Prompt action, appropriate treatment required to manage status epilepticus
Prompt action and appropriate treatment are required for management of convulsive status epilepticus (SE) to achieve optimal outcomes.
“According to the International League Against Epilepsy, SE is defined as a condition resulting either from the failure of mechanisms responsible for seizure termination or from the initiation of mechanisms for seizure, which lead to abnormally prolonged seizure [5 minutes] and can have long-term consequences if the seizure persists for >30 minutes,” explained Dr Eva Fung, Department of Paediatrics, Chinese University of Hong Kong. [Epilepsia 2015;56:1515-1523]
“Treatment delay remains the main problem in SE management, which impacts treatment success,” she warned. “Optimization of SE management requires prompt action, improved awareness and good adherence to guidelines.”
“The Hong Kong Epilepsy Society published a local guideline for the management of convulsive SE in 2009,” Fung said. [Hong Kong Med J 2009;15(Suppl 5):6S-28S] “There have been a lot of medical advances in this field since then. To address this, the society published an updated guideline in 2017.” [Hong Kong Med J 2017;23:67-73]
In the updated guideline, benzodiazepines remain the mainstay of initial therapy for SE. Apart from the previously recommended intravenous (IV) lorazepam and IV diazepam, intramuscular (IM) midazolam is now also included as a treatment option. “The inclusion of midazolam in the present guideline was based on the phase III RAMPART study, which showed that IM midazolam was at least as safe and effective as IV lorazepam for prehospital seizure cessation,” noted Fung. [N Engl J Med 2012;366:591-600] “Importantly, clinicians should initiate benzodiazepines at full dose to stop seizure as soon as possible. No more than two doses should be given if the seizure is not controlled.”
A second antiepileptic drug is needed when first-line benzodiazepine treatment fails. Apart from the previously recommended phenytoin and phenobarbital, valproate and levetiracetam are also recommended as second-line treatment for patients with established SE. “However, there is no good evidence to suggest superiority of one drug over the others,” noted Fung. “Therefore, selection of treatment for patients with established SE largely relies on clinical experience and individual patient characteristics.”
“If seizure continues despite two lines of therapy, the patient will probably be having seizure for more than 30 minutes and is thus at risk of long-term consequences,” she pointed out. “These patients are best managed in intensive care unit [ICU].
“The anaesthetics midazolam, propofol and thiopentone are recommended for use in this setting, but the optimal depth and duration remain to be elucidated,” Fung continued. “Electroencephalography is essential when monitoring the effects of anaesthetics.”
“The updated guideline also includes management of super-refractory SE, which refers to SE that continues or recurs ≥24 hours after the onset of anaesthesia, including those cases in which SE recurs on the reduction or withdrawal of anaesthesia,” she added. “Management of this condition is challenging. Treatment options include ketamine, immunomodulatory treatment, ketogenic diet, IV magnesium, pyridoxine injection, hypothermia, electroconvulsive therapy and epilepsy surgery. It is important to identify the underlying cause so that these patients can be treated accurately.”