Predictive factors of chronic respiratory failure in bronchiectasis

Chronic respiratory failure (CRF) is one of the complications of bronchiectasis (BE). It is associated to a poor prognosis. Aims: To determine the predictive factors of CRF in BE. Methods: A retrospective single-center study of patients with BE followed between 2005 and 2015. We considered the PaO2 threshold of 70 mmHg measured at ambient air, at rest, during a stable period, and confirmed twice over a three-week period to confirm the diagnosis of CRF. We considered the consensus-based definition for bronchiectasis acute exacerbation (AE) (EMBARC 2017). We compared different parameters of severity of BE between two groups: G1: patients with BE at the stage of CRF (G1:32 cases), G2: BE without CRF (68 cases). Results: The study included 100 patients with BE (mean age: 57 years). No differences were seen between the 2 groups in terms of age or number of comorbidities. G1 Patients were more symptomatic than G2 (mMRC≥2: G1:75% vs G2:47%; p=0.009), with a higher mean number of involved lobes (4,2 vs 2.8; p<0.001), a lower FVC (1.34 vs 2.28L; p<0.001), a lower FEV1 (p<0.001), a greater obstruction (p=0.011), a higher number of AE/year (2.2 vs 1.06; p<0.001), and more hospitalizations (H) for AE (1.37, 0.56 H/patient/year; p=0.001). The mean FACED score was higher in G1 (3.7 vs 1.9; p<0.001). Multivariate logistic regression analysis demonstrated that FVC (OR:0.41; 95%CI 0.20-0.85) and the number of AE/year (OR:2.77; 95%CI 1.53-5.01) are independent predictive factors of CRF in BE. Conclusion: The deterioration of the respiratory function and the frequency of AE-BE are independent risk factors for CRF in BE. Preventive therapeutics targeting the reduction of AE-BE may reduce the risk of evolution towards CRF.