Seizure (Pedi)



 

Classification

Primary Seizure: those without a clear casue

Secondary Seizures: Result from another identifiable neurologic condition such as mass or stroke.

Classification of Seizures
Generalized seizures (consciousness always lost)
  • Tonic-clonic seizures (grand mal)
  • Absence seizures (petit mal)
  • Others (myoclonic, tonic, clonic, or atonic seizures)
Partial (focal) seizures
  • Simple partial (no alteration of consciousness)
  • Complex partial (consciousness impaired)
  • Partial seizures (simple or complex) with secondary generalization
Unclassified (due to inadequate information)

Status Epilepticus:

  • Continuous or intermittent seizure for more than 5 min. without recovery or consciousnes.

Differential Diagnosis

Paroxysmal Disorders: Differential Diagnosis
  • Seizures
  • Syncope
  • Pseudoseizures
  • Hyperventilation syndrome
  • Complex Migraine headache
  • Movement disorders
  • Narcolepsy/cataplexy

Etiology

 
Common Causes of Secondary Seizures
Trauma (recent or remote)
Intracranial hemorrhage (subdural, epidural, subarachnoid, intraparenchymal)
Structural CNS abnormalities
  •  Vascular lesion (aneurysm, arteriovenous malformation)
  •  Mass lesions (primary or metastatic neoplasms)
  •  Degenerative neurologic diseases
  •  Congenital brain abnormalities
Infection (meningitis, encephalitis, abscess)
Metabolic disturbances
  • Hypo- or hyperglycemia
  • Hypo- or hypernatremia
  • Hyperosmolar states
  • Uremia
  • Hepatic failure
  • Hypocalcemia, hypomagnesemia (rare)
Toxins and drugs (many)
  • Cocaine, lidocaine
  • Antidepressants
  • Theophylline
  • Alcohol withdrawal
  • Drug withdrawal
Hypertensive encephalopathy
Anoxic-ischemic injury (cardiac arrest, severe hypoxemia)

 

Workup

- Labs:
  • Vitals (inluding Temp)
  • Finger-Stick sugar : Treat if < 80 or unable to determine
  • CMP, Ca, Mg, Ammonia, UA
  • CXR if indiacted
  • Anti-epileptic drug level
  • +/- UDS
  • Consider CSF/LP studies if CNS infection suspected

-Imaging:

  • CT scan of head w/o contrast
    • History of mental status changes
    • Focal findings that persist after seizure stops
  • EEG
    • All patients with status epilepticus
      • Do NOT delay treatment for an EEG
    • All patients who need barbiturate or benzodiazepine drips
    • Patients who cannot be aroused after seizure
      • R/O subclinical status epilepticus

 

Symptoms

Head deviation
Eye deviation
Rhythmic or repetitive arm or leg movement
  Posturing
  Stiffening
  Jerking
Change in breathing pattern
Increase in heart rate
Increase in blood pressure
Cyanosis or apnea
Eye dilatation
Vomiting
Lip smacking
Tongue biting
Incontinence of bowel or bladder
Postictal or sleepy period after a seizure
Mood or behavior changes before a seizure
Subjective aura before seizure (noted in older patients)

 

ED care and Disposition

  1. Secure Airway, O2 to only seizing pts, Assist ventilation prn.
    • If RSI is required, continues EEG monitoring should be arranged as neuromuscular blockade obscures the ability to clinically assess ongoing seizure.
       
  2. Tx Hypoglyemia
    • 5 mL/kg D10W in infants or
    • 2 mL/kg D25W in older children IV/IO.
       
  3. Immediate seizure control [Dose Calc]
    • Diazepam 0.3 mg/kg IV q 5-10 min x 2 (Max: 10 mg/dose)
      • Max infusion rate < 2 mg/min
    • Lorazepam 0.05-0.1 mg/kg IV/IO q 5-10 min x 2 (Max: 4 mg/dose)
      • Max infusion rate < 2 mg/min
    • Midazolam 
      • 0.1 mg/kg IV/IM
      • 0.2 mg/kg IN (Max: 10 mg)
      • For young adult or pediatric patient presenting in status epilepticus, non-IV midazolam is a safe and effective option for seizure cessation
         
  4. Administer 2nd-line anti-epileptic drugs if more than 2 doses of benzodiazepine are required. Dose Calc
    • Infants: use phenobarbital 20 mg/kg IV/IO (Max: 800 mg).
    • Older children: use  fosphenytoin 20 mg/kg IV/IO over 20 min.
       
