Do you have a plan for your little patient when he just won’t stop seizing? What do you do when your typical treatment is not enough? Get up-to-date in the understanding and management of pediatric status epilepticus.
Definition of status epilepticus:
Continuous seizure activity of 5 minutes or greater
– OR –
Recurrent activity without recovery between intervals. (This definition includes clinically apparent seizures as well as those seen only on EEG.)
During a seizure, GABA receptors in the neuron’s membrane are internalized and destroyed. Seizure activity itself starts this self-defeating process – this is the first reason we need to act as quickly as possible and take advantage of the GABA receptors that are still recruitable.
Excitatory receptors – the NMDA receptors – are acutely upregulated and mobilize to the neuron’s surface. This is the second reason to act quickly and avoid this kindling effect.
In other words – time is brain.
Or… is it something else as well?
Pediatric status epilepticus is analogous to the multi-organ dysfunction syndrome in severe sepsis. Status epilepticus affects almost every organ system.
Cardiac – dysrhythmias, high output failure, and autonomic dysregulation resulting in hypotension or hypertension.
Respiratory – apnea and hypoxia, ARDS, and potentially aspiration pneumonia.
Renal – rhabdomyolysis, myoglobinuria, and acute renal failure.
Metabolic – lactic acidosis, hypercapnia, hyperglycemia, sometimes hypoglycemia, hyperkalemia, and leukocytosis.
Autonomic – hyperpyrexia and breakdown of cerebral circulation.
DeLorenzo et al.: Mortality correlated with time seizing. Once the seizure has met the 30 min mark, Delorenzo reported a jump from 4.4% mortality to 22%! If the seizure lasts greater than 2 hours, 45%. Time spent seizing is a vicious cycle: it’s harder to break the longer it goes on, and the longer it goes on, the higher the mortality.
Think about treatment of pediatric status epilepticus in terms of time: prehospital care, status epilepticus (greater than 5 min), initial refractory status epilepticus (greater than 10 min), later refractory status (at 20 min), and coma induction (at 25 minutes).
Case 1: Hyponatremic Status Epilepticus
Give 3 mL/kg of 3% saline over 30 min.
Stop the infusion as soon as the seizure stops.
Case 2: INH toxicity
Empiric treatment -- you are the test. If we know the amount of ingestion in adults or children, we give a gram-for-gram replacement, up to 5 grams.
If a child under 2 years of age arrives to you in stats epilepticus, give 100 mg of IV pyridoxime for potentially undiagnosed congenital deficiency.
Case 3: Headache and Arteriovenous Malformation
Unlike in adults, stroke in children is divided evenly between hemorrhagic and ischemic etiologies.
The differential is vast: cardiac, hematologic, infectious, vascaulr, syndromic, metabolic, oncologic, traumatic, toxic.
Treatment: stabilization, embolization by interventional radiology, elective extirpation when more stable. Other options for stable patients include an endovascular flow-directed microcatheter using cyanoacrylate. Radiosurgery is an options for others.
Non-convulsive Status Epilepticus
Risk factors include age < 18, especially age < 1, no prior history of seizures, and traumatic brain injury. This would prompt you to ask for continuous EEG monitoring for non-convulsive status epilepticus, especially when there is a change in mental status for no other reason. Also, a prolonged post-ictal state or prolonged altered mental status. Other considerations are those who had a seizure and cardiac arrest - ROSC without RONF, those with traumatic brain injury, and those needing ECMO – all within the context of seizures.
SUMMARY POINTS
The longer the seizure lasts, the harder it is to break – act quickly
Have a plan for normal escalation of care, and Search for an underlying cause
Recognize when the routine treatment is not enough.
Before You Go
“Healing is a matter of time, but it is sometimes also a matter of opportunity.”
“Extreme remedies are very appropriate for extreme diseases.”
– Hippocrates of Kos
Selected References
Abend NS et al. Nonconvulsive seizures are common in critically ill children. Neurology. 2011; 76(12):1071-7
Baren J. Pediatric Seizures and Strokes: Beyond Benzos and Brain Scans. ACEP Scientific Assembly. October 8th, 2009. Boston, MA.
Brophy et al. Guidelines for the Evaluation and Management of Status Epilepticus. Neurocrit Care. 2012; DOI 10.1007/s12028-012-9695-z
Capovilla G et al. Treatment of convulsive status epilepticus in childhood: Recommendations of the Italian League Against Epilepsy. Epilepsia. 2013; 54 Suppl 7:23-34
Chin RFM et al., for the NLSTEPSS Collaborative Group. Incidence, cause, and short-term outcome of convulsive status epilepticus in childhood: prospective population-based study. Lancet. 2006; 368: 222–29.
Chen JW, Chamberlain CG. Status epilepticus: pathophysiology and management in adults. Lancet Neurol. 2006; 5:246-256.
DeLorenzo RJ. Comparison of status epilepticus with prolonged seizure episodes lasting from 10 to 29 minutes. Epilepsia. 1999 Feb;40(2):164-9.
LaRoche SM, Helmers SL. The New Antiepileptic Drugs: Scientific Review. JAMA. 2004;291:605-614.
Minns AB, Ghafouri N, Clark RF. Isoniazid-induced status epilepticus in a pediatric patient after inadequate pyridoxine therapy. Pediatr Emerg Care. 2010; 26(5):380-1.
Ogilvy CS et al. Recommendations for the Management of Intracranial Arteriovenous Malformations: A Statement for Healthcare Professionals From a Special Writing Group of the Stroke Council, American Stroke Council. Stroke. 2001; 32: 1458-1471
Rosati A et al. Efficacy and safety of ketamine in refractory status epilepticus in children. Neurology. 2012; 79:2355-2358.
Schwartz ID. Hyponatremic seizure in a child using desmopressin for nocturnal enuresis. Arch Pediatr Adolesc Med. 1998 Oct;152(10):1037-8
Trommer BL, Pasternak JF. NMDA receptor antagonists inhibit kindling epileptogenesis and seizure expression in developing rats. Brain Res Dev Brain Res. 1990 May 1;53(2):248-52.
Waterhouse EJ et al. Prospective population-based study of intermittent and continuous convulsive status epilepticus in Richmond, Virginia. Epilepsia. 1999 Jun;40(6).
