Emergency management of the paediatric patient with convulsive status epilepticus

---

The Canadian Paediatric Society gives permission to print single copies of this document from our website. For permission to reprint or reproduce multiple copies, please see our copyright policy.

Background and epidemiology

The conventional definition of convulsive status epilepticus (CSE) is continuous generalized tonic-clonic seizure activity with loss of consciousness for longer than 30 minutes, or two or more discrete seizures without a return to baseline mental status ^[1]. Additionally, the terms ‘early’ or ‘impending’ status epilepticus have been defined as continuous or intermittent seizures lasting longer than 5 minutes without full recovery of consciousness between seizures. Research has shown that early treatment is more effective in stopping such seizures, while treatment delay results in increased morbidity and mortality ^[2][3].

The annual incidence of CSE in children is reported as 10 to 73 episodes/100,000 children and is highest in children younger than 2 years of age ^[4]. Common etiologies are listed in Table 1. Mortality has been reported to be between 2.7% and 8%, with an overall morbidity (including newly diagnosed neurological disorders, hemodynamic instability, long-term focal neurological deficits, persisting cognitive impairment, and behaviour problems) of between 10% and 20% ^[2].

This statement addresses CSE in children and infants older than one month of age.

TABLE 1. Common etiologies of convulsive status epilepticus (CSE) in children

Acute pathology Acute symptomatic Acute CNS infection (meningitis or encephalitis) Anoxic injury Metabolic derangement (hypoglycemia, hyperglycemia, hyponatremia, hypocalcemia) Traumatic injury Drug-related Antiepileptic drug non-compliance or withdrawal Antiepileptic drug overdose Non-antiepileptic drug overdose Prolonged febrile convulsion

Remote pathology Cerebral dysgenesis Perinatal hypoxic-ischemic encephalopathy Progressive neurodegenerative disorders Prior brain injury (meningitis, stroke, trauma)

Idiopathic/cryptogenic

CNS Central nervous system Adapted from reference [4]

Protocols and guidelines

There is limited evidence in paediatrics on which to base a ‘gold standard’ protocol for the management of CSE. Many different guidelines currently in use are based on varying combinations of evidence, consensus opinion, local experience, and drug availability ^[2]-[16]. Despite minor variations in detail, these guidelines are similar in many ways.

Status epilepticus is a medical emergency requiring prompt, definitive management. Although the outcome of status epilepticus is mainly determined by its cause, the duration of CSE is also important. A timely approach may be more important than specific pharmacological intervention.

The objectives in acute management of CSE are to:

1. Maintain adequate airway, breathing, and circulation (the ‘ABCs’).
2. Terminate the seizure and prevent recurrence.
3. Manage refractory status epilepticus (RSE). 
4. Diagnose and initiate therapy for life-threatening causes of CSE (e.g., hypoglycemia, meningitis, and cerebral space-occupying lesions).

1. Maintain adequate ABCs

Inadequate airway maintenance is the most critical immediate risk to the child or youth with CSE. Hypoxia is frequently present. Managing the airway includes positioning the child on their side and suctioning easily accessible secretions. The mouth should not be pried open. After suctioning, reposition the patient on their back and apply a chin lift or jaw thrust to help open the airway, if needed. Administer 100% oxygen by face mask, and use cardiorespiratory and oxygen saturation monitors. Consider assisted ventilation when the child shows signs of respiratory depression or oxygen saturations remain low (under 90%) despite receiving 100% oxygen by face mask.

Increased heart rate and blood pressure (BP) are usually observed in the convulsing patient, but should return to normal when the seizure stops. Bradycardia, hypotension, and poor perfusion are ominous signs. They indicate severe hypoxia and an immediate need to establish the airway and ventilate the patient, either by bag-valve-mask ventilation or intubation. Intravenous (IV) access should be obtained as soon as possible (two large-bore IV lines, if possible). 

A bedside blood glucose level should be obtained. 

2. Terminate the seizure and prevent recurrence

Principles of treatment and monitoring

The main goal of treatment is to stop the seizure and, in doing so, prevent brain injury ^[3][15]. Use of medications to terminate the seizure should be considered for seizures lasting longer than 5 to 10 minutes. When administering medications, obtain IV access as soon as possible. 