  5. Refractory Status Epileptius: Dose Calc
    • 3rd-line agent:
      • Valproic acid: 15-20 mg/kg IV/IO over 1-5 min (max. 40 mg/kg)
        • 5 mg/kg/hr IV drip
      • Keppra 20-30 mg/kg IV/IO
         
  6. 4rth-line treatment include continuous infusion in the ICU setting of propofol, midazolam, or pentobarbital or induction of general inhaled anesthesia, such as: Dose Calc
    • Midazolam 0.15-0.2 mg/kg IV load
      • 0.1-0.3 mg/kg/hr IV drip
    • Pentobarbital: 5-15 mg/kg IV load
      • 0.5-5 mcg/kg/hr IV drip
    • Propofol: 1-3 mg/kg/hr IV load
      • 2-10 mg/kg/hr IV drip
         
  7. If no IV access
    • Rectal Diazepam: 0.5 mg/kg (Max: 10 mg)
    • IM Midazolam: 0.2 mg/kg IV
    • Rectal paraldehyde 0.3 mL/kg diluted 1:2 with mineral or vegatable oil
      • Contraindicated in hepatic, pulmonary, renal disease
         
  8. IV calcium for tetany or hypocalcemic seizures
    • Calcium gluconate: 1-2 mL/kg IV (10-20 mg/kg elemental calcium)
      • Give slowly over 5-10 min
      • 50-75 mg/kg/day IV infusion
         
  9. If INH overdose
    • B6: 50 mg IV
       
  10. Treat electrolyte abnormality as follows:
    • Hyponatremia < 120 = 3% NaCl 4-6 mL/kg
    • Hypocalcemia < 7, < 0.8 of ionized Ca = 0.3 mL/kg 0f 10% Ca Gluconate over 10 min.
    • Hypomagnesemia <1.5 = 50 mg/kg of magnesium sulphate over 20 min.

 

Disposition:

  1. For ongoing seizure admit to PICU; neurology consult
  2. For first seizure (controlled) admit
    • Observation; PICU or floor as determined by patient stability
    • May D/C home after Neuro consult
  3. For patient with specific medical etiology of seizure
    • Admit prn based on primary disorder
  4. For patient with H/O seizure
    • May discharge after consultation with patient's primary care MD or neurologist
  5. Prognosis
    • Chance of second seizure 40% if
      • Single short generalized seizure
      • Normal neuro development
      • Normal neuro exam
      • EEG
        • Normal EEG drops this to 25%
        • Abnormal EEG increases tchance to 50-70%
    • Significantly higher risk if
      • Focal neurological deficits
      • Structural CNS lesions
      • Developmental problems

     

Febrile Seizure:

  • Seizures in the setting of fever are common in children & usually benign. Simple febrile seizures (SFS) occur between 6 Mo and 6 yr of life, are brief (<15 min), & generalized.
  • Patients with SFS require no specific ED evaluation or medication for their seizure, though evaluation for a treatable source of fever, and antipyretics may be indicated.
  • Children experiencing simple febrile seizure have the same 1% risk of developing epilepsy as the general population.
  • Complex febrile seizures (> 15 min in duration, focal, recurrent) carry a slightly increased risk for epilepsy, but also do not routinely require ED evaluation or treatment.
  • Febrile status is treated as above with the addition of neuroimaging, CSF analysis & culture, and potential ABx and acyclovir in the right setting.

First Seizure:

  • The overall risk of recurrence after single afebrile seizure is about 40%. Emergent neuroimaging is not necessary in the ED in the pt with a nonfocal neurologic exam, though outpatient MRI & EEG may be of benefit. Most neurologists do not recommend starting anti-convulsant medication after a first seizure.
     




Refractory Seizure



 

Drugs

Benzodiazepines for Initial Treatment of Status Epilepticus
Drug Route Dose* Maximum Onset of Action Duration of Action
Lorazepam IV, IO, IN
 
0.1 mg/kg 4 mg 1–5 min 12–24 h
IM 0.1 mg/kg 4 mg 15–30 min 12–24 h
Diazepam IV, IO 0.1–0.3 mg/kg 10 mg 1–5 min 15–60 min
PR 0.5 mg/kg 20 mg 3–5 min 15–60 min
Midazolam IV, IO 0.1–0.2 mg/kg 4 mg 1–5 min 1–6 h
IM 0.2 mg/kg 10 mg 5–15 min 1–6 h
IN 0.2 mg/kg 10 mg 1–5 min 1–6 h
Buccal
 
