Refractory Status Epilepticus with Burst Suppression and Hypotension
A 47-year-old woman with a prior right middle cerebral artery stroke presents with 90 minutes of generalized convulsive activity that stopped after 8 mg IV loracaine-equivalent benzodiazepine given prehospital and 4 mg IV lorazepam in the ED. She is now unresponsive with subtle right facial and arm twitching. Weight 70 kg. Vitals: BP 92/54 mmHg on 5 mcg/min norepinephrine, HR 118, SpO2 94% on 4 L nasal cannula, temp 38.4 C. Fingerstick glucose 168 mg/dL. Labs: Na 138, K 4.1, creatinine 1.4 mg/dL (baseline 0.8), AST 210 U/L, ALT 180 U/L, ammonia 68 umol/L. Continuous EEG shows ongoing 2.5 Hz generalized spike-wave discharges with no clinical correlate. She has received fosphenytoin 20 mg PE/kg and levetiracetam 60 mg/kg IV over 30 minutes; seizures continue.
1. What is your next anticonvulsant step, and how do the renal and hepatic parameters change your choice?
Read the worked answer
This is convulsive status epilepticus that has evolved into nonconvulsive status epilepticus (NCSE) - the EEG pattern with 2.5 Hz generalized spike-wave and persistent coma after motor cessation confirms ongoing electrographic seizures. After benzodiazepines plus two adequately dosed second-line agents (fosphenytoin 20 PE/kg and levetiracetam 60 mg/kg), the patient meets criteria for refractory status epilepticus and requires a continuous IV anesthetic infusion.
Choice: Midazolam is a reasonable first-line continuous agent, but note the creatinine rise to 1.4 (from 0.8) and transaminases ~2x ULN. Propofol is attractive for rapid titration and EEG suppression but carries propofol infusion syndrome risk with escalating dose and duration; the modest hepatic/renal dysfunction is not an absolute contraindication but argues for caution with very high-dose, prolonged (>48 h) propofol. Midazolam accumulates in renal failure (active metabolite alpha-hydroxymidazolam glucuronide), risking prolonged sedation and delayed wake-up - relevant here. Pentobarbital is highly effective but causes profound hypotension, unacceptable at MAP ~67 on pressors.
Reasonable plan: Start midazolam 0.2 mg/kg bolus (14 mg) then 0.05–0.2 mg/kg/h, titrating to EEG burst suppression with a goal of ~1 burst every 10 seconds; simultaneously correct the hypovolemia/vasoplegia (fluids, escalate norepinephrine), treat fever, and reassess renal function. If seizures persist at high midazolam doses or hypotension limits titration, switch to propofol (watch for lactic acidosis, rhabdomyolysis, lipemia) or consider ketamine as an adjunct (hemodynamically favorable). Avoid phenytoin loading further given the creatinine. Escalate to pentobarbital only with adequate vasopressor support and airway/ICU resources.
2. The team wants to maintain burst suppression for 48 hours. What is the evidence-based justification, and what monitoring parameters do you set?
Read the worked answer
The evidence for prolonged burst suppression as a fixed 24–48 h target is weak; the landmark RCTs (e.g., the ESETT trial) addressed second-line agents, and the older VA cooperative study used a burst-suppression endpoint, but no high-quality trial shows that maintaining a fixed duration of burst suppression improves outcomes over titrating to seizure cessation. Current practice: titrate the anesthetic to electrographic seizure suppression (and often burst suppression for 12–24 h), then attempt a cautious taper while monitoring EEG; prolonged deep suppression increases hypotension, infection, ileus, and ICU length of stay without proven benefit.
Monitoring to set:
- Continuous EEG with a dedicated reader/remote review; document burst rate, suppression ratio, and any recurrent electrographic seizures.
- Hemodynamics: arterial line, hourly MAP, vasopressor requirement; goal MAP ≥65 (higher if known chronic hypertension).
- Ventilation: target normocapnia (PaCO2 35–45), lung-protective settings; daily sedation interruption is not appropriate during burst suppression, but a planned taper trial is.
- Metabolic: ABG/lactate q6–12h (propofol infusion syndrome), CK, triglycerides, daily LFTs and creatinine, glucose.
- Infection: fever workup, given the presenting temp 38.4 C - treat empirically while awaiting cultures; daily chest imaging as indicated.
- Nutrition/DVT prophylaxis and pressure injury prevention.
- Anticonvulsant maintenance: continue levetiracetam (renally dosed) and consider whether phenytoin should be transitioned given renal function.