A brief history and focused physical exam should be performed. Pay particular attention to any history of seizure disorder, other symptoms (e.g., fever), medication usage, and allergies to medications. 

A bedside glucose test will establish the need for a bolus of dextrose. If the blood glucose (BG) level is ≤2.6 mmol/L, the recommended management is a bolus of 0.5 g/kg of dextrose. Administer 2 mL/kg of 25% dextrose water (D25W) via central line, or 5 mL/kg of 10% dextrose water (D10W) by peripheral IV. When the patient is hypoglycemic, BG level should be rechecked 3 to 5 minutes post-bolus, and a repeat bolus administered if necessary.

If IV access is unavailable, then other routes should be used while efforts to establish vascular access continue. Consider starting an intraosseous (IO) line if IV access is not possible and the seizure is prolonged or the patient is decompensating.

During the administration of medications, continuous cardio-respiratory monitoring is advised. Anticonvulsant medications can cause loss of airway reflexes, respiratory depression, hypotension, and cardiac arrhythmias.

Increased intracranial pressure (ICP) or sepsis should be considered and treated, as needed.

Monitor the child’s temperature and aim for normothermia, using antipyretics as appropriate.

Management of status epilepticus is outlined in Figure 1. Medication doses are detailed in Table 2.

FIGURE 1. Guidelines for emergency department (ED) management of convulsive status epilepticus (CSE) in infants (older than one month of age) and children is available as a supplementary file.

 

TABLE 2. Anticonvulsant drug therapies for convulsive status epilepticus (CSE) is available as a supplementary file.

First-line treatment

Benzodiazepines are the first-line drugs of choice ^[6]. Because rapid intervention is critically important, if no IV access is available, benzodiazepines should be given by an alternate route while IV access is being obtained. First-line treatment may begin before arrival at the hospital ^[3][16][17].

Prehospital: Treatment options include the following: intramuscular (IM), intranasal, or buccal midazolam; buccal lorazepam; or rectal diazepam (see Table 2). For pre-hospital treatment, midazolam is the preferred first-line medication for treatment of seizures in children without IV access ^[2][18]-[23].

In hospital: Either lorazepam (IV route) or midazolam (IV or IM route) are equally appropriate first-line options, with similar efficacy ^[18][24]. When IV access is not rapidly available, alternative routes of administration (buccal, nasal, IM) should be considered. Lorazepam and midazolam have been shown to be more effective than diazepam or phenytoin for first-line treatment of seizures ^[18][25][26]. If the seizure has not stopped within 5 minutes after a single dose of benzodiazepine, a second dose should be administered. If the seizure persists after 2 doses of benzodiazepine, including doses given before arrival at the hospital, initiating second-line medications is recommended. Treatment with more than 2 doses of benzodiazepines is associated with increased risk for respiratory depression ^[17].

Second-line treatment

Current evidence suggests that fosphenytoin and phenytoin, levetiracetam, and valproate are equally effective for managing seizures that are refractory to benzodiazepines ^{[4][11][12][14][15][27]-[30]}. In Canada, fosphenytoin/phenytoin and phenobarbital have been the two most commonly used second-line medications, due to familiarity and availability. Recently, IV levetiracetam has also become widely available for use in managing CSE. As of July 2020, IV valproate is only available through the Health Canada’s Special Access Programme. Variations in availability, potential for adverse reactions, and the individual clinical scenario will help guide the choice of second-line medications. 

If one second-line medication is administered but is not successful in controlling the seizure, there is no clear consensus about further management ^[11]. Options include the use of another (different) second-line medication, or proceeding to the use of anesthetic agents. Within the first hour of seizure, there is little evidence to suggest that anesthetic agents are more efficacious than traditional second-line medications. Also, anesthetic agents are more likely to cause respiratory depression and hypotension. Therefore, it is recommended that a second ‘second-line’ medication be administered if the seizure persists for 5 minutes after the initial second-line medication has been completely administered.

