E-learning-an interventional element of the PRiVENT project to improve weaning expertise

BACKGROUND

PRiVENT (PRevention of invasive VENTilation) is an evaluation of a bundle of interventions aimed at the prevention of long-term invasive mechanical ventilation. One of these elements is an e-learning course for healthcare professionals to improve weaning expertise. The aim of our analysis is to examine the implementation of the course in cooperating intensive care units.

METHODS

The course has been developed through a peer review process by pulmonary and critical care physicians in collaboration with respiratory therapists, supported by health services researchers and a professional e-learning agency. The e-learning platform "weLearn" was made available online to participating healthcare professionals. Feedback on the e-learning programme was obtained and discussed in quality circles (QCs). We measured the acceptance and use of the programme through access statistics.

RESULTS

The e-learning course "Joint Prevention of Long-Term Ventilation" consists of 7 separate modules with practice-oriented training units as well as a cross-module area and corresponding interactive case studies. Users can receive 23 CME (continuing medical education) credits. The platform was released on July 1, 2021. By June 28, 2023, 214 users from 33 clinics had registered. Most users (77-98%) completed the modules, thus performing well in the test, where 90-100% passed. In the QCs, the users commended the structure and practical relevance of the programme, as well as the opportunity to earn CME credits.

CONCLUSION

Especially for medical staff in intensive care units, where continuous training is often a challenge during shift work, e-learning is a useful supplement to existing medical training.

TRIAL REGISTRATION

The PRiVENT study is registered at ClinicalTrials.gov (NCT05260853) on 02/03/2022.

Effects of triple therapy on disease burden in patients of GOLD groups C and D: results from the observational COPD cohort COSYCONET

BACKGROUND

Randomized controlled trials described beneficial effects of inhaled triple therapy (LABA/LAMA/ICS) in patients with chronic obstructive pulmonary disease (COPD) and high risk of exacerbations. We studied whether such effects were also detectable under continuous treatment in a retrospective observational setting.

METHODS

Data from baseline and 18-month follow-up of the COPD cohort COSYCONET were used, including patients categorized as GOLD groups C/D at both visits (n = 258). Therapy groups were defined as triple therapy at both visits (triple always, TA) versus its complement (triple not always, TNA). Comparisons were performed via multiple regression analysis, propensity score matching and inverse probability weighting to adjust for differences between groups. For this purpose, variables were divided into predictors of therapy and outcomes.

RESULTS

In total, 258 patients were eligible (TA: n = 162, TNA: n = 96). Without adjustments, TA patients showed significant (p < 0.05) impairments regarding lung function, quality of life and symptom burden. After adjustments, most differences in outcomes were no more significant. Total direct health care costs were reduced but still elevated, with inpatient costs much reduced, while costs of total and respiratory medication only slightly changed.

CONCLUSION

Without statistical adjustment, patients with triple therapy showed multiple impairments as well as elevated treatment costs. After adjusting for differences between treatment groups, differences were reduced. These findings are compatible with beneficial effects of triple therapy under continuous, long-term treatment, but also demonstrate the limitations encountered in the comparison of controlled intervention studies with observational studies in patients with severe COPD using different types of devices and compounds.

Role of multidrug-resistant bacteria in weaning from invasive mechanical ventilation

BACKGROUND

Although multidrug-resistant bacteria (MDR) are common in patients undergoing prolonged weaning, there is little data on their impact on weaning and patient outcomes.

METHODS

This is a retrospective analysis of consecutive patients who underwent prolonged weaning and were at a university weaning centre from January 2018 to December 2020. The influence of MDR colonisation and infection on weaning success (category 3a and 3b), successful prolonged weaning from invasive mechanical ventilation (IMV) with or without the need for non-invasive ventilation (NIV) compared with category 3c (weaning failure 3cI or death 3cII) was investigated. The pathogen groups considered were: multidrug-resistant gram-negative bacteria (MDRGN), methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus spp. (VRE).

RESULTS

A total of 206 patients were studied, of whom 91 (44.2%) showed evidence of MDR bacteria (32% VRE, 1.5% MRSA and 16% MDRGN), with 25 patients also meeting the criteria for MDR infection. 70.9% of the 206 patients were successfully weaned from IMV, 8.7% died. In 72.2% of cases, nosocomial pneumonia and other infections were the main cause of death. Patients with evidence of MDR (infection and colonisation) had a higher incidence of weaning failure than those without evidence of MDR (48% vs. 34.8% vs. 21.7%). In multivariate analyses, MDR infection (OR 4.9, p = 0.004) was an independent risk factor for weaning failure, along with male sex (OR 2.3, p = 0.025), Charlson Comorbidity Index (OR 1.2, p = 0.027), pH (OR 2.7, p < 0.001) and duration of IMV before admission (OR 1.01, p < 0.001). In addition, MDR infection was the only independent risk factor for death (category 3cII), (OR 6.66, p = 0.007).

CONCLUSION

Patients with MDR infection are significantly more likely to die during the weaning process. There is an urgent need to develop non-antibiotic approaches for the prevention and treatment of MDR infections as well as clinical research on antibiotic stewardship in prolonged weaning as well as in ICUs.

Risk factors for long-term invasive mechanical ventilation: a longitudinal study using German health claims data

BACKGROUND

Long-term invasive mechanical ventilation (IMV) is a major burden for those affected and causes high costs for the health care system. Early risk assessment is a prerequisite for the best possible support of high-risk patients during the weaning process. We aimed to identify risk factors for long-term IMV within 96 h (h) after the onset of IMV.

METHODS

The analysis was based on data from one of Germany's largest statutory health insurance funds; patients who received IMV ≥ 96 h and were admitted in January 2015 at the earliest and discharged in December 2017 at the latest were analysed. OPS and ICD codes of IMV patients were considered, including the 365 days before intubation and 30 days after discharge. Long-term IMV was defined as evidence of invasive home mechanical ventilation (HMV), IMV ≥ 500 h, or readmission with (re)prolonged ventilation.

RESULTS

In the analysis of 7758 hospitalisations, criteria for long-term IMV were met in 38.3% of cases, of which 13.9% had evidence of HMV, 73.1% received IMV ≥ 500 h and/or 40.3% were re-hospitalised with IMV. Several independent risk factors were identified (p < 0.005 each), including pre-diagnoses such as pneumothorax (OR 2.10), acute pancreatitis (OR 2.64), eating disorders (OR 1.99) or rheumatic mitral valve disease (OR 1.89). Among ICU admissions, previous dependence on an aspirator or respirator (OR 5.13), and previous tracheostomy (OR 2.17) were particularly important, while neurosurgery (OR 2.61), early tracheostomy (OR 3.97) and treatment for severe respiratory failure such as positioning treatment (OR 2.31) and extracorporeal lung support (OR 1.80) were relevant procedures in the first 96 h after intubation.

CONCLUSION

This comprehensive analysis of health claims has identified several risk factors for the risk of long-term ventilation. In addition to the known clinical risks, the information obtained may help to identify patients at risk at an early stage. Trial registration The PRiVENT study was retrospectively registered at ClinicalTrials.gov (NCT05260853). Registered at March 2, 2022.

