Abstract Background The association of obstructive sleep apnea (OSA) with cardiovascular morbidity has been repeatedly reported in numerous studies and argues for treatment initiation even in the ...absence of significant day time sleepiness. While the long-term consequences of positive airway pressure (PAP) treatment on OSA related comorbidities like secondary hypertension are based on substantial clinical evidence, less is known about the immediate hemodynamic effects. Methods This study tried to investigate the impact of PAP treatment on different hemodynamic parameters in 48 patients with OSA by extending the standard polysomnographic assessment with non-invasive hemodynamic monitoring using impedance cardiography (ICG). On two consecutive nights under diagnostic and therapeutic conditions, polysomnographic and hemodynamic data were acquired. In addition, we subdivided the participants according to their treatment related change in stroke volume (SV) and assigned the hemodynamic measurements to the corresponding sleep stage. Results Comparing both conditions, a non-statistically significant decrease in SV and cardiac output (CO) was observed for all participants. Treatment initiation was associated with a statistically significant prolongation of the pre-ejection period (PEP) for the entire study population (p = 0.001) and the subgroup with decreasing SV (p = 0.008). In addition, systolic blood pressure (SBP) (p = 0.026) and pulse pressure (PP) (p = 0.041) were lowered significantly for patients with a therapeutically reduced SV under treatment conditions. A higher BMI (p = 0.020) and a more pronounced reduction of the respiratory distress index (RDI) (p = 0.030) and the arousal-index (p = 0.021) were observed for patients with decreasing SV. Correlational analysis revealed a negative relationship between the diagnostic values for both SBP (r=-0.324, p = 0.025) and PP (r=-0.407, p = 0.004) with the change in SV and a positive correlation with the change of the SBP (r = 0.317, p = 0.028) for all participants. Conclusions To conclude, our results indicate that treatment with a PAP device in patients with OSA can lead to a decrease in SV which is associated with a lowering of the SBP. This may be caused by a reduced sympathetic tone due to less respiratory events and an improved sleep profile.
Abstract Background This study is aimed to evaluate the effect of inspiratory muscle training (IMT) added to rehabilitation in patients with chronic obstructive pulmonary disease (COPD) who remain ...hypercapnic and use non-invasive ventilation after successful weaning. Methods Patients received rehabilitation and were randomized to inspiratory muscle or sham training for 4 weeks. The primary outcome was distance walked within 6 min. Secondary outcomes were inspiratory muscle strength, endurance, lung function, and blood gas levels. Results Twenty-nine patients participated in this study. Walking distance of the sham group increased from 93 ± 52 m at baseline to 196 ± 85 m at week 4 (p = 0.019, 95% CI: 11–196 m). Patients in the IMT group significantly improved their walking distance from 94 ± 32 to 290 ± 75 m (p < 0.0001 107–286 m; p = 0.04 3–186 m for between-group comparison). Patients in the IMT group increased their maximal inspiratory pressure from −35 ± 8 to −55 ± 11 cmH2 O (p = 0.001; −6 to −33 cmH2 O), while the increase in the sham group failed to reach significance (−29 ± 10 to −37 ± 13 cmH2 O −22 to 6 cmH2 O). Inspiratory power increased from 9.6 ± 5.4 to 20.7 ± 9.7 joules/min (2.6–19.5 joules/min, p = 0.003) in the IMT group, while no significant change occurred in the sham group (7.6 ± 4.2 joules/min at study entry and 11.1 ± 6.9 joules/min −5.2–12.3 joules/min at study end). Conclusions Rehabilitation of successfully weaned patients with COPD and persistent hypercapnia significantly improves functional exercise capacity. Additional IMT significantly enhances functional exercise capacity and increases respiratory muscle strength and power.
Non-invasive and invasive ventilation have become essential for therapy in acute and chronic respiratory failure. More than one-third of patients in intensive care units receive invasive ventilation, ...and the number of ventilated patients in out-of-hospital care is also steadily increasing. While normalization of blood gases was considered the most significant goal in past decades, and the idea that mechanical ventilation also poses dangers played little role, the dominant thought at present is the application of ventilation from the most protective point of view possible. Because fundamental change in equipment technology is likely to be difficult, improvement of protective ventilation and further development of understanding of pathophysiologic processes in acute and chronic respiratory failure will continue to be of great importance in the future. This article summarizes different aspects of the technical basis of noninvasive and invasive ventilation and their practical implementation.
Severe acute respiratory syndrome coronavirus 2 is transmitted through aerosols and droplets. Nasal high-flow therapy could possibly increase the spreading of exhalates from patients. The aim of this ...study is to investigate whether nasal high-flow therapy affects the range of the expiratory plume compared with spontaneous breathing.
Interventional experiment on single breaths of a healthy volunteer.
Research laboratory at the Bauhaus-University Weimar.
A male subject.
Videos and images from a schlieren optical system were analyzed during spontaneous breathing and different nasal high-flow rates.
The maximal exhalation spread was 0.99, 2.18, 2.92, and 4.1 m during spontaneous breathing, nasal high-flow of 20 L/min, nasal high-flow of 40 L/min, and nasal high-flow of 60 L/min, respectively. Spreading of the expiratory plume in the sagittal plane can completely be blocked with a surgical mask.
Nasal high-flow therapy increases the range of the expiratory air up to more than 4 meters. The risk to pick up infectious particles could be increased within this range. Attachment of a surgical mask over the nasal high-flow cannula blocks the expiratory airstream.
