CRITICAL CARE OF SPINAL CORD

INJURY

Dr. Amr EL-SaidProfessor of Anaesthesia

& Intensive CareFaculty of Medicine

Ain Shams University

Case Presentation

26-year-old male with unstable

cervical fracture following motor vehicle crash is placed in halo for immobilization and is admitted to ICU. Few hours later, he develops acute hypoxemic respiratory failure that improves significantly with noninvasive positive pressure ventilation.

Halo Brace

Spinal Cord Injury

It can cause myelopathy or damage

to nerve roots or myelinated fiber tracts that carry signals to & from brain. This injury could also damage grey matter in central part of cord, causing segmental losses of interneurons & motor neurons.

Epidemiology

• In the United States 12,000 cases/year

• In China 60,000 cases/year

• Male predominance 4:1

• Average age 38 years old

ClassificationAmerican Spinal Injury Association &

International Spinal Cord Injury Classification System

• A "complete" spinal cord injury, no motor or sensory function preserved in sacral segments S4-S5.

• B "incomplete" spinal cord injury, sensory but not motor function preserved below neurological level & includes sacral segments S4-S5.

• C "incomplete" spinal cord injury, motor function preserved below neurological level with more than half of key muscles below neurological level have muscle grade < 3.

• D "incomplete" spinal cord injury, motor function preserved below neurological level with at least half of key muscles below neurological level have muscle grade ≥ 3.

• E "normal“, motor & sensory scores are normal.

Segmental Spinal Cord Level & Function

LEVEL FUNCTION LEVEL FUNCTION

C1-C6 Neck flexors L1, L2, L3, L4

Thigh flexion

C1-T1 Neck extensors L2, L3, L4 Thigh adduction

C3, C4, C5 Supply diaphragm (mostly C4)

L4, L5, S1 Thigh abduction

C5, C6 Shoulder movement, raise arm (deltoid);

flexion of elbow (biceps); C6 externally rotates arm

(supinates)

L5, S1, S2 Extension of leg at hip (gluteus maximus)

C6, C7 Extends elbow & wrist (triceps & wrist

extensors); pronates wrist

L2, L3, L4 Extension of leg at knee (quadriceps femoris)

C7, T1 Flexes wrist, Supply small muscles of the hand

L4, L5, S1, S2

Flexion of leg at knee (hamstrings)

T1 –T6 Intercostals & trunk above the waist

L4, L5, S1 Dorsiflexion of foot (tibialis anterior); extension of toes

T7-L1 Abdominal muscles L5, S1, S2 Plantar flexion of foot; flexion of toes

Complications• BP changes - can be extreme (autonomic hyperreflexia)• Complications of immobility:

– Deep vein thrombosis– Pulmonary infections– Skin breakdown– Contractures

risk of injury to numb areas of body risk of kidney damage risk of Urinary tract infections• Loss of bladder control• Loss of bowel control• Loss of sensation• Loss of sexual functioning (male impotence)• Muscle spasticity• Pain• Paralysis of breathing muscles• Paralysis (paraplegia, quadriplegia)• Shock

Causes• Trauma (automobile crashs, falls, gunshots, diving

accidents, war injuries)• Tumor (meningiomas, ependymomas, astrocytomas,

metastatic cancer)• Ischemia resulting from occlusion of spinal BV

(dissecting aortic aneurysms, emboli, arteriosclerosis)• Developmental disorders (spina bifida,

meningomyelocoele)• Neurodegenerative diseases (Friedreich’s ataxia,

spinocerebellar ataxia)• Demyelinative diseases (Multiple Sclerosis)• Transverse myelitis (resulting from stroke,

inflammation)• Vascular malformations (AVM, dural arteriovenous

fistula [AVF], spinal hemangioma, cavernous angioma & aneurysm)

Protocol of Management1. Initial Management & Evaluation

• “A” “B” Immobilize cervical spine, Protect airway & ensure adequate oxygenation & ventilation.

Two-person oral intubation with in-line cervical spine traction. Do not electively place too-small tube. Serial ABG to assess ventilation and oxygenation.

• “C” Stabilize blood pressure. Resuscitation with crystalloid, red cells and colloid to stabilize SBP to 100-110 mm Hg. Other sources of potential hemorrhagic shock must also be ruled out. If patient is adequately resuscitated and remains hypotensive, dopamine infusion should be initiated.

Insert nasogastric or orogastric tube. Insert Foley catheter if there are no signs of genitourinary trauma.