Phenytoin and fosphenytoin: Phenytoin has been shown to control 50% to 80% of prolonged seizures ^[27][31]. Because of its high pH, extravasation of phenytoin can result in severe subcutaneous irritation characterized by edema, discolouration, and pain distal to the site of administration. This side effect does not occur with fosphenytoin, which is a water­soluble prodrug of phenytoin. Therefore, fosphenytoin may be given by IM injection when there is no IV or IO access. Fosphenytoin is the only second-line medication that does not require IV access, but it is comparatively expensive and not universally available ^[6]. Phenytoin and fosphenytoin should not be given to the same patient as separate second-line drugs.  If one has already been administered, then the other should not be used. 

The benefits of phenytoin include broad availability and less respiratory depression than phenobarbital.

Side effects of both phenytoin and fosphenytoin include cardiac arrhythmias, bradycardia, and hypotension, such that continuous BP and electrocardiogram (ECG) monitoring is recommended during infusion. 

Phenytoin is not recommended as a second-line medication to treat seizures caused by toxic ingestions or drug withdrawals, and may actually be harmful if used to treat seizures caused by ingestion of theophylline and tricyclic antidepressants ^[32][33]. 

Phenobarbital: Phenobarbital has similar anticonvulsant efficacy to phenytoin but has been associated with greater incidence of respiratory depression, especially when used in conjunction with benzodiazepines. Additional side effects include hypotension and sedation. Phenobarbital’s mechanism of action is similar to the benzodiazepines and thus it may be less effective for treating seizures refractory to these drugs ^[6].

Phenobarbital may be the second-line agent of choice to treat children <6 months old, prolonged febrile seizures, and seizures caused by toxic ingestions or drug withdrawal ^[32][34][35]. IV phenobarbital is readily available in most hospitals. Alternative medications should be considered when the patient is already experiencing respiratory depression or hemodynamic instability. 

Levetiracetam: The IV form of levetiracetam was brought to market in Canada in 2019, and studies suggest that it has similar efficacy to phenytoin, phenobarbital, and valproate ^{[13][27][29][30][36]-[39]}. Levetiracetam appears to be a well-tolerated medication with fewer respiratory and cardiovascular side effects than phenytoin and -phenobarbital. However, one study found an increase in post-ictal psychosis when levetiracetam was used ^[13]. 

Levetiracetam should be considered as a second-line medication in children who are experiencing respiratory depression or are hemodynamically compromised. Levetiracetam has relatively fewer interactions with other medications compared with other anti-epileptic drugs, and may be a good choice in cases of polypharmacy (such as with chemotherapy or use of anti-inflammatory medications). 

Valproate: There is increasing interest in the use of IV valproate as a second-line treatment. Recent trials have demonstrated similar efficacy to phenytoin, levetiracetam, and phenobarbital, and valproate may cause less respiratory and cardiovascular compromise ^{[4][11][13][27][36][37][40]-[46]}.  

As of July 2020, access to IV valproate has been limited because it is only available through Health Canada’s Special Access Programme. Valproate is a reasonable choice as a second-line medication in children who are experiencing respiratory depression or are hemodynamically compromised. Valproate is also useful in children who use this medication to control their epilepsy but have had poor compliance. Valproate should be used with caution in children with pre-existing liver disease. Valproate must be strictly avoided in children with known or suspected mitochondrial disease, including children under 2 years old with unexplained developmental delay. 

Pyridoxine: For children younger than 18 months of age in whom seizures may be caused by an undiagnosed metabolic disorder, a trial of pyridoxine (vitamin B6) 100 mg by IV initially, then 50 mg by IV or by mouth, twice a day, should be considered if there is a failure to respond to the medications described above.

Other medications: Paraldehyde has been used previously to manage CSE but is no longer available in Canada. Lacosamide is another medication that has shown some promise as a second-line agent, but there is insufficient data to recommend it routinely at this time ^[12][37].

3. Manage refractory status epilepticus (RSE)

CSE that is unresponsive to adequate doses of first- and second-line therapies is considered to be refractory, although some organizations require that the seizure lasts longer than 1 h to meet criteria for RSE ^[4][16][47]. Beyond the first hour of seizure, second-line medications are less likely to be effective and new medication strategies are used. RSE strategies may involve administering a continuous midazolam infusion, pentobarbital, high-dose phenobarbital, or propofol. These medications have significant risks, including respiratory suppression and hypotension. At this stage, the patient’s care is beyond the scope of the usual ED setting, and transfer to a paediatric intensive care unit with neurological consultation for further management is necessary.

