[Non-invasive Home-Ventilation: Pathophysiology, Initiation and Follow-up]. / Nicht-invasive außerklinische Beatmung: Pathophysiologie, Einstellung und Kontrolle.

COPD is the most common reason for hypercapnia. However, it is - by far - not the only reason. In fact, numerous neuromuscular disorders (not only ALS) as well as restrictive thoracic disorders do also lead to clinically highly relevant hypercapnia. Early diagnosis of hypercapnic ventilatory failure usually takes place at nighttime. NIV devices work with a periodic interplay of alternating IPAP and EPAP which results in a ventilation of the lungs, thereby elimination CO2 to treat hypercapnic respiratory failure. Firstline settings for a NIV therapy to treat "stable hypercapnia" are as follows: Pressure Support Ventilation Modus, EPAP 5 cm H2O, IPAP 15 cm H2O, Back Up rate 15/Minute. The overall goal of NIV treatment is a successful reduction in CO2. This can be achieved by changing the following variables of the ventilator settings: increase in IPAP ± increase in back up respiratory rate ± use of assisted pressure controlled ventilation mode (APCV)-.

Nasal versus oronasal masks for home non-invasive ventilation in patients with chronic hypercapnia: a systematic review and individual participant data meta-analysis.

BACKGROUND: The optimal interface for the delivery of home non-invasive ventilation (NIV) to treat chronic respiratory failure has not yet been determined. The aim of this individual participant data (IPD) meta-analysis was to compare the effect of nasal and oronasal masks on treatment efficacy and adherence in patients with COPD and obesity hypoventilation syndrome (OHS). METHODS: We searched Medline and Cochrane Central Register of Controlled Trials for prospective randomised controlled trials (RCTs) of at least 1 month's duration, published between January 1994 and April 2019, that assessed NIV efficacy in patients with OHS and COPD. The main outcomes were diurnal PaCO2, PaO2 and NIV adherence (PROSPERO CRD42019132398). FINDINGS: Of 1576 articles identified, 34 RCTs met the inclusion criteria and IPD were obtained for 18. Ten RCTs were excluded because only one type of mask was used, or mask data were missing. Data from 8 RCTs, including 290 IPD, underwent meta-analysis. Oronasal masks were used in 86% of cases. There were no differences between oronasal and nasal masks for PaCO2 (0.61 mm Hg (95% CI -2.15 to 3.38); p=0.68), PaO2 (-0.00 mm Hg (95% CI -4.59 to 4.58); p=1) or NIV adherence (0·29 hour/day (95% CI -0.74 to 1.32); p=0.58). There was no interaction between the underlying pathology and the effect of mask type on any outcome. INTERPRETATION: Oronasal masks are the most used interface for the delivery of home NIV in patients with OHS and COPD; however, there is no difference in the efficacy or tolerance of oronasal or nasal masks.

Obesity hypoventilation syndrome treated with non-invasive ventilation: Is a switch to CPAP therapy feasible?

BACKGROUND AND OBJECTIVE: Obesity hypoventilation syndrome (OHS) can be treated with either continuous positive airway pressure (CPAP) or non-invasive ventilation (NIV) therapy; the device choice has important economic and operational implications. METHODS: This multicentre interventional trial investigated the safety and short-term efficacy of switching stable OHS patients who were on successful NIV therapy for ≥3 months to CPAP therapy. Patients underwent an autotitrating CPAP night under polysomnography (PSG); if the ensuing parameters were acceptable, they were sent home on a fixed CPAP for a 4-6-week period. It was hypothesized that blood gas analysis, PSG parameters and lung function tests would remain unchanged. RESULTS: A total of 42 OHS patients were recruited, of whom 37 patients were switched to CPAP therapy. All patients had a history of severe obstructive sleep apnoea syndrome; chronic obstructive pulmonary disease (COPD) (Global Initiative for Obstructive Lung Disease (GOLD) I/II) was present in 52%. Regarding the primary outcome, 30 of 42 patients (71%, 95% CI: 55-84%) maintained daytime partial pressure of carbon dioxide (PaCO2 ) levels ≤45 mm Hg after the home CPAP period. There was no further impairment in quality of life, sleep parameters or lung function. Interestingly, 24 patients (65%) preferred CPAP as their long-term therapy, despite the high pressure levels used (mean: 13.8 ± 1.8 mbar). After the CPAP period, 7 of 37 patients were categorized as CPAP failure, albeit only due to mild hypercapnia (mean: 47.9 ± 2.7 mm Hg). CONCLUSION: It is feasible to switch most stable OHS patients from NIV to CPAP therapy, a step that could significantly reduce health-related costs. The auto-adjusted CPAP device, used in combination with the analysis of the PSG and capnometry, is a valid titration method in OHS patients.

