Sojourn Special Precautions

Sevoflurane should be administered only by trained personnel in the administration of general anaesthesia.
Ensure that facilities for maintenance of a patent airway, artificial ventilation, oxygen enrichment and circulatory resuscitation are immediately available.
Sevoflurane should be delivered via a vaporiser specifically calibrated for use with sevoflurane so that the concentration delivered can be accurately controlled. Hypotension and respiratory depression increase as anaesthesia is deepened.
Sevoflurane should be used with caution in patients with renal insufficiency.
Sevoflurane may present an increased risk in patients with known sensitivity to volatile halogenated anaesthetic agents.
Rare cases of seizures have been reported in association with sevoflurane use.
The recovery from general anaesthesia should be assessed carefully before patients are discharged from the recovery room.
Maintenance of anaesthesia: During the maintenance of anaesthesia, increasing the concentration of sevoflurane produces dose-dependent decreases in blood pressure.
Excessive decrease in blood pressure may be related to depth of anaesthesia and in such instances may be corrected by decreasing the inspired concentration of sevoflurane.
Malignant Hyperthermia: In susceptible individuals, potent inhalation anaesthetic agents may trigger a skeletal muscle hypermetabolic state leading to high oxygen demand and the clinical syndrome known as malignant hyperthermia. The syndrome may include muscle rigidity, tachycardia, tachypnoea, cyanosis, arrhythmias and/or unstable blood pressure.
Treatment includes discontinuation of triggering agents (e.g. Sevoflurane), administration of intravenous dantrolene sodium, and application of supportive therapy.
Renal failure may appear later, and urine flow should be monitored and sustained if possible.
Perioperative hyperkalaemia: Use of inhaled anaesthetic agents has been associated with very rare increases in serum potassium levels that have resulted in cardiac arrhythmias and death in children during the postoperative period. The condition has been described in patients with latent as well as overt neuromuscular disease, particularly Duchenne muscular dystrophy. Use of succinylcholine has been associated with most, but not all of these cases. These patients showed evidence of increased serum creatine kinase concentration and myoglobinuria. These patients did NOT have classical signs of malignant hyperthermia such as muscle rigidity, rapid increase in body temperature, or increased oxygen uptake and carbon dioxide production. Prompt and vigorous treatment for hyperkalaemia and arrhythmias is recommended. Subsequent evaluation for latent neuromuscular disease is indicated.
Renal Function: Because clinical experience in administering sevoflurane to patients with renal insufficiency (creatinine >1.5 mg/dL) is limited, its safety in these patients has not been established. Limited pharmacology data in these patients appear to suggest that the half-life of sevoflurane may be increased. The clinical significance is unknown at this time. Thus, sevoflurane should be used with caution in these patients.
Hepatic Function: Results of evaluations of laboratory parameters (e.g., ALT, AST, alkaline phosphatase, and total bilirubin, etc.), as well as investigator-reported incidence of adverse events relating to liver function, demonstrate that sevoflurane can be administered to patients with normal or mild-to-moderately impaired hepatic function.
However, patients with severe hepatic dysfunction were not investigated.
Occasional cases of transient changes in postoperative hepatic function tests were reported with both sevoflurane and reference agents. Sevoflurane was found to be comparable to isoflurane with regard to these changes in hepatic function.
Very rare cases of mild, moderate and severe post-operative hepatic dysfunction or hepatitis with or without jaundice have been reported from post marketing experiences.
Clinical judgement should be exercised when sevoflurane is used in patients with underlying hepatic conditions or under treatment with drugs known to cause hepatic dysfunction.
Compound A: Sevoflurane produces low levels of Compound A (pentafluoroisopropenyl fluoromethyl ether (PIFE)) and trace amounts of Compound B (pentafluoromethoxy isopropyl fluoromethyl ether (PMFE)), when in direct contact with CO₂ absorbents. Levels of Compound A INCREASE with: increase in canister temperature; increase in anaesthetic concentration; decrease in fresh gas flow rate and increase more with the use of desiccated CO₂ absorbents rather than Soda lime. (See also Pharmaceutical Precautions as follows.)
It is reported from some studies in rats, nephrotoxicity was seen in animals exposed to levels of Compound A in excess of those usually soon in routine clinical practice. The mechanism of this renal toxicity in rats is unknown and its relevance to man has not been established.
Replacement of Desiccated CO₂ Absorbents: The exothermic reaction that occurs with 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 extreme heat, smoke and/or spontaneous fire in the anesthesia machine have been reported during sevoflurane use in conjunction with the use of desiccated CO₂ absorbent. An unusually delayed rise or unexpected decline of inspired sevoflurane concentration compared to the vaporizer setting may be associated with excessive heating of the CO₂ absorbent canister.
When a clinician suspects that the CO₂ absorbent may be desiccated, it should be replaced before administration of sevoflurane. The color indicator of most CO₂ absorbents does not necessarily change as a result of desiccation. Therefore, the lack of significant color change should not be taken as an assurance of adequate hydration. CO₂ absorbents should be replaced routinely regardless of the state of the color indicator.
Laboratory findings: Transient elevations in glucose and white blood cell count may occur as with use of other anaesthetic agents.
Occasional cases of transient changes in hepatic function tests were reported with sevoflurane.
Pharmaceutical precautions: Sevoflurane is chemically stable. As with some halogenated anaesthetics, minor degradation occurs through direct contact with CO₂ absorbents. The extent of degradation is clinically insignificant and no dose adjustments or change in clinical practice is necessary when rebreathing circuits are used. Higher levels of Compound A are obtained when using desiccated CO absorbents rather than Soda lime.
Effects on driving ability and operation of machinery: As with other anaesthetic agents, patients should be advised that performance of activities requiring mental alertness, such as operating hazardous machinery, may be impaired for some time after general anaesthesia. Patients should not be allowed to drive for a suitable period after sevoflurane anaesthesia.