[Adverse effects of modern inhalation anesthetics. 2. Control of amounts and elimination of escaping anesthesia gases].

This paper presents a review on the pathological effects caused by acute or chronic exposure to the inhalation anesthetics halothane, methoxyflurane, or enflurane. Methoxyflurane has a dose-related nephrotoxicity due to its metabolic degradation with release of fluoride ions whereas suggested pathological renal effects of halothane or enflurane are still under discussion. As to the syndrome of halothane- (or enflurane-, methoxyflurane-) associated hepatitis no dose-dependent hepatotoxicity has been proven but interactions with hypoxia, hypotension, drug-pretreatment, and perhaps genetic abnormalities should be kept in mind. Severe hematologic alterations are effected by prolonged exposure to N2O or halothane and alterations of tumor immunity caused by anesthetic agents are reported, too. From clinical studies and observations of pregnant animals, a correlation between the incidence of miscarriages or malformations and chronic exposure to low doses of inhalation agents may be stated. Nevertheless, an inhalation agent is easy to control because it can be eliminated quickly in the case of complications. Therefore, one would not like to miss these inhalation agents in clinical practice but the immission into the operating room should be limited. Moreover, the best way to keep the operating room clean from waste anesthetic gases is the installation of a scavenging system which is connected to suction.