Jens Bräunlich

Effects of nasal high flow on ventilation in volunteers, COPD and idiopathic pulmonary fibrosis patients.

Background: A high flow of air applied by large bore nasal cannulae has been suggested to improve symptoms of chronic respiratory insufficiency. In pediatric patients, nasal high-flow (nHF) ventilation was similarly effective compared to noninvasive ventilation with a face mask. Objectives: The aim of this study was to describe changes in respiratory parameters. Methods: We measured pressure amplitudes during the respiratory cycle and mean pressures in patients with idiopathic pulmonary fibrosis (IPF) and COPD. In order to achieve tidal volume and minute volume measurements, we used a polysomnography device. Capillary blood was taken for blood gas analysis before and after nHF breathing (8 h). Results: nHF led to an increase in pressure amplitude and mean pressure in healthy volunteers and in patients with COPD and IPF in comparison with spontaneous breathing. In COPD, nHF increased tidal volume, while no difference in tidal volume was observed in patients with IPF. Interestingly, tidal volume decreased in healthy volunteers. Breathing rates and minute volumes were reduced in all groups. Capillary pCO2 decreased in patients with IPF and COPD. Conclusions: nHF resulted in significant effects on respiratory parameters in patients with obstructive and restrictive pulmonary diseases. The rise in pressure amplitude and mean pressure and the decrease in breathing rate and minute volume will support inspiratory efforts, helps to increase effectiveness of ventilation and will contribute to a reduction in the work of breathing. A CO2 wash-out effect in the upper airway part of the anatomical dead space may contribute to the beneficial effects of the nHF instrument.

Nasal highflow improves ventilation in patients with COPD

Background Nasal highflow (NHF) provides a warmed and humidified air stream up to 60 L/min. Recent data demonstrated a positive effect in patients with acute hypoxemic respiratory failure, especially when caused by pneumonia. Preliminary data show a decrease in hypercapnia in patients with COPD. Therefore, NHF should be evaluated as a new ventilatory support device. This study was conducted to assess the impact of different flow rates on ventilatory parameters in patients with COPD. Materials and methods This interventional clinical study was performed with patients suffering from severe COPD. The aim was to characterize flow-dependent changes in mean airway pressure, breathing volumes, breathing frequency, and decrease in partial pressure of CO2 (pCO2). Mean airway pressure was measured in the nasopharyngeal space (19 patients). To evaluate breathing volumes, we used a polysomnographic device (18 patients). All patients received 20 L/min, 30 L/min, 40 L/min, and 50 L/min and – to illustrate the effects – nasal continuous positive airway pressure and nasal bilevel positive airway pressure. Capillary blood gas analyses were performed in 54 patients with hypercapnic COPD before and two hours after the use of NHF. We compared the extent of decrease in pCO2 when using 20 L/min and 30 L/min. Additionally, comfort and dyspnea during the use of NHF were surveyed. Results NHF resulted in a minor flow dependent increase in mean airway pressure. Tidal volume increased, and breathing rate decreased. The calculated minute volume decreased under NHF breathing. In spite of this fact, hypercapnia decreased with increasing flow (20 L/min vs 30 L/min). Additionally, an improvement in dyspnea was observed. The rapid shallow breathing index shows a decrease when using NHF. Conclusion NHF leads to a flow-dependent reduction in pCO2. This is most likely achieved by a washout of the respiratory tract and a functional reduction in dead space. In summary, NHF enhances effectiveness of breathing in patients with COPD, reduces pCO2, the work of breathing, and rapid shallow breathing index as an indicator of respiratory work load.

Nasal High-flow versus non-invasive ventilation in stable hypercapnic COPD: a preliminary report

BackgroundThere are no data available about effectiveness of Nasal High-flow (NHF)in chronic respiratory insufficiency.MethodsEleven COPD patients with stable hypercapnia were adjusted to NHF-system with a flow of 20 l/min. After six weeks patients were switched to non-invasive ventilation (NIV) for another six weeks period.ResultsNHF led to significant decreases in resting pCO2. Between the devices we found no differences in pCO2 levels.ConclusionsNHF may thus be an alternative treatment device in stable hypercapnic COPD patients.

NHF and hypercapnia: How brief can you look?