European Respiratory Society guidelines on long-term home non-invasive ventilation for management of COPD.

BACKGROUND: While the role of acute non-invasive ventilation (NIV) has been shown to improve outcome in acute life-threatening hypercapnic respiratory failure in COPD, the evidence of clinical efficacy of long-term home NIV (LTH-NIV) for management of COPD is less. This document provides evidence-based recommendations for the clinical application of LTH-NIV in chronic hypercapnic COPD patients. MATERIALS AND METHODS: The European Respiratory Society task force committee was composed of clinicians, methodologists and experts in the field of LTH-NIV. The committee developed recommendations based on the GRADE (Grading, Recommendation, Assessment, Development and Evaluation) methodology. The GRADE Evidence to Decision framework was used to formulate recommendations. A number of topics were addressed under a narrative format which provides a useful context for clinicians and patients. RESULTS: The task force committee delivered conditional recommendations for four actionable PICO (target population-intervention-comparator-outcome) questions, 1) suggesting for the use of LTH-NIV in stable hypercapnic COPD; 2) suggesting for the use of LTH-NIV in COPD patients following a COPD exacerbation requiring acute NIV 3) suggesting for the use of NIV settings targeting a reduction in carbon dioxide and 4) suggesting for using fixed pressure support as first choice ventilator mode. CONCLUSIONS: Managing hypercapnia may be an important intervention for improving the health outcome of COPD patients with chronic respiratory failure. The task force conditionally supports the application of LTH-NIV to improve health outcome by targeting a reduction in carbon dioxide in COPD patients with persistent hypercapnic respiratory failure. These recommendations should be applied in clinical practice by practitioners that routinely care for chronic hypercapnic COPD patients.

Sleep-disordered breathing in patients with newly diagnosed lung cancer.

BACKGROUND: There are currently no data on the prevalence of sleep-disordered breathing (SDB) in patients with newly-diagnosed lung cancer. This might be of interest given that SDB is associated with increased cancer incidence and mortality. Furthermore, intermittent hypoxia has been linked with tumor growth and progression. The aim of the current study was to investigate the prevalence of SDB in patients with newly-diagnosed lung cancer. METHODS: Patients with newly-diagnosed lung cancer from three centers in Germany were screened for SDB using a two-channel screening system (ApneaLink™). SDB was defined as an apnea-hypopnea index of > 5/h, and was classified as mild if the AHI was 5-15/h whereas an AHI ≥15/h was classified as severe SDB. The presence of SDB-related symptoms was assessed using the Epworth Sleepiness Scale (ESS) and the Pittsburgh Sleep Quality Index (PSQI). RESULTS: A total of 100 patients were included. The overall prevalence of SDB was 49%; 32 patients (32%) had mild SDB with a median AHI of 7.7/h (quartile [Q1 5.4/h, Q3 10.4/h]) and a median oxygen desaturation index of 8.5 [Q1 4.2/h; Q3 13.4/h] and seventeen patients (17%) had moderate to severe SDB with a median AHI of 25.2 [Q1 18/h, Q3 45.5/h] and a median oxygen desaturation index of 20.6/h [Q1 9.6/h, Q3 36.6/h]. Patients with moderate to severe SDB had mild daytime sleepiness (ESS score 8.24 ± 3.96 vs. 5.74 ± 3.53 in those without SDB vs. 6.22 ± 2.72 in those with mild SDB; p = 0.0343). The PSQI did not differ significantly between the three groups (p = 0.1137). CONCLUSIONS: This study showed a high prevalence of SDB in patients with newly-diagnosed lung cancer. In these patients SDB was associated with intermittent hypoxia and increased daytime sleepiness. Additional research is needed to determine whether SDB influences prognosis and morbidity in patients with lung cancer. TRIAL REGISTRATION: NCT02270853 (ClinicalTrials.gov), date of registration: 14th October 2014.

