Status epilepticus: SAQ

This boy is in established convulsive status epilepticus. The seizure has lasted twenty minutes, which places him between the ILAE t1 of five minutes and the t2 of thirty minutes, and he has already received one benzodiazepine dose without effect. His glucose is normal, so the cause is not hypoglycaemia, and his fever raises an infectious trigger. The priority is to give a second-line agent now, because a third benzodiazepine dose adds respiratory depression without adding efficacy, as the GABA-A receptors have begun to internalise. [1]

Question 1 (10 marks)

Outline the stepwise management of this boy from the moment of arrival, including the drugs and doses you would give and the time frame for each step. [2]

I would apply the APLS stepwise pathway. On arrival I would call for senior and anaesthetic help, start the clock, place the child in the lateral position, give high-flow oxygen, and apply cardiac and oxygen monitoring. I would confirm the bedside glucose is normal, which it is at 4.2 millimoles per litre, and I would weigh the child at 16 kilograms to anchor every dose. [2]

For the first-line benzodiazepine, the team has already given one dose of intravenous lorazepam eight minutes ago. I would give a second dose of lorazepam at 0.1 mg per kg, which is 1.6 mg intravenously, to a maximum of 4 mg, and I would give it now because he is still seizing and only one dose has been given. No more than two benzodiazepine doses are given in total, because the GABA-A receptors internalise and the efficacy falls steeply with time, so a third dose adds respiratory depression without adding seizure control. [2]

Because the seizure has lasted twenty minutes and persists despite the first benzodiazepine, I would proceed directly to a second-line agent. My preferred agent is levetiracetam at 40 mg per kg intravenously, which is 640 mg, to a maximum of 4.5 g, infused over five minutes. The alternative is fosphenytoin at 20 mg phenytoin-equivalent per kg, which is 320 mg phenytoin-equivalent, to a maximum of 1500 mg phenytoin-equivalent, infused over ten minutes with cardiac monitoring. [3]

If the seizure persists beyond thirty minutes despite adequate first and second-line therapy, the boy has refractory status epilepticus, and I would escalate to rapid sequence intubation to protect the airway and ventilate, and I would start a continuous midazolam, propofol, or thiopentone infusion titrated to burst suppression. Continuous EEG monitoring would be mandatory from this point, because the boy would be paralysed and the brain could still be seizing. [2]

Question 2 (10 marks)

Discuss the evidence for the choice of second-line agent, and outline how you would investigate and treat the reversible causes and counsel the family. [5]

The evidence for the second-line agent comes from three trials. The Established Status Epilepticus Treatment Trial, ESETT, reported by Kapur and colleagues, randomised adults and children with established status to levetiracetam, fosphenytoin, or valproate, and found that all three stopped the seizure in just over half of patients, with no significant difference between them. The age-group analysis confirmed that the efficacy held in children, including in young children. [5]

The two dedicated paediatric trials addressed the same comparison. Dalziel and colleagues reported the ConSEPT trial across Australia and New Zealand, and Lyttle and colleagues reported the EcLiPSE trial in the United Kingdom, and both compared levetiracetam with phenytoin as second-line therapy in children. Neither trial found a difference in seizure cessation, and their shared finding that levetiracetam is at least as effective as phenytoin with a more favourable safety profile underpins its place as the preferred second-line agent in modern paediatric pathways, which is why I would choose levetiracetam for this boy. [3][4]

I would investigate and treat the reversible causes in parallel with the drugs. The fever of 38.5 degrees and the known epilepsy raise an intercurrent infection and a possible subtherapeutic level, so I would send a full blood count, a blood culture, electrolytes including calcium and magnesium, a venous gas, and an antiseizure drug level. Once the seizure is controlled and the coagulation and platelets are checked, I would perform a lumbar puncture and start empirical antibiotics and aciclovir if central nervous system infection is suspected. Neuroimaging would follow once the boy is stable. [6]

I would counsel the family in honest terms at each stage. I would explain that their son has been in a prolonged seizure that did not stop on its own, that the medicines are being given in a stepwise order to stop it, and that the blood tests and the possible lumbar puncture are looking for a treatable cause such as an infection or a drop in his epilepsy medicine level. I would explain that if the seizure does not stop with the second-line drug he will need a breathing machine and intensive care, that the team will watch his brain with an EEG throughout, and that I will return to explain the findings and the plan as soon as the seizure is controlled. The family would be offered a rescue benzodiazepine plan and a follow-up in the paediatric neurology clinic before discharge. [6]