Sevoflurane (Ultane)

Anesthesia Implications

Classification: Volatile inhalation anesthetic
Therapeutic Effects: Inhalation anesthesia, inducing and maintaining anesthesia.
Time to Onset: Dose dependent – for 1.8 MAC Sevoflurane + 66% N2O it takes approximately 1.6 minutes to achieve a loss of eyelid reflex.
Time to Peak: Dose-dependent; usually reaches peak sedation levels quickly due to low blood/gas solubility.
Duration: Short duration, with rapid emergence due to low fat/blood partition coefficient, allowing fast elimination post-administration.

Contraindications

Known or suspected genetic susceptibility to malignant hyperthermia.

Primary Considerations

Malignant Hyperthermia – Assess patient history for susceptibility, as sevoflurane can trigger this condition.

Compound A – Ensure flow rates above 2 L/min to reduce the risk of Compound A (a nephrotoxic byproduct) production.

Side Effects –  Causes dose-dependent respiratory depression and reduced blood pressure due to peripheral vasodilation. Minimal effect on heart rate.

Uterine contractility – Sevoflurane reduces uterine contractility

MAC – The MAC for sevoflurane in elderly patients is 1.5%, which is lower than the MAC for children (2.5%) and adults (1.7–2.0%).

Nephrotoxicity – Soda Lime + Sevoflurane = Compound A, which is nephrotoxic.  No data currently exists that links acute kidney injury to compound A.  HOWEVER, the FDA still recommends that sevoflurane be administered at a minimum flow rate of 1 liter/min for no longer than 2 MAC hours.  If the duration of the procedure is longer, the flow rate should be increased to 2 liters/min.

Reversal

No direct reversal; Effects wear off rapidly after cessation of inhalation due to its low solubility and high rate of pulmonary elimination.

Method of Action

Acts by enhancing inhibitory neurotransmission and reducing excitatory neurotransmission in the CNS, leading to loss of consciousness and sensation.

Metabolism

Hepatic

Elimination

Pulmonary, hepatic, and renal.