Sevoflurane (Sevorane®), a fluorinated derivative of methyl isopropyl ether, is a nonflammable liquid anaesthetic agent administered by vaporisation.It is documented in the literature that exothermic reactions can occur with inhalational anaesthetics, including sevoflurane, and CO₂ absorbents. This reaction becomes more severe when the CO₂ absorbent becomes desiccated by, for example, an extended period of dry gas flow through the CO₂ absorbent canister.

Abbott has recently reported to the HSA of rare, isolated cases of extreme heat, smoke, and/or fire that occurred in anaesthesia machines during procedures where sevoflurane was used with a desiccated CO2. There are a total of 18 of such reports worldwide received since 1996 - Germany (6), Belgium (2) and US (10). Abbott has not received any local reports to-date.

The following findings have been reported in patients in association with these events:

a. Failed inhalation induction or inadequate anaesthesia with sevoflurane
b. Patient signs of airway irritation, such as coughing
c. Oxygen desaturation, increased airway pressures, and difficult ventilation
d. Severe airway oedema and erythema
e. Elevated carboxyhaemoglobin levels

Abbott has issued a Dear Healthcare Provider Letter and will update the local package insert to reflect these findings. HSA would like to remind healthcare professionals to follow the best practices with respect to the maintenance of anaesthesia machines. Please report any adverse events associated with the use of seroflurane to HSA.