately, this is an attempt to increase blood pressure by relying on increasing stroke volume by increasing preload; therefore there may come a point where further increases in preload will be fruitless
• Noradrenaline is the drug of choice at this stage.

Bradycardia

• This is due to unopposed parasympathetic tone in the sinus node, leading to sinus bradycardia.
• Apparently, the first 14 days after the injury are the worst.

Haemodynamic areflexia

• These patients will be very sensitive to changes in volume, as they are unable to adjust their cardiac output or smooth muscle tone in response to changes in circulating volume.

Definitive management

Surgical decompression

• There is some evidence that surgery within 24 hours may reduce length of intensive care unit stay and reduce post-injury medical complications.
• If there is persisting spinal cord compression, there is evidence that urgent decompression can lead to significant functional improvement (even from complete motor quadriplegia to independent ambulation).
• The recent (2012) STASCIS trial has confirmed that this is a real effect; the major enrolment criterion was MRI evidence of ongoing cord compression.

Surgical stabilisation

• The bones are broken, and must be surgically reduced.
• It is unclear when the best time to operate might be. Do you leave it for a little while, or do you operate immediately?
• Arguments for early stabilisation are largely from convenience; nursing care is simpler with a stable spine.
• Some evidence exists that polytrauma patients benefit (or at least, aren't harmed by) early open reduction of spinal fractures.
• Some evidence also exists that in unstable polytrauma patients, estensive spinal surgery should be delayed (as the perioperative morbidity is increased)

Corticosteroids?

• For a time, on the basis of the NASCIS and NASCIS II trials everybody adopted the early use of methylprednisone.
• These days, it has gone out of fashion, and is no longer recommended. In fact various eminent neurosurgical societies have issued statements against their use.

Endocrine and environmental

Monitoring of electrolytes

• There are several electrolyte disturbances to be expected:
  • Hyponatremia (SIADH)
  • Hypercalcemia (osteoporotic resorption)
  • Hyperaldosternoism and hypokalemia

Management of diabetes

• Insulin resistance develops due to inactivity, muscle wasting and adiposity.
• Diet may require adjustment (see below).
• Sympathetic response to hypoglycaemia is abolished; there will be no warning of severe hypoglycaemia.

Temperature control

• Quadriplegic patients are unable to use cutaneous blood flow to self-regulate their body temeprature
• Careful attention is required to prevent hypothermia

Renal / urinary

Neurogenic bladder

• Needless to say, these people need catheters to empty their bladder. Hydronephrosis will result from overdistension otherwise (it will fill to ~150% capacity before the denervated sphincters will release the urine).
• Botox may be the answer to this.

Renal calculi

• Hypercalcemia of dissolving bone scan give rise to renal calculi. These will not be apparent until the patient or carer are alerted to their presence by gross haematuria.

Pyelonephritis

• Presence of calculi and catheters gives rise to chronic urinary tract colonisation and frequent infections.
• Generally, pyuria merits antibiotic therapy, but prophylaxis seems excessive and will probably lead to the development of resistance.

Gastrointestinal

Acute gastric dilatation amd the "body cast syndrome"

• Gastric emptying is impaired because of a loss of sympathetic control of autonomic reflexes.
• A dilated stomach and a lax lower oesophageal sphincter are a recipe for aspiration.
• An NG tube for decompression is one option.
• A post-pyloric nasoduodenal tube for feeding is another option.

Ileus

• Intestinal oedema due to pooling of blood, opiate analgesia as well as lost control of evacuation. All are going to cause ileus.
• Lots of rehabilitative strategies are available, such as regular enemas, stool softeners, digital rectal stimulation etc.

Stress ulceration

• A common complication early in the process
• Largely due to unopposed vagal stimulation of the stomach secretory functions
• Greatest risk of gastric ulceration is between the fourth and tenth day after the spinal injury.
• Later, risk of perforated ulcer revers to population average
• Ergo, a brief course of PPI is indicated.

FASTHUG issues

Feeding

• Early protein intake should be high (~ 2g/kg/day) in polytrauma patients
• Subsequenetly, worsening insulin resistance may merit a low-carbohydrate diet.

Thromboprophylaxis

• The risk is greatly increased not just from immobility but the whole polytrauma setting.
• In the first 72 hours, that risk is lower; one can safely withold heparin during that time.
• Mechanical devices are insufficient prophylaxis on their own
• Standard twice-a-day heparin doses are also apparently not good enough
• Low molecular weight heparin is apparently the recommended choice of agent
• Prophylaxis should continue for a minimum of 8 weeks