Amounts to be administered and administration route:
Inspired concentration:
Sevohale should be administered via a vaporiser specifically calibrated for use with sevoflurane so that the concentration delivered can be accurately controlled. Sevohale contains no stabiliser and does not affect the calibration or operation of these vaporisers in any way. The administration of sevoflurane must be individualised based on the dog's or cat’s response.
Premedication:
The necessity for and choice of premedication is left to the discretion of the veterinarian. Preanaesthetic doses for premedicants may be lower than the label directions for their use as a single medication.
Induction of anaesthesia:
For mask induction using sevoflurane, inspired concentrations of 5 to 7% sevoflurane with oxygen are employed to induce surgical anaesthesia in the healthy dog, and 6 to 8% sevoflurane with oxygen in the cat. These concentrations can be expected to produce surgical anaesthesia within 3 to 14 minutes in dogs and within 2 to 3 minutes in cats. Sevoflurane concentration for induction may be set initially, or may be achieved gradually over the course of 1 to 2 minutes. The use of premedicants does not affect the concentration of sevoflurane required for induction.
Maintenance of anaesthesia:
Sevoflurane may be used for maintenance anaesthesia following mask induction with sevoflurane or following induction with injectable agents. The concentration of sevoflurane necessary to maintain anaesthesia is less than that required for induction.
Surgical levels of anaesthesia in the healthy dog may be maintained with inhaled concentrations of 3.3 to 3.6% in the presence of premedication. In the absence of premedication, inhaled concentrations of sevoflurane in the range 3.7 to 3.8% will provide surgical levels of anaesthesia in the healthy dog. In the cat surgical anaesthesia is maintained with sevoflurane concentrations of 3.7- 4.5%.
The presence of surgical stimulation may require an increase in the concentration of sevoflurane. The use of injectable induction agents without premedication has little effect on the concentrations of sevoflurane required for maintenance. Anaesthetic regimens that include opioid, alpha-2-agonist, benzodiazepine or phenothiazine premedication will allow the use of lower sevoflurane maintenance concentrations.