Status Epilepticus Management

1. Definition (ILAE 2015)

• Operational Definition (Time $t_1$): A seizure lasting > 5 minutes or recurrent seizures without return of consciousness between events. Treatment should begin immediately at this point.
• Tissue Injury Threshold (Time $t_2$): A seizure lasting > 30 minutes. Risk of long-term neuronal injury and pharmacoresistance increases significantly.

2. General Principles (ABCDE)

• Airway: Position head, suction secretions, consider intubation if GCS < 8 or airway compromised.
• Breathing: High-flow oxygen (100%). Monitor SpO2 and EtCO2.
• Circulation: Establish 2 large-bore IV lines. Monitor BP and ECG.
• Dextrose: Bedside glucometry. If Hypoglycemia (<60 mg/dL): Give Dextrose 10% (2–5 mL/kg) or D25 (2 mL/kg).
• Electrolytes: Send samples for Na+, Ca++, Mg++, AED levels, ABG, Toxicology.

3. Stepwise Management Algorithm (Time-Based)

Phase I: Stabilization (0 – 5 Minutes)

• Start timing the seizure.
• Stabilize Airway, Breathing, Circulation.
• Check Glucose. Treat hypoglycemia if present.
• Attempt IV access. (Do not delay first-line treatment > 5 mins for IV access; use IO or IM/Intranasal/Buccal).

Phase II: Initial Therapy / Early Status (5 – 20 Minutes)

• Goal: Stop seizure using Benzodiazepines.
• First-Line Agent (Choose ONE):
  • IV Lorazepam: 0.1 mg/kg (Max 4 mg). (Gold Standard)
  • IV Diazepam: 0.2–0.3 mg/kg (Max 10 mg).
  • IM Midazolam: 0.2 mg/kg (Max 10 mg). (If no IV access).
• If seizure continues after 5 minutes:
  • Repeat the chosen benzodiazepine dose ONCE.
  • Do not exceed 2 doses (risk of respiratory depression).

Phase III: Second Therapy / Established Status (20 – 40 Minutes)

• Goal: Initiate long-acting anti-seizure medication (ASMs) immediately if benzodiazepines fail.
• Drugs of Choice (ESETT Trial showed equal efficacy for Fosphenytoin, Valproate, Levetiracetam):
  • IV Fosphenytoin: 20 mg PE/kg. (Rate: 150 mg PE/min). Preferred over Phenytoin (less hypotension/tissue necrosis).
  • IV Valproate (Sodium Valproate): 20–40 mg/kg. (Rate: 3–6 mg/kg/min). Avoid in suspected metabolic/liver disease.
  • IV Levetiracetam: 40–60 mg/kg (Max 4500 mg). (Infuse over 15 mins).
  • IV Phenobarbital: 20 mg/kg. (Rate: 1 mg/kg/min). Consider if others unavailable or in febrile status.
• Support: Monitor for hypotension and arrhythmias during infusion.

Phase IV: Third Therapy / Refractory Status (40 – 60 Minutes)

• Definition: Seizure persists despite adequate Benzodiazepine + One Second-line ASM.
• Action:
  • Rapid Sequence Intubation (RSI) and mechanical ventilation.
  • Continuous EEG monitoring (cEEG) is mandatory.
  • Initiate Continuous IV Anesthetic Infusion.

Agent	Loading Dose	Maintenance Infusion	Remarks
Midazolam	0.2 mg/kg bolus	1–5 mcg/kg/min (Titrate up q15min)	Preferred in children. Less hemodynamic instability. Tachyphylaxis occurs.
Pentobarbital / Thiopental	3–5 mg/kg bolus	1–5 mg/kg/hr	Effective but causes severe hypotension/myocardial depression. Requires vasopressors.
Propofol	1–2 mg/kg bolus	1–5 mg/kg/hr	Caution: Risk of Propofol Infusion Syndrome (PRIS) in children with high doses >48hrs. Generally avoided in young children if alternatives exist.
Ketamine	1–2 mg/kg bolus	10–50 mcg/kg/min	NMDA antagonist. Neuroprotective. Good for hemodynamic stability.

Phase V: Super-Refractory Status (> 24 Hours)

• Definition: SE continues > 24 hours despite anesthetics, or recurs on weaning.
• Therapies:
  • Ketogenic Diet (4:1 ratio via NG tube).
  • Immunotherapy (IVIG, Methylprednisolone, Plasma Exchange) – Assume autoimmune/inflammatory cause (NORSE).
  • Inhalational Anesthetics (Isoflurane).
  • Vagus Nerve Stimulation (VNS).
  • Hypothermia (Therapeutic hypothermia 32–35°C).

4. Summary Table of Pediatric Doses

Drug	Dose	Max Dose	Rate
Lorazepam	0.1 mg/kg IV	4 mg	2 mg/min
Midazolam	0.2 mg/kg IM/IN/Buccal	10 mg	Bolus
Diazepam	0.2–0.3 mg/kg IV	10 mg	2 mg/min
Fosphenytoin	20 mg PE/kg IV	1500 mg PE	150 mg/min
Valproate	20–40 mg/kg IV	3000 mg	6 mg/kg/min
Levetiracetam	40–60 mg/kg IV	4500 mg	15 mins
Phenobarbital	20 mg/kg IV	1000 mg	30 mg/min

5. Investigations (Concurrent with Management)

• Immediate: Glucose, Electrolytes (Na, Ca, Mg), ABG.
• Urgent: AED levels (if known epileptic), CBC, Renal/Liver function.
• If Indicated: Neuroimaging (CT/MRI) after stabilization. Lumbar Puncture (if fever/meningeal signs present and ICP normal).