Wednesday, November 25, 2009

New concepts in status epilepticus

From a review in Emergency Medicine Clinics of North America, here are a few key points:

Definition of SE---

Traditional: 30 minutes of unrelenting seizure(s).

New (proposed): greater than 5 minutes or two or more without intervening full return of consciousness.


The longer durations traditionally used to define SE were selected based on assumptions about underlying pathophysiology that are now known not to be true rather than on any kind of clinical relevance…

Data from continuous electroencephalographic (EEG) monitoring indicate that the average length of a benign, self-limited, adult generalized tonic-clonic seizure (including pre-tonic-clonic, tonic, and clonic phases) is just longer than a minute and only rarely persists beyond 2 minutes. Patients with seizures that last more than 5 minutes are not likely to improve spontaneously. Consequently, most of these patients are more similar to those with seizures of 30 to 60 minutes' duration than they are to patients with benign seizures of less than 5 minutes' duration. Thus, the new definition is better at discriminating prognostically.

Prehospital treatment by paramedics---effective, safe, reduces likelihood of ICU admission and shows a trend toward reduced mortality.

Initial hospital treatment---

A new accelerated protocol has been proposed in which the previously sequential steps of lorazepam and phenytoin are now stacked and given simultaneously and in which phenobarbital has been omitted. In principle, this accelerated strategy should allow more aggressive treatment of patients who have SE and should reduce the delay to the induction of pharmacologic coma (thereby improving the outcomes) in those with the most refractory seizures. Clinical research to determine if this is true in practice is still required.

The lorazepam dose in the protocol is 0.05-0.1 mg/kg. The phenytoin dose is 18-20 mg/kg with the option to repeat once. Drugs for the induction of pharmacologic coma in refractory SE include midazolam 0.2mg/kg then 1.2 mcg/kg/min. Propofol and pentobarbital are listed as alternatives.

Nonconvulsive SE---need EEG to diagnose.

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