Tue16November0750PM 1

A 20-year-old male is admitted to the Emergency department with a diagnosis of status epilepticus.

The paramedics have already administered high flow oxygen and 10 mg rectal diazepam. The vital signs are a pulse rate of 140 beats per minute; respiratory rate 25 breaths per minute; blood pressure 130/80 mmHg; oxygen saturation 98% and a patent airway but continued tonic-clonic seizures. His blood glucose is 7.0 mmol/L.

Which of the following agents is the most appropriate initial pharmacological treatment?

(Please select 1 option)

Phenobarbitone

Propofol

Thiopentone

Phenytoin

Lorazepam Correct

Explanation

Lorazepam has emerged as the preferred benzodiazepine for acute management of status epilepticus.

Lorazepam differs from diazepam in two important respects. It is less lipid-soluble than diazepam, with a distribution half life of two to three hours versus 15 minutes for diazepam. Therefore, it should have a longer duration of clinical effect. Lorazepam also binds the GABAergic receptor more tightly than diazepam, resulting in a longer duration of action. The intravenous dose is 0.1 mg/kg. The second line drug is intravenous phenytoin 15-20 mg/kg.

Status epilepticus is defined as convulsions lasting for 5 or more minutes or recurrent episodes of convulsions in a 5-minute period without return to pre-convulsive neurological baseline. A typical secondarily generalize tonic-clonic seizure generally stops by three minutes and almost always by 5-minutes. Status epilepticus was previously defined as continuous seizure activity of at least 30 minutes duration or intermittent seizure activity of at least 30 minutes duration during which consciousness is not regained.

Phenytoin is one of the most effective drugs for treating acute seizures and status epilepticus. The main advantage of phenytoin is the lack of a sedating effect. However, a number of potentially serious adverse effects may occur. Arrhythmias and hypotension have been reported. The side effects of phenytoin have largely been attributed to its diluent propylene glycol or rapid administration. Fosphenytoin (a prodrug) is more cardiovascularly stable.

Phenobarbital typically is used after a benzodiazepine or phenytoin has failed to control status epilepticus. The normal loading dose is 15 to 20 mg per kg. Because high-dose phenobarbital is sedating, airway protection is an important consideration.

Where airway protection or control ventilation is required, then the drugs of choice are intravenous thiopentone or propofol.

Answer Statistics

1

1%

2

2%

3

19%

4

80%

Times answered: 267