Anesthesiology APPLIED Exam › Neuroanesthesia and neuromuscular

Seizure disorders

Neuroanesthesia and neuromuscular·~4 min read· Physician-reviewed✓ Sourced · 4

Stem

A 32-year-old man, 80 kg, with focal epilepsy and occasional secondary generalization, presents for laparoscopic inguinal hernia repair as an outpatient. He takes carbamazepine and levetiracetam; his last seizure was two months ago, after a missed dose. He describes a typical seizure as a rising feeling in his stomach, then staring and lip-smacking, sometimes followed by a generalized convulsion. He is otherwise healthy and has fasted since midnight, including his morning medications.

Question

How do you manage his seizure disorder through the perioperative period?

Ideal answer

HeadlineMy priority is avoiding a perioperative seizure, and the biggest risk is a missed dose: he takes his morning carbamazepine and levetiracetam now, with a sip of water.

Confirm seizure type, frequency and triggers, so I recognize his pattern in recovery.
Short fast; no hypoglycemia, hyponatremia or hypothermia, because each lowers the seizure threshold.
Propofol induction; avoid threshold-lowering drugs. Propofol is anticonvulsant; where I can, I avoid meperidine, large local anesthetic doses, and hyperventilation at the end of the case.
Rocuronium by quantitative train-of-four, not the clock. Chronic anticonvulsant therapy shortens its duration and can produce resistance;¹ enzyme induction raises opioid needs, so multimodal analgesia and a TAP block.
Discharge only at baseline, medications resumed, adult present. Levetiracetam IV if he cannot swallow; if he seizes, airway and oxygen first, then a benzodiazepine at five minutes.²

Breaking down the answer

Know the seizure — focal seizures with impaired awareness can be mistaken for delirium or delayed emergence; knowing his pattern lets me recognize one in recovery.
The mechanism of resistance — patients on chronic carbamazepine or phenytoin show shorter neuromuscular block and apparent resistance to rocuronium, likely from receptor up-regulation.¹ Quantitative monitoring turns that into a dosing decision instead of a surprise.
Drug choice beyond induction — benzodiazepines and volatile agents also suppress seizures; deep hyperventilation is proconvulsant. Continuity of medication matters more than fasting rules.
Have the status pathway ready — stabilization from 0 to 5 minutes, benzodiazepine from 5 minutes, second-line drug at 20 minutes, and anesthetic doses with EEG at 40 minutes.³^,2

Follow-up question

Twenty minutes after arrival in recovery he has a generalized tonic-clonic seizure. At four minutes it is still going, his SpO2 is 86%, and he has an IV in place. What do you do, step by step?

Follow-up answer

HeadlineA generalized seizure approaching status epilepticus; I call for help and note the time.

On his side, 100% oxygen by mask, airway supported, glucose checked. At five minutes, lorazepam 4 mg IV as a single full dose, or midazolam 10 mg IM if IV access fails.³ Second-line if it persists: levetiracetam 60 mg/kg, capped at 4,500 mg, or fosphenytoin 20 mg PE/kg, capped at 1,500 mg PE, or valproate 40 mg/kg, up to 3,000 mg; they work about equally, stopping roughly half.⁴^,2 Past 40 minutes I intubate and start a propofol or midazolam infusion with continuous EEG.² Then the cause (missed doses, low sodium, hypoglycemia, drug toxicity); he is admitted, not discharged.

Pitfalls that cost points

Giving benzodiazepines in small repeated doses instead of one full dose.³
Holding antiepileptic drugs because the patient is fasting.

Rapid-fire

Q: When does initial therapy start in convulsive status? A: At 5 minutes of continuous seizure activity, with response assessed by 20 minutes.³

Q: Is there a preferred second-line drug? A: No; fosphenytoin, valproate and levetiracetam have no clear difference, and phenobarbital is an alternative.²

Q: Why are patients on carbamazepine resistant to rocuronium? A: Chronic therapy is associated with shorter block and apparent resistance, with receptor up-regulation a likely contributor.¹

Q: What third-line options exist? A: Repeat second-line therapy or anesthetic doses of thiopental, midazolam, pentobarbital or propofol with EEG monitoring.²

Q: What IM option works without IV access? A: Midazolam 10 mg IM in adults.³

Numbers to know

Item	Value
Lorazepam IV	4 mg, may repeat once³
Midazolam IM	10 mg (5 mg if 13–40 kg)³
Levetiracetam	60 mg/kg, max 4,500 mg⁴
Fosphenytoin	20 mg PE/kg, max 1,500 mg PE⁴
Valproate	40 mg/kg, max 3,000 mg⁴
Phases	0–5, 5–20, 20–40, over 40 min³

Sources

1.Rocuronium bromide injection: Drug interactions (section 7.2) · Pfizer (FDA labeling) · pfizermedical.com
2.American Epilepsy Society issues guideline and treatment algorithm for convulsive status epilepticus · American Epilepsy Society, 2016 · aesnet.org
3.Evidence-Based Guideline: Treatment of Convulsive Status Epilepticus in Children and Adults · American Epilepsy Society, 2016 · journals.sagepub.com
4.New randomised control trial evidence for treatment of status epilepticus (ESETT) · European Academy of Neurology, 2020 · ean.orgSummary of the ESETT trial doses and outcomes.

Facts on this page were checked against these sources on Oct 16, 2026. Guidelines change; confirm doses against current institutional protocols.