title: Viability and distribution of bacteria after passage through a circle anaesthetic system.
abstract: We have assessed in vitro the viability of eight species of micro-organism suspended as aerosols and passed through a soda-lime absorber rebreathing system. As had been predicted, the soda-lime exerted a potent cidal effect on non-sporing organisms, all of which were rendered non-viable. One percent of the spore bearing organism, Bacillus subtilis, was still viable after 30 min contact. Although Bacillus subtilis is an organism of low pathogenicity, spores may be more resistant to the alkaline medium of the soda-lime. The micro-organisms were observed to lodge in all components of the breathing system, with the greatest concentration being recovered from the corrugated tubing. We recommend that disposable components of the circle breathing system should be changed, and the non-disposable parts sterilized or disinfected, daily. Soda-lime cannisters should be sterilized or disinfected when changing the soda-lime.
authors.affiliation: Department of Anaesthesia, Odstock Hospital, Salisbury.
authors.forename: P M
authors.initials: PM
authors.lastname: Murphy
authors.forename: R B
authors.initials: RB
authors.lastname: Fitzgeorge
authors.forename: R F
authors.initials: RF
authors.lastname: Barrett
mesh_terms: D000764:Anesthesia, Closed-Circuit / Q000295:instrumentation*; D001412:Bacillus subtilis / Q000187:drug effects; D001419:Bacteria / Q000187:drug effects*; D017610:Calcium Compounds; D002176:Candida albicans / Q000187:drug effects; D015169:Colony Count, Microbial; D004203:Disinfection; D004866:Equipment Contamination; D004926:Escherichia coli / Q000187:drug effects; D007711:Klebsiella pneumoniae / Q000187:drug effects; D010087:Oxides; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D012706:Serratia marcescens / Q000187:drug effects; D012972:Sodium Hydroxide / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects; D013242:Sterilization; D013296:Streptococcus pneumoniae / Q000187:drug effects
chemical_list: D017610:Calcium Compounds; D010087:Oxides; C004569:soda lime; D012972:Sodium Hydroxide