A 15-month-old boy, dichorionic diamniotic twin gestation, who had been born via repeat cesarean section at 26 weeks 5 days, birth weight 1151 grams, for preterm labor, with a maternal history of methamphetamine use in early pregnancy. He presented in infancy with multiple generalized tonic clonic seizures. Brain MRI revealed a large left thalamic arteriovenous malformation, so he was scheduled for staged endovascular embolization over three sessions. He remained symptomatic and the target of the current treatment was the anterior choroidal artery. The patient was intubated with a 4 mm endotracheal tube, and a left radial arterial line was established. He was maintained on sevoflurane and propofol remained hemodynamically stable with heart rate 80-110 bpm and blood pressure 90s/50s.
With neuromonitoring, the neurosurgery team proceeded with diagnostic cerebral angiogram and roadmap creationPrior to embolization of the lesion with Onyx 18, the surgical team requested increasing the patient’s anesthetic depth for anticipated stimulation. At two other points 90 minutes after this initial episode, the surgeons again requested deeper anesthetic, so dexmedetomidine was administered at lower doses of 0.7 mcg/kg and 0.5 mcg/kg . Despite these lower doses, the heart rate and blood pressure again increased dramatically and resolved with discontinuation of dexmedetomidine and administration of fentanyl and propofol boluses.
The surgery team successfully embolized the lesion and there were no adverse neuromonitoring events during the procedure. The patient remained intubated and was transported to the pediatric ICU post-operatively.
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