• “D” Perform baseline neurological assessment. ```Other CNS injuries should be ruled out.

Cervical spine (AP & lateral views) & supine chest x-ray. Abdominal assessment (CT scan, peritoneal lavage, or FAST ultrasound).

Protocol of Management2. Methylprednisolone Bolus & Infusion

Steroids should not be given to patients with:• Only spinal cord injury of nerve root or cauda

equina. • Gunshot or penetrating injury to spine. • Life threatening morbidity.

STEROIDs MUST ONLY BE GIVEN WITHIN 8 HOURS OF INJURY

Dose: 30 mg/kg administered as IV bolus over 15 minutes,45 minute pause; then 23 hour

continuous infusion of 5.4 mg/kg/hr.

Protocol of Management3. Radiological Diagnosis & Assessment

• CT scan or MRI of spine may show location & extent of damage & reveal problems (hematomas).

• Myelogram may be necessary in rare cases.

• Somatosensory evoked potential (SSEP) testing.

• Spine x-rays may show fracture or damage to bones of spine.

Protocol of Management4. Surgical Stabilization • Rapid alignment of spine to normal anatomic

position. Follow up x-ray evaluation to confirm adequate alignment. If neurosurgical stabilization is postponed, halo traction is recommended.

• If spinal cord compression is caused by mass (such as hematoma or bony fragment), surgery may be necessary (decompression laminectomy).

Protocol of Management5. Cardiovascular Support • CVP & arterial line for monitoring. • Adequate volume resuscitation. • Patients may require vasoactive agents (dopamine

or epinephrine) to maintain SBP > 100 mm Hg. • Patients may also develop bradycardia.

Attempt to avoid vagal maneuvers. Unless patient becomes hypotensive with bradycardic episodes, there is no indication for ttt. If bradycardia is associated with hypotension, bolus of atropine, 0.5 mg IV, to be repeated at 0.5 mg increments up to total of 2 mgs. Temporary cardiac pacing is rarely required in these patients.

Vasoactive Agents Agent Common

Dosage Ranges

Comments

Dopamine(µg/kg/min)

1–10 Has primarily β-adrenergic effects at low doses & primarily α-adrenergic effects at higher doses; a commonly used agent in SCI

Dobutamine(µg/kg/min)

5–15 Most prominent effect is augmentation of cardiac performance but may lower systemic blood pressure so generally less useful agent in SCI

Epinephrine(µg/min)

1–8 Both α- and β-adrenergic effects, may promote arrhythmias

Norepinephrine(µg/min)

1–20 Has some β-adrenergic but predominately α adrenergic effects; a useful agent for BP support, especially in cervical and high thoracic SCI

Phenylephrine(µg/min)

10–100 Exclusively α–adrenergic agent; should be used with caution in cervical SCI because of potential for reflex bradycardia

Protocol of Management6. Respiratory Support• 1/3 of cervical SCI patients will require intubation.

• Any intervention before neck is stable or fixed requires cervical in-line stabilization.

• Work of breathing can be gauged by assessing patient comfort, trends in RR, changes in ability and quality of speech, and monitoring for increasing PaCO2.

• Spontaneous ventilatory parameters (TV, VC, maximum inspiratory effort) are monitored with FVC < 12–15 ml/kg for assisted ventilation.

• Abdominal binding and nursing patients supine can offset decline in pulmonary function due to flaccid abdominal muscles.

Protocol of Management6. Respiratory Support• Frequent turning of patients is necessary to avoid

pressure sore formation, to maintain adequate suctioning and to prevent atelectasis.

• Patients who remain in cervical traction and are not able to be sat up may benefit from ROTO BED to improve pulmonary toilet.

• Bronchoscopy.

ROTO Bed

Roto- Bed

Protocol of Management6. Respiratory Support

• Physiotherapy reduces accumulation of secretions and hence load placed on fatiguing muscles.

• Meticulous pulmonary toilet. • Aerosol treatments (alupent, albuteral) may be

helpful.• Nebulized N-acetylcysteine, oral carbocysteine can

help to loosen and clear secretions.• Non-invasive ventilation (CPAP, Bilevel or pressure

assisted non-invasive ventilation) can increase minute ventilation and FRC, improve compliance and reduce work of breathing.

• Mechanical ventilation is preferred when there is associated lung injury (contusion or underlying infection).

