What is the recommended anesthetic management for a 12-year-old patient with syringomyelia undergoing surgery for Functional Movement Disorder (FMD)?

Anesthetic Management for a 12-Year-Old with Syringomyelia Undergoing Surgery

For a 12-year-old patient with syringomyelia undergoing any surgical procedure, use total intravenous anesthesia (TIVA) with propofol and short-acting opioids like remifentanil, avoid succinylcholine absolutely, carefully position to prevent spinal cord compression, maintain meticulous hemodynamic stability, and ensure continuous SpO2 and end-tidal CO2 monitoring with an experienced anesthesiologist and ICU availability.

Preoperative Assessment and Optimization

Neurological Evaluation

• Assess the extent and location of the syrinx cavity using recent MRI to understand spinal cord involvement and any associated Chiari malformation, as these anatomical factors directly impact positioning and hemodynamic management 1, 2.
• Document baseline neurological deficits including motor weakness, sensory loss, and autonomic dysfunction, as syringomyelia can cause progressive neurological deterioration 3, 4.
• Evaluate for signs of increased intracranial pressure or brainstem compression if Chiari malformation is present, as this affects airway management and ventilation strategies 2, 4.

Cardiopulmonary Assessment

• Obtain pulmonary function tests including FVC, MIP, MEP, and PCF if there is cervical or high thoracic syrinx involvement that could compromise respiratory muscle function 5.
• Perform cardiac evaluation to assess for any autonomic dysfunction-related cardiac abnormalities, as syringomyelia can affect autonomic pathways 5.
• Measure baseline SpO2 and consider arterial blood gas if respiratory compromise is suspected 5.

Multidisciplinary Planning

• Coordinate with neurosurgery to understand the surgical approach, expected duration, and positioning requirements specific to the procedure 5.
• Ensure ICU bed availability for postoperative monitoring, as patients with significant neurological conditions require close observation 5.
• Discuss risks and benefits with the patient and family, including potential for neurological deterioration and respiratory complications 5.

Intraoperative Anesthetic Management

Pharmacologic Agent Selection

• Use total intravenous anesthesia (TIVA) with propofol (100-200 mcg/kg/min) and remifentanil as the primary anesthetic technique 5, 6.
• Administer remifentanil at 0.5-1 mcg/kg/min for induction, followed by 0.25 mcg/kg/min for maintenance (range 0.05-2 mcg/kg/min), with supplemental boluses of 1 mcg/kg every 2-5 minutes as needed for surgical stimulation 6.
• Absolutely avoid succinylcholine due to risk of hyperkalemic cardiac arrest and rhabdomyolysis in patients with neuromuscular conditions, even though syringomyelia is not a primary muscle disease, the precautionary principle applies to all neurological disorders with potential muscle involvement 5.
• Use non-depolarizing muscle relaxants (rocuronium, vecuronium) if paralysis is required, with careful neuromuscular monitoring 5.
• Consider avoiding or minimizing volatile anesthetics in favor of TIVA, as volatile agents can complicate neurological monitoring and hemodynamic management 5.

Airway and Ventilation Management

• Perform careful airway assessment for potential difficult intubation due to cervical spine involvement or limited neck mobility from syringomyelia 5.
• Use video laryngoscopy or fiberoptic intubation if cervical spine pathology limits neck extension 5.
• Maintain strict neutral cervical spine positioning during intubation to avoid spinal cord compression or syrinx expansion 1, 2.
• Provide controlled mechanical ventilation with careful titration of tidal volumes and respiratory rate to maintain normocapnia, as hypercapnia can increase intraspinal pressure 5.
• Monitor end-tidal CO2 continuously to ensure adequate ventilation and avoid respiratory acidosis 5.