Midregional proatrial naturetic peptide (MRproANP) and copeptin (COPAVP) as predictors of all-cause mortality in recently diagnosed mild to moderate COPD-results from COSYCONET

BACKGROUND

MRproANP and COPAVP are prognostic markers for mortality in chronic obstructive pulmonary disease (COPD). Furthermore, these biomarkers predict mortality due to cardiovascular diseases, which are important prognostically determining comorbidities in patients with COPD. However, less is known about these biomarkers in recently diagnosed mild to moderate COPD. Therefore, we analyzed these biomarkers as potential predictors of mortality in recently diagnosed mild to moderate COPD.

METHODS

The blood biomarkers considered were copeptin (COPAVP), midregional adrenomedullin (MRproADM), midregional proatrial naturetic peptide (MRproANP), and fibrinogen. Analyses were performed in patients with stable "recently diagnosed mild to moderate COPD" defined by GOLD grades 0-2 and diagnosis of COPD ≤ 5 years prior to inclusion into the COSYCONET cohort (COPD and Systemic Consequences-Comorbidities Network), using Cox regression analysis with stepwise adjustment for multiple COPD characteristics, comorbidities, troponin and NT-proBNP.

RESULTS

655 patients with recently diagnosed mild to moderate COPD were included. In the initial regression model, 43 of 655 patients died during the 6-year follow-up, in the final model 27 of 487. Regression analyses with adjustment for confounders identified COPAVP and MRproANP as statistically robust biomarkers (p < 0.05 each) of all-cause mortality, while MRproADM and fibrinogen were not. The fourth quartile of MRproANP (97 pmol/L) was associated with a hazard ratio of 4.5 (95%CI: 1.6; 12.8), and the fourth quartile of COPAVP (9.2 pmol/L) with 3.0 (1.1; 8.0). The results for MRproANP were confirmed in the total cohort of grade 0-4 (n = 1470 finally).

CONCLUSION

In patients with recently diagnosed mild to moderate COPD, elevated values of COPVP and in particular MRproANP were robust, independent biomarkers for all-cause mortality risk after adjustment for multiple other factors. This suggests that these markers might be considered in the risk assessment of early COPD.

Alpha-1-antitrypsin-deficiency is associated with lower cardiovascular risk: an approach based on federated learning

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is an inflammatory multisystemic disease caused by environmental exposures and/or genetic factors. Inherited alpha-1-antitrypsin deficiency (AATD) is one of the best recognized genetic factors increasing the risk for an early onset COPD with emphysema. The aim of this study was to gain a better understanding of the associations between comorbidities and specific biomarkers in COPD patients with and without AATD to enable future investigations aimed, for example, at identifying risk factors or improving care.

METHODS

We focused on cardiovascular comorbidities, blood high sensitivity troponin (hs-troponin) and lipid profiles in COPD patients with and without AATD. We used clinical data from six German University Medical Centres of the MIRACUM (Medical Informatics Initiative in Research and Medicine) consortium. The codes for the international classification of diseases (ICD) were used for COPD as a main diagnosis and for comorbidities and blood laboratory data were obtained. Data analyses were based on the DataSHIELD framework.

RESULTS

Out of 112,852 visits complete information was available for 43,057 COPD patients. According to our findings, 746 patients with AATD (1.73%) showed significantly lower total blood cholesterol levels and less cardiovascular comorbidities than non-AATD COPD patients. Moreover, after adjusting for the confounder factors, such as age, gender, and nicotine abuse, we confirmed that hs-troponin is a suitable predictor of overall mortality in COPD patients. The comorbidities associated with AATD in the current study differ from other studies, which may reflect geographic and population-based differences as well as the heterogeneous characteristics of AATD.

CONCLUSION

The concept of MIRACUM is suitable for the analysis of a large healthcare database. This study provided evidence that COPD patients with AATD have a lower cardiovascular risk and revealed that hs-troponin is a predictor for hospital mortality in individuals with COPD.

Characteristics of Current Smokers versus Former Smokers with COPD and Their Associations with Smoking Cessation Within 4.5 Years: Results from COSYCONET

Background

Many patients with chronic obstructive pulmonary disease (COPD) continue smoking. We used data from the "real-life" COSYCONET COPD cohort to evaluate whether these patients differed from patients with COPD who either had ceased smoking prior to inclusion or ceased during the follow-up time of the study.

Methods

The analysis was based on data from visits 1-5 (covering 4.5 years), including all patients with the diagnosis of COPD who were either ex-smokers or smokers and categorized as GOLD 1-4 or the former GOLD 0 category. We compared the characteristics of smokers and ex-smokers at baseline (visit 1), as well as the course of lung function in the follow-up of permanent ex-smokers, permanent smokers and incident ex-smokers (smokers at visit 1 who ceased smoking before visit 5). We also identified baseline factors associated with subsequent smoking cessation.

Results

Among 2500 patients who were ever-smokers, 660 were current smokers and 1840 ex-smokers at baseline. Smokers were younger than ex-smokers (mean 61.5 vs 66.0 y), had a longer duration of smoking but fewer pack-years, a lower frequency of asthma, higher forced expiratory volume in 1 sec (FEV1, 59.4 vs 55.2% predicted) and higher functional residual capacity (FRC, 147.7 vs 144.3% predicted). Similar results were obtained for the longitudinal subpopulation, comprising 713 permanent ex-smokers, 175 permanent smokers, and 55 incident ex-smokers. When analyzing the time course of lung function, higher FRC, lower FEV1 and the presence of asthma (p < 0.05 each) were associated with incident cessation prior to visit 5, while less airway obstruction was associated with smoking continuation.

Conclusion

These findings, which were consistent in the cross-sectional and longitudinal analyses, suggest that lung hyperinflation was associated with being or becoming ex-smoker. Possibly, it is perceived by patients as one of the factors motivating their attempts to quit smoking, independent from airway obstruction.

Causes and Risk Factors for Absenteeism among Medical Staff in German Specialized Lung Clinics during the COVID Pandemic

BACKGROUND

Staff shortages pose a major challenge to the health system.

OBJECTIVES

The objective of this study was to clarify the role of different causative factors we investigated on staff absenteeism during the COVID pandemic.

METHODS

The prospective multicentre cohort study assessed the private and professional impact of the pandemic on health care workers (HCWs) using a specially developed questionnaire. HCWs from 7 specialist lung clinics throughout Germany were surveyed from December 1 to December 23, 2021. The current analysis addresses pandemic-related absenteeism.

RESULTS

1,134 HCW (55% female; 18.4% male, 26.3% not willing to provide information on age or gender) participated. 72.8% had received at least one vaccination dose at the time of the survey, and 9.4% reported a COVID infection. Of those with positive tests, 98% reported home quarantine for median (IQR) 14 (12-17) days; 10.3% of those who ultimately tested negative also reported quarantine periods of 14 (7-14) days. 32.2% of vaccinated respondents reported absenteeism due to vaccine reactions of 2 (1-3) days. Overall, 37% (n = 420) of HCW reported pandemic-related absenteeism, with 3,524 total days of absenteeism, of which 2,828 were due to illness/quarantine and 696 to vaccination effects. Independent risk factors for COVID-related absenteeism ≥5 days included already having COVID, but also concern about long-term effects of COVID (OR 1,782, p = 0.014); risk factors for vaccine-related absenteeism ≥2 days included concerns of late effects of vaccination (OR 2.2, 95% CI: 1.4-3.1, p < 0.000).

CONCLUSION

Staff shortages due to quarantine or infections and vaccine reactogenicity have put a strain on German respiratory specialists. The fact that staff concerns also contributed to absenteeism may be helpful in managing future pandemic events to minimize staff absenteeism.