Impact of High-Intensity-NIV on the heart in stable COPD: a randomised cross-over pilot study.

BACKGROUND: Although high-intensity non-invasive ventilation has been shown to improve outcomes in stable COPD, it may adversely affect cardiac performance. Therefore, the aims of the present pilot study were to compare cardiac and pulmonary effects of 6 weeks of low-intensity non-invasive ventilation and 6 weeks of high-intensity non-invasive ventilation in stable COPD patients. METHODS: In a randomised crossover pilot feasibility study, the change in cardiac output after 6 weeks of each NIV mode compared to baseline was assessed with echocardiography in 14 severe stable COPD patients. Furthermore, CO during NIV, gas exchange, lung function, and health-related quality of life were investigated. RESULTS: Three patients dropped out: two deteriorated on low-intensity non-invasive ventilation, and one presented with decompensated heart failure while on high-intensity non-invasive ventilation. Eleven patients were included in the analysis. In general, cardiac output and NTproBNP did not change, although individual effects were noticed, depending on the pressures applied and/or the co-existence of heart failure. High-intensity non-invasive ventilation tended to be more effective in improving gas exchange, but both modes improved lung function and the health-related quality of life. CONCLUSIONS: Long-term non-invasive ventilation with adequate pressure to improve gas exchange and health-related quality of life did not have an overall adverse effect on cardiac performance. Nevertheless, in patients with pre-existing heart failure, the application of very high inspiratory pressures might reduce cardiac output. TRIAL REGISTRATION: The trial was registered in the Deutsches Register Klinischer Studien (DRKS-ID: DRKS00007977 ).

Continuous non-invasive PCO2 monitoring in weaning patients: Transcutaneous is advantageous over end-tidal PCO2.

BACKGROUND AND OBJECTIVE: Continuous partial pressure of carbon dioxide (PCO2 ) assessment is essential for the success of mechanical ventilation (MV). Non-invasive end-tidal PCO2 (PetCO2 ) and transcutaneous PCO2 (PtcCO2 ) measurements serve as alternatives to the gold standard arterial PCO2 (PaCO2 ) method, but their eligibility in critical care is unclear. METHODS: The present study therefore performed methodological comparisons of PaCO2 versus PetCO2 and PtcCO2 , respectively, in weaning patients receiving invasive MV via tracheal cannulas. PetCO2 and PtcCO2 were recorded continuously, while PaCO2 was analysed at baseline, and after 30 and 60 min. Using the Bland-Altman analysis, a clinically acceptable range was defined as a mean difference of ±4 mm Hg between PaCO2 and non-invasive strategies. RESULTS: A total of 60 patients (COPD (n = 30) and non-COPD (n = 30)) completed the protocol. Mean PCO2 values were 42.4 ± 8.6 mm Hg (PaCO2 ), 36.5 ± 7.5 mm Hg (PetCO2 ) and 41.7 ± 8.7 mm Hg (PtcCO2 ). Mean differences between PtcCO2 and PaCO2 were -0.7 ± 3.6 mm Hg (95% CI: -1.6/0.3 mm Hg; 95% limits of agreement: -7.8 to 6.4 mm Hg), and between PetCO2 and PaCO2 -5.9 ± 5.3 mm Hg (95% CI: -7.2/-4.5 mm Hg; 95% limits of agreement: -16.2 to 4.5 mm Hg). Underestimation of PaCO2 by PetCO2 was most pronounced in COPD patients. CONCLUSION: Our data therefore support PtcCO2 as a suitable means for monitoring PCO2 in patients undergoing invasive MV. This is in contrast to PetCO2 , which clearly underestimated PaCO2 , especially in patients with COPD.

Impact of Pseudomonas aeruginosa Infection on Respiratory Muscle Function in Adult Cystic Fibrosis Patients.

