Category:

• General anesthetic

Description:

• Barbiturate general anesthetic

Indications:

• General anesthesia

• Increased intracranial pressure

• Narcoanalysis

• Sedation induction

• Status epilepticus

Contraindications:

• Acute porphyria

• Porphyria history

Precautions:

• Pregnancy category C; do not breast feed

• Hepatic disease

• Preexisting respiratory depression

Adverse Reactions (Side Effects):

• CV: cardiac disease, hypertension, hypotension, myxedema, peripheral vascular disease

• MISC: respiratory insufficiency, anemia, adrenal insufficiency, shock, uremia

Dosage:

Administered intravenously, rectally

• General anesthesia induction and maintenance:

  • Adult: 

    • IV 50-100mg initially, intermittent dose 20-40 seconds intervals, or 3-5 mg/kg IV as single dose. 

    • May give additional doses up to 500mg max. 

    • Once anesthesia established, 25-50mg each time patient moves.  

    • Alternatively, a 0.2%-0.4% solution can be used as continuous drip; adjust drip rate as necessary.

  • Child 1-12 years: 

    • IV 5-6 mg/kg over 10-60 minutes, followed by maintenance dose 1 mg/kg as needed

  • Infants: 

    • IV 5-8 mg/kg over 10-60 minutes

  • Neonates: 

    • IV 3-4 mg/kg over 10-60 minutes

• Preanesthetic induction: 

  • Adult: 30 mg/kg PR prior to anesthesia

• Basal narcosis: 

  • Adult: 9 mg/kg PR, max 3-4g for adult > 90 kg

• Child: 

  • 9 mg/kg PR, max 1-1.5g for child > 34 kg

• Treatment of increased intracranial pressure: 

  • Adult: 

    • IV bolus 1.5-3.5 mg/kg, ventilation must be provided

• Treatment of status epilepticus: 

  • Adult: 

    • IV 50-125mg as soon as possible after onset of seizures,  

    • Seizures caused by local anesthetics may require up to 250mg IV over 10 minutes

• Narcoanalysis: 

  • Adult: IV slow injection 100 mg/min (4ml/min of a 2.5% solution) with patient counting backwards from 100.  

  • Stop infusion after patient becomes confused, but before sleep.  

  • All patients to return to semidrowsy state where conversation is coherent.  

  • Alternatively, a 0.2% solution in D5W may be given by rapid IV drip not greater than 50 ml/min