Costs of Weaning Failure: A Prospective, Multicentre, Controlled, Non-Randomised, Interventional Study on Economic Implications for the German Health Care System

BACKGROUND

Intensive care patients with respiratory failure often need invasive mechanical ventilation (IMV). With increasing population age and multimorbidity, the number of patients who cannot be weaned from IMV rises as well. Up to 85% of these patients have no access to a certified weaning centre. Their medical care is associated with impaired quality of life and high costs for the German health care system.

OBJECTIVES

This study examined the weaning outcome of patients in certified weaning centres after a primarily unsuccessful weaning attempt in order to calculate saving expenses compared to patients on long-term IMV in an outpatient setting.

METHODS

In this multicentre, controlled, non-randomised, interventional, prospective study, 61 patients (16 from out-of-hospital long-term IMV, 49 from other hospitals) were referred to a certified weaning centre for a second weaning phase. The incurred costs after 1 year of the latter were compared to insurance claim data of patients who were discharged from an acute hospital stay to receive IMV in an outpatient setting.

RESULTS

In the intervention group, 50 patients (82%) could be completely weaned or partially weaned using non-invasive ventilation, thus not needing IMV any longer. The costs per patient for weaning and out-of-hospital care in the intervention group were EUR 114,877.08, and the costs in the comparison cohort were EUR 234,442.62.

CONCLUSIONS

Early transfer to a certified weaning centre can increase weaning success and reduce total costs by approximately EUR 120,000 per patient in the first year. Given the existing structural prerequisites in Germany, every patient should have access to a weaning centre before being transferred to long-term IMV, from a medical and health economical point of view.

Prevention of invasive ventilation (PRiVENT)-a prospective, mixed-methods interventional, multicentre study with a parallel comparison group: study protocol

BACKGROUND

Invasive mechanical ventilation (IMV) is a standard therapy for intensive care patients with respiratory failure. With increasing population age and multimorbidity, the number of patients who cannot be weaned from IMV increases, resulting in impaired quality of life and high costs. In addition, human resources are tied up in the care of these patients.

METHODS

The PRiVENT intervention is a prospective, mixed-methods interventional, multicentre study with a parallel comparison group selected from insurance claims data of the health insurer Allgemeine Ortskrankenkasse Baden-Württemberg (AOK-BW) conducted in Baden-Württemberg, Germany, over 24 months. Four weaning centres supervise 40 intensive care units (ICUs), that are responsible for patient recruitment. The primary outcome, successful weaning from IMV, will be evaluated using a mixed logistic regression model. Secondary outcomes will be evaluated using mixed regression models.

DISCUSSION

The overall objective of the PRiVENT project is the evaluation of strategies to prevent long-term IMV. Additional objectives aim to improve weaning expertise in and cooperation with the adjacent Intensive Care Units.

TRIAL REGISTRATION

This study is registered at ClinicalTrials.gov (NCT05260853).

Characterization of three new SERPINA1 variants PiQ0Heidelberg II, PiQ0Heidelberg III and PiQ0Heidelberg IV in patients with severe alpha-1 antitrypsin deficiency

Background

The clinical and molecular characteristics of three patients with previously unreported SERPINA1 mutations associated with severe alpha-1 antitrypsin deficiency (AATD) are described. The pathophysiology of the chronic obstructive pulmonary disease (COPD) present in these patients was characterized through clinical, biochemical, and genetic examinations.

Case presentations

Case 1: A 73-year-old male with bilateral centri-to panlobular emphysema and multiple increasing ventrobasal bullae and incomplete fissures, COPD (Global Initiative for Chronic Obstructive Lung Disease (GOLD) grade III B), progressive dyspnea on exertion (DOE), AAT level of 0.1-0.2 g/L. Genetic testing revealed a unique SERPINA1 mutation: Pi*Z/c.1072C > T. This allele was designated PiQ0_{Heidelberg II}. Case 2: A 47-year-old male with severely heterogenous centri-to panlobular emphysema concentrated in the lower lobes, COPD GOLD IV D with progressive DOE, AAT <0.1 g/L. He also had a unique Pi*Z/c.10del mutation in SERPINA1. This allele was named PiQ0_{Heidelberg III}. Case 3: A 58-year-old female with basally accentuated panlobular emphysema, GOLD II B COPD, progressive DOE. AAT 0.1 g/L. Genetic analysis revealed Pi*Z/c.-5+1G > A and c.-472G > A mutations in SERPINA1. This variant allele was named PiQ0_{Heidelberg IV}.

Conclusions

Each of these patients had a unique and previously unreported SERPINA1 mutation. In two cases, AATD and a history of smoking led to severe lung disease. In the third case, timely diagnosis, and institution of AAT replacement stabilized lung function. Wider screening of COPD patients for AATD could lead to faster diagnosis and earlier treatment of AATD patients with AATD which could slow or prevent progression of their disease.

Oxygenated hemoglobin as prognostic marker among patients with systemic sclerosis screened for pulmonary hypertension

Oxygenated hemoglobin (OxyHem) in arterial blood may reflect disease severity in patients with systemic sclerosis (SSc). The aim of this study was to analyze the predictive value of OxyHem in SSc patients screened for pulmonary hypertension (PH). OxyHem (g/dl) was measured by multiplying the concentration of hemoglobin with fractional oxygen saturation in arterialized capillary blood. Prognostic power was compared with known prognostic parameters in SSc using uni- and multivariable analysis. A total of 280 SSc patients were screened, 267 were included in the analysis. No signs of pulmonary vascular disease were found in 126 patients, while 141 patients presented with mean pulmonary arterial pressure ≥ 21 mmHg. Interstitial lung disease (ILD) was identified in 70 patients. Low OxyHem ≤ 12.5 g/dl at baseline was significantly associated with worse survival (P = 0.046). In the multivariable analysis presence of ILD, age ≥ 60 years and diffusion capacity for carbon monoxide (DLCO) ≤ 65% were negatively associated with survival. The combination of low DLCO and low OxyHem at baseline could predict PH at baseline (sensitivity 76.1%). This study detected for the first time OxyHem ≤ 12.5 g/dl as a prognostic predictor in SSc patients. Further studies are needed to confirm these results.

Gender-specific differences in COPD symptoms and their impact for the diagnosis of cardiac comorbidities

BACKGROUND

In chronic obstructive pulmonary disease (COPD), gender-specific differences in the prevalence of symptoms and comorbidity are known.

RESEARCH QUESTION

We studied whether the relationship between these characteristics depended on gender and carried diagnostic information regarding cardiac comorbidities.

STUDY DESIGN AND METHODS

The analysis was based on 2046 patients (GOLD grades 1-4, 795 women; 38.8%) from the COSYCONET COPD cohort. Assessments comprised the determination of clinical history, comorbidities, lung function, COPD Assessment Test (CAT) and modified Medical Research Council dyspnea scale (mMRC). Using multivariate regression analyses, gender-specific differences in the relationship between symptoms, single CAT items, comorbidities and functional alterations were determined. To reveal the relationship to cardiac disease (myocardial infarction, or heart failure, or coronary artery disease) logistic regression analysis was performed separately in men and women.

RESULTS

Most functional parameters and comorbidities, as well as CAT items 1 (cough), 2 (phlegm) and 5 (activities), differed significantly (p < 0.05) between men and women. Beyond this, the relationship between functional parameters and comorbidities versus symptoms showed gender-specific differences, especially for single CAT items. In men, item 8 (energy), mMRC, smoking status, BMI, age and spirometric lung function was related to cardiac disease, while in women primarily age was predictive.

