Post op SeizureBy

Dr. AHMED ABDELRAHMANLecturer of anesthesia and intensive

care

OBJECTIVES

1. Definition of seizure2. Classification3. Causes of post op seizures4. Management

Definition Seizure : means a convulsion or other transient event caused by a paroxysmal discharge of cerebral neurons.

Classification Generalized :

Means bilateral abnormal electrical activity, with bilateral motor manifestations and impaired consciousness.

Partial seizure:

Means that the electrical activity is localized to one part of the brain;1. Simple - without loss of

consciousness, e.g. one limb jerking.2. Complex – with loss of awareness ,

e.g. temporal lobe attack.

Status epilepticus : Any seizure lasting more than 5

minutes is considered status epilepticus.

Mortality is between 5% to 30% because of hypoxia, hyperpyrexia and hypotension.

Aggressive prompt intervention is the key of survival.

Causes Epilepsy

Acute CNS lesion Cerebrovascular accidents ( ischemic stroke, ICH, SAH), Traumatic brain injury Global hypoxic – ischemic brain injury Encephalitis and Meningitis

Chronic CNS lesions Existing stroke - Brain tumor

Toxic and Metabolic derangement : Hypoglycemia Drug withdrawal ( alcohol,benzodiazepines) Electrolytes ( NA , Mg, Ca ,K) Iatrogenic: medications e.g. B-lactamases, Thyophylline. Febrile convulsions in young children

Local anesthetic toxicity. Post-partum Eclampsia.

Management

General measures:

1. Assess and protect airway2. Monitor vital signs3. Check bedside glucose level4. Obtain IV access5. Send lab Specific TTT.

Initial anticonvulsant TTT

1. Lorazepam 4mg IV repeat 2-4 mg every 2-3 min to a max of 0.01 mg /kg.

2. Phenytoin or fosphenytoin loading of 18-20 mg/kg, Max rate of infusion 50 mg/ min. phenytoin and 150 mg/ min fosphenytoin.

3. Consider giving thiamine 100 mg Iv with glucose ( 50 ml of D50).

If seizure continue :Additional 10- 20 mg IV phenytoin.Consider second line agents:1. Valproate 20 – 40 mg IV bolus over

10 min,2. levetiracetam 2 gm. IV bolus.3. Phenobarbital 5 mg /kg to a max of

20 mg/ kg give q 15 min.

Consider intubation in case of hypoxia or aspiration.

Convulsive seizure stop: Check phenytoin level every 1-2 hr

post load. Perform additional diagnostic

studies .e.g. CT scan lumbar puncture.

Consider EEG monitoring for non convulsive seizure.

Persistent seizure activity:General management1. Intubate for airway protection.2. Continue EEG monitoring.3. Close hemodynamic monitor.4. Continue maintenance AEDs.5. TTT of underlying cause.6. Neurology consultation.

Seizure control1. Initiate infusion to control clinical

and electrographic seizure.2. Can give loading bolus of the same

agent.3. Titrate infusion to maintain seizure

control,4. If not controlled consider alternate

agent with goal of inducing Burst suppression.

5. Finally consider therapeutic hypothermia.

Seizure controlled:1. Continue infusion for 24 hr at rate

that achieved target.2. Monitor closely for complication of

TTT .e.g. ileus, hemodynamic instability, infections.

3. After 24 hr try to gradually wean infusion off and watch for recurrent seizure.

Specific management

Electrolyte disturbances -------- Correction

Post-partum eclampsia --------- Mg sulphate

Local anesthetic toxicity --------lipid emulsion (20%)

Febrile convulsion ---------------- cooling