AMSORB reduces the compound A production in vitro and clinical results

At first we analytically determined compound A production in vitro followin g Sevoflurane interactions with Soda Lime and "Amsorb" (Amstrong) at room t emperature and at 45 degrees C. The difference in compound A production after Soda Lime and Amsorb absorpti on is particularly evident at 45 degrees C, compound A concentrations in So da Lime being about ten times higher than in the Amsorb. We also measured the time course of compound A concentrations in the inspir atory and expiratory branch of the anesthetic circuit during a general anes thesia at low flows (500ml/min) using as carbon dioxide absorbents Soda Lim e (Acef)0 and the new Amsorb. In the Soda Lime group we found compound A concentrations after 30 minutes from the start (3 +/- 2 ppm in the inspiratory branch and 3 +/- 1 ppm in th e expiratory one). The maximum concentrations, after 3 hours of anaesthesia , were on the inspiratory branch 14,8 ppm and on the expiratory one 11,2 pp m. In the Amsorb group the maximum compound A concentrations after 2 hours of anaesthesia were 1,9 ppm in the inspiratory branch and 1,4 ppm in the ex piratory one.