0.5 mg/kg 10 mg 3–5 min 1–6 h

 
Medications for Refractory Status Epilepticus
Drug Route Loading Dose Repeat Dose Maximum IV Infusion
Fosphenytoin IV, IM 15–20 mg/kg PE 5–10 mg/kg PE 30 mg/kg PE 3 mg/kg/min PE
Phenobarbital IV 15–20 mg/kg 5–10 mg/kg 40 mg/kg 1–30 mg/min
Valproic acid IV 20 mg/kg 15–20 mg/kg 40 mg/kg 5 mg/kg/h
Levetiracetam IV 20–30 mg/kg 3 grams
Pentobarbital IV 5–15 mg/kg 1–2 mg/kg 15 mg/kg 0.5–5.0 mg/kg/h
Propofol IV 0.5–2.0 mg/kg 0.5–1.0 mg/kg 5 mg/kg 1.5–4.0 mg/kg/h
Midazolam IV 0.1–0.2 mg/kg 0.1–0.2 mg/kg 10 mg 0.05–0.4 mg/kg/h

Admit Orders:
Seizure (Pedi)

1. Admit to: Pediatric intensive care unit.

2. Diagnosis: Seizure.

3. Condition:

4. Vital Signs: Vitals and neurochecks q2-6h; call MD if:

5. Activity:

6. Nursing: Seizure and aspiration precautions, ECG and EEG monitoring.

7. Diet: NPO

8. IV Fluids and Oxygen: 0.45% normal saline at 100 cc/h. Oxygen at 2 L per minute by nasal cannula.

9. Special Medications:

Febrile Seizures: Control fever with antipyretics and cooling measures. Anticonvulsive therapy is usually not required.

Status Epilepticus:

10. Maintain airway, 100% O2 by mask; obtain brief history, fingerstick glucose.

11. Start IV NS. If hypoglycemic, give 1-2 mL/kg D25W IV/IO (0.25-0.5 gm/kg).

12. Lorazepam (Ativan) 0.1 mg/kg (max 4 mg) IV/IM. Repeat q15-20 min x 3 prn.

13. Phenytoin (Dilantin) 15-18 mg/kg in normal saline at <1 mg/kg/min (max 50 mg/min) IV/IO. Monitor BP and ECG (QT interval).

14. If seizures continue, intubate and give phenobarbital loading dose of 15-20 mg/kg IV or 5 mg/kg IV every 15 minutes until seizures are controlled or 30 mg/kg is reached.

15. If seizures are refractory, consider midazolam (Versed) infusion (0.1 mg/kg/hr) or general anesthesia with EEG monitoring.

16. Rectal Valium gel formulation

<2 years: not recommended

2-5 years: 0.5 mg/kg

6-11 years: 0.3 mg/kg

>=12 years: 0.2 mg/kg

Round dose to 2.5, 5, 10, 15, and 20 mg/dose. Dose may be repeated in 4-12 hrs if needed. Do not use more than five times per month or more than once every five days.[rectal gel (Diastat): pediatric rectal tip - 5 mg/mL (2.5, 5, 10 mg size); adult rectal tip - 5 mg/mL (10, 15, 20 mg size)]

Generalized Seizures Maintenance Therapy:

-Carbamazepine (Tegretol):

<6 year: initially 10-20 mg/kg/day PO bid, then may increase in 5-7 day intervals by 5 mg/kg/day; usual max dose 35 mg/kg/day PO q6-8h.

6-12 year: initially 100 mg PO bid (10 mg/kg/day PO bid), then may increase by 100 mg/day at weekly intervals; usual maintenance dose 400-800 mg/day PO bid-qid.

>12 year: initially 200 mg PO bid, then may increase by 200 mg/day at weekly intervals; usual maintenance dose 800-1200 mg/day PO bid-tid.

Dosing interval depends on product selected. Susp: q6-8h; tab: q8- 12h; tab, chew: q8-12h; tab, ER: q12h

[susp: 100 mg/5 mL; tab: 200 mg; tab, chewable: 100 mg; tab, ER: 100, 200, 400 mg] OR

 

-Divalproex sodium (Depakote, Valproic acid) PO: Initially 10-15 mg/kg/day bid-tid, then increase by 5-10 mg/kg/day weekly as needed; usual maintenance dose 30-60 mg/kg/day bid-tid. Up to 100 mg/kg/day tid-qid may be required if other enzyme-inducing anticonvulsants are used concomitantly. IV: total daily dose is equivalent to total daily oral dose but divide q6h. PR: dilute syrup 1:1 with water for use as a retention enema, loading dose 17-20 mg/kg x 1 or maintenance 10-15 mg/kg/dose q8h.