INTERPRETATION

Gender-specific differences in COPD not only comprised differences in symptoms, comorbidities and functional alterations, but also differences in their mutual relationships. This was reflected in different determinants linked to cardiac disease, thereby indicating that simple diagnostic information might be used differently in men and women.

CLINICAL TRIAL REGISTRATION

The cohort study is registered on ClinicalTrials.gov with identifier NCT01245933 and on GermanCTR.de with identifier DRKS00000284, date of registration November 23, 2010. Further information can be obtained on the website http://www.asconet.net .

Clinical factors linked to the type of respiratory medication in COPD: results from the COSYCONET cohort

BACKGROUND

The use of maintenance medication in patients with chronic obstructive pulmonary disease (COPD) in real life is known to deviate from recommendations in guidelines, which are largely based on randomized controlled trials and selected populations.

OBJECTIVES

We used the COSYCONET (COPD and Systemic Consequences - Comorbidities Network) cohort to analyze factors linked to the use of COPD drugs under non-interventional circumstances.

DESIGN

COSYCONET is an ongoing, multi-center, non-interventional cohort of patients with COPD.

METHODS

Patients with COPD of Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades 0-4 participating in visits 1-5 were included. Data covered the period from 2010 to 2018. Generalized linear models were used to examine the relation of COPD characteristics to different types of respiratory medication.

RESULTS

A total of 1043 patients were included. The duration of observation was 4.5 years. Use of respiratory medication depended on GOLD grades 0-4 and groups A-D. Long-acting muscarinic antagonist therapy increased over time, and was associated with low carbon monoxide (CO) diffusing capacity, while inhaled corticosteroid (ICS) use decreased. Active smoking was associated with less maintenance therapy in general, and female sex with less ICS use. From the eight items of the COPD Assessment Test, only hill and stair climbing were consistently linked to treatment.

CONCLUSION

Using data from a large, close to real-life observational cohort, we identified factors linked to the use of various types of respiratory COPD medication. Overall, use was consistent with GOLD recommendations. Beyond this, we identified other correlates of medication use that may help us to understand and improve therapy decisions in clinical practice.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01245933.

Standardized airway wall thickness Pi10 from routine CT scans of COPD patients as imaging biomarker for disease severity, lung function decline, and mortality

BACKGROUND

Chest computed tomography (CT) is increasingly used for phenotyping and monitoring of patients with COPD. The aim of this work was to evaluate the association of Pi10 as a measure of standardized airway wall thickness on CT with exacerbations, mortality, and response to triple therapy.

METHODS

Patients of GOLD grades 1-4 of the COSYCONET cohort with prospective CT scans were included. Pi10 was automatically computed and analyzed for its relationship to COPD severity, comorbidities, lung function, respiratory therapy, and mortality over a 6-year period, using univariate and multivariate comparisons.

RESULTS

We included n = 433 patients (61%male). Pi10 was dependent on both GOLD grades 1-4 (p = 0.009) and GOLD groups A-D (p = 0.008); it was particularly elevated in group D, and ROC analysis yielded a cut-off of 0.26 cm. Higher Pi10 was associated to lower FEV₁ % predicted and higher RV/TLC, moreover the annual changes of lung function parameters (p < 0.05), as well as to an airway-dominated phenotype and a history of myocardial infarction (p = 0.001). These associations were confirmed in multivariate analyses. Pi10 was lower in patients receiving triple therapy, in particular in patients of GOLD groups C and D. Pi10 was also a significant predictor for mortality (p = 0.006), even after including multiple other predictors.

CONCLUSION

In summary, Pi10 was found to be predictive for the course of the disease in COPD, in particular mortality. The fact that Pi10 was lower in patients with severe COPD receiving triple therapy might hint toward additional effects of this functional therapy on airway remodeling.

REGISTRATION

ClinicalTrials.gov, Identifier: NCT01245933.

Cardiovascular predictors of mortality and exacerbations in patients with COPD

In chronic obstructive pulmonary disease (COPD), comorbidities and worse functional status predict worse outcomes, but how these predictors compare with regard to different outcomes is not well studied. We thus compared the role of cardiovascular comorbidities for mortality and exacerbations. Data from baseline and up to four follow-up visits of the COSYCONET cohort were used. Cox or Poisson regression was employed to determine the relationship of predictors to mortality or mean annual exacerbation rate, respectively. Predictors comprised major comorbidities (including cardiovascular disease), lung function (forced expiratory volume in 1 s [FEV₁], diffusion capacity for carbon monoxide [TLCO]) and their changes over time, baseline symptoms, exacerbations, physical activity, and cardiovascular medication. Overall, 1817 patients were included. Chronic coronary artery disease (p = 0.005), hypertension (p = 0.044) and the annual decline in TLCO (p = 0.001), but not FEV₁ decline, were predictors of mortality. In contrast, the annual decline of FEV₁ (p = 0.019) but not that of TLCO or cardiovascular comorbidities were linked to annual exacerbation rate. In conclusion, the presence of chronic coronary artery disease and hypertension were predictors of increased mortality in COPD, but not of increased exacerbation risk. This emphasizes the need for broad diagnostic workup in COPD, including the assessment of cardiovascular comorbidity.Clinical Trials: NCT01245933.

Orphan drug development in alpha-1 antitypsin deficiency

Alpha-1 antitrypsin deficiency (AATD, OMIM #613490) is a rare metabolic disorder affecting lungs and liver. The purpose of this study is to assess the impact of the US orphan drug act on AATD by providing a quantitative clinical-regulatory insight into the status of FDA orphan drug approvals and designations for compounds intended to treat AATD. This is across-sectional analysis of the FDA database for orphan drug designations. Primary endpoint: orphan drug approvals. Secondary endpoint: orphan drug designations by the FDA. Close of database was 16 July 2021. STROBE criteria were respected. Primary outcome: one compound, alpha-1-proteinase inhibitor (human) was approved as an orphan drug in 1987 with market exclusivity until 1994. Secondary outcome: sixteen compounds received FDA orphan drug designation including protein, anti-inflammatory, mucolytic, gene, or cell therapy. Drug development activities in AATD were comparable to other rare conditions and led to the FDA-approval of one compound, based on a relatively simple technological platform. The current unmet medical need to be addressed are extrapulmonary manifestations, in this case the AATD-associated liver disease. Orphan drug development is actually focusing on (1) diversified recombinant AAT production platforms, and (2) innovative gene therapies, which may encompass a more holistic therapeutic approach.

Risk Factors for Prolonged Mechanical Ventilation and Weaning Failure: A Systematic Review

INTRODUCTION

Prolonged mechanical ventilation (PMV) and weaning failure are factors associated with prolonged hospital length of stay and increased morbidity and mortality. In addition to the burden these places on patients and their families, it also imposes high costs on the public health system. The aim of this systematic review was to identify risk factors for PMV and weaning failure.

METHODS

The study was conducted according to PRISMA guidelines. After a comprehensive search of the COCHRANE Library, CINHAL, Web of Science, MEDLINE, and the LILACS Database a PubMed request was made on June 8, 2020. Studies that examined risk factors for PMV, defined as mechanical ventilation ≥96 h, weaning failure, and prolonged weaning in German and English were considered eligible; reviews, meta-analyses, and studies in very specific patient populations whose results are not necessarily applicable to the majority of ICU patients as well as pediatric studies were excluded from the analysis. This systematic review was registered in the PROSPERO register under the number CRD42021271038.