BACKGROUND: Pseudomonas aeruginosa infection impairs respiratory muscle function in adolescents with cystic fibrosis, but its impact on adult patients has not been characterised. OBJECTIVES: To investigate respiratory muscle function in adult cystic fibrosis patients according to P. aeruginosa status (repetitive samples over 12 months). METHODS: The pressure-time index of the respiratory muscles (PTImus), a measure of their efficiency, served as the primary outcome. In addition, respiratory load and maximal respiratory muscle strength were assessed. RESULTS: In 51 patients examined (65% female; median age 32 years, IQR 24-40), a median of 3.0 (IQR 2-4) different pathogens was found in each patient. The PTImus was 0.113 and 0.126 in Pseudomonas-positive (n = 33) and -negative (n = 18) patients, respectively (p = 0.53). Univariate analysis showed a lower PTImus in male than in female patients (p = 0.006). Respiratory muscle load and strength were otherwise comparable, with the exception of higher nasal sniff pressures in Pseudomonas-positive patients who were chronically infected (>50% of positive samples). Quality of Life (according to the Cystic Fibrosis Questionnaire-Revised) was higher if both respiratory load and the PTImus were low (high respiratory muscle efficiency). CONCLUSIONS: Chronic P. aeruginosa infection does not influence respiratory muscle efficiency in adult cystic fibrosis patients with otherwise multiple co-infections. In addition, patients with reduced respiratory muscle efficiency had worse Quality of Life.

Long-Term Oxygen Therapy: Comparison of the German and British Guidelines.

BACKGROUND: The German guideline on long-term oxygen therapy (LTOT) was published in 2008 by the German Respiratory Society (DGP), while the British Thoracic Society (BTS) published their most recent guideline in 2015. OBJECTIVES: The aim of the present article was to highlight the major areas of consensus and disagreement in the recently published BTS and DGP guidelines on LTOT. METHODS: The BTS and DGP guidelines were directly compared in terms of congruencies and differences. A critical appraisal was then performed and authors' suggestions were provided. RESULTS: The 2 guidelines are almost congruent in 2 major areas, namely, (1) the indication criteria for LTOT in chronic obstructive pulmonary disease (COPD) patients at rest and (2) the recommended duration of LTOT over a 24-h period. However, 8 major areas in which the guidelines differ considerably were identified: (1) techniques for blood gas analysis; (2) timing of LTOT in stable patients; (3) LTOT in post-exacerbation COPD patients; (4) ambulatory oxygen therapy; (5) nocturnal oxygen therapy; (6) titration of oxygen flow rates; (7) follow-up visits; and (8) LTOT for patients who still smoke. Furthermore, the BTS guideline is much more detailed, includes more references (161 vs. 71) and is more up to date than the DGP guideline. CONCLUSION: There are major differences between the 2 guidelines. Many of the aspects raised by the BTS guideline appear to be reasonable with regard to the current literature, clinical experience and prescription practices. However, an international consensus on LTOT is lacking.

Assessment of Sleep in Patients Receiving Invasive Mechanical Ventilation in a Specialized Weaning Unit.

INTRODUCTION: A restful sleep is essential for regenerative processes and remains crucial for patients recovering from stressful periods in the intensive care unit. The current study aimed to assess sleep quality in critically ill patients receiving invasive mechanical ventilation within a specialized weaning unit in hospital. METHODS: Tracheotomized subjects undergoing prolonged weaning from mechanical ventilation were included in the study. Polysomnography and gas exchange monitoring was performed during nocturnal ventilation. Subjective evaluation of sleep quality and health-related quality of life were also assessed. RESULTS: Nineteen subjects completed the study protocol. Sleep architecture was highly heterogeneous across individual subjects. Mean total sleep time (TST) was 273 ± 114 min, sleep efficacy 70 ± 23%, slow-wave sleep 25.7 ± 18.4%/TST, rapid eye movement sleep 9.6 ± 7.5%/TST, and arousal index 18.7 ± 12.4/h. No significant difference in sleep quality was found between subjects with successful (N = 7) or unsuccessful (N = 12) weaning. Bicarbonate levels were negatively correlated both with sleep efficacy and sleep quality, that latter of which was subjectively assessed by the subjects using a visual analogue scale. CONCLUSION: Subjects who were undergoing prolonged weaning from mechanical ventilation and admitted to a specialized weaning unit, showed reduced sleep quality with preservation of high amounts of slow-wave sleep.