[cap: 250 mg; cap, sprinkle: 125 mg; inj: 100 mg/mL; syrup: 250 mg/5 mL; tab, DR: 125, 250, 500 mg] OR

-Phenobarbital (Luminal): Loading dose 10-20 mg/kg IV/IM/PO, then maintenance dose 3-5 mg/kg/day PO qd-bid.

[cap: 16 mg; elixir: 15 mg/5mL, 4 mg/mL; inj: 30 mg/mL, 60 mg/mL, 65 mg/mL, 130 mg/mL; tabs: 8, 15, 16, 30, 32, 60, 65,100 mg] OR

-Phenytoin (Dilantin): Loading dose 15-18 mg/kg IV/PO, then maintenance dose 5-7 mg/kg/day PO/IV q8-24h (only sustained release capsules may be dosed q24h).

[caps: 30, 100 mg; elixir: 125 mg/5 mL; inj: 50 mg/mL; tab, chewable: 50 mg]

-Fosphenytoin (Cerebyx): >5 years: loading dose 10-20 mg PE IV/IM, maintenance dose 4-6 mg/kg/day PE IV/IM q12-24h. Fosphenytoin 1.5 mg is equivalent to phenytoin 1 mg which is equivalent to fosphenytoin 1 mg phenytoin equivalent (PE) unit. Fosphenytoin is a water-soluble pro-drug of phenytoin and must be ordered as mg of phenytoin equivalent.

[inj: 150 mg (equivalent to phenytoin sodium 100 mg) in 2 mL vial; 750 mg (equivalent to phenytoin sodium 500 mg) in 10 mL vial]

Partial Seizures and Secondary Generalized Seizures:

-Carbamazepine (Tegretol), see aboveOR

-Phenytoin (Dilantin), see above.

-Phenobarbital (Luminal), see above OR

-Valproic acid (Depacon, Depakote, Depakene), see above.

-Lamotrigine (Lamictal):

Adding to regimen containing valproic acid: 2-12 years: 0.15 mg/kg/day PO qd-bid during weeks 1-2, then increase to 0.3 mg/kg/day PO qd-bid during weeks 3-4, then increase q1-2 weeks by 0.3 mg/kg/day to maintenance dose 1-5 mg/kg/day (max 200 mg/day).

>12 years: 25 mg PO qOD during weeks 1-2, then increase to 25 mg PO qd during weeks 3-4, then increase q1-2 weeks by 25-50 mg/day to maintenance dose of 100-400 mg/day PO qd-bid.

Adding to regimen without valproic acid: 2-12 years: 0.6 mg/kg/day PO bid during weeks 1-2, then increase to 1.2 mg/kg/day PO bid during weeks 3-4, then increase q1-2 weeks by 1.2 mg/kg/day to maintenance dose 5-15 mg/kg/day PO bid (max 400 mg/day).

>12 years: 50 mg PO qd weeks 1-2, then increase to 50 mg PO bid during weeks 3-4, then increase q1-2 weeks by 100 mg/day to maintenance dose 300-500 mg/day PO bid.

[tabs: 25, 100, 150, 200 mg].

-Primidone (Mysoline) PO: 8 years: 50-125 mg/day qhs, increase by 50-125 mg/day q3-7d; usual dose 10-25 mg/kg/day tid-qid.

>8 years: 125-250 mg qhs; increase by 125-250 mg/day q3-7d, usual dose 750-1500 mg/day tid-qid (max 2 gm/day).

[susp: 250 mg/5mL; tabs: 50, 250 mg]

10. Extras and X-rays: MRI with and without gadolinium, EEG with hyperventilation, CXR, ECG. Neurology consultation.

11. Labs: ABG/CBG, CBC,CMP, calcium, phosphate, magnesium, liver panel, VDRL, anticonvulsant levels, blood and urine culture. UA, drug and toxin screen.
 

Therapeutic Serum Levels

Carbamazepine

4-12 mcg/mL

Clonazepam

20-80 ng/mL

Ethosuximide

40-100 mcg/mL

Phenobarbital

15-40 mcg/mL

Phenytoin

10-20 mcg/mL

Primidone

5-12 mcg/mL

Valproic acid

50-100 mcg/mL