Neuromuscular Scoliosis Spinal Fusion — Intraoperative Considerations for Anesthesia Providers — Clinical Pathway

Neuromuscular Scoliosis Spinal Fusion Clinical Pathway — ICU, Inpatient, Outpatient Specialty Care

Intraoperative Considerations for Anesthesia Providers

The anesthesia team is tasked with providing a safe and efficient anesthetic care. Particular attention should be paid to the child's positioning (care of face and pressure points), vascular access based on the child's comorbidities and disposition, and hemodynamic goals for the various stages of the correction. Active communication between the anesthesia, surgery and nursing team is vital to ensure optimal care. Intraoperative recommendations outlined below are meant to serve as a guidelines and should be tailored based on the individual child's needs or considerations.

Induction and Maintenance
  • Pre-heat OR to 72°F prior to child's arrival to offset heat loss during induction/preparation
  • Minimize child's exposure during preparation and cover with a warm blanket when feasible
  • Inhalational induction acceptable but consider IV induction for teenagers
  • Bolus medications:
    • Propofol:
      • 2-3 mg/kg, two syringes
    • Fentanyl:
      • 1-3 mcg/kg for induction
      • Additional doses available for maintenance
    • Lidocaine, consider for IV induction:
      • 1.0-1.5 mg/kg
    • Methadone:
      • Dispensed as 10 mg/ml syringe
      • 0.1mg/kg, max 10 mg
    • Tranexamic acid:
      • 30 mg/kg over 10 min, max 2000 mg
  • Infusions for TIVA:
    • Propofol: 100-250 mcg/kg/min
    • Remifentanil: 0.1-0.2 mcg/kg/min
  • TIVA management:
    • Propofol management active throughout case and tailored to the child's response and depth
    • Monitor anesthetic depth in conjunction with neuromonitoring team and document SEF in record:
      • Target SEF 13-16 Hz
    • During TIVA, propofol bolus should always be available to quickly deepen anesthetic
    • Communicate with neurophysiologists:
      • Boluses, infusion rates, depth of anesthetic/EEG
Airway Positioning Considerations
  • Oral ETT:
    • Attention should be paid to securing ETT as the child will be prone for case
    • Tissue integrity may be a concern in neuromuscular population
    • Consider benzoin to maximize adhesion and cover tape with Tegaderm®
  • In coordination with attending anesthesiologist, nursing, and neurophysiologist:
    • Tegaderm eyes after +/-eye ointment
    • OG tube, temp probe
    • Bite block to prevent tongue injury
    • Consider Mepilex or Duoderm on chin, forehead, other pressure points to prevent skin injury
    • Once prone, ensure Foley is visibly draining
    • Lower body forced air warming blanket (Bair Hugger)
Vascular Access
  • 2 peripheral IVs
  • Arterial line:
    • Radial or ulnar preferred
    • Femoral acceptable with plan to remove when clinically stable
  • Central line:
    • Strongly recommend if planning to recover in PICU
    • Consider discussion with PICU team if not planning for CVC
    • Right internal jugular vein preferred location
    • Ultrasound guided placement recommended
    • CXR prior to the child's positioning to confirm placement and rule out pneumothorax
Antibiotics
  • Children with neuromuscular scoliosis require additional gram-negative coverage and the team should refer to the following when determining intraoperative antibiotics:
  • Dosing for Perioperative Antibiotics
Analgesia
  • Methadone IV:
    • 0.1 mg/kg, max 10 mg prior to incision per anesthesia team
  • or
  • Ketamine infusion:
    • Can be considered in children with global delay, respiratory insufficiency and/or severe neuromuscular scoliosis — GMFCS IV-V
    • Intraoperative infusion 0.2-0.3 mg/kg/hr
    • This can be continued into the postoperative care in the PICU at a lower rate (0.1 mg/kg/hr) but care coordination with the PICU and Pain service is required
  • Pain service consult placed by surgeons, anesthesia calls after start of case
