What to order in the Emergency Department (ED) for a patient with a generalized tonic-clonic seizure (formerly known as grand mal seizure)?

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Last updated: May 15, 2025View editorial policy

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From the Guidelines

In the emergency department for a patient with a grand mal seizure, immediate management includes securing the airway, breathing, and circulation, followed by administering benzodiazepines such as lorazepam 4mg IV or diazepam 10mg IV to stop the seizure, as recommended by the American College of Emergency Physicians (ACEP) in their 2024 clinical policy 1. When managing a patient with a grand mal seizure in the ED, it is crucial to prioritize interventions that address the immediate cause of the seizure and prevent further neuronal damage.

  • Essential diagnostic tests include:
    • Complete blood count
    • Comprehensive metabolic panel
    • Toxicology screen
    • Antiepileptic drug levels (if on medication)
    • Blood glucose
    • Calcium, magnesium, and phosphate levels
  • Neuroimaging with CT or MRI should be considered, especially for first-time seizures or focal neurological deficits, to rule out any underlying structural causes.
  • An electroencephalogram (EEG) may be ordered if status epilepticus is suspected, as it can help identify any ongoing seizure activity. If seizures persist despite initial treatment with benzodiazepines, second-line treatments may be considered, such as levetiracetam, valproic acid, or phenytoin, although the specific choice of agent may depend on various factors, including the patient's medical history and the suspected cause of the seizure 1. After stabilization, determining the seizure etiology is essential for preventing recurrence, with common causes including medication non-compliance, alcohol withdrawal, electrolyte abnormalities, intracranial lesions, or idiopathic epilepsy.
  • A thorough evaluation, including a detailed medical history, physical examination, and diagnostic testing, is necessary to identify the underlying cause of the seizure and guide further management.

From the FDA Drug Label

Parenteral Phenytoin Sodium Injection is indicated for the treatment of generalized tonic clonic status epilepticus and prevention and treatment of seizures occurring during neurosurgery. For Status Epilepticus and Non-emergent Loading Dose: Adult loading dose is 10 to 15 mg/kg at a rate not exceeding 50 mg/min.

To manage a gran mal seizure in the ED, phenytoin (IV) can be ordered with a loading dose of 10 to 15 mg/kg at a rate not exceeding 50 mg/min 2.

  • The patient should be closely monitored, including electrocardiogram, blood pressure, and respiratory function.
  • Maintenance doses of oral or intravenous Phenytoin Sodium Injection should be given every 6 to 8 hours after the initial loading dose.

From the Research

Management of Gran Mal Seizure in the ED

To manage a gran mal seizure in the ED, the following steps can be taken:

  • Order laboratory tests to rule out any underlying causes of the seizure, such as electrolyte imbalances or infections
  • Perform a physical examination to assess for any focal neurologic deficits
  • Obtain a thorough medical history, including any history of seizure disorders or other medical conditions
  • Consider ordering neuroimaging studies, such as a CT scan, to evaluate for any structural abnormalities in the brain 3

Medications for Gran Mal Seizure

The following medications can be used to treat gran mal seizures in the ED:

  • Lorazepam, which is a benzodiazepine that can be administered intravenously to rapidly control seizures 4, 5
  • Phenytoin, which is an antiepileptic medication that can be administered intravenously to control seizures 4, 6, 5
  • Valproate, which is an antiepileptic medication that can be administered intravenously to control seizures 4, 6, 5
  • Levetiracetam, which is an antiepileptic medication that can be administered intravenously to control seizures 4, 6, 5

Side Effects of Medications

The medications used to treat gran mal seizures can have side effects, including:

  • Dizziness and drowsiness, which are common side effects of benzodiazepines and antiepileptic medications 7
  • Mental slowing, which can be a side effect of benzodiazepines and antiepileptic medications 7
  • Weight gain, metabolic acidosis, nephrolithiasis, angle closure glaucoma, skin rash, hepatotoxicity, colitis, and movement and behavioral disorders, which are potential side effects of antiepileptic medications 7

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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