Invasive home mechanical ventilation: living conditions and health-related quality of life.

BACKGROUND: The number of patients with invasive home mechanical ventilation (HMV) following unsuccessful weaning is steadily increasing, but little is known about the living conditions and health-related quality of life (HRQL) in these patients. OBJECTIVES: To establish detailed information on living conditions and HRQL in patients with invasive HMV. METHODS: The Severe Respiratory Insufficiency Questionnaire (SRI) was used to measure specific HRQL aspects in addition to patient interviews on individual living conditions during home visits. RESULTS: Thirty-two patients with lung disease, most prominently COPD (n = 18), and neuromuscular disorders (n = 14) were included. The overall mean SRI summary scale score (range 0-100) was 53 ± 16, with a broad range amongst individuals (23-86). Neuromuscular patients were younger than those with lung diseases (49 ± 18 vs. 67 ± 11 years; p < 0.005), and although they had a higher nursing dependency and fewer comorbidities, they tended to have higher (better) SRI summary scale scores (58 ± 16 vs. 48 ± 15; p = 0.092). Living in a private home compared to living in nursing facilities did not influence the SRI scores. CONCLUSIONS: Patients undergoing invasive HMV primarily following unsuccessful weaning reported an individual HRQL which, when taken together, was highly heterogeneous and ranged from very good to extremely bad. Older patients with COPD and more comorbidities are likely to have a worse HRQL than neuromuscular patients, while the living situation does not influence the HRQL.

Spot check analysis of gas exchange: invasive versus noninvasive methods.

BACKGROUND: Correct measurement of PO2 and PCO2 is essential to establish appropriate therapy such as long-term oxygen therapy (LTOT) in patients suffering from respiratory failure. OBJECTIVES: We aimed to compare common invasive and noninvasive methods for assessing blood gas components for spot check analysis. METHODS: Arterial (PaO2, PaCO2) and capillary blood gas (PCBGO2, PCBGCO2) measurements were taken consecutively in a randomized order and were compared with noninvasive measurements obtained from the transcutaneous monitoring of PO2 and PCO2 (PtcOv, PtcCO2, sensor-temperature 44°C). Capillary samples were taken from both arterialized earlobes, where samples of right earlobes were defined as a reference value. Pain assessment of all measurements was evaluated by each subject using the 100-mm visual analogue scale. RESULTS: 83 patients and 17 healthy subjects were included. The mean difference between PaO2 and PtcO2 was 11.9 ± 15.0 mm Hg, with lower limits of agreement (LLA) of -17.4 mm Hg (95% confidence interval (CI) -22.5 to -12.3 mm Hg), and upper limits of agreement (ULA) of 41.1 mm Hg (95% CI 36.0-46.2 mm Hg). The comparison of PaO2 with PCBGO2 showed a mean difference of 5.6 ± 7.2 mm Hg (LLA -11.0; ULA 19.6 mm Hg). The mean difference between PaCO2 and PtcCO2 was 1.1 ± 4.9 mm Hg (LLA -8.6; ULA 10.8 mm Hg) and that between PaCO2 and PCBGCO2 was 0.7 ± 2.0 mm Hg (LLA -3.3; ULA 4.8 mm Hg). The analysis of capillary blood gases (36.2 ± 22.3 mm) was rated as more painful than the analysis of arterial blood gases (26.1 ± 20.6 mm), while transcutaneous measurement was rated as the least painful method (1.9 ± 7.4 mm; all p < 0.0001). CONCLUSIONS: The comparison of different methods for blood gas measurements showed substantial differences between capillary and arterial PO2 and between transcutaneous and arterial PO2. Therefore, arterial PO2 analysis is the essential method evaluating indication for LTOT. Nevertheless, comparative analysis further indicated capillary PCO2 as an adequate surrogate for arterial PCO2.

Walking with Non-Invasive Ventilation Does Not Prevent Exercise-Induced Hypoxaemia in Stable Hypercapnic COPD Patients.

