**18. Bone mineral density in cystic fibrosis**

in patients who are a) colonised but not sensitised, b) sensitised but do not meet ABPA diagnostic criteria, and c) those with a diagnosis of ABPA [79]. Suitable studies assessing the

*Stenotrophomonas Maltophilia (*SM*)* and its relevance has been a point of debate for some time. Previously regarded as a bystander in the CF microbiome there is growing belief that it represents a true pathogen with potentially significant impact of mortality [80]. Antibiotic options for the treatment of SM are limited and dedicated studies assessing treatment effec‐

*Candida Species* are highly prevalent in CF airway culture [82]. Difficulty arises in differentiat‐ ing oropharyngeal contamination from bronchial colonisation without bronchoscopic sam‐ pling. Data from 2010 suggests that colonisation with *Candida Albicans* is associated with increased exacerbation rate and significant decline in FEV1 [83]. There is a paucity of data

Despite being a predictable outcome of progressive lung disease, the management of respira‐ tory failure in CF, both hypoxic (Type 1 Respiratory Failure) and hypercapnic (Type 2 Respiratory Failure), is lacking in terms of an evidence base [84]. Prescribing habits for oxygen (nocturnal, ambulatory, or resting) borrow largely from guidelines for other conditions. Hypoxia as a determinant of prognosis therefore has not been assessed, although there are suggestions that patients at higher mortality risk have an association with worsening six minute walk test results [85]. However, baseline hypercapnia has been shown to be an independent risk factor for death, even in patients with an FEV1 greater than 30% predicted [86]. There is a paucity of reliable data regarding the benefits of maintenance non-invasive bilevel positive airway pressure ventilation (BIPAP) in CF. One randomised placebo controlled trial from 2008 [87] did show significant benefits with nocturnal BIPAP in terms of symptoms (quality of life questionnaires scores, dyspnoea indices, and chest symptoms), improvements in modified shuttle walk test distances, and improved nocturnal (but not diurnal) arterial hypercapnia, but no significant improvements were shown in lung function. Data does suggest, however, that in the setting of acute respiratory failure requiring admission to intensive care units, non-invasive ventilation (NIV) was associated with significantly im‐ proved outcomes when compared to intubation and mechanical ventilation in patients with CF [88-90]. Hence, the importance of respiratory failure in predicting prognosis needs further

**17. Nutritional status and weight in determining outcome in cystic fibrosis**

The impact of malnutrition in CF is of great interest; exocrine and endocrine dysfunction, coupled with high basal metabolic requirements in the setting of chronic disease, exposes

relating to the benefits of treating *Candida Species* routinely in CF.

**16. Impact of respiratory failure on prognosis in cystic fibrosis**

value of AspF eradication in patients with CF not meeting ABPA criteria are lacking.

tiveness are lacking [81].

14 Cystic Fibrosis in the Light of New Research

study in CF.

Low bone mineral density (BMD) and subsequently osteopenia and osteoporosis are common in CF. Thus far, no convincing association has been shown between lung function and BMD and predictors of low BMD include BMI, weight, and age [97, 98]. Despite much research focus in this area, recent evidence raises the possibility that, unlike lung function and life expectancy, there has not been a significant improvement inter-generationally in BMD [99]. The lack of clinical data proving concrete improvements in outcomes with bisphosphonate therapy, other than BMD change itself, has left a clinical conundrum regarding the management of low BMD in CF [100]. Further studies are needed to guide clinical decisions which are currently dictated by experience and judgement. However, there is no prognostic value in BMD scores in CF patients.