4. Diagnose and initiate therapy for life-threatening causes of CSE

Investigations should be individualized based on clinical scenario (Table 1). The most common cause of CSE is a prolonged febrile seizure, which may not require an extensive work-up. The same may apply to children with a known seizure disorder who are already on anticonvulsant therapy. However, a full clinical assessment should involve a search for precipitating causes, with focus on signs of infection, meningeal irritation, trauma, focal neurological deficits, and intoxication.

When the etiology of the seizure is unclear, consider the following investigations: blood for electrolytes, glucose (to verify earlier bedside determination), complete blood count and differential, cultures (if sepsis is suspected), and blood gas ^[1]. Anticonvulsant levels should be measured for patients on long-term anticonvulsant therapy. Urine and blood can be sent for toxicology screening. Serum calcium, blood urea nitrogen, magnesium, liver enzymes, lactate, and ammonia may be required in specific cases. A decision regarding the need for lumbar puncture (LP) should be deferred until the patient’s vital signs are stable, there is no suspicion of increased ICP, and the convulsion has stopped.

When meningitis or encephalitis is believed to be causing seizure, administer IV antibiotics and antivirals urgently. Attempts to obtain cultures should not delay treatment. 

A history of trauma, evidence of increased ICP, focal neurological signs, unexplained loss of consciousness, or suspicion of cerebral herniation are indications for a computed tomography (CT) scan of the head. Head CT may be performed after the ABCs have been stabilized and the convulsion has terminated ^[1]. A magnetic resonance image (MRI) of the brain may be able to identify problems not seen on CT, but this technology is not always readily available ^[16].

When there are clinical indications of raised ICP or herniation, these must be treated immediately before further investigation. A normal CT scan does not exclude significantly increased ICP. LP must be deferred when clinical or radiological signs of increased ICP are present.

Intoxication should always be considered. When intoxication is proven or strongly suspected, and the convulsive activity has stopped, consider using activated charcoal as soon as the airway has been protected.

Non-convulsive status epilepticus (non-CSE)

Non-CSE refers to a persistent change in the baseline level of consciousness, with associated continuous epileptiform changes in the electroencephalogram (EEG), but without motor signs. If the child’s level of consciousness does not recover as expected after the convulsion has stopped, or when neuromuscular paralysis is being used, then an EEG should be performed to exclude non-CSE. When an EEG cannot be obtained, consultation with neurology and empirical treatment for non-CSE is indicated ^[9].

Conclusion

Status epilepticus is a common paediatric neurological emergency. Appropriate management includes maintaining respiratory and hemodynamic stability, prompt administration of appropriate medications at appropriate doses, and the specific diagnosis and management of potentially life-threatening causes of seizure. All health care professionals involved in the acute medical management of children must be ready to apply up-to-date, evidence-based strategies for the emergency management of children with CSE.

Acknowledgements

The authors wish to thank Michael De Guzman, BScPharm, PharmD, ACPR, RPh (Clinical Pharmacist, The Hospital for Sick Children), for his detailed pharmacy review of this statement. The statement was reviewed by the Adolescent Health, Community Paediatrics, and Drug Therapy and Hazardous Substances Committees of the Canadian Paediatric Society. It was also reviewed by the CPS Hospital Paediatrics and Paediatric Emergency Medicine Sections, and by the Canadian Association of Child Neurology.

---

CANADIAN PAEDIATRIC SOCIETY ACUTE CARE COMMITTEE

Members: Carolyn Beck MD, Kevin Chan MD (Chair), Kimberly Dow MD (Board Representative), Karen Gripp MD, Kristina Krmpotic MD, Marie-Pier Lirette MD (Resident Member), Kyle C McKenzie MD (past member), Evelyne D. Trottier MD
Liaisons: Laurel Chauvin-Kimoff MD (Past Chair 2012-2019), CPS Paediatric Emergency Medicine Section; Sidd Thakore MD, CPS Hospital Paediatrics Section
Principal authors: Kyle C McKenzie MD, Cecil D Hahn MD, Jeremy N Friedman MD

---

References

---

Disclaimer: The recommendations in this position statement do not indicate an exclusive course of treatment or procedure to be followed. Variations, taking into account individual circumstances, may be appropriate. Internet addresses are current at time of publication.