sevoflurane: clinical use

Prescribing considerations

• Administration is restricted to trained anaesthesia personnel with immediate airway, ventilation, oxygenation and resuscitation facilities.
• Use a sevoflurane-calibrated vaporiser; replace suspected desiccated carbon-dioxide absorbent because excessive heat, smoke or fire may occur.
• Exercise caution with renal or hepatic impairment, coronary disease, hypovolaemia, raised intracranial pressure, seizure susceptibility, neuromuscular or mitochondrial disorders, myasthenia gravis and QT prolongation.
• Review previous or repeated exposure to halogenated anaesthetics and all interacting medicines.

Contraindications and cautions

• Known or suspected hypersensitivity to sevoflurane or another halogenated anaesthetic.
• Known or suspected genetic susceptibility to malignant hyperthermia.
• Previous confirmed halogenated-anaesthetic hepatitis or relevant unexplained hepatic dysfunction after exposure.
• Any clinical situation in which general anaesthesia itself is contraindicated.

Monitoring

• Continuous ECG, blood pressure, oxygen saturation and end-tidal carbon dioxide monitoring.
• Airway patency, ventilation, anaesthetic depth, haemodynamics and temperature.
• Neuromuscular function when blocking agents are used.
• Postoperative renal function where renal impairment is present.
• Potassium, creatine kinase and arrhythmias when perioperative hyperkalaemia or occult neuromuscular disease is suspected.
• Recovery agitation, seizures, respiratory depression, hepatic injury and adequate postoperative analgesia.

Clinical pharmacology

Sevoflurane is a halogenated methyl isopropyl ether with low blood–gas solubility. Most absorbed sevoflurane is eliminated through the lungs; a small proportion undergoes CYP2E1-mediated metabolism to hexafluoroisopropanol and inorganic fluoride. Its cardiovascular and respiratory depressant effects increase with anaesthetic depth.

Formulation and product differences

• Both selected products are volatile inhalation liquids intended for sevoflurane-specific vaporisers.
• The Piramal product contains sevoflurane without excipients and is supplied in amber glass bottles.
• The AbbVie product lists water as a Lewis-acid inhibitor and is supplied in amber polymer bottles.
• Bottle and filling-system compatibility should be checked against the specific product and vaporiser.