Contamination of the nebulization systems used in the prophylaxis with amphotericin B nebulized in lung transplantation

The contamination of nebulizer may be the origin of respiratory infections. The aim of this study was to determine the incidence of contamination in nebulizers used to nebulize amphotericin B in lung transplant (LT) patients and the relationship with bacterial isolation in sputum culture. A prospective, cross-sectional study was conducted with 41 LT patients who were administered amphotericin B with a jet nebulizer. Samples were taken from the nebulizers (prior to nebulization). Sputum culture was carried out and patients were asked whether or not they followed a cleaning and disinfection protocol (washing and brushing with soap and water followed by subsequent disinfection with the Milton method after each nebulization). Contamination was defined as such when potentially pathogenic bacteria were isolated in the nebulizer. Seventeen of the 41 nebulizers (41.4%) were contaminated. In 7 of the 17 cases (41.1%) contamination was polymicrobial. The most common microorganism was Pseudomonas aeruginosa. Fourteen of the 41 patients (34.1%) presented positive sputum cultures, most common was P aeruginosa. In 10 patients (24.3%) pathogenic bacteria was isolated both in the nebulizer and in the sputum. In four of these patients (9.7%) the species was the same. The cleaning and disinfection protocol was carried out by 16 of the 41 patients (39.0%). In 2 of the 16 patients (12.5%) who were following the protocol the nebulizer was contaminated, compared to 15 of 25 patients (60.0%) whose nebulizer was not contaminated (P <.05). Two of the 16 patients (12.%) who were following the protocol presented positive sputum culture compared to 12 of 25 (48.0%) who did not (P <.05). In conclusion, the contamination of the nebulizing systems is frequent when no strict cleaning and disinfection protocol is followed. Patients who did not follow the protocol presented a greater isolation of pathogenic bacteria in the sputum.