RESULTS

Of 532 articles identified, 23 studies with a total of 23,418 patients met the inclusion criteria. Fourteen studies investigated risk factors of PMV including prolonged weaning, 9 studies analyzed risk factors of weaning failure. The concrete definitions of these outcomes varied considerably between studies. For PMV, a variety of risk factors were identified, including comorbidities, site of intubation, various laboratory or blood gas parameters, ventilator settings, functional parameters, and critical care scoring systems. The risk of weaning failure was mainly related to age, previous home mechanical ventilation (HMV), cause of ventilation, and preexisting underlying diseases. Elevated PaCO2 values during spontaneous breathing trials were indicative of prolonged weaning and weaning failure.

CONCLUSION

A direct comparison of risk factors was not possible because of the heterogeneity of the studies. The large number of different definitions and relevant parameters reflects the heterogeneity of patients undergoing PMV and those discharged to HMV after unsuccessful weaning. Multidimensional scores are more likely to reflect the full spectrum of patients ventilated in different ICUs than single risk factors.

Oxygenated Hemoglobin Predicts Outcome in Patients with Chronic Lung Allograft Dysfunction

BACKGROUND

Long-term outcome of lung transplantation (LTx) recipients is limited by chronic lung allograft dysfunction (CLAD). In this setting of new onset respiratory failure, the amount of oxygenated hemoglobin (OxyHem; hemoglobin (Hb) concentration × fractional oxygen saturation) may provide valuable information.

OBJECTIVE

We hypothesized that OxyHem predicts survival of LTx recipients at the onset of CLAD.

METHODS

Data from 292 LTx recipients with CLAD were analyzed. After excluding patients with missing data or supplemental oxygen, the final population comprised 218 patients. The relationship between survival upon CLAD and OxyHem was analyzed by Cox regression analyses and ROC curves.

RESULTS

Among the 218 patients (102 males, 116 females), 128 (58.7%) died, median survival time after CLAD onset being 1,156 days. Survival was significantly associated with type of transplantation, time to CLAD, CLAD stage at onset, and OxyHem, which was superior to Hb or oxygen saturation. The risk for death after CLAD increased by 14% per reduction of OxyHem by 1 g/dL, and values below 11 g/dL corresponded to an 80% increase in mortality risk.

CONCLUSION

Thus, OxyHem was identified as an independent predictor of mortality after CLAD onset. Whether it is useful in supporting therapeutic decisions and potentially home monitoring in the surveillance of lung transplant recipients has to be studied further.

Reduced decline of lung diffusing capacity in COPD patients with diabetes and metformin treatment

We studied whether in patients with COPD the use of metformin for diabetes treatment was linked to a pattern of lung function decline consistent with the hypothesis of anti-aging effects of metformin. Patients of GOLD grades 1–4 of the COSYCONET cohort with follow-up data of up to 4.5 y were included. The annual decline in lung function (FEV₁, FVC) and CO diffusing capacity (KCO, TLCO) in %predicted at baseline was evaluated for associations with age, sex, BMI, pack-years, smoking status, baseline lung function, exacerbation risk, respiratory symptoms, cardiac disease, as well as metformin-containing therapy compared to patients without diabetes and metformin. Among 2741 patients, 1541 (mean age 64.4 y, 601 female) fulfilled the inclusion criteria. In the group with metformin treatment vs. non-diabetes the mean annual decline in KCO and TLCO was significantly lower (0.2 vs 2.3, 0.8 vs. 2.8%predicted, respectively; p < 0.05 each), but not the decline of FEV₁ and FVC. These results were confirmed using multiple regression and propensity score analyses. Our findings demonstrate an association between the annual decline of lung diffusing capacity and the intake of metformin in patients with COPD consistent with the hypothesis of anti-aging effects of metformin as reflected in a surrogate marker of emphysema.

Clinical characterization of a novel alpha1-antitrypsin null variant: PiQ0Heidelberg

The clinical characterization of a null variant of SERPINA1 - PiQ0_Heidelberg - resulting in alpha1-antitrypsin (AAT) deficiency is described. This rare mutation (c.-5+5 G > A) has been previously identified but not clinically described. The 77 year-old female patient had GOLD-3, Group B COPD, severe destructive panlobular emphysema and newly observed respiratory failure on exertion at the time the genetic analysis was performed. Serum AAT level was 0.1 g/L (reference 0.9-2.0 g/L). Isoelectric focusing showed only the Z-protein indicating that this was a null mutation. The patient has started AAT replacement. Early screening and identification of AAT deficiency would allow for earlier intervention.

Basic Determinants of Disease Knowledge in COPD Patients: Results from COSYCONET

INTRODUCTION

In many chronic diseases, including COPD, the patients' basic knowledge of the disorder has been shown to be relevant for the course of the disease. We studied which clinical and functional characteristics were related to this knowledge as well as the patients' satisfaction with their knowledge about COPD.

METHODS

The study population comprised 645 patients of GOLD grades 1-4 who participated in Visit 6 of the COSYCONET cohort (COPD and Systemic Consequences - Comorbidities Network). The assessments covered a broad panel of clinical and functional characteristics, including generic and disease-specific quality of life and the COPD Assessment Test (CAT). The study aim was addressed by two questions, referring to patients' knowledge of the meaning of FEV₁ and the overall satisfaction with their knowledge of COPD.

RESULTS

Knowledge of FEV₁ was higher in patients of higher spirometric GOLD grades or exacerbation risk, in males, with higher educational level, and after participation in a prior educational training on COPD. Patients with more detailed knowledge showed a higher satisfaction with their knowledge. Satisfaction was associated with higher generic quality of life and a lower CAT score. Furthermore, satisfaction was higher in patients with a treatment plan but lower in patients with cardiac comorbidities. It appeared that females with basic education, high burden from COPD and low quality of life had the greatest knowledge deficits.

DISCUSSION

The results suggest room for education programs adapted to the educational level of the participants. They also emphasize the major role of a disease management plan for the patients.

Lower Prevalence of Osteoporosis in Patients with COPD Taking Anti-Inflammatory Compounds for the Treatment of Diabetes: Results from COSYCONET

Background

Patients with chronic obstructive pulmonary disease (COPD) often have osteoporosis and diabetes as comorbid conditions. Anti-diabetic medication, including metformin, has protective effects on osteoporosis in experimental studies. We therefore studied whether patients with COPD receiving anti-diabetic medication had a lower osteoporosis prevalence in a large COPD cohort, COSYCONET.

Methods

Assessment of osteoporosis was based on patients’ reports of physician-based diagnoses and the presence of disease-specific medication. The predictive value of physical characteristics, lung function, comorbidities, cardiovascular medication, and the use of anti-inflammatory diabetes medication, including metformin, sulfonylureas, glinides or DPP4I, was evaluated using logistic regression analysis. ClinicalTrials.gov: NCT01245933.

Results

In total, 2222 patients were eligible for analysis (863 [39%] female, mean age 65 y), 515 of whom had higher symptoms and exacerbations (Global Initiative for Chronic Obstructive Lung Disease group D). Osteoporosis was present in 15.8% of the overall cohort, and in 24.1% of GOLD D patients. Regression analyses identified the following as associated with osteoporosis (p < 0.05): female sex, higher age, lower body-mass index, asthma, higher air trapping, oral steroids, and cardiovascular medication. Although oral anti-diabetic medication was overall not associated with a lower prevalence of osteoporosis (p = 0.131), anti-inflammatory anti-diabetic medication (p = 0.009) and metformin-containing therapy (p = 0.039) were. This was driven by GOLD D patients.

