James Lee, MD, Linda Huh, MD, FRCPC, Paul Korn, MD, FRCPC, Kevin Farrell, MD, MBChB Guideline for the management of convulsive status epilepticus in infants and children Children treated more aggressively and those with shorter episodes of status epilepticus have been found less likely to develop neuro- logical deficits. ABSTRACT: Convulsive status epi - onvulsive status epilepticus underlying cause is considered to be lep ticus is a medical emergency accounts for 70% of episodes the most important determinant of out- requiring early and effective treat- Cof status epilepticus (SE) oc - come, and the morbidity appears to be ment. Airway, respiratory, and circu- curring in infants and children.1 Status less in those with febrile and unpro- latory support should be provided epilepticus, whether convulsive or non- voked status epilepticus.6 Studies of immediately. Initial investigations convulsive, is “an epileptic seizure status epilepticus in primates have should then focus on possible meta- that is sufficiently prolonged or re - demonstrated a direct relationship bolic derangements and conditions peated at sufficiently brief intervals between the duration of the seizure that require immediate treatment, so as to produce an unvarying and and the development of permanent such as meningitis. The recommen - enduring epileptic condition.”2 Early brain injury that probably occurs as a ded first-line therapy includes a fast- studies used a definition of continu- result of the depletion of energy sub- acting benzodiazepine followed by a ous seizure activity lasting for 30 min- strate.10 In addition, children treated longer-acting antiepileptic. In cases utes or recurrent seizures without any more aggressively and those with of refractory status epilepticus, fur- intervening recovery of full con- shorter episodes of SE are less likely ther treatment will depend on the sciousness.3 However, most seizures to develop subsequent neurological setting. When pediatric intensive in children that last for longer than 7 deficits or epilepsy.9 Similarly, resist- care is not available, phenobarbital minutes will last for at least 30 min- ance to first- and second-line treat- or paraldehyde might be used. When utes.4 Consequently, it is generally ments for SE is directly related to the pediatric intensive care is available, recommended that seizures lasting for duration of seizures prior to treat- midazolam, barbiturates, and pro - more than 5 minutes should be treated ment.11,12 These studies demonstrate pofol are options. Neuroimaging by as for status epilepticus.5 Because of that a prolonged seizure per se can either CT or MRI should be under- the significant morbidity and mortali- result in brain injury and emphasize taken only after the patient has been ty associated with SE, early and effec- stabilized and the convulsive seizure tive treatment is essential. Dr Lee is a pediatric neurology resident at activity controlled. BC Children’s Hospital (BCCH). Dr Huh is Morbidity and mortality an assistant professor in the Division of More effective treatment of status Pediatric Neurology at the University of epilepticus has reduced the mortality British Columbia. Dr Korn is a clinical asso- rate in children to between 1% and ciate professor in the Department of Pedi- 5%.6-9 However, status epilepticus can atrics at UBC. Dr Farrell is a neurologist at be associated with significant morbid- BC Children’s Hospital (BCCH) and a pro- ity, including epilepsy, motor disor- fessor in the Department of Pediatrics at This article has been peer reviewed. ders, and cognitive abnormalities. The the University of British Columbia. www.bcmj.org VOL. 53 NO. 6, JULY/AUGUST 2011 BC MEDICAL JOURNAL 279 Guideline for the management of convulsive status epilepticus in infants and children the importance of early and effective convulsive status epilepticus in infants trose administered if blood glucose is treatment of SE. and children recommended by phy - less than 3 mmol/L. Antiepileptic drug sicians at BC Children’s Hospital levels should be determined if the pa - Causes of status (BCCH). The initial management in - tient is receiving phenobarbital, phen - epilepticus in children volves stabilization of the airway, ytoin, carbamazepine, or valproic acid. It is important to consider the under- maintenance of adequate ventilation A computed tomography or mag- lying cause of status epilepticus. The (with oxygen administered as neces- netic resonance imaging scan of the cause will guide the investigations, sary), and circulatory support. Intra- head should be considered if there are may require immediate treatment, and venous access should then be estab- clinical indications, such as a focal has a major influence on the progno- lished as this permits the most