Managing and Detecting Seizures in the ICU

Special thanks to:

Katherine Nickels, MD

Assistant Professor of Neurology and Pediatrics

Mayo Clinic

Epileptic events

• Stereotyped, rhythmic, synchronous

• Not distractible or suppressible

• Eyes open

• Injury

• Incontinence

• Post-ictal confusion

• Onset during wakefulness or sleep

Generalized Status Epilepticus

• Duration:

• if szs last longer than 5-10 min, they are unlikely to stop spontaneously

Remember…..Non-convulsive status epilepticus in the ICU

• Simple partial, complex partial, or absence

• Can include twitching of extremity, rythmic facial movements, etc..

• Affects the patient’s mental state, in the absence of obvious motor manifestations

• Need high level of suspicion in sedated intubated patient – consider EEG to confirm

Treatment• ABCs

• Most pts breathe adequately as long as airway is clear

• 100% O2 by mask. • Intubate if evidence of respiratory

compromise• use short-acting NM blocker so one does

not lose clinical ability to determine if seizure is persisting

• If a long-acting paralytic is used, will need EEG monitoring to determine if still seizing

Treatment

• R/O acute metabolic cause: hypoglycemia, electrolyte disturbance

• The longer the status has gone on, the less responsive it is to drug therapy

• TREAT EARLY

• Recurrent seizure after treatment with benzodiazepine warrants consideration of an antiepileptic drug as the next step

Further Hx and Px

• Prior sz history

• Other medical illnesses

• Trauma

• Focal neuro signs

• Signs of medical illness – infection, substance abuse, etc

• Labs to consider: glu, lytes, calcium, gas, renal and liver function, serum AED levels, tox screen, blood cultures

What is the first medication to give?

Drug Treatment

• (5 minutes) Benzodiazepines (1st line):• Lorazepam and diazepam equivalent in

efficacy and lorazepam longer acting, therefore usually use the latter. Midazolam also can be used. Dose of lorazepam: 0.1 mg/kg slow IV

push (2 mg/min) Dose of midazolam: 0.2 mg/kg Dose of diazepam: 0.5 mg/kg

• Median time to response 2-3 minutes• Risks: respiratory depression, hypotension

Non-IV drug routes

• Rectal: diazepam, Diastat

• Buccal: diazepam, lorazepam, midazolam

• IM: fosphenytoin, midazolam, diazepam, lorazepam

Persistent Seizure after Benzodiazepine

May repeat benzodiazepine while drawing up:

Phenytoin or Fosphenytoin (2nd line)• Fosphenytoin can be given IM without

causing tissue necrosis• Use if IV unattainable, or• In small child with tenuous IV site

• Fosphenytoin is ++++ more expensive than phenytoin

• Dose 20 mg/kg of phenytoin or 20 mg/kg PE of fosphenytoin.

• Infuse fosphenytoin 1-3 mg/kg/min• Side effects: hypotension, arrhythmias,

tissue necrosis with phenytoin

Next steps if seizures persist despite phenytoin

Additional antiepileptic drug treatment

• IV Valproic acid 25 mg/kg at 5 mg/kg/min• Unless <2 years or• Known/suspected liver disease or• Inborn error of metabolism, then use:

• Alternative: IV Levetiracetam 20 mg/kg at 5 mg/kg/min

Seizures continue…..

Next steps: Phenobarbital

• Can also be given as a first line drug after benzodiazepine

• Can be given as second line drug after Phenytoin

• Phenobarbital• 20 mg/kg IV at rate of 50-75 mg/min• Watch for respiratory depression• Give slowly over about 20 minutes to

avoid side effects if necessary

Still Seizing……

Anesthesia/ICU Management

• Indications for Anaesthesia/ICU• Severe systemic complications such as

severe hyperthermia• Seizures lasting longer than 60 minutes• Seizures refractory to adequate doses of

benzodiazepines, phenytoin, VPA/LEV, and phenobarbital

Anesthesia/ICU options

• All require continuous EEG monitoring, central access, intubation

• Midazolam infusion

• Pentobarbital

• Goal is burst suppression:• bursts <1 second in duration,

interspersed by periods of suppression lasting at least 10 seconds. This pattern should be present for at least 90% of the recording.

Midazolam infusion• Initiation:

• 0.2 mg/kg bolus followed by infusion at 0.12 mg/kg/hour,

• Still seizing• Give additional 0.2 mg/kg bolus and

increase to 0.24 mg/kg/hr• Maintenance

• continue increasing by 0.12 mg/kg/hr every 10 minutes to a maximum of 1.92 mg/kg/hr to achieve burst suppression

Seizures refractory to multi-drug therapy and high dose midazolam

infusion:

Consider Pentobarbital Coma

IV anesthetics

• Thiopentol or pentobarb infusion• Initiation: 5 mg/kg IV• Maintenance: 1-3 mg/kg/hr• Cardiac depression, agranulocytosis,

hepatic injury

• Propofol infusion: • In children, contra-indicated due to

rhabdomyolysis, propofol infusion syndrome, metabolic acidosis

Anesthesia/ICU options• Isoflurane inhalation therapy

• Must be done under the guidance of Pediatric Neurology, Pediatric Intensive Care, Pediatric Anesthesia

• Initiation:• 1% to 2% and adjust by 0.1% every 5–

10 mins to a goal of controlling seizure activity.

• Any changes in administration should be done under by Pediatric Anesthesia.

Treatment Summary

• ABCs

• Treat early for best results!

• Benzos first line, followed by phenytoin, then VPA/LEV, then phenobarb

• ICU/Anaesthesia if prolonged >60 min, refractory or significant systemic complication