Conclusion

In a large COPD cohort, anti-inflammatory diabetes therapy, including metformin, was associated with a lower prevalence of osteoporosis, especially in patients with higher symptoms and exacerbations. These findings suggest a protective effect of common anti-diabetic medication on osteoporosis, possibly as a result of attenuated systemic inflammation.

Prediction of lung emphysema in COPD by spirometry and clinical symptoms: results from COSYCONET

Background

Lung emphysema is an important phenotype of chronic obstructive pulmonary disease (COPD), and CT scanning is strongly recommended to establish the diagnosis. This study aimed to identify criteria by which physicians with limited technical resources can improve the diagnosis of emphysema.

Methods

We studied 436 COPD patients with prospective CT scans from the COSYCONET cohort. All items of the COPD Assessment Test (CAT) and the St George’s Respiratory Questionnaire (SGRQ), the modified Medical Research Council (mMRC) scale, as well as data from spirometry and CO diffusing capacity, were used to construct binary decision trees. The importance of parameters was checked by the Random Forest and AdaBoost machine learning algorithms.

Results

When relying on questionnaires only, items CAT 1 & 7 and SGRQ 8 & 12 sub-item 3 were most important for the emphysema- versus airway-dominated phenotype, and among the spirometric measures FEV₁/FVC. The combination of CAT item 1 (≤ 2) with mMRC (> 1) and FEV₁/FVC, could raise the odds for emphysema by factor 7.7. About 50% of patients showed combinations of values that did not markedly alter the likelihood for the phenotypes, and these could be easily identified in the trees. Inclusion of CO diffusing capacity revealed the transfer coefficient as dominant measure. The results of machine learning were consistent with those of the single trees.

Conclusions

Selected items (cough, sleep, breathlessness, chest condition, slow walking) from comprehensive COPD questionnaires in combination with FEV₁/FVC could raise or lower the likelihood for lung emphysema in patients with COPD. The simple, parsimonious approach proposed by us might help if diagnostic resources regarding respiratory diseases are limited.

Trial registration ClinicalTrials.gov, Identifier: NCT01245933, registered 18 November 2010, https://clinicaltrials.gov/ct2/show/record/NCT01245933.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-021-01837-2.

Impact of the COVID-19 pandemic on the behaviour and health status of patients with COPD: results from the German COPD cohort COSYCONET

Background:

Infection control measures for coronavirus disease 2019 (COVID-19) might have affected management and clinical state of patients with COPD. We analysed to which extent this common notion is fact-based.

Methods:

Patients of the COSYCONET cohort were contacted with three recurring surveys (COVID1, 2 and 3 at 0, 3 and 6 months, respectively). The questionnaires comprised behaviour, clinical and functional state, and medical treatment. The responses to the questionnaires were compared amongst themselves and with pre-COVID information from the last visit of COSYCONET.

Results:

Overall, 594 patients were contacted and 375 patients (58% males, forced expiratory volume in 1 s (FEV₁) 61±22% predicted) provided valid data in COVID1 and COVID2. Five patients reported infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Most patients – except for patients with higher education – reported compliance with recommended protective measures, whereby compliance to hygiene, contact and access to physicians slightly improved between COVID1 and COVID2. Also, patients obtained more information from physicians than from public media. In the majority of cases, the personal physician could not be substituted by remote consultation. Over time, symptoms slightly increased and self-assessed physical capacity decreased. Results of COVID3 were similar. Women and patients with more exacerbations and dyspnoea avoided medical consultations, whereas Global Initiative for Chronic Obstructive Lung Disease (GOLD) D patients were more amenable to tele-consultation.

Conclusion:

In well-characterised COPD patients, we observed on average slight deteriorations of clinical state during the period of COVID-19 restrictions, with high and partially increasing adherence to protective measures. The data suggest that in particular, women and GOLD D patients should be actively contacted by physicians to identify deteriorations.

During the period of #COVID19 restrictions, slight deteriorations of clinical state with increasing adherence to protective measures were observed. In particular, women and GOLD D patients are at risk of deterioration.https://bit.ly/2S7fhEo

Treatment of COPD Groups GOLD A and B with Inhaled Corticosteroids in the COSYCONET Cohort - Determinants and Consequences

Background

In COPD patients of GOLD groups A and B, a high degree of treatment with inhaled corticosteroids (ICS) has been reported, which is regarded as overtreatment according to GOLD recommendations. We investigated which factors predict ICS use and which relationship it has to clinical and functional outcomes, or healthcare costs.

Methods

We used pooled data from visits 1 and 3 of the COSYCONET cohort (n=2741, n=2053, interval 1.5 years) including patients categorized as GOLD grades 1-4 and GOLD group A or B at both visits (n=1080). Comparisons were performed using ANOVA, and regression analyses using propensity matching and inverse probability weighting to adjust for differences between ICS groups. These were defined as having ICS at both visits (always) vs no ICS at both visits (never). Measures were divided into predictors of ICS treatment and outcomes.

Results

Among 1080 patients, 608 patients were eligible for ICS groups (n=297 never, n=311 always). Prior to matching, patients with ICS showed significantly (p<0.05 each) impaired lung function, symptoms and exacerbation history. After matching, the outcomes generic quality of life and CO diffusing capacity were increased in ICS patients (p<0.05 each). Moreover, costs for respiratory medication, but not total health care costs, were significantly elevated in the ICS group by 780€ per year.

Conclusion

ICS therapy in COPD GOLD A/B patients can have small positive and negative effects on clinical outcomes and health care costs, indicating that the clinical evaluation of ICS over-therapy in COPD requires a multi-dimensional approach.

Prognostic Value of Oxygenated Hemoglobin Assessed during Acute Exacerbations of Chronic Pulmonary Disease

BACKGROUND

Oxygenated hemoglobin(OxyHem) is a simple-to-measure marker of oxygen content capable of predicting all-cause mortality in stable chronic obstructive pulmonary disease (COPD).

OBJECTIVES

We aimed to analyze its predictive value during acute exacerbations of COPD (AECOPD).

METHODS

In this retrospective study, data from 227 patients discharged after severe AECOPD at RoMed Clinical Center Rosenheim, Germany, between January 2012 and March 2018, was analyzed. OxyHem (hemoglobin concentration [Hb] × fractional SpO2, g/dL) was calculated from oxygen saturation measured by pulse oximetry and hemoglobin assessed within 24 h after admission. The follow-up (1.7 ± 1.5 years) covered all-cause mortality, including readmissions for severe AECOPD.

RESULTS

During the follow-up period, 127 patients died, 56 due to AECOPD and 71 due to other reasons. Survivors and non-survivors showed differences in age, FVC % predicted, C-reactive protein, hemoglobin, Cr, Charlson Comorbidity Index (CCI), and OxyHem (p < 0.05 each). Significant independent predictors of survival were BMI, Cr or CCI, FEV1 % predicted or FVC % predicted, Hb, or OxyHem. The predictive value of OxyHem (p = 0.006) was superior to that of Hb or SpO2 and independent of oxygen supply during blood gas analysis. OxyHem was also predictive when using a cutoff value of 12.1 g/dL identified via receiver operating characteristic curves in analyses including either the CCI (hazard ratio 1.85; 95% CI 1.20, 2.84; p = 0.005) or Cr (2.04; 95% CI 1.35, 3.10; p = 0.001) as covariates.

