Choice of nebulisers and compressors for delivery of carbenicillin aerosol.

Although aerosol antibiotics have been used successfully to treat respiratory tract infection in patients with cystic fibrosis, little information exists concerning the correct nebulisation technique for antibiotic solutions. We have measured aerosol output, droplet size and nebulisation time for 1 g carbenicillin (Pyopen, Beechams) diluted with 3 ml or 4 ml water for injection and delivered from six brands of jet nebuliser (Cirrus, DeVilbiss, Inspiron, Turret, Unicorn and Upmist). Three relatively weak compressors (Medix Traveller, Medic-Aid PortaNeb 50 and Inspiron) and three more powerful compressors (Medix WOBL, Medix Maxi mark I and Gast) were used as driving sources. Maxi and Gast compressors increased the quantity of "respirable" (less than 5 micron diameter) carbenicillin aerosol, and reduced nebulisation times; with the weaker compressors, nebulisation times (up to 50 min) were unacceptably long. The Turret nebuliser proved to be the most efficient, but several other brands would also be acceptable if used with a powerful compressor.