Status epilepticus

Status epilepticus is defined as epileptic activity that continues for longer than 5–30 minutes, either as a single seizure or as recurrent seizures without inter-ictal return of consciousness. The seizure activity is usually classified as partial or generalized. Most episodes of status develop without a prior history of epilepsy. This fact is of major clinical relevance as the emergency management of all patients with status epilepticus must include a search for underlying causes. Although status epilepticus is an uncommon admission diagnosis among patients admitted to a general intensive care unit, a sound knowledge of the causes and treatment of this medical emergency is essential for prompt and effective management. Convulsive seizure activity causes marked systemic disturbances and neuronal injury proportional to the duration of seizure activity. Non-convulsive status epilepticus should be suspected in patients with impaired consciousness without obvious cause and can be definitely diagnosed only with electroencephalography monitoring. An intravenous bolus dose of a benzodiazepine (diazepam or lorazepam) should be used initially to terminate seizures. After this, an appropriate antiepileptic agent (phenytoin) should be started and any systemic disturbances treated. Patients with status epilepticus refractory to the above treatment measures should have general anaesthesia induced and maintained with infusions of an agent with γ-aminobutyric acid (GABA)-ergic activity (thiopentone, propofol or midazolam), aiming for electro-encephalographic burst suppression for 24 hours in the first instance, but longer if necessary.