What are the anesthetic considerations for a patient with spinal cord injury?

Anesthetic Considerations for Spinal Cord Injury

Patients with spinal cord injury require meticulous anesthetic management focused on preventing autonomic dysreflexia, maintaining spinal cord perfusion with MAP ≥70 mmHg, careful airway management with manual in-line stabilization, and avoiding succinylcholine after 48 hours post-injury. 1

Immediate Stabilization and Airway Management

Spinal Immobilization

• Apply manual in-line stabilization (MILS) immediately for all suspected spinal cord injuries to prevent secondary neurological deterioration. 2, 1
• Remove only the anterior portion of the cervical collar during intubation to improve glottic exposure while maintaining posterior stabilization. 2, 1, 3
• Transport on a rigid backboard with vacuum mattress maintaining head-neck-chest stabilization. 1, 3

Intubation Technique

• Perform rapid sequence induction with direct laryngoscopy using a gum elastic bougie to increase first-attempt success rate. 2, 1
• Maintain cervical spine in neutral axis without Sellick maneuver. 2, 1
• For high cervical injuries (C2-C5), immediate intubation is mandatory. 1
• Videolaryngoscopy with MILS is recommended when available. 3

Critical Medication Warning

• Succinylcholine can be safely used ONLY within the first 48 hours after spinal cord injury. 1
• After 48 hours, succinylcholine risks life-threatening hyperkalemia due to upregulation of extrajunctional acetylcholine receptors. 1

Hemodynamic Management

Blood Pressure Targets

• Maintain systolic blood pressure >110 mmHg before injury assessment to reduce mortality. 1, 3, 4
• Target mean arterial pressure ≥70 mmHg continuously during the first 7 days post-injury to prevent secondary neurological deterioration. 1, 3, 4
• Spinal perfusion pressure >50 mmHg correlates with better neurological outcomes at 6 months. 4
• Continuous arterial line monitoring is essential as MAP falls below target 25% of the time. 4

Neurogenic Shock Recognition

• Neurogenic shock presents with hypotension AND bradycardia (distinguishing it from septic shock which shows tachycardia). 4
• Occurs with injuries above T6 due to loss of sympathetic tone. 4, 5
• Requires immediate vasopressor support to maintain perfusion targets. 1, 4

Autonomic Dysreflexia

High-Risk Population

• Autonomic dysreflexia is the most dangerous complication in chronic spinal cord injury above T6, resulting from overstimulation of sympathetic reflex circuits. 5
• Presents with severe hypertension, bradycardia, headache, and sweating. 6, 5
• Can be precipitated by surgery, especially bladder distension or any noxious stimulus below the level of injury. 6

Prevention Strategies

• General or neuraxial anesthesia of sufficient depth effectively prevents autonomic dysreflexia during surgery. 6, 5
• Spinal anesthesia is safe, effective, and technically simple in this population. 6
• For patients with low, complete lesions undergoing surgery below the injury level without history of autonomic dysreflexia, surgery may proceed without anesthesia but with anesthesiologist monitoring present. 6, 7

Respiratory Management

Acute Phase

• Respiratory complications are life-threatening in high cervical injuries and must be identified immediately. 1, 3
• Perform early tracheostomy within the first 7 days for high cervical injuries (C2-C5) to accelerate ventilatory weaning and reduce ICU hospitalization times. 1, 3
• Consider early tracheostomy when prolonged airway support is anticipated or residual vital capacity is significantly decreased. 3

Chronic Considerations

• Patients with high thoracic or cervical injuries have compromised respiratory function due to intercostal and diaphragmatic muscle involvement. 5, 8
• Respiratory dysfunction is a significant risk with general anesthesia. 6, 8

Pharmacological Considerations

Contraindicated Medications

• Do NOT administer corticosteroids for spinal cord injury—they provide no neurological benefit and significantly increase infectious complications (GRADE 1+ strong recommendation). 4
• This contradicts older practices based on flawed NASCIS II and III trial designs. 1, 4

Analgesic Management

• Implement multimodal analgesia combining non-opioid analgesics, antihyperalgesic drugs (ketamine), and opioids during acute management. 1
• For neuropathic pain developing later, use oral gabapentinoids for more than 6 months. 1

Positioning and Pressure Ulcer Prevention

Intraoperative Positioning

• Specific arrangements for installing and mobilizing these patients are critical. 2
• Visual and tactile checks of all at-risk areas at least once daily. 1
• Repositioning every 2-4 hours with pressure zone checks. 1

Prevention Supports

• Use high-level prevention supports including air-loss mattress or dynamic mattress. 1
• Begin early mobilization as soon as the spine is stabilized. 1

Level-Specific Considerations

Injuries Above T6

• Highest risk for autonomic dysreflexia. 6, 5
• Cardiovascular instability with both hypotension and hypertension risks. 5, 8
• Require aggressive hemodynamic monitoring and management. 1, 4

Complete vs. Incomplete Lesions

• Patients with complete injuries below the level of surgery may not require anesthesia if no history of autonomic dysreflexia or troublesome spasms exists. 6, 7
• However, significant proportions still require anesthesia even for surgery below the injury level. 7

Systems-Based Approach to Care

Transport and Definitive Care

• Direct admission to Level 1 trauma centers within the first hours after trauma reduces morbidity and mortality, enables earlier surgical procedures, reduces ICU length of stay, and improves neurological outcomes. 1, 3
• Transfer all patients with traumatic spinal cord injury to a specialized care unit to decrease morbidity and long-term mortality (GRADE 2+). 4

Urological Management

• Implement intermittent urinary catheterization as soon as daily diuresis volume is adequate. 1
• Self-intermittent urethral catheterization is the gold standard to reduce urinary tract infections and urolithiasis. 1
• Remove indwelling catheters as soon as the patient is medically stable. 1

Early Rehabilitation

• Begin rehabilitation immediately after stabilization to maximize neurological recovery. 1
• Physical exercise enhances central nervous system regeneration through neurotrophic factors. 1
• Activity-based therapy should be initiated early. 1

Critical Pitfalls to Avoid

• Never leave the cervical collar fully in place during intubation—remove the anterior portion while maintaining MILS. 3
• Never use succinylcholine after 48 hours post-injury due to hyperkalemia risk. 1
• Inadequate blood pressure support below MAP 70 mmHg increases secondary ischemic injury to the spinal cord. 1, 4
• Delaying immobilization in suspected spinal cord injury leads to worsening neurological outcomes. 1
• Failing to recognize and prevent autonomic dysreflexia in injuries above T6 can be fatal. 6, 5
• Using steroids increases infectious complications without neurological benefit. 1, 4
• Delaying transport to specialized centers worsens outcomes. 1, 3

Monitoring Requirements

Intraoperative Monitoring

• Continuous arterial blood pressure monitoring is essential. 4, 8
• Spinal cord function monitoring when indicated. 8
• Close attention to cardiovascular and respiratory responses, particularly in injuries above T6. 7, 5

Postoperative Care

• Maintain MAP targets for 7 days post-injury. 1, 4
• Monitor for autonomic dysreflexia triggers. 6, 5
• Early identification of respiratory complications. 1, 3