BACKGROUND: Non-invasive positive pressure ventilation (NPPV) in addition to supplemental oxygen improves arterial oxygenation, walking distance and dyspnea when applied during exercise in stable hypercapnic COPD patients. The aim of the current study was to investigate whether NPPV without supplemental oxygen is capable of preventing severe exercise-induced hypoxemia in these patients when applied during walking. METHODS AND RESULTS: 15 stable hypercapnic COPD patients (FEV1 29.9 ± 15.9%) performed two 6-minute walk tests (6MWT) with a rollator in a randomized cross-over design: using either supplemental oxygen (2.4 ± 0.7 L/min) or NPPV (inspiratory/expiratory positive airway pressure of 28.2 ± 2.8 / 5.5 ± 1.5 mbar) without supplemental oxygen. RESULTS: 10 patients were able to complete both 6MWT. 6MWT with supplemental oxygen resulted in no changes for PO2 (pre: 67.3 ± 11.2 mmHg vs. post: 65.6 ± 12.0 mmHg, p = 0.72) whereas PCO2 increased (pre: 50.9 ± 8.1 mmHg vs. post: 54.3 ± 10.0 mmHg (p < 0.03). During 6MWT with NPPV PO2 significantly decreased from 66.8 ± 7.2 mmHg to 55.5 ± 10.6 mmHg (p < 0.02) whereas no changes occurred in PCO2 (pre: 50.6 ± 7.5 mmHg vs. post: 53.0 ± 7.1 mmHg; p = 0.17). Walking distance tended to be lower in 6MWT with NPPV compared to 6MWT with supplemental oxygen alone (318 ± 160 m vs. 377 ± 108 m; p = 0.08). CONCLUSION: The use of NPPV during walking without the application of supplemental oxygen does not prevent exercise-induced hypoxemia in patients with stable hypercapnic COPD.

Impact of intelligent volume-assured pressure support on sleep quality in stable hypercapnic chronic obstructive pulmonary disease patients: a randomized, crossover study.

BACKGROUND: Noninvasive positive-pressure ventilation (NPPV) using intelligent volume-assured pressure support (iVAPS) combines volume- and pressure-preset NPPV and therefore uses a variation of inspiratory positive airway pressures. OBJECTIVES: The effect of iVAPS on sleep quality in stable hypercapnic patients with chronic obstructive pulmonary disease (COPD) has not been determined. METHODS: In this randomized, open-label, two-treatment, two-period, crossover study, patients were randomized to receive high-intensity (HI)-NPPV and then iVAPS or iVAPS and then HI-NPPV. Patients were studied in hospital for 2 consecutive nights, employing full polysomnography (PSG), transcutaneous partial pressure of CO2 (PtcCO2) monitoring, blood gas analysis and a visual analog scale (VAS)-based sleep questionnaire. After discharge, patients used HI-NPPV and iVAPS at home, each for 6 weeks. They had to answer a VAS question concerning sleep every morning, and were telephoned weekly and asked additional questions. At the end of each treatment period, they were visited at home for the determination of blood gases and treatment adherence, and to change the NPPV mode. RESULTS: Fourteen patients were enrolled. In-hospital PSG measurements showed no difference in sleep quality between iVAPS and HI-NPPV. At home, patients reported more restful sleep during iVAPS than HI-NPPV (p = 0.04). Blood gases during spontaneous breathing at home did not differ with iVAPS and HI-NPPV, and there was a greater decrease in PtcCO2 during iVAPS than during HI-NPPV (p = 0.003). CONCLUSION: Although sleep quality in hospital was not different between iVAPS and HI-NPPV, COPD patients with chronic hypercapnic respiratory failure reported a trend towards more restful sleep at home with iVAPS. In addition, nocturnal hypercapnia was effectively treated with iVAPS.

Minute ventilation during spontaneous breathing, high-intensity noninvasive positive pressure ventilation and intelligent volume assured pressure support in hypercapnic COPD.