Hemodynamic and Physiologic Monitoring

• Monitor SpO2 continuously with a target of ≥95% to prevent hypoxemia-related spinal cord ischemia 5.
• Maintain mean arterial pressure within 10-20% of baseline to ensure adequate spinal cord perfusion, as syringomyelia patients may have impaired autoregulation 5.
• Avoid hypotension through judicious fluid administration and vasopressor use (phenylephrine or norepinephrine) as needed 5.
• Monitor blood or end-tidal CO2 levels to detect hypoventilation or hyperventilation 5.
• Consider invasive arterial blood pressure monitoring for major procedures or patients with significant cardiovascular involvement 5.

Positioning and Spinal Cord Protection

• Position the patient carefully to avoid excessive neck flexion, extension, or rotation that could compress the spinal cord or exacerbate syrinx dynamics 1, 2.
• Use adequate padding at all pressure points to prevent peripheral nerve injury 5.
• Avoid prone positioning if possible, or ensure meticulous attention to spinal alignment if required 1.
• Maintain normothermia as hypothermia can worsen neurological outcomes 5.

Personnel and Setting Requirements

• Ensure an experienced anesthesiologist familiar with neurological conditions is present throughout the procedure 5.
• Have a respiratory therapist available if the patient has baseline respiratory compromise 5.
• Perform the procedure in a fully equipped operating room with immediate access to advanced airway equipment and resuscitation capabilities 5.

Postoperative Management

Emergence and Extubation

• Plan for smooth emergence with minimal coughing or straining to avoid sudden increases in intraspinal pressure 5.
• Consider delayed extubation if there are concerns about airway patency, respiratory drive, or neurological status 5.
• Extubate to supplemental oxygen with close monitoring of respiratory rate and SpO2 5.
• Avoid extubating deeply as this increases risk of airway obstruction and aspiration 5.

Respiratory Support and Monitoring

• Monitor SpO2 continuously in the recovery room and for at least 24 hours postoperatively 5.
• Use supplemental oxygen cautiously, as excessive oxygen can mask hypoventilation; monitor end-tidal CO2 or arterial blood gases if hypoxemia occurs 5.
• Consider non-invasive positive pressure ventilation (NPPV) if the patient develops respiratory insufficiency, though this is more commonly needed in patients with primary muscle disease 5.
• Assess for hypoventilation, atelectasis, or secretion retention as causes of postoperative hypoxemia 5.

Pain Management

• Optimize postoperative analgesia using multimodal techniques including acetaminophen, NSAIDs (if not contraindicated), and regional anesthesia when feasible 5, 6.
• Use opioids judiciously with careful titration to avoid respiratory depression, as patients with neurological conditions may have increased sensitivity 5, 6.
• Avoid bolus opioid administration in favor of continuous low-dose infusions (remifentanil 0.025-0.2 mcg/kg/min) if continued into the immediate postoperative period, though transition to longer-acting analgesics is preferred 6.
• Consider regional anesthesia techniques (epidural, peripheral nerve blocks) to minimize systemic opioid requirements 5.

Neurological Monitoring

• Perform frequent neurological assessments to detect any new or worsening deficits that could indicate spinal cord compromise 1, 3.
• Monitor for signs of syrinx expansion including new-onset weakness, sensory changes, or autonomic dysfunction 1, 3, 4.
• Maintain strict blood pressure control to ensure adequate spinal cord perfusion 5.

Level of Care

• Admit to ICU or high-dependency unit for continuous monitoring, especially if the patient has significant baseline neurological deficits or underwent a high-risk procedure 5.
• Continue monitoring for at least 24-48 hours as delayed respiratory or neurological complications can occur 5.

Critical Pitfalls to Avoid

• Never use succinylcholine in any patient with neurological disease due to risk of fatal hyperkalemia 5.
• Avoid excessive neck manipulation during intubation or positioning that could worsen spinal cord compression 1, 2.
• Do not rely solely on supplemental oxygen to treat postoperative hypoxemia without investigating the underlying cause 5.
• Avoid aggressive fluid resuscitation that could worsen cerebral or spinal cord edema 5.
• Do not discharge the patient to an unmonitored setting within 24 hours of surgery 5.