An observational study of in adult long-term ventilation.

Introduction: increases morbidity and mortality in respiratory disease. To date the long-term ventilation population does not have clear guidelines regarding its management.

Method: We undertook a retrospective observational study in a regional long-term ventilation population (837 patients). We defined the primary outcome as isolation. In addition positive cultures for copathogens (, species, , complex and nontuberculous mycobacteria) were recorded Logistic regression and odds ratios were calculated.

Results: 17.6% of the cohort isolated , and this pathogen was cultured more frequently in patients with a tracheostomy (logistic regression coefficient 2.90, p≤0.0001) and cystic fibrosis/bronchiectasis (logistic regression coefficient 2.48, p≤0.0001). 6.3% of patients were ventilated tracheostomy. In the positive cohort 46.9% of patients were treated with a long-term macrolide, 36.7% received a nebulised antibiotic and 21.1% received both. Tracheostomised positive patients received a nebulised antibiotic more frequently (OR 2.63, 95% CI 1.23-5.64, p=0.013). Copathogens were isolated in 33.3% of the cohort. In this cohort patients with a tracheostomy grew a copathogen more frequently than those without (OR 2.75, 95% CI 1.28-5.90).

Conclusions: isolation is common within the adult long-term ventilation population and is significantly associated with tracheostomy, cystic fibrosis and bronchiectasis. Further research and international guidelines are needed to establish the prognostic impact of and to guide on antimicrobial management. The increased risk of should be considered when contemplating long-term ventilation tracheostomy.