Pediatrics

Loss of Evoked Potentials

Diagnosis

Management of signal changes during spine surgery

Diagnosis

Management of signal changes during spine surgery

  1. Notify all members of health care team. Call a “time out"

  2. Loss of evoked potentials (EP) requires definitive steps to re-establish perfusion/remove mechanical cause; MEP loss for > 40 min may increase possibility of long term injury

    • Assure presence of attending surgeon, attending anesthesiologist, senior neurologist or neurophysiologist, and experienced nurse
    • Each service: review situation, report on management and corrective actions taken
      • Surgeon: rule out mechanical causes for loss/change including traction weights
      • EP technologist: rule out technical causes for loss/change
      • Anesthesiologist: assure no neuromuscular blockade is present; reverse NMB if necessary

  3. Check patient positioning (neck, upper and lower extremities)

  4. Review anesthetic and consider improving spinal cord perfusion by modifying:

    • Mean arterial pressure: MAP > 65 mmHg using ephedrine 0.1 mg/kg IV (MAX 10 mg/dose) and/or phenylephrine 0.3-1 MICROgrams/kg IV (MAX 100 MICROgrams/dose), with repeated doses as needed
    • Hemoglobin: if anemic, transfuse RBC to improve oxygen delivery
    • pH and PaCO2: ensure normocarbia or slight hypercarbia (↑ I/E ratio, ↓ PEEP)
    • Temperature: ensure normothermia
    • Check for “unintended” drugs given (e.g. neuromuscular blocker)
    • Decrease depth of anesthetic and ensure N20 is under 50%
    • 0.1 mg/kg IV, MAX 10 mg
    • 0.3-1 MICROgrams/kg IV, MAX 100 MICROgrams

  5. Discuss feasibility of a useful wake-up test:

    • Patient is appropriate candidate if capable of following verbal commands

  6. Consider high-dose steroid if no improvement:

    • Methylprednisolone 30 mg/kg IV over one hour, then 5.4 mg/kg/hour IV for 23 hours
    • 30 mg/kg IV over one hour
    • Then infusion 5.4 mg/kg/hour IV for 23 hours

  7. Consider DDx

  8. Crisis Management (If Severe)

    Notify surgeon, call for help and code cart

  9. Call for Transesophageal Echocardiography

  10. Start chest compressions

  11. Give epinephrine 10 MICROgrams/kg IV/IO

  12. If cardiac arrest, go to CARDIAC ARREST

  13. Consider ECMO

Patient weight

Between 0.5 kg and 120 kg

Reset the checklist?

Checked steps, the timer and this crisis log are cleared. The patient’s weight is kept.

Finish the crisis?

The timer pauses, and you can review the case and the event log.