Introduction
Status epilepticus (SE) is a neurologic emergency associated with significant mortality and morbidity.
Definition
Conventionally defined as "prolonged seizure activity lasting longer than 30 min or series of seizures without recovery of consciousness in the interim".
The term refractory SE is used when there is the failure to respond to first-line drugs and seizures persist for more than 60 minutes.
Early recognition of SE is of utmost importance because the longer the SE, the more difficult the control and more the risk of neurologic sequelae. Therefore, SE should be considered and treatment initiated when a patient presents in an emergency with continuous seizures or a series of seizures without recovery of consciousness lasting 10 or even 5 min.
Incidence
SE is more common in children (more often in less than 3 yr olds) than adults with a frequency of around 3.7%.
Etiology of SE
There are three main situations in which SE can present:
Acute situation related:
- CNS infections: meningitis, encephalitis
- Acute anoxic insult
- Metabolic: hypoglycemia, inborn errors of metabolism (IEM), Reye syndrome
- Electrolyte imbalance
- CNS trauma/haemorrhage/tumors
- Drugs, intoxications, poisoning
- Hypoxic ischemic encephalopathy and IEM in newborn period
First unprovoked seizures presenting as SE - most commonly febrile status
SE in patients with epilepsies: epileptics on irregular treatment, sleep deprivation, intercurrent infections and symptomatic epilepsies are more prone to developing SE.
Investigations
Basic investigations to be carried out in all cases of SE irrespective of etiology include blood sugar, serum electrolytes, blood gases, blood urea, complete blood count. Serum Ca and Mg should be in neonates.
Certain other investigations may be required depending on individual situation:
- Lumbar puncture
- CT/MRI
- EEG
- Serum anticonvulsant levels
- Liver function tests, serum ammonia
- Blood cultures
- Toxicology screen
Role of EEG: EEG is useful to recognize SE in paralyzed patients, nonconvulsive SE, and in neonates. It is also of use in refractory SE which requires to be treated with midazolam infusion or general anesthetics.
Treatment
- To stop seizures
- Treatment of complications
- Treatment of underlying etiology
Seizure control should be achieved rapidly and effectively since the duration of SE is a vital determinant in the response to treatment, mortality, and neurologic sequelae. Thus, SE is divided into early-stage (0-30 min), established (30-60 min), and late stages (more than 60 min).
Team approach (pediatric neurologist, anesthetist, and critical care staff) along with predetermined protocol management gives the best results.
There are no standard internationally/nationally accepted protocols but the following flow chart gives the practical approach to managing a child with SE.
On Admission In Emergency
- Diagnose SE (continuous seizures for more than 5-10 min)
- Assess Airway/Breathing/Circulation, start O2 by nasal catheter
- Position, suction, oral airway without force
- IV/IO access - dextrostix/S. electrolytes/ABG
- Rapid evaluation for etiology
- Monitors - pulse oximeter, ECG.
- If dextrostix low or unavailable - Inj 10% dextrose 4 ml/kg followed by Inj Lorazepam - 0.1 mg/kg at 2 mg/min or Inj Diazepam - 0.2 mg/kg (max 10 mg) at 5 mg/min (can be repeated twice if seizures do not stop after 5 min of inj)
- Seizure continue - Inj Phenytoin 20 mg/kg (or fosphenytoin, newer derivative, less adverse effects) at 1 mg/kg/min with monitoring of BP, HR, RR (use normal saline flush, no glucose/Ca)
- Seizures continue - consider intubation, inj Phenobarbitone 20 mg/kg at not more than 100 mg/min
- Seizures continue - Repeat inj phenobarb 10 mg/kg
Most seizures stop with the above treatment. No control with the above measures, treat as refractory SE. Consider intubation and artificial ventilation & EEG monitoring.