[Absorption and desorption of ethylene-oxide in anaesthesia-supplies (author's transl)].

After ethylene oxide sterilization unwanted side effects are possible if the sterilized materials are not aerated sufficiently. The desorption of ethylene oxide depends upon many factors. Some of these are the composition of the sterilized materials and the various aeration provisions. It is nearly impossible to make general aeration recommendations because almost each item has different characteristics in regard to the absorption and desorption of ethylene oxide. We investigated the ethylene oxide residues in endotracheal tubes, nasal and oropharyngeal airways of various manufacturers as well as breathing tubes and bags of the Rüsch Company. For sterilization we used two DMB STERIVIT high pressure sterilizers, one Webeco ATOMAT 18, one Webeco ATOMAT 170 and one STERI-VAC 400 B Sterilizer of the 3 M Deutschland Company which operated under a low pressure system. For determination of the residues wer performed a total of about 1000 gaschromatographic analyses. The materials were aerated for 7-10 days at room temperature of 22 to 25 degrees C. IOn addition we perfused children PVC endotracheal tubes with 3 liter/min N2O/O2. By this considerable higher amounts of ethylene oxide were released than in quiet room air. The following recommendations can be made: Portex Blue Line and Rüsch Rüschelit acult tubes should aerate for 10 days. For Portex Blue Line children tubes a shorter time will be sufficient. Portex "green"PVC and Rüsch red rubber tubes retained less ethylene oxide than Blue Line and Rüschelit tubes. Portex oral airways must be vented for 10 days. Rüsch breathing tubes and bags can be used after 48 hours. The recommended aeration time must be observed precisely. Modern heated aerators with continuous air exchange accelerate the degassing process considerably.