Epileptic status in children. Clinical lecture
Epileptic status (ES) is characterized by prolonged or repeated seizures / episodes without a return to the normal state for this patient. ES is often found in pediatric practice, it affects 18–23 out of 100 thousand children per year, mortality reaches 2–7%. Treatment measures include the introduction of anticonvulsants, the identification and elimination of factors that trigger ES, as well as the prevention of possible complications.
Definition and classification of ES
Historically, ES has been defined as “a condition characterized by an epileptic seizure / seizure long enough or recurring at short enough intervals to cause an unchanged and stable epileptic state”.
This definition was supplemented by the International League for the Control of Epilepsy, which decided that an attack / seizure should last at least 30 minutes, or during this period of time there should be several seizures without restoration of functions between them for more than 30 minutes.
The first 5 min of an attack is called the preliminary / prodromal (prodromal) period, or initial (incipient) ES. Further activity during the attack is divided into early ES (5–30 min), steady ES (more than 30 min) and refractory ES. Emergency intervention corresponds to the temporal definitions of early ES, and emergency – to the established ES. With ES, pathophysiological changes develop,
causing resistance to anticonvulsants. In children with an initial attack lasting more than 5-10 minutes, the probability of ending the attack without medication is very low.
In children, the highest frequency of ES in the neonatal period, then it decreases for about 5 years. The incidence of ES is from 10.3 to 61 per 100 thousand people. It is maximum in children of the first year of life and amounts to 135–165 per 100 thousand of the population. Despite the fact that episodes of ES in children occur more often than in adults, mortality due to ES in children is lower than in adults, and is 3%. Most often, ES develops in children with acute or chronic neurological diseases. In individuals aged 5 to 40 years, episodes of ES are relatively rare.
Emergency diagnostic and treatment measures for ES
In ES, emergency measures are taken to stabilize the patient’s vital functions while identifying the causes of the attack and possible complications. The steps to be taken in the first 5 minutes include ensuring airway patency, assessing the adequacy of ventilation and perfusion / blood supply (assessing vital functions), installing an intravenous port (catheter) in a peripheral vein, determining the level of blood glucose with a glucometer, and sampling blood for general and biochemical analyzes, determination of acid-base status, concentrations of electrolytes and anticonvulsants. As soon as the intravenous port / catheter is installed, the introduction of emergency drugs begins –
benzodiazepines. If the drug cannot be administered intravenously, other routes of administration should be used: intramuscular, rectal, buccal or nasal.
Diagnosis of ES causes
Correctable causes of ES, such as hypoglycemia, hypocalcemia, hyponatremia, or hypomagnesemia, should be identified as soon as possible. Hyperthermia and hyperglycemia also require close attention, because they are often associated with an unfavorable outcome for some types of neurological diseases that can cause ES. Some patients may require additional instrumental and laboratory tests: lumbar puncture, neuroimaging, determination of liver function indicators, coagulogram, screening of blood or urine for the presence of drugs, screening for congenital metabolic disorders. All these studies are recommended to be performed within the first hour. Some patients may also need to perform tests to identify rare causes of ES (identification of specific antibodies, detection of virus RNA by PCR for the diagnosis of viral encephalitis, a blood test for autoantibodies).
Monitoring of the electroencephalogram (EEG) should be started 15-60 minutes from the start of the attack in order to assess the state of non-convulsive ES in patients who do not return to normal levels within 10 minutes after the cessation of convulsions or within 60 minutes in patients where it is possible to suspect ongoing attack. In the future, monitoring should continue for 48 hours in patients with severe encephalopathy in order to determine non-convulsive ES; as well as in patients in a coma, patients with cerebral hemorrhage of any type, with epileptiform changes on a routine EEG, or in patients whose altered mental state can be caused by a non-convulsive attack. Continuous EEG monitoring is indicated for all children after convulsive ES with persistent changes in their mental state.