Dehydration of Baralyme increases compound A resulting from sevoflurane degradation in a standard anesthetic circuit used to anesthetize swine

Comparison of the renal safety between carbon dioxide absorbent products under sevoflurane anesthesia: a pilot study

Background

The chemical reaction of carbon dioxide absorbent and sevoflurane is known to produce compound A. However, carbon dioxide absorbents are not controlled by the Food and Drug Administration, but are treated as industrial products in some nations. Moreover, carbon dioxide absorbents differ in their capacities to produce compound A, because their chemical compositions differ. In this study, we compared the renal safety between carbon dioxide absorbent products in patients under sevoflurane anesthesia.

Methods

Eighty patients with no preexisting renal disease undergoing elective gynecologic surgery were randomly assigned to receive sevoflurane or isoflurane anesthesia with one of four carbon dioxide absorbent products (Sodasorblime®, Sodalyme®, Sodasorb®, Spherasorb®) at the same fresh gas flow of 2 L/min. The renal safety was evaluated by changes of blood urea nitrogen (BUN), creatinine and urine N-acetyl-b-glucoseaminidase (NAG)-creatinine ratio at 24 hours and 72 hours after surgery from preoperative level.

Results

There was no significant difference in the renal safety indicators between carbon dioxide absorbents during sevoflurane anesthesia (P > 0.05). However, the BUN and urine NAG-creatinine ratios at 72 hours after surgery were higher in isoflurane anesthesia in some carbon dioxide absorbent groups (P = 0.03 and 0.04, respectively).

Conclusions

We could not find significant differences of renal safety indicators with carbon dioxide absorbents. Although the adverse effect of carbon dioxide absorbents on renal function was not proved, consideration should be given to their contol by the regulation on their efficacy and safety because carbon dioxide absorbents can produce compound A.

The mechanisms of carbon monoxide production by inhalational agents

Carbon monoxide can be formed when volatile anaesthetic agents such as desflurane and sevoflurane are used with anaesthetic breathing systems containing carbon dioxide absorbents. This review describes the possible chemical processes involved and summarises the experimental and clinical evidence for the generation of carbon monoxide. We emphasise the different conditions that were used in the experimental work, and explain some of the features of the clinical reports. Finally, we provide guidelines for the prevention and detection of this complication.

Carbon dioxide absorption: toxicity from sevoflurane and desflurane

The degradation of volatile anaesthetics by desiccated carbon dioxide absorbents can result in adverse outcomes. Desiccated carbon dioxide absorbent reacting with desflurane can cause potentially life-threatening intraoperative carbon monoxide exposure; the reaction with sevoflurane can cause the formation of several toxic breakdown products, e.g. compound A. Compound A-related renal toxicity in humans is still a matter of controversy.