Compound A concentrations during sevoflurane anesthesia in children

Area of Science:

• Anesthesiology
• Pediatric Anesthesia
• Inhalation Agents

Background:

• Sevoflurane is a widely used inhalation anesthetic agent.
• Degradation of sevoflurane can occur in the presence of carbon dioxide absorbents, forming compound A.
• Quantification of compound A during pediatric anesthesia is crucial for safety.

Purpose of the Study:

• To evaluate sevoflurane degradation product (compound A) concentrations during pediatric anesthesia.
• To assess the safety of sevoflurane anesthesia in children with normal renal and hepatic function.
• To investigate the relationship between absorbent temperature, patient factors, and compound A levels.

Main Methods:

• Nineteen pediatric patients (3 months-7 years) received sevoflurane anesthesia with a 2-1 fresh gas flow in a circle system.
• Compound A concentrations were measured in the inspiratory and expiratory limbs of the anesthesia circuit.
• Absorbent temperatures and plasma inorganic fluoride ion concentrations were monitored; hepatic and renal function tests were performed.

Main Results:

• Maximum inspiratory compound A concentrations were 5.4 ± 4.4 ppm, with a peak of 15 ppm in one patient.
• Compound A levels peaked at intubation and remained stable, declining after 120 minutes.
• Positive correlations were found between maximum absorbent temperature and compound A concentration (r²=0.58), and between body surface area and compound A concentration (r²=0.59).
• Peak plasma inorganic fluoride ion concentration was 21.5 ± 6.1 µmol/L.
• No clinically significant changes in hepatic or renal function were observed up to 24 hours post-anesthesia.

Conclusions:

• Sevoflurane anesthesia (up to 4 hours) in children using a 2-1 flow circle system resulted in compound A concentrations of 15 ppm or less.
• No evidence of renal or hepatic function abnormalities was found up to 24 hours post-anesthesia.
• Larger studies are needed to confirm the absence of organ toxicity.