BACKGROUND: High-intensity noninvasive positive pressure ventilation (HI-NPPV) is an effective treatment option in patients with stable hypercapnic chronic obstructive pulmonary disease (COPD). However, the effect of HI-NPPV compared with spontaneous breathing (SB) on minute ventilation (MV) in patients receiving long-term treatment remains to be determined. This study compared MV during HI-NPPV and SB. In addition, the ability of intelligent volume assured pressure support (iVAPS) to increase MV to the same extent as HI-NPPV was determined. METHODS: Daytime pneumotachographic measurements were performed during SB, HI-NPPV and iVAPS. RESULTS: Twenty-seven stable hypercapnic COPD patients (mean FEV1 34 ± 15% predicted) who had been treated with HI-NPPV for a median of 22 months (interquartile range 8.5-84 months) were enrolled. Mean MV was 9.5 ± 1.7 L/min during SB and 12.1 ± 2.8 L/min during HI-NPPV, an increase of 2.5 L/min (95% CI [1.5-3.6] p < 0.001), or 26%. MV during iVAPS was 11.7 ± 3.6 L/min, an increase of 1.8 L/min (95%CI [0.7-3.0], p = 0.003) compared with SB. There was no difference in MV between HI-NPPV and iVAPS (p = 0.25). CONCLUSION: Long-term HI-NPPV increased MV by an average of 26% compared with SB in stable hypercapnic COPD patients. A similar increase in MV was observed during use of iVAPS.

The Impact of Non-Invasive Ventilation on Sleep Quality in COPD Patients.

BACKGROUND: Non-invasive ventilation (NIV) has been shown to be the most appropriate therapy for COPD patients with chronic respiratory failure. While physiological parameters and long-term outcome frequently serve as primary outcomes, very few studies have primarily addressed the impact of NIV initiation on sleep quality in COPD. METHODS: This single-center prospective cohort study comprised NIV-naïve patients with COPD. All patients underwent polysomnographic evaluation both at baseline and at 3 months follow-up, accompanied by the assessment of health-related quality of life (HRQL) using the Severe Respiratory Insufficiency Questionnaire (SRI) and the Epworth Sleepiness Scale (ESS). A subgroup evaluation was performed to address the impact of comorbid obstructive sleep apnea syndrome (OSAS). RESULTS: Forty-six patients were enrolled and twenty-five patients completed the follow-up period (66.7 ± 7.4 years). NIV resulted in an increase in slow-wave sleep (+2% (-3.5/7.5), p = 0.465) and rapid eye movement sleep (+2.2% (-1.0/5.4), p = 0.174), although no statistical significance could be detected. ESS (-1.7(-3.6/0.1), p = 0.066) also showed a positive trend. Significant improvements in the Respiratory Disturbance Index (RDI) (-12.6(-23.7/-1.5), p = 0.027), lung function parameters, transcutaneous PCO2 and the SRI summary scale (4.5(0.9/8), p = 0.016) were observed. CONCLUSION: NIV therapy does not decrease sleep quality and is even capable of improving HRQL, transcutaneous PaCO2, daytime sleepiness and RDI, and the latter especially holds true for patients with comorbid OSAS.

[Non-invasive Home-Ventilation: Pathophysiology, Initiation and Follow up]. / Nichtinvasive außerklinische Beatmung: Pathophysiologie, Einstellung, Kontrolle.

COPD is the most common reason for hypercapnia. However, it is -by far- not the only reason. In fact, numerous neuromuscular disorders (not only ALS) as well as restrictive thoracic disorders do also lead to clinically highly relevant hypercapnia. Early diagnosis of hypercapnic ventilatory failure usually takes place at nighttime. NIV devices work with a periodic interplay of alternating IPAP and EPAP which results in a ventilation of the lungs, thereby elimination CO2 to treat hypercapnic respiratory failure. Firstline settings for a NIV therapy to treat "stable hypercapnia" are as follows: Pressure Support Ventilation Modus, EPAP 5 cmH2O, IPAP 15 cmH2O, Back Up rate 15/Minute. The overall goal of NIV treatment is a successful reduction in CO2. This can be achieved by changing the following variables of the ventilator settings: increase in IPAP ± increase in back up respiratory rate ± use of assisted pressure controlled ventilation mode (APCV).

Oronasal versus Nasal Masks for Non-Invasive Ventilation in COPD: A Randomized Crossover Trial.

