Pulmonary Embolism: An Update Based on the Revised AWMF-S2k Guideline

Pulmonary embolism (PE) is the third most common acute cardiovascular disease. The risk of PE increases with age and mortality is high. Patients are stratified into hemodynamically stable versus unstable patients, as this has important implications for diagnosis and therapy. Since clinical signs and symptoms of acute PE are nonspecific, the clinical likelihood of PE is estimated to guide diagnostic pathways. D-dimer testing is performed in hemodynamically stable patients with low or intermediate probability of PE and the visualization of thromboembolism and its sequelae is commonly achieved with computed tomography pulmonary angiography (CTPA), supplemented by ultrasound techniques. With confirmed PE, another risk stratification estimates disease severity and defines intensity and setting of the ensuing treatment. The therapeutic spectrum ranges from outpatient treatment with initial oral anticoagulation to thrombolytic or interventional treatment in the intensive care unit or catheterization laboratory. In single cases, even acute surgical thrombectomy is attempted.

Post-Pulmonary Embolism Syndrome: An Update Based on the Revised AWMF-S2k Guideline

In survivors of acute pulmonary embolism (PE), the post-PE syndrome (PPES) may occur. In PPES, patients typically present with persisting or progressive dyspnea on exertion despite 3 months of therapeutic anticoagulation. Therefore, a structured follow-up is warranted to identify patients with chronic thromboembolic pulmonary disease (CTEPD) with normal pulmonary pressure or chronic thromboembolic pulmonary hypertension (CTEPH). Both are currently understood as a dual vasculopathy, that is, secondary arterio- and arteriolopathy, affecting the large and medium-sized pulmonary arteries as well as the peripheral vessels (diameter < 50 µm). The follow-up algorithm after acute PE commences with identification of clinical symptoms and risk factors for CTEPH. If indicated, a stepwise performance of echocardiography, ventilation-perfusion scan (or alternative imaging), N-terminal prohormone of brain natriuretic peptide (NT-proBNP) level, cardiopulmonary exercise testing, and pulmonary artery catheterization with angiography should follow. CTEPH patients should be treated in a multidisciplinary center with adequate experience in the complex therapeutic options, comprising pulmonary endarterectomy, balloon pulmonary angioplasty, and pharmacological interventions.

Using Machine Learning-Based Algorithms to Identify and Quantify Exercise Limitations in Clinical Practice: Are We There Yet?

INTRODUCTION

Well-trained staff is needed to interpret cardiopulmonary exercise tests (CPET). We aimed to examine the accuracy of machine learning-based algorithms to classify exercise limitations and their severity in clinical practice compared with expert consensus using patients presenting at a pulmonary clinic.

METHODS

This study included 200 historical CPET data sets (48.5% female) of patients older than 40 yr referred for CPET because of unexplained dyspnea, preoperative examination, and evaluation of therapy progress. Data sets were independently rated by experts according to the severity of pulmonary-vascular, mechanical-ventilatory, cardiocirculatory, and muscular limitations using a visual analog scale. Decision trees and random forests analyses were calculated.

RESULTS

Mean deviations between experts in the respective limitation categories ranged from 1.0 to 1.1 points (SD, 1.2) before consensus. Random forests identified parameters of particular importance for detecting specific constraints. Central parameters were nadir ventilatory efficiency for CO 2 , ventilatory efficiency slope for CO 2 (pulmonary-vascular limitations); breathing reserve, forced expiratory volume in 1 s, and forced vital capacity (mechanical-ventilatory limitations); and peak oxygen uptake, O 2 uptake/work rate slope, and % change of the latter (cardiocirculatory limitations). Thresholds differentiating between different limitation severities were reported. The accuracy of the most accurate decision tree of each category was comparable to expert ratings. Finally, a combined decision tree was created quantifying combined system limitations within one patient.

CONCLUSIONS

Machine learning-based algorithms may be a viable option to facilitate the interpretation of CPET and identify exercise limitations. Our findings may further support clinical decision making and aid the development of standardized rating instruments.

[Non-invasive Mechanical Ventilation in Acute Respiratory Failure. Clinical Practice Guidelines - on behalf of the German Society of Pneumology and Ventilatory Medicine]

The guideline update outlines the advantages as well as the limitations of NIV in the treatment of acute respiratory failure in daily clinical practice and in different indications.Non-invasive ventilation (NIV) has a high value in therapy of hypercapnic acute respiratory failure, as it significantly reduces the length of ICU stay and hospitalization as well as mortality.Patients with cardiopulmonary edema and acute respiratory failure should be treated with continuous positive airway pressure (CPAP) and oxygen in addition to necessary cardiological interventions. This should be done already prehospital and in the emergency department.In case of other forms of acute hypoxaemic respiratory failure with only mild or moderately disturbed gas exchange (PaO2/FiO2 > 150 mmHg) there is no significant advantage or disadvantage compared to high flow nasal oxygen (HFNO). In severe forms of ARDS NIV is associated with high rates of treatment failure and mortality, especially in cases with NIV-failure and delayed intubation.NIV should be used for preoxygenation before intubation. In patients at risk, NIV is recommended to reduce extubation failure. In the weaning process from invasive ventilation NIV essentially reduces the risk of reintubation in hypercapnic patients. NIV is regarded useful within palliative care for reduction of dyspnea and improving quality of life, but here in concurrence to HFNO, which is regarded as more comfortable. Meanwhile NIV is also recommended in prehospital setting, especially in hypercapnic respiratory failure and pulmonary edema.With appropriate monitoring in an intensive care unit NIV can also be successfully applied in pediatric patients with acute respiratory insufficiency.