CONCLUSION

The concentration of OxyHem provides independent, easy-to-assess information on long-term mortality risk in COPD, even if measured during acute exacerbations. It therefore seems worth to be considered for broader clinical use.

Impact of Education on COPD Severity and All-Cause Mortality in Lifetime Never-Smokers and Longtime Ex-Smokers: Results of the COSYCONET Cohort

Background

Beyond smoking, several risk factors for the development of chronic obstructive pulmonary disease (COPD) have been described, among which socioeconomic status including education is of particular interest. We studied the contribution of education to lung function and symptoms relative to smoking in a group of never-smokers with COPD compared to a group of long-time ex-smokers with COPD.

Methods

We used baseline data of the COSYCONET cohort, including patients of GOLD grades 1-4 who were either never-smokers (n=150, age 68.5y, 53.3% female) or ex-smokers (≥10 packyears) for at least 10 years (n=616, 68.3y, 29.9% female). Socioeconomic status was analyzed using education level and mortality was assessed over a follow-up period of 4.5 years. Analyses were performed using ANOVA and regression models.

Results

Spirometric lung function did not differ between groups, whereas CO diffusing capacity and indicators of lung hyperinflation/air-trapping showed better values in the never-smoker group. In both groups, spirometric lung function depended on the education level, with better values for higher education. Quality of life and 6-MWD were significantly different in never-smokers as well as patients with higher education. Asthma, alpha-1-antitrypsin deficiency, and bronchiectasis were more often reported in never-smokers, and asthma was more often reported in patients with higher education. Higher education was also associated with reduced mortality (hazard ratio 0.46; 95% CI 0.22-0.98).

Conclusion

Overall, in the COSYCONET COPD cohort, differences in functional status between never-smokers and long-time ex-smokers were not large. Compared to that, the dependence on education level was more prominent, with higher education associated with better outcomes, including mortality. These data indicate that non-smoking COPD patients' socioeconomic factors are relevant and should be taken into account by clinicians.

Relationship between clinical and radiological signs of bronchiectasis in COPD patients: Results from COSYCONET

Bronchiectasis (BE) might be frequently present in COPD but masked by COPD symptoms. We studied the relationship of clinical signs of bronchiectasis to the presence and extent of its radiological signs in patients of different COPD severity. Visit 4 data (GOLD grades 1-4) of the COSYCONET cohort was used. Chest CT scans were evaluated for bronchiectasis in 6 lobes using a 3-point scale (0: absence, 1: ≤50%, 2: >50% BE-involvement for each lobe). 1176 patients were included (61%male, age 67.3y), among them 38 (3.2%) with reported physicians' diagnosis of bronchiectasis and 76 (6.5%) with alpha1-antitrypsin deficiency (AA1D). CT scans were obtained in 429 patients. Within this group, any signs of bronchiectasis were found in 46.6% of patients, whereby ≤50% BE occurred in 18.6% in ≤2 lobes, in 10.0% in 3-4 lobes, in 15.9% in 5-6 lobes; >50% bronchiectasis in at least 1 lobe was observed in 2.1%. Scores ≥4 correlated with an elevated ratio FRC/RV. The clinical diagnosis of bronchiectasis correlated with phlegm and cough and with radiological scores of at least 3, optimally ≥5. In COPD patients, clinical diagnosis and radiological signs of BE showed only weak correlations. Correlations became significant with increasing BE-severity implying radiological alterations in several lobes. This indicates the importance of reporting both presence and extent of bronchiectasis on CT. Further research is warranted to refine the criteria for CT scoring of bronchiectasis and to determine the relevance of radiologically but not clinically detectible bronchiectasis and their possible implications for therapy in COPD patients.

Time-updated resting heart rate predicts mortality in patients with COPD

High resting heart rate (RHR) is associated with higher mortality in the general population and in cardiovascular disease. Less is known about the association of RHR with outcome in chronic obstructive pulmonary disease (COPD). In particular, the time-updated RHR (most recent value before the event) appears informative. This is the first study to investigate the association of time-updated RHR with mortality in COPD. We compared the baseline and time-updated RHR related to survival in 2218 COPD patients of the German COSYCONET cohort (COPD and Systemic Consequences-Comorbidities Network). Patients with a baseline RHR > 72 beats per minute (bmp) had a significantly (p = 0.049) higher all-cause mortality risk (adjusted hazard ratio (HR) of 1.37 (1.00-1.87) compared to baseline RHR ≤ 72 bpm. The time-updated RHR > 72 bpm was markedly superior (HR 1.79, 1.30-2.46, p = 0.001). Both, increased baseline and time-updated RHR, were independently associated with low FEV1, low TLCO, a history of diabetes, and medication with short-acting beta agonists (SABAs). In conclusion, increased time-updated RHR is associated with higher mortality in COPD independent of other predictors and superior to baseline RHR. Increased RHR is linked to lung function, comorbidities and medication. Whether RHR is an effective treatment target in COPD, needs to be proven in controlled trials.

The association of cognitive functioning as measured by the DemTect with functional and clinical characteristics of COPD: results from the COSYCONET cohort

Alterations of cognitive functions have been described in COPD. Our study aimed to disentangle the relationship between the degree of cognitive function and COPD characteristics including quality of life (QoL).

Data from 1969 COPD patients of the COSYCONET cohort (GOLD grades 1–4; 1216 male/ 753 female; mean (SD) age 64.9 ± 8.4 years) were analysed using regression and path analysis. The DemTect screening tool was used to measure cognitive function, and the St. George‘s respiratory questionnaire (SGRQ) to assess disease-specific QoL.

DemTect scores were < 9 points in 1.6% of patients and < 13 points in 12% when using the original evaluation algorithm distinguishing between < 60 or > =60 years of age. For statistical reasons, we used the average of both algorithms independent of age in all subsequent analyses. The DemTect scores were associated with oxygen content, 6-min-walking distance (6-MWD), C-reactive protein (CRP), modified Medical Research Council dyspnoea scale (mMRC) and the SGRQ impact score. Conversely, the SGRQ impact score was independently associated with 6-MWD, FVC, mMRC and DemTect. These results were combined into a path analysis model to account for direct and indirect effects. The DemTect score had a small, but independent impact on QoL, irrespective of the inclusion of COPD-specific influencing factors or a diagnosis of cognitive impairment.

We conclude that in patients with stable COPD lower oxygen content of blood as a measure of peripheral oxygen supply, lower exercise capacity in terms of 6-MWD, and higher CRP levels were associated with reduced cognitive capacity. Furthermore, a reduction in cognitive capacity was associated with reduced disease-specific quality of life. As a potential clinical implication of this work, we suggest to screen especially patients with low oxygen content and low 6-MWD for cognitive impairment.

Consequences of chronic kidney disease in chronic obstructive pulmonary disease

Background

The combination of chronic obstructive pulmonary disease (COPD) and chronic kidney disease (CKD) is associated with a higher prevalence of comorbidities and increased mortality. The impact of kidney function on patient-centered outcomes in COPD has not been evaluated.