rapid neurological abnormality, or if the sis. In approximately one-quarter of delivery of a drug to the brain. If dif- cause is unknown. If neuroimaging is children affected, status epilepticus is ficulty is encountered achieving intra- done, it should be undertaken only the sign of an underlying acute brain venous access within 3 minutes, then after the patient has been stabilized disorder, such as traumatic brain in jury intraosseous access should be estab- and the convulsive seizure activity or meningitis. Approximately one- lished if possible. During the manage- controlled.13 third of children affected will have a ment of the patient, it is important to history of previous epileptic seizures, consider the duration of the seizure Drugs developmental delay, or other neuro- both prior to and during treatment. Physicians are generally aware of the logical abnormality. One-quarter of The initial laboratory studies doses of anticonvulsant medications children affected will have a prolonged should focus on the possible causes of used in adults, but unfamiliarity with febrile convulsion and no other cause status epilepticus, particularly those the doses and routes used in children will be demonstrated. An underlying that require immediate treatment, such sometimes results in administration of cause will not be found in the remain- as meningitis and reversible derange- inappropriate doses.14,15 Table 1 des - ing children. ments of metabolism.13 Investigations cribes the doses for initial treatment in should include complete blood count, children based on their weight. Initial management and blood culture (in febrile children), investigations serum electrolytes, and blood glucose. Benzodiazepines The accompanyingFigure describes Blood glucose should also be checked Benzodiazepines act rapidly and are the organized approach to managing at the bedside and 5 mL/kg 10% dex- the medications for first-line treatment of convulsive status epilepticus. The dose of whichever benzodiazepine is Table 1. Drugs for initial treatment of convulsive status epilepticus. used should be repeated after 5 min- Drug Dose and route Notes utes if the seizure continues. Lorazepam. Intravenous lorazepam Lorazepam 0.1 mg/kg (max 4 mg) IV • Can be repeated once after 5 min is the treatment of choice for status 0.3 mg/kg (max 5 mg in infants and • IV dose should be given over 2 to 5 epilepticus. It has a longer duration of Diazepam 10 mg in children) IV, IO min to avoid respiratory depression 0.5 mg/kg (max 10 mg) PR • Can be repeated once after 5 min action and fewer adverse effects than 15,16 0.2 mg/kg (max 10 mg) IN or diazepam, and has been reported Midazolam • Can be repeated once after 5 min 0.5 mg/kg (max 10 mg) buccal to be associated with more rapid seizure • Should be given over 20 min control than IV diazepam.17 Peak con- Phenytoin 18–20 mg/kg IV, IO • Monitor for bradycardia, hypotension, centrations of sublingual lorazepam cardiac arrhythmia may not occur for 60 minutes18 and • IV 1.5–3.0 mg/kg/min (max 150 19 18–20 mg/kg of phenytoin rectal absorption is erratic. Conse- Fosphenytoin mg/min) equivalents IV or IM • IM in single or divided doses quently, sublingual and rectal loraze - pam are not recommended for the • Monitor for respiratory depression, Phenobarbital 15–20 mg/kg IV hypotension treatment of status epilepticus. Diazepam. 0.3–0.4 mL/kg (max total volume 10 Intravenous diazepam Paraldehyde mL) mixed in an equal amount of should be administered over 2 min- mineral or olive oil PR utes because the risk of respiratory IV = intravenous; IO = intraosseous; PR = per rectal; IN = intranasal; IM = intramuscular depression is increased with more 280 BC MEDICAL JOURNAL VOL. 53 NO. 6, JULY/AUGUST 2011 www.bcmj.org Guideline for the management of convulsive status epilepticus in infants and children Status epilepticus is defined as a seizure that lasts for > 30 min or recurrent seizures without full recovery between seizures for > 30 min. A child who has been convulsing for > 5 minutes should be treated as for status epilepticus. Manage ABCs Blood tests Cardiac monitor; oximeter CBC, electrolytes and glucose; glucometer Establish IV access Measure blood level if on PHB, DPH, Place in the recovery position CBZ or VPA Attempt IV IV lorazepam 0.1 mg/kg over Buccal midazolam 0.5 mg/kg ½–1 min (max 4 mg) (max 10 mg) Or Rapid IV Or IV diazepam 0.3 mg/kg over Yes access No Intranasal midazolam 2 min (max 5 mg in infants obtained? 0.2 mg/kg (max 10 mg) and 10 mg in child) Or Benzodiazepine can be Rectal diazepam 0.5 mg/kg/ repeated once after 5 min Insert intraosseous (max 10 mg) needle if seizure is Benzodiazepine can be not stopped with repeated once after 5 min rectal benzo Is child on phenytoin? Yes No IV phenobarbital 20 mg/kg over IV/I0