Retention of airborne latex particles by a bacterial and viral filter usedin anaesthesia

We have developed a series of laboratory tests to evaluate the efficiency o f a heat and moisture exchanger tilter (Pall (TM) BB25) in retaining latex particles in order to protect allergic patients during anaesthesia. Latex p articles were nebulised with cornstarch as a support and collected for assa y in a flask, with or without the filter integrated into the experimental c ircuit. With the Pall BB25 filter in the circuit, no natural latex proteins were detected by measurement of either total protein or antigenic latex pr oteins. The Pall BB25 filter may represent a useful means of preventing inh alation of latex particles during anaesthesia in susceptible patients.