ABSTRACT
BACKGROUND: Bronchiectasis is the consequence of chronic bronchial inflammation, inappropriate mucus clearance, bacterial colonization, and recurrent or chronic infection. High flow therapy (HFT) is a type of non-invasive respiratory therapy, usually delivered through a nasal cannula interface (HFNC). It delivers heated and humidified air with a stable fraction of inspired oxygen and a wide range of possible flow rates. AIM OF THE STUDY: Determine the effectiveness of HFNC as add-on therapy in adult primary and secondary bronchiectasis with frequent acute exacerbations (AEs) and/or hospitalizations. METHODS: This is a single-center crossover study on long-term home therapy with HFNC in adult bronchiectasis. Pharmacological therapy included pulse therapy with mucolytics and bronchodilators. After one year, all patients were switched to additional HFNC. The temperature range was 31-37 °C. The flow range was 35-60 L/m. FiO2 was 0.21. RESULTS: Seventy-eight patients completed the follow-up; 54% were females; the median age was 70 years (IQR 60-76). The etiology of bronchiectasis was mainly post-infective (51%), COPD related (26%), and congenital (11%). AEs at baseline were 2.81 (±2.15). A significant reduction in AEs was observed after 24 months with a mean of 0.45 (±0.66) (f-ratio value 79.703. p-value < 0.00001). No significant difference was observed after HFNC therapy on FEV1 (2.39 ± 0.87 vs. 2.55 ± 0.82; f-ratio 0.79. p-value 0.45) and FVC (2.73 ± 0.88 vs. 2.84 ± 0.90; f-ratio 0.411. p-value 0.66). A significant reduction in mMRC score was observed after HFNC therapy (2.40 ± 0.81 vs. 0.97 ± 0.97 at 2 months vs. 0.60 ± 0.78 at 24 months; f-ratio value 95.512. p-value < 0.00001). CONCLUSIONS: HFNC is a well-tolerated add-on therapy for adult bronchiectasis. Dyspnea improved after 2 months and further after 2 years. The exacerbation rate decreased during the 2 years follow-up. No significant difference was observed in lung function.
ABSTRACT
High-flow nasal cannula (HFNC) therapy is an oxygen delivery method particularly used in patients affected by hypoxemic respiratory failure. In comparison with the conventional "low flow" oxygen delivery systems, it showed several important clinical benefits. The possibility to nebulize drugs via HFNC represents a desirable medical practice because it allows the administration of inhaled drugs, mostly bronchodilators, without the interruption or modification of the concomitant oxygen therapy. HFNC, by itself has shown to exert a small but significant bronchodilator effect and improves muco-ciliary clearance; thus, the nebulization of bronchodilators through the HFNC circuit may potentially increase their pharmacological activity. Several technical issues have been observed which include the type of the nebulizer that should be used, its position within the HFNC circuit, and the optimal gas flow rates to ensure an efficient drug delivery to the lungs both in "quiet" and "distressed" breathing patterns. The aim of this review has been to summarize the scientific evidence coming from "in vitro" studies and to discuss the results of "in vivo" studies performed in adult subjects, mainly affected by obstructive lung diseases. Most studies seem to indicate the vibrating mesh nebulizer as the most efficient type of nebulizer and suggest to place it preferentially upstream from the humidifier chamber. In a quite breathing patterns, the inhaled dose seems to increase with lower flow rates while in a "distressed" breathing pattern, the aerosol delivery is higher when gas flow was set below the patient's inspiratory flow, with a plateau effect seen when the gas flow reaches approximately 50% of the inspiratory flow. Although several studies have demonstrated that the percentage of the loaded dose nebulized via HFNC reaching the lungs is small, the bronchodilator effect of albuterol seems not to be impaired when compared to the conventional inhaled delivery methods. This is probably attributed to its pharmacological activity. Prospective and well-designed studies in different cohort of patients are needed to standardize and demonstrate the efficacy of the procedure.
ABSTRACT
Background and objective: Insertion/deletion polymorphisms of angiotensin-converting enzyme (ACE) have been previously described in association with adult respiratory distress syndrome (ARDS) and correlated to outcome. The ACE deletion/deletion(D/D)genotype represents a marker of thrombosis in subjects apparently without predisposing factors and/or traditional thrombophilic alterations and increases the risk of venous thromboembolism in subjects in whom a thrombogenic condition occurs. Thrombosis seems to play a role very early in the disease caused by SARS-CoV-2, in particular in those with severe COVID-19 pneumonia. The counterbalance between angiotensin-converting enzyme (ACE) and ACE2 activities in COVID-19 disease may play a crucial role in the thrombo-inflammatory process. We hypothesised that a genetic predisposition could condition the severity and complications of SARS-CoV-2 infection. Materials and methods: We conducted a spontaneous, single centre observational study in the Sub-Intensive Care Unit of A.O.R.N. Ospedali dei Colli, Cotugno Hospital, Naples (Italy). In this study, we performed genetic screening for ACE D/D genotype and other thrombophilic mutations in 20 patients affected by ARDS related to COVID-19 pneumonia, compared to 19 age- and sex-matched healthy controls. Results: All tested patients had multiple polymorphisms and, in particular, a significantly higher prevalence of ACE D/D polymorphism in severe COVID-19 patients Conclusion: We found that the majority of patients who tested positive for ACE D-D genotype and who were not associated with other risk factors for VTE showed an evolution to ARDS. This finding could have a predicting role in the selection of patients more prone to developing severe COVID-19 during clinical observation in emergency department.