Pulmonology最新文献

Background: Nasal high flow (NHF) has been proposed to sustain high intensity exercise in people with COPD, but we have a poor understanding of its physiological effects in this clinical setting.

Research question: What is the effect of NHF during exercise on dynamic respiratory muscle function and activation, cardiorespiratory parameters, endurance capacity, dyspnoea and leg fatigue as compared to control intervention.

Study design and methods: Randomized single-blind crossover trial including COPD patients. Two constant workload exercise testing were performed at 75% of peak power with NHF (30L/min, 34°C) or with control intervention. Pressure time product of the transdiaphragmatic pressure (PTPdi/min) and other physiological measurements were continuously monitored. Dyspnoea and lower limb fatigue were assessed using the 10-Borg scale.

Results: 14 patients with severe obstruction (median FEV1: 40 (IQR 28 to 52) %) were included. Their median age was 70 (IQR 57 to 72) years. At isotime, NHF had little to no effect on PTPdi/min (MD -15cmH2O.s/min, 95% CI -62 to 33) but increased tidal volume (MD 77mL, 95% CI 21 to 133). NHF also improved endurance capacity (MD 20s, 95% CI 2 to 40) and dyspnoea at isotime (MD -1.1, 95% CI -2.1 to -0.1). NHF had no or uncertain effect on other outcomes.

Conclusion: NHF has little to no effect on dynamic respiratory muscle function and activation but improves Vt. It leads to a trivially small increase in endurance capacity but a worthwhile improvement in dyspnoea. NHF may be beneficial for individuals experiencing critical inspiratory constraints and significant dyspnoea.

Background: Chronic obstructive pulmonary disease (COPD) induces an imbalance in T helper (Th) 17/regulatory T (Treg) cells that contributes to of the dysregulation of inflammation. Exercise training can modulate the immune response in healthy subjects.

Objective: We aimed to evaluate the effects of exercise training on Th17/Treg responses and the differentiation of Treg phenotypes in individuals with COPD.

Methods: This randomized controlled trial included 50 individuals with severe or very severe COPD who were allocated to the Exercise or Control groups. The Exercise group underwent eight weeks of aerobic and muscle strength training, whereas the Control group received usual care. The primary outcome was the change in the phenotypic characteristics of Tregs and Th17 profile differentiation in systemic inflammation.

Results: Exercise training increased the frequency of total and activated Tregs and decreased the frequency of Th17 cells in between-group comparisons. Additionally, Th17/Treg responses were moderately correlated with improvements in the six-minute walking test, muscle strength of the upper and lower limbs, and daily life physical activity levels.

Conclusion: Exercise training improved functional exercise capacity, muscle strength, and physical fitness, which was associated with a decrease in the Th17 inflammatory response and an increase in Treg cell phenotypes immunosuppressive activity.

Nasal high flow (NHF) therapy is an established form of non invasive respiratory support used in acute and chronic care. Recently, a new high flow nasal cannula with asymmetric prongs was approved for clinical use. The clinical benefits of the new cannula have not yet been defined and no evidence are available on the use of asymmetric NHF support in patient with Chronic Obstructive Pulmonary Disease (COPD). We conducted a single-centre, prospective, physiologic, crossover, randomised study to investigate the effects on partial pressure of carbon dioxide (PaCO²) levels of two different nasal cannula ("asymmetric" vs "standard" nasal interface) in 20 COPD hypercapnic patients. All patients were recovering from an acute exacerbation that required hospitalisation and had persistent hypercapnia, despite having attained a stable pH. After enrolment, two 90-min trials with the asymmetric nasal high flow interface (Optiflow + Duet, Fisher & Paykel Healthcare Ltd., New Zealand) or the standard interface (Optiflow, Fisher & Paykel Healthcare Ltd., New Zealand) were randomly applied and a washout period of 60 min between the two treatments was performed for minimising the carryover effect. Study results suggested that the asymmetrical cannula did not significantly decrease PaCO² compared with the standard cannula. Similar performances were also observed in terms of diaphragm activity, dyspnoea and patient's comfort. Interestingly, asymmetric NHF cannula performed significantly better in reducing the dead space ventilation and increasing the ventilatory efficiency in more advanced COPD patients with more severe hypercapnia higher baseline PaCO² values (PaCO² ≥ 65 mmHg at baseline).   .

Background: Traditionally, Venturi-based flow generators have been preferred over mechanical ventilators to provide continuous positive airway pressure (CPAP) through the helmet (h-CPAP). Recently, modern turbine-driven ventilators (TDVs) showed to be safe and effective in delivering h-CPAP. We aimed to compare the pressure stability during h-CPAP delivered by Venturi devices and TDVs and assess the impact of High Efficiency Particulate Air (HEPA) filters on their performance.

Methods: We performed a bench study using an artificial lung simulator set in a restrictive respiratory condition, simulating two different levels of patient effort (high and low) with and without the interposition of the HEPA filter. We calculated the average of minimal (Pmin), maximal (Pmax) and mean (Pmean) airway pressure and the time product measured on the airway pressure curve (PTPinsp). We defined the pressure swing (Pswing) as Pmax - Pmin and pressure drop (Pdrop) as End Expiratory Pressure - Pmin.

Results: Pswing across CPAP levels varied widely among all the tested devices. During "low effort", no difference in Pswing and Pdrop was found between Venturi devices and TDVs; during high effort, Pswing (p<0.001) and Pdrop (p<0.001) were significantly higher in TDVs compared to Venturi devices, but the PTPinsp was lower (1.50 SD 0.54 vs 1.67 SD 0.55, p<0.001). HEPA filter addition almost doubled Pswing and PTPinsp (p<0.001) but left unaltered the differences among Venturi and TDVs systems in favor of the latter (p<0.001).

Conclusions: TDVs performed better than Venturi systems in delivering a stable positive pressure level during h-CPAP in a bench setting.

Fibrotic hypersensitivity pneumonitis (f-HP) is an interstitial lung disease in which various antigens in susceptible individuals may play a pathogenetic role. This study evaluates the role of transbronchial lung cryobiopsy (TBLC) and bronchoalveolar lavage (BAL) in identifying a UIP-like pattern and its association with fibrosis progression. We conducted a multicentre retrospective cohort study of patients diagnosed with f-HP who underwent BAL and TBLC between 2011 and 2023. A UIP-like pattern was defined by the presence of (A) patchy fibrosis and fibroblastic foci or (B) honeycombing ± (A). We investigated BAL's role in predicting UIP-like patterns within a clinical-radiological-serological framework, examining disease progression in these patients using spirometry and mortality data. A total of 195 patients were enrolled, 59 (30%) of whom exhibited a UIP-like pattern. These patients showed greater lung function decline, lower BAL lymphocytosis (14.4% vs. 37.4%, p < 0.001), higher nintedanib prescription (35% vs. 14%, p < 0.001), and higher 10-year mortality (HR 2.8, 95% CI 1.3-5.8, p = 0.004). f-HP patients with a UIP-like pattern exhibit worse clinical outcomes and higher mortality. In cases of low BAL lymphocytosis with a high pre-test clinical suspicion of f-HP, lung biopsy may not be necessary as it increases the likelihood of identifying a UIP-like pattern.