Canadian Anaesthetists' Society journal
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This study was designed to assess operating room contamination with nitrous oxide and halothane when nitrous oxide 3 1/min and oxygen 2 1/min containing halothane one per cent were passed into a semiclosed circle absorber system from which the patients' lungs were ventilated with an Ohio ventimeter through a cuffed tracheal tube, with the exhaled gas vented to the floor. The normal room ventilation did not consistently maintain levels below the suggested amounts, which are nitrous oxide 25 ppm and halothane 2 ppm. ⋯ The Protection Filter Foregger 7--365--001 was only effective in removing halothane and only if the plastic holder provided was radically modified. Attention is drawn to the numerous factors influencing the magnitude of contamination, aspects of controlling it, and the necessity to cope with the problem of dealing with scavenged gases and vapours.