See DOI: 10.1111/resp.13050

Nasal highflow eliminates CO2 from lower airways

INTRODUCTION Nasal highflow (NHF) has a growing evidence in treatment of hypoxemic respiratory failure. There are preliminary data available about use in acute and chronic type-II-respiratory failure. Unfortunately underlying mechanisms of NHF are not well understood. Increase in airway pressure seems too small to explain the observed reduction in hypercapnia. Most interesting effects are wash-out of upper airways and reduction of functional dead space. There are no data available about a wash-out of lower airways. METHODS We established a sheep lung model to evaluate CO2-wash-out in lower airways. Therefore we placed measuring and insufflation catheter in maximal expanded lung. The lung was not ventilated in order to minimize influence of CO2 rebreathing and increase in airway pressure. Airway pressure and CO2 values were measured in lower airways and in tracheal space. RESULTS CO2 was decreased by NHF in lower airways and in tracheal space. Changes in CO2 were flow dependent. There was also an increase in airway pressure in these settings. CONCLUSIONS NHF is able to decrease CO2 in lower airways in a flow-dependent manner. This effect is independent of an increase in airway pressure and CO2-rebreathing. So wash-out is an important reason for efficiency of NHF in decreasing hypercapnia.

Oral Versus Nasal High-Flow Bronchodilator Inhalation in Chronic Obstructive Pulmonary Disease

BACKGROUND Nasal high flow (NHF) alters breathing patterns, stabilizes fraction of inspired oxygen (FiO2) during respiratory distress, helps to keep up hemostasis in the airways, and washes out the upper airways. Particularly the support of inspiratory flow and decrease in functional dead space are interesting mechanisms of action with regard to aerosol delivery. Several laboratory investigations have studied aerosol delivery via the nasal route by using NHF, whereas clinical benefits are poorly evaluated. METHODS Thirty patients with stable chronic obstructive pulmonary disease Gold D were recruited. In a randomized order, they inhaled a salbutamol 2.5 mg/ipratropium bromide 500 μg solution oral or NHF adapted on the second study day. A jet nebulizer was used as aerosol delivery device. The chosen flow rate was 35 L/min. RESULTS Four patients refused to repeat the procedure, for example, for inconvenience or fear of delayed discharge, and were not included in the intention-to-treat analysis. All remaining patients tolerated both inhalation systems well. Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), airway resistance (Rtot), and residual volume (RV) were significantly altered after bronchodilator inhalation with each of the both devices. The two different ways of combined bronchodilator inhalation resulted in very comparable changes in FVC, FEV1, relative 1 second-capacity (FEV1%FVC), Rtot, total lung capacity (TLC), RV, and residual volume expressed as percent of TLC (RV%TLC). However, in between devices, no difference was observed on comparing the postinhalational measurements of FVC, FEV1, Rtot, and RV. CONCLUSIONS We conclude from this proof-of-principle kind of study that inhalation of combined bronchodilators adapted to an NHF device is similarly effective to inhalation with a standard oral aerosol nebulizer. (Clinical Trails NCT02885103).

Diffuse Interstitial Pulmonary Infiltrates in Malignant Melanoma

Only a few cases of sarcoidosis-like reaction to a pharmacologic compound have been reported in patients with melanoma in the literature. Long-term treatment with interferon alpha may be assumed. We report a case of a 25-y-old man who presented to our department with diffuse interstitial pulmonary infiltrates and slightly enlarged mediastinal lymph nodes as determined by computed tomography. He had a history of malignant melanoma with 18 months of interferon alpha-2 therapy. Histological analysis of a transbronchial biopsy revealed sarcoidosis-like reactions.

Nasaler Highflow – Bessere Alternative der Sauerstoffapplikation bei schwerer Hypoxie?

Nasal High Flow (NHF) provides a warmed and humidified air stream. In pediatrics, this method is already in widespread use and is increasingly replacing the CPAP. New studies show success in treating adults. Currently the acute hypoxemic insufficiency cause of pneumoniae is a secured area of use. NHF is not inferior in comparison to other oxygen delivery systems. At this juncture effectiveness of this easy to use method is not clear. Preliminary reports describe an improvement in ventilation by the NHF. Here, a wash-out of the airways and improved alveolar ventilation seem to be the main operating principles.