- Status epilepticus (SE) is a neurologic emergency that is associated with significant morbidity and mortality.
- Generalized convulsive status epilepticus (GCSE) is defined as any recurrent or continuous seizure activity lasting longer than 30 minutes in which the patient does not regain baseline mental status. Any seizure that does not stop within 5 minutes should be treated as impending SE.
- There are two types of SE, GCSE and nonconvulsive status epilepticus (NCSE). GCSE is the most common type.
- Most GCSE develops in patients with no history of epilepsy; however, a patient with preexisting epilepsy may experience GCSE as a result of acute anticonvulsant withdrawal, metabolic disorder, concurrent illness, or progression of neurologic disease.
- Although the pathophysiology of GCSE is unknown, experimental models have shown that there is a dramatic decrease in γ-aminobutyric acid–mediated inhibitory synaptic transmission and that glutamatergic excitatory synaptic transmission sustains the seizures.
- General treatment includes patient stabilization, adequate oxygenation, preservation of cardiorespiratory function, management of systemic complications, and aggressive assessment of underlying causes.
- The main purpose of treatment is to prevent or decrease morbidity and mortality of prolonged seizures. Pharmacologic treatment needs to be rapid and aimed at terminating both electrical and clinical seizures. The probability of poorer outcomes increases with increased length of electrographic seizure activity.
- Lorazepam is the preferred benzodiazepine in treatment of GCSE because of its efficacy and long duration of action in the CNS. Midazolam is the preferred benzodiazepine for intramuscular (IM) administration.
- Currently, the hydantoins (phenytoin and fosphenytoin) are the long-acting anticonvulsants used most frequently. Either phenytoin or fosphenytoin should be given concurrently with benzodiazepines.
- The maximum rate of infusion for phenytoin and fosphenytoin in adults is 50 mg/min and 150 mg PE/min, respectively.
- If GCSE is not controlled by two first-line agents (benzodiazepine plus hydantoin or phenobarbital), the GCSE is considered to be refractory. In these cases, anesthetic doses of midazolam, pentobarbital, or propofol may be used.
After reviewing this chapter, the reader should be able to:
Given a patient’s medical history and clinical presentation, differentiate a patient in generalized convulsive status epilepticus (GCSE) from one in nonconvulsive status epilepticus (NCSE).
Recommend common medical tests used in the evaluation and diagnosis of status epilepticus.
Contrast the classic International League Against Epilepsy definition of status epilepticus (SE) and the currently recognized time in which aggressive treatment is recommended.
Describe the etiologies and risk factors for GCSE and how they are associated with patient prognosis.
Describe the pathophysiology of GCSE and how it relates to responsiveness to treatment and patient outcome.
When given a specific case, be able to individualize a nonpharmacologic treatment plan for a patient with GCSE.
When given a specific case, be able to individualize a pharmacologic treatment plan for a patient with GCSE.
Contrast diazepam and lorazepam based on their pharmacodynamic properties (onset, duration of action) and be able to discuss their place in GCSE therapy.
Discuss the advantages and disadvantages of phenytoin and fosphenytoin, and be able to ...