PURPOSE: The impact of oronasal and nasal masks on the quality of nocturnal non-invasive ventilation (NIV) needs to be clarified. This trial was designed to compare the impact of oronasal and nasal masks on the objective quality and subjective acceptance of nocturnal NIV in COPD-patients. PATIENTS AND METHODS: In a randomized crossover trial, 30 COPD-patients with well-established high-intensity NIV (mean inspiratory/expiratory positive airway pressure 26±3/5±1 cmH2O, mean respiratory back-up rate 17±1/min) were ventilated for two consecutive nights on oronasal and nasal masks, respectively. RESULTS: Full polysomnography, nocturnal blood gas measurements, and subjective assessments were performed. There was a tendency towards improved sleep efficiency (primary outcome) when an oronasal mask was worn (+9.9%; 95% CI:-0.2%-20.0%; P=0.054). Sleep stages 3/4 were favored by the oronasal mask (+12.7%; 95% CI: 6.0%-19.3%; P=<0.001). Subjective assessments were comparable with the exception of items related to leakage (P<0.05 in favor of nasal masks). The mean transcutaneous PCO2 value for oronasal masks (47.7±7.4 mmHg) was comparable to that of nasal masks (48.9±6.6 mmHg) (P=0.11). There was considerable diversity amongst individual patients in terms of sleep quality and gas exchange following mask exchange. Subjective mask preference was not associated with sleep quality, but with nocturnal dyspnea. Over 40% of patients subsequently switched to the mask that they were not previously accustomed to. CONCLUSION: In general, oronasal and nasal masks are each similarly capable of successfully delivering NIV in COPD-patients. However, the individual response to different interfaces is extremely heterogeneous, while subjective mask preference is independent from objective measures, but associated with dyspnea. TRIAL REGISTRATION: German Clinical Trials Registry (DRKS00007741).

Newly detected rapid eye movement associated sleep apnea after coronavirus disease 2019 as a possible cause for chronic fatigue: two case reports.

BACKGROUND: Coronavirus disease 2019 has become a health problem spreading worldwide with pandemic characteristics since March 2020. Post coronavirus disease 2019 symptoms are more frequent than initially expected, with fatigue as an often-mentioned issue. CASE PRESENTATIONS: We describe a 32-year-old white male and a 55-year-old white female who suffered from post coronavirus disease 2019 fatigue syndrome. On polysomnography, rapid eye movement associated sleep apnea with an increased hypopnea index during rapid eye movement phases of 36.8 and 19.5 events per hour was found. Based on the patients' burdensome fatigue symptoms, we initiated automatic positive airway pressure therapy, which diminished sleep apnea (rapid eye movement index: 0.0 in both patients) and, consequently, also the fatigue symptoms. CONCLUSIONS: Since sleep apnea and coronavirus disease 2019 are both associated with fatigue, a screening for sleep apnea might be considered in coronavirus disease 2019 patients with fatigue syndrome.

Patient-Ventilator Synchronization During Non-invasive Ventilation: A Pilot Study of an Automated Analysis System.

Background: Patient-ventilator synchronization during non-invasive ventilation (NIV) can be assessed by visual inspection of flow and pressure waveforms but it remains time consuming and there is a large inter-rater variability, even among expert physicians. SyncSmart™ software developed by Breas Medical (Mölnycke, Sweden) provides an automatic detection and scoring of patient-ventilator asynchrony to help physicians in their daily clinical practice. This study was designed to assess performance of the automatic scoring by the SyncSmart software using expert clinicians as a reference in patient with chronic respiratory failure receiving NIV. Methods: From nine patients, 20 min data sets were analyzed automatically by SyncSmart software and reviewed by nine expert physicians who were asked to score auto-triggering (AT), double-triggering (DT), and ineffective efforts (IE). The study procedure was similar to the one commonly used for validating the automatic sleep scoring technique. For each patient, the asynchrony index was computed by automatic scoring and each expert, respectively. Considering successively each expert scoring as a reference, sensitivity, specificity, positive predictive value (PPV), κ-coefficients, and agreement were calculated. Results: The asynchrony index assessed by SynSmart was not significantly different from the one assessed by the experts (18.9 ± 17.7 vs. 12.8 ± 9.4, p = 0.19). When compared to an expert, the sensitivity and specificity provided by SyncSmart for DT, AT, and IE were significantly greater than those provided by an expert when compared to another expert. Conclusions: SyncSmart software is able to score asynchrony events within the inter-rater variability. When the breathing frequency is not too high (<24), it therefore provides a reliable assessment of patient-ventilator asynchrony; AT is over detected otherwise.