  • If using remifentanil, addition a of intermediate acting opioid may be required (morphine/hydromorphone):
    • Consider titrating in additional opioid after child is extubated unless tachypneic, prolonged emergence and sedation has been observed in neuromuscular population
    • Note: Be especially cautious administering additional opioids if using a fentanyl infusion
  • Acetaminophen IV:
    • 15 mg/kg, max 1000 mg at surgery conclusion
Anti-emetics
  • Dexamethasone IV:
    • 0.1-0.2 mg/kg, max 10 mg, pre-incision
  • Ondansetron IV:
    • 0.1 mg/kg, max 4 mg, at case conclusion
Fluids
  • Avoid excessive crystalloid
  • Consider lactated ringers at 3mL/kg/hr
  • Bolus 10 mL/kg lactated ringers PRN for hypotension, see MAP goals
Laboratory Testing
  • i-STAT should be available for urgent measurements
  • Consider sending an arterial blood sample to the lab for blood gas analysis prior to correction
  • Repeat as needed based on clinical status
Hemodynamic Goals and Management
  • BP/hemodynamic goals:
    • Prevent spinal cord ischemia
    • Minimize bleeding
    • Maintain appropriate perfusion pressure
  • Standard MAP guidelines:
    • Dissection/screw placement: 60-70 mmHg
    • Rod placement/distraction: 70-80 mmHg
    • Closure: 65-75 mmHg
  • Vasoactive infusions:
    • Nicardipine: 0.5-2 mcg/kg/min
    • Phenylephrine: 0.1-0.3 mcg/kg/min
  • Loss of Signals (SSEP/MEP) – Contact Attending Anesthesiologist
Ventilation
  • TV 6-8 ml/kg IBW
  • PEEP should be titrated to optimize oxygenation
  • Reduce FiO2 to < 30%, once prone
  • Goal of SpO2 > 95%
  • Intermittent blood gas analysis can be helpful to guide management
  • Consider recruitment maneuver towards conclusion of procedure or for SpO2 < 95% when FiO2 is < 30%:
    • Note: Use caution with recruitment breaths during the procedure as these maneuvers may increase blood loss
Blood Transfusion and Conservation
  • Obtain from blood bank 1-2 units PRBCs, depending on child's size and blood loss expected
  • Antifibrinolytic management:
    • Tranexamic acid 30 mg/kg bolus over 10 min (max 2 grams)
    • Provide bolus before turning the child prone to maximize onset of medication
    • Tranexamic acid infusion: 10 mg/kg/hr
  • Cell saver arranged by surgery
  • Maintain hemoglobin > 7 g/dl
  • Discuss transfusion plan with surgery team when indicated
  • Special considerations:
    • For cases with larger expected blood loss, consider transfusing PRBC and FFP in a reconstituted 1:1 ratio to avoid dilutional coagulopathy
    • Platelets ordered intraoperatively as clinically indicated, typically following massive blood loss (> 1xblood volume) and documented platelet count < 100,000 with further intraoperative blood loss anticipated
    • Children with extensive blood loss replaced with PRBCs and crystalloid may develop coagulopathy with hypofibrinogenemia, requiring cryoprecipitate administration
Emergence
  • Children with severe neuromuscular scoliosis, significant blood loss, or significant medical comorbidities may remain sedated and intubated postoperatively
  • For children where extubation is planned, neurological examination is not required prior to transport to PACU/PICU unless there are intraoperative issues or a specific request from the surgeon
  • In the event of delayed emergence, extubation of appropriate children based on respiratory criteria is acceptable:
    • Suggested criteria for extubation:
      • Respiratory rate > 10
      • Tidal volume > 6 ml/kg
      • Stable ETCO2
Postoperative Disposition
  • PICU:
    • Severe neuromuscular scoliosis
    • Moderate neuromuscular scoliosis with complicating comorbidities (seizures, developmental delay, baseline respiratory support, etc.)
    • A review of postoperative disposition should take place in the morning huddle
    • May remain intubated overnight
  • Surgical Floor:
    • Mild neuromuscular scoliosis
    • Moderate neuromuscular scoliosis without complicating comorbidities (this decision should be made by the managing surgeon and anesthesiologist)