Fentanyl‐induced suppression of transcranial Motor Evoked Potentials (tcMEPs)

Abstract

A child with Hurlers syndrome and severe kyphosis underwent kyphectomy and posterior spinal fusion under TIVA with propofol and remifentanil. The patient was given boluses of intravenous fentanyl (25 mcg) at three separate time points during the course of surgery, each resulting in suppression of the transcranial motor evoked potential (tcMEP) amplitudes by greater than 50% and lasting for approximately 30 minutes. One bolus resulted in near loss of tcMEP responses during screw placement. This case highlights the previously undescribed potential of fentanyl to result in isolated critical suppression of tcMEP amplitudes.