Protocol of Management7. Gastrointestinal • Decompression with orogastric or nasogastric tube.• Early feeding and prokinetic agents

(metoclopramide).• Immediately GI prophylaxis with H2-antagonists,

Proton pump inhibitors.• Bowel regime should be started on day 1 of

admission with regular use of laxatives (colace, orally and dulcolax, per rectum daily).

8. Genito-Urinary • Foley Catheter is placed at time of admission and

should be continued until patient stability permits.

Protocol of Management9. Metabolic • Early stabilization and early physical therapy

consultation to increase mobilization may decrease immobilization complications i.e. hypercalcemia.

• Temperature regulation.• Hyperglycemia Good glycemic contol.10. Extremities

DVT prophylaxis should be initiated on day 1: • Thigh high Ted hose, pneumatic compression.• Anticoagulants (heparin, low molecular weight

heparin, or warfarin). • Physical therapy consultation for range of motion

exercises and mobilization. • femoral IV access should be avoided.

Protocol of Management11. Pain Management• Acute pain due to Pressure sores (including occipital

sores), frequent turning and inability to scratch. • Chronic neuropathic pain (Hyperesthesia and

allodynia).It is often opioid-resistant. Gabapentin and amitriptyline are effective but need to be commenced as early as possible. Ketamine may be beneficial.

12. Nutrition • Nutritional support should be started as soon as

gastric residuals indicate resolution of ileus. • Enteral feeding is preferred & switch from parenteral

to enteral feeding should occur as soon as feasible.

Protocol of Management13. Skin • All pressure areas should be padded. • Patient should be turned every two hours.• Spasticity is common and Contractures can result

from spasticity. Conservative measures such as stretches, splinting, and casting.good pain control.Medication is often necessary; baclofen, dantrolene, and gabapentin. More invasive treatments; botulinum injections and intrathecal baclofen. Severe contractures may need to be released surgically.

Protocol of Management14. Psycho-Social

• Depression, anxiety and confusion.• Psychiatry and Social Work

consults may be necessary.• Rehabilitation.

15. General

• Avoid full bladders, constipation, or painful sensations.

The decision is made to intubate this patient due to gradual worsening although it is not emergent at this time. Which of following is BEST option for airway management?

1. Obtain expert consultation for flexible fiberoptic intubation.

2. Rapid sequence intubation with an orotracheal tube.

3. Immediate surgical cricothyrotomy.4. Needle cricothyrotomy.

Pharmacological agents useful for endotracheal intubation immediately after injury include

1. Etomidate 0.3-0.4 mg/kg as single bolus.2. Succinylcholine 1.0-1.5 mg/kg as single bolus.3. Midazolam 1 mg bolus every several minutes.

repeated as necessary4. Fentanyl 25-100 µg bolus every several

minutes repeated as necessary.5. All of above.

Patient has complete spinal cord transection above C3. which one of following is MOST APPROPRIATE setting for initiation of mechanical ventilation?

1. FiO2 1.0 with SIMV, TV 6-8 ml/kg, RR 10-12/min & PEEP 5 cm H2O.

2. FiO2 1.0 with PCV, set at level of 40 cm H2O, RR 10-12/min & CPAP of 10 cm H2O.

3. FiO2 0.3 with SIMV, TV 12-15 ml/kg, RR 15-18/min & PEEP 5 cm H2O

4. FiO2 0.3 with PSV, set at level of 20 cm H2O, & CPAP of 5 cm H2O

Which of following statements regarding non-invasive positive-pressure ventilation (NPPV) is MOST CORRECT?

1. Less patient monitoring is required with NPPV than invasive mechanical ventilation.

2. NPPV is not recommended for patients with hemodynamic instability.

3. NPPV is rarely useful in treatment of respiratory failure.

4. The need for specialized machines and masks limits the utility of NPPV.

Patient presents to ICU with BP of 84/42 mm Hg, HR of 110/min & flaccid paralysis of four extremities. Which one of following is MOST APPROPRIATE initial treatment?

1. Crystalloid volume resuscitation.2. Immediate intubation & institution of

mechanical ventilation.3. Initiation of vasopressors to achieve SBP>150

mm Hg.4. External transthoracic cardiac pacing if HR

drops below 75 beats/min.

Which one of following dose ranges of dopamine is LIKELY to maximize inotropic effect while minimizing vasopressor effect?

1. 1 – 2 µg/kg/min2. 4 – 8 µg/kg/min3. 10 – 15 µg/kg/min4. 15 – 20 µg/kg/min

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