Methods

Patients from the German COPD and Systemic Consequences - Comorbidities Network (COSYCONET) cohort COPD were analysed. CKD was diagnosed if the estimated glomerular filtration rate (eGFR) measurements were < 60 mL/min/1.73m² at study inclusion and six month later. The effect of CKD, on comorbidities, symptoms [modified British Medical Research Council dyspnoea scale], physical capacity [six-minute walk test, and timed up and go] and St George’s Respiratory Questionnaire were analysed. Restricted cubic spline models were used to evaluate a nonlinear relationship between eGFR with patient-centered outcomes, cox survival analysis was applied to evaluate mortality.

Results

2274 patients were analysed, with CKD diagnosed in 161 (7.1%). Spline models adjusted for age, gender, BMI, FEV₁ and cardiovascular comorbidities revealed independent associations between eGFR with modified British Medical Research Council dyspnoea scale, St George’s Respiratory Questionnaire, (p < 0.001 and p = 0.011), six-minute walk test (p = 0.015) and timed up and go (p < 0.001). CKD was associated with increased mortality, independently from for other cardiovascular comorbidities (hazard ratio 2.3; p < 0.001).

Conclusion

These data show that CKD is a relevant comorbidity in COPD patients which impacts on patient-centered outcomes and mortality.

Trial registration

NCT01245933

Electronic supplementary material

The online version of this article (10.1186/s12931-019-1107-x) contains supplementary material, which is available to authorized users.

Combined effects of lung function, blood gases and kidney function on the exacerbation risk in stable COPD: Results from the COSYCONET cohort

RATIONALE

Alterations of acid-base metabolism are an important outcome predictor in acute exacerbations of COPD, whereas sufficient metabolic compensation and adequate renal function are associated with decreased mortality. In stable COPD there is, however, only limited information on the combined role of acid-base balance, blood gases, renal and respiratory function on exacerbation risk grading.

METHODS

We used baseline data of the COPD cohort COSYCONET, applying linear and logistic regression analyses, the results of which were implemented into a comprehensive structural equation model. As most informative parameters it comprised the estimated glomerular filtration rate (eGFR), lung function defined via forced expiratory volume in 1 s (FEV₁), intrathoracic gas volume (ITGV) and (diffusing capacity for carbon monoxide (DLCO), moreover arterial oxygen content (CaO₂), partial pressure of oxygen (PaCO₂), base exess (BE) and exacerbation risk according to GOLD criteria. All measures were adjusted for age, gender, body-mass index, the current smoking status and pack years.

RESULTS

1506 patients with stable COPD (GOLD grade 1-4; mean age 64.5 ± 8.1 y; mean FEV₁ 54 ± 18 %predicted, mean eGFR 82.3 ± 16.9 mL/min/1.73 m²) were included. BE was linked to eGFR, lung function and PaCO₂ and played a role as indirect predictor of exacerbation risk via these measures; moreover, eGFR was directly linked to exacerbation risk. These associations remained significant after taking into account medication (diuretics, oral and inhaled corticosteroids), whereby corticosteroids had effects on exacerbation risk and lung function, diuretics on eGFR, BE and lung function.

CONCLUSION

Even in stable COPD acid-base metabolism plays a key integrative role in COPD risk assessment despite rather small deviations from normality. It partially mediates the effects of impairments in kidney function, which are also directly linked to exacerbation risk.

[Epidemiology, Clinical Presentation, Diagnosis and Treatment of Infections Caused by Mycobacterium chimaera]

The recognition, correct diagnosis and adequate clinical management of infections caused by atypical mycobacteria are challenging tasks in clinical practice. Invasive infections caused by Mycobacterium chimaera, a member of the Mycobacterium avium-intracellulare complex, have been increasingly reported over the past few years. Most infections occurred in patients who had undergone open-chest cardiothoracic surgery. Epidemiological and molecular studies showed that transmission of M. chimaera occurred through intraoperative aerosols derived from contaminated heater-cooler units, i. e. devices that are used to enable the extracardiac circuit in cardiothoracic surgery. Thus far, approximately 120 patient cases have been reported worldwide. The latency between exposure and onset of clinical symptoms may comprise several years. Clinical manifestations of M. chimaera infections include not only endocarditis and implant-associated infections, but also non-cardiac entities such as sarcoidosis-like symptoms, vertebral osteomyelitis and chorioretinitis. The pathogen can be detected in blood culture vials and in surgically obtained specimens from affected tissues, if specific microbiological tests for detection of mycobacteria are employed. There are no simple-to-use screening tests and a high clinical index of suspicion is thus mandatory in patients with previous exposure and compatible signs and symptoms. The successful treatment of M. chimaera infections requires the removal of infected devices and prolonged combination therapy with antimycobacterial drugs. This review summarises the clinical relevance, epidemiology, symptomatology, diagnosis and treatment of infections caused by M. chimaera, with a specific focus on pneumological aspects.

Weaning from prolonged veno-venous extracorporeal membrane oxygenation (ECMO) after transfer to a specialized center: a retrospective study

Veno-venous extracorporeal membrane oxygenation (vvECMO) is increasingly used as rescue therapy in severe respiratory failure. In patients with pre-existent lung diseases or persistent lung injury weaning from vvECMO can be challenging. This study sought to investigate outcomes of patients transferred to a specialized ECMO center after prolonged ECMO therapy. We performed a retrospective analysis of all patients admitted to our medical intensive care unit (ICU) between 01/2013 and 12/2016 who were transferred from an external ICU after > 8 days on vvECMO. 12 patients on ECMO for > 8 days were identified. Prior to transfer, patients underwent ECMO therapy for 18 ± 9.5 days. Total time on ECMO was 60 ± 46.6 days. 11/12 patients could be successfully weaned from ECMO, 7/12 in the first 28 days after transfer (8 ± 8.8 ECMO-free days at day 28). In 7 patients, ECMO could be terminated after at least partial lung recovery, in 4 patients after salvage lung transplant. No patient died or needed re-initiation of ECMO therapy at day 28. In summary, weaning from vvECMO was feasible even after prolonged ECMO courses and salvage lung transplant could be avoided in most cases. Patients may benefit from transfer to a specialized ECMO center.

Microbiological airway colonization in COPD patients with severe emphysema undergoing endoscopic lung volume reduction

Background

Endoscopic lung volume reduction (eLVR) is a therapeutic option for selected patients with COPD and severe emphysema. Infectious exacerbations are serious events in these vulnerable patients; hence, prophylactic antibiotics are often prescribed postinterventionally. However, data on the microbiological airway colonization at the time of eLVR are scarce, and there are no evidence-based recommendations regarding a rational antibiotic regimen.

Objective

The aim of this study was to perform a clinical and microbiological analysis of COPD patients with advanced emphysema undergoing eLVR with endobronchial valves at a single German University hospital, 2012–2017.

Patients and methods

Bronchial aspirates were obtained prior to eLVR and sent for microbiological analysis. Antimicrobial susceptibility testing of bacterial isolates was performed, and pathogen colonization was retrospectively compared with clinical parameters.

Results

At least one potential pathogen was found in 47% (30/64) of patients. Overall, Gram-negative bacteria constituted the most frequently detected pathogens. The single most prevalent species were Haemophilus influenzae (9%), Streptococcus pneumoniae (6%), and Staphylococcus aureus (6%). No multidrug resistance was observed, and Pseudomonas aeruginosa occurred in <5% of samples. Patients without microbiological airway colonization showed more severe airflow limitation, hyperinflation, and chronic hypercapnia compared to those with detected pathogens.

Conclusion

Microbiological airway colonization was frequent in patients undergoing eLVR but not directly associated with poorer functional status. Resistance testing results do not support the routine use of antipseudomonal antibiotics in these patients.