SevoFlo 100% w/w inhalation Vapour, Liquid for Dogs and Cats

None.

Revised: May 2025
AN: 00047/2025

i) Special precautions for use in animals
Halogenated volatile anaesthetics can react with dry carbon dioxide (CO2)
absorbents to produce carbon monoxide (CO) that may result in elevated levels of
carboxyhaemoglobin in some dogs. In order to minimise this reaction in rebreathing
anaesthetic circuits, the veterinary medicinal product should not be passed through
soda lime or barium hydroxide that has been allowed to dry out.
The exothermic reaction that occurs between inhalation agents (including
sevoflurane) and CO2 absorbents is increased when the CO2 absorbent becomes
desiccated, such as after an extended period of dry gas flow through the CO2
absorbent canisters. Rare cases of excessive heat production, smoke and/or fire in
the anaesthetic machine have been reported during the use of a desiccated CO2
absorbent and sevoflurane. An unusual decrease in the expected depth of
anaesthesia compared to the vaporiser setting may indicate excessive heating of the
CO2 absorbent canister.
If it is suspected that the CO2 absorbent may be desiccated, it must be replaced. The
colour indicator of most CO2 absorbents does not necessarily change as a result of
desiccation. Therefore, the lack of significant colour change should not be taken as
an assurance of adequate hydration. CO2 absorbents should be replaced routinely
regardless of the state of the colour indicator.
1,1,3,3,3-pentafluoro-2-(fluoromethoxy)propene (C4H2F6O), also known as
Compound A, is produced when sevoflurane interacts with soda lime or barium
hydroxide. Reaction with barium hydroxide results in a greater production of
Compound A than does the reaction with soda lime. Its concentration in a circle
absorber system increases with increasing sevoflurane concentrations and with
decreasing fresh gas flow rates. Sevoflurane degradation in soda lime has been
shown to increase with temperature. Since the reaction of carbon dioxide with
absorbents is exothermic, this temperature increase will be determined by the
quantities of CO2 absorbed, which in turn will depend on fresh gas flow in the
anaesthetic circle system, metabolic status of the dog and ventilation. Although
Compound A is a dose-dependent nephrotoxin in rats, the mechanism of this renal
toxicity is unknown. Long-duration, low-flow sevoflurane anaesthesia should be
avoided due to the risks of Compound A accumulation.
During maintenance of anaesthesia, increasing the concentration of sevoflurane
produces a dose-dependent decrease in blood pressure. Due to sevoflurane's low
solubility in blood, these haemodynamic changes may occur more rapidly than with
other volatile anaesthetics. Arterial blood pressure should be monitored at frequent
intervals during sevoflurane anaesthesia. Facilities for artificial ventilation, oxygen
enrichment and circulatory resuscitation should be immediately available. Excessive
decreases in blood pressure or respiratory depression may be related to the depth of
anaesthesia and may be corrected by decreasing the inspired concentration of
sevoflurane. The low solubility of sevoflurane also facilitates rapid elimination by the
lungs. The nephrotoxic potential of certain NSAIDs, when used in the perioperative
period, may be exacerbated by hypotensive episodes during sevoflurane

Revised: May 2025
AN: 00047/2025
anaesthesia. In order to maintain renal blood flow, prolonged episodes of
hypotension (mean arterial pressure below 60 mmHg) should be avoided in dogs
and cats during sevoflurane anaesthesia.
In common with all volatile agents, sevoflurane may cause hypotension in
hypovolaemic animals such as those requiring surgery to repair traumatic injury, and
lower doses should be administered in combination with appropriate analgesics.
Sevoflurane may trigger episodes of malignant hyperthermia in susceptible dogs and
cats. If malignant hyperthermia develops, the anaesthetic supply should be
interrupted immediately and 100% oxygen administered using fresh anaesthetic
hoses and a rebreathing bag. Appropriate treatment should readily be instituted.
Compromised or debilitated dogs and cats
Doses of sevoflurane may need adjustment for geriatric or debilitated animals.
Doses required for maintenance of anaesthesia may need to be reduced by
approximately 0.5% in geriatric dogs (i.e. 2.8% to 3.1% in premedicated geriatric
dogs and 3.2 to 3.3% in unpremedicated geriatric dogs). There is no information on
the adjustment of the maintenance dose in cats. Adjustment is, therefore, left to the
discretion of the veterinarian. Limited clinical experience in administering sevoflurane
to animals with renal, hepatic and cardiovascular insufficiency suggests that
sevoflurane may be safely used in these conditions. However, it is recommended
that such animals be monitored carefully during sevoflurane anaesthesia.
Sevoflurane may cause a small increase in intracranial pressure (ICP) under
conditions of normocapnia in dogs. In dogs with head injuries or other conditions
placing them at risk from increased ICP, it is recommended that hypocapnia be
induced by means of controlled hyperventilation as a means of preventing changes
in ICP.
There are limited data to support the safety of sevoflurane in animals less than 12
weeks of age. Therefore, it should only be used in these animals according to a
benefit-risk assessment by the responsible veterinary surgeon.
ii) Special precautions to be taken by the person administering the veterinary
medicinal product to animals
In order to minimise exposure to sevoflurane vapour, the following recommendations
are made:
•
veterinary medicinal product during maintenance anaesthesia.
•
general anaesthesia.
•
adequate ventilation or scavenging systems to prevent the accumulation of
anaesthetic vapour.
•
•
product and should avoid operating rooms and animal recovery areas.

Revised: May 2025
AN: 00047/2025
•
immediate removal of any spillage.
•
•
•
idiosyncratic response very occasionally seen after repeated exposure.
•
charcoal filters with scavenging equipment.
Direct exposure to eyes may result in mild irritation. If eye exposure occurs, the eye
should be flushed with plenty of water for 15 minutes. Medical attention should be
sought if irritation persists.
In case of accidental contact with the skin, wash affected area with abundant water.
Symptoms of human overexposure (inhalation) to sevoflurane vapour include
respiratory depression, hypotension, bradycardia, shivering, nausea and headache.
If these symptoms occur, the individual should be removed from the source of
exposure and medical attention sought.
To the physician:
Maintain a patent airway and give symptomatic and supportive treatment.
Special precautions for the protection of the environment:
Not applicable.