Against the background of the pandemic caused by infection with the SARS-CoV-2 virus, the German Respiratory Society has appointed experts to develop therapy strategies for COVID-19 patients with ...acute respiratory failure (ARF). Here we present key position statements including observations about the pathophysiology of (ARF). In terms of the pathophysiology of pulmonary infection with SARS-CoV-2, COVID-19 can be divided into 3 phases. Pulmonary damage in advanced COVID-19 often differs from the known changes in acute respiratory distress syndrome (ARDS). Two types (type L and type H) are differentiated, corresponding to early- and late-stage lung damage. This differentiation should be taken into consideration in the respiratory support of ARF. The assessment of the extent of ARF should be based on arterial or capillary blood gas analysis under room air conditions, and it needs to include the calculation of oxygen supply (measured from the variables of oxygen saturation, hemoglobin level, the corrected values of Hüfner's factor, and cardiac output). Aerosols can cause transmission of infectious, virus-laden particles. Open systems or vented systems can increase the release of respirable particles. Procedures in which the invasive ventilation system must be opened and endotracheal intubation carried out are associated with an increased risk of infection. Personal protective equipment (PPE) should have top priority because fear of contagion should not be a primary reason for intubation. Based on the current knowledge, inhalation therapy, nasal high-flow therapy (NHF), continuous positive airway pressure (CPAP), or noninvasive ventilation (NIV) can be performed without an increased risk of infection to staff if PPE is provided. A significant proportion of patients with ARF present with relevant hypoxemia, which often cannot be fully corrected, even with a high inspired oxygen fraction (FiO2) under NHF. In this situation, the oxygen therapy can be escalated to CPAP or NIV when the criteria for endotracheal intubation are not met. In ARF, NIV should be carried out in an intensive care unit or a comparable setting by experienced staff. Under CPAP/NIV, a patient can deteriorate rapidly. For this reason, continuous monitoring and readiness for intubation are to be ensured at all times. If the ARF progresses under CPAP/NIV, intubation should be implemented without delay in patients who do not have a "do not intubate" order.
To compare the treatment effect of noninvasive positive pressure ventilation (NPPV) and anticyclic servoventilation in patients with continuous positive airway pressure (CPAP)-induced central sleep ...apnea (complex sleep apnea).
Randomized controlled trial.
Sleep center.
Thirty patients who developed complex sleep apnea syndrome (CompSAS) during CPAP treatment.
NPPV or servoventilation.
Patients were randomized to NPPV or servo-ventilation. Full polysomnography (PSG) was performed after 6 weeks. On CPAP prior to randomization, patients in the NPPV and servoventilator arm had comparable apnea-hypopnea indices (AHI, 28.6 ± 6.5 versus 27.7 ± 9.7 events/h (mean ± standard deviation SD)), apnea indices (AI,19 ± 5.6 versus 21.1 ± 8.6 events/h), central apnea indices (CAI, 16.7 ± 5.4 versus 18.2 ± 7.1 events/h), oxygen desaturation indices (ODI,17.5 ± 13.1 versus 24.3 ± 11.9 events/h). During initial titration NPPV and servoventilation significantly improved the AHI (9.1 ± 4.3 versus 9 ± 6.4 events/h), AI (2 ± 3.1 versus 3.5 ± 4.5 events/h) CAI (2 ± 3.1 versus 2.5 ± 3.9 events/h) and ODI (10.1 ± 4.5 versus 8.9 ± 8.4 events/h) when compared to CPAP treatment (all P < 0.05). After 6 weeks we observed the following differences: AHI (16.5 ± 8 versus 7.4 ± 4.2 events/h, P = 0.027), AI (10.4 ± 5.9 versus 1.7 ± 1.9 events/h, P = 0.001), CAI (10.2 ± 5.1 versus 1.5 ± 1.7 events/h, P < 0.0001)) and ODI (21.1 ± 9.2 versus 4.8 ± 3.4 events/h, P < 0.0001) for NPPV and servoventilation, respectively. Other sleep parameters were unaffected by any form of treatment.
After 6 weeks, servoventilation treated respiratory events more effectively than NPPV in patients with complex sleep apnea syndrome.
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•Mid distance hypobaric flight simulation decreases six minute walking distance by 10%.•In flight hypoxia was determined to be 72% at average, was well tolerated and unrelated to ...dyspnea symptoms.•Lung diffusion capacity was the only significant predictor for in-flight hypoxemia.
Chronic obstructive pulmonary disease (COPD) is a disease that compromises fitness to fly.
To investigate, whether hypobaric mid-distance flight simulation limits exercise endurance in COPD patients.
Patients with COPD GOLD stages 2–4 were challenged by hypobaric flight simulation. Patients completed 6-minute walking distances before and after the simulation test. Pulse oximetry and Borg dyspnea scale were measured every 30 min during the test.
Thirty-five patients were included in the study. The distance of the 6-min walking exercise decreased from 343 ± 93 m to 308 ± 101 m (p < 0.0001). The oxygen saturation nadir for the whole group was 72.2% ± 9.1%. The Borg-dypnea-score did not correlate with oxygen desaturation (R-square 0.009, p > 0.05).
A 3-h hypobaric flight simulation compromises exercise endurance by 35 m or 10%. Hypoxia was well tolerated and more liberal recommendations might by justifiable since hypoxemia appears to be unrelated to dyspnea perception.
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