Protein expression profiling suggests relevance of noncanonical pathways in isolated pulmonary embolism

Patients with isolated pulmonary embolism (PE) have a distinct clinical profile from those with deep vein thrombosis (DVT)-associated PE, with more pulmonary conditions and atherosclerosis. These findings suggest a distinct molecular pathophysiology and the potential involvement of alternative pathways in isolated PE. To test this hypothesis, data from 532 individuals from the Genotyping and Molecular Phenotyping of Venous ThromboEmbolism Project, a multicenter prospective cohort study with extensive biobanking, were analyzed. Targeted, high-throughput proteomics, machine learning, and bioinformatic methods were applied to contrast the acute-phase plasma proteomes of isolated PE patients (n = 96) against those of patients with DVT-associated PE (n = 276) or isolated DVT (n = 160). This resulted in the identification of shared molecular processes between PE phenotypes, as well as an isolated PE-specific protein signature. Shared processes included upregulation of inflammation, response to oxidative stress, and the loss of pulmonary surfactant. The isolated PE-specific signature consisted of 5 proteins: interferon-γ, glial cell line-derived neurotrophic growth factor, polypeptide N-acetylgalactosaminyltransferase 3, peptidyl arginine deiminase type-2, and interleukin-15 receptor subunit α. These proteins were orthogonally validated using cis protein quantitative trait loci. External replication in an independent population-based cohort (n = 5778) further validated the proteomic results and showed that they were prognostic for incident primary isolated PE in individuals without history of VTE (median time to event: 2.9 years; interquartile range: 1.6-4.2 years), supporting their possible involvement in the early pathogenesis. This study has identified molecular overlaps and differences between VTE phenotypes. In particular, the results implicate noncanonical pathways more commonly associated with respiratory and atherosclerotic disease in the acute pathophysiology of isolated PE.

[Differential Diagnosis of Pulmonary Hypertension Using the Example of Collagenosis-associated PAH in the Context of Chronic Lung and Left Heart Disease]

Pulmonary hypertension (PH) can be diagnosed in the context of connective tissue diseases (CTD) as well as in elderly patients with multiple comorbidities. A correct clinical differential diagnosis and classification is essential before adequate therapeutic decisions can be made. Differential diagnosis of PH in CTD comprises associated pulmonary arterial hypertension (APAH), group 2 or 3 PH (PH arising from left heart or chronic lung disease), chronic thromboembolic PH (PH) and group 5 (e. g. in the context of terminal renal insufficiency). This is also true of elderly patients in whom the decision has to be made if the increasing number of coincident diseases lead to PH or have to be interpreted as comorbidities. In this manuscript, the differential diagnosis of PH is elucidated, focusing on CTD, in the context of left heart disease and chronic lung disease. Furthermore, criteria are presented facilitating an objective approach in this context.

Successful implementation of modern critical care in the low-resources country Bosnia and Herzegovina : Single-center experience

Background

Critical care medicine is a relatively young discipline, developed in the mid-1950s in response to the outbreak of poliomyelitis. The mass application of mechanical ventilation and its subsequent technical advancement helped manage large numbers of patients with respiratory failure. This branch of medicine evolved much faster in high-income (HIC) than low- and middle-income countries (LMIC). Seventy years later, mankind’s encounter with coronavirus disease 2019 (COVID-19) represents another major challenge for critical care medicine especially in LMIC countries where over two thirds of the world population live.

Methods

Systematic analysis of written documents related to the establishment of the first multidisciplinary medical intensive care unit (MICU) in Bosnia and Herzegovina and its development to the present day.

Results

We describe the experience of setting up a modern critical care program under LMIC constraints as a promising way forward to meet the increased worldwide demand for critical care. Successful development is contingent on formal education and continued mentorship from HIC, establishment of a multidisciplinary team, the support from local health care authorities, development of a formal subspecialty training, academic faculty development, and research. Novel technologies including tele-education provide additional opportunities for rapid development and dissemination of critical care medicine programs in LMIC.

Conclusion

Critical care medicine is a critical public health need in HIC and LMIC alike. The challenges associated with the coronavirus pandemic should serve as a wakeup call for rapid development of critical care programs around the world.

[Current Aspects of Definition and Diagnosis of Pulmonary Hypertension]

At the 6th World Symposium on Pulmonary Hypertension (WSPH), which took place from February 27 until March 1, 2018 in Nice, scientific progress over the past 5 years in the field of pulmonary hypertension (PH) was presented by 13 working groups. The results of the discussion were published as proceedings towards the end of 2018. One of the major changes suggested by the WSPH was the lowering of the diagnostic threshold for PH from ≥ 25 to > 20 mmHg mean pulmonary arterial pressure, measured by right heart catheterization at rest. In addition, the pulmonary vascular resistance was introduced into the definition of PH, which underlines the importance of cardiac output determination at the diagnostic right heart catheterization.In this article, we discuss the rationale and possible consequences of a changed PH definition in the context of the current literature. Further, we provide a current overview on non-invasive and invasive methods for diagnosis, differential diagnosis, and prognosis of PH, including exercise tests.

[Exercise Testing in Respiratory Medicine - DGP Recommendations]

This document replaces the DGP recommendations published in 1998 and 2013. Based on recent studies and a consensus conference, the indications, choice and performance of the adequate exercise testing method and its necessary technical and staffing setting are discussed. Detailed recommendations are provided: for blood gas analysis and right heart catheterization during exercise, walk tests, spiroergometry, and stress echocardiography. The correct use of different exercise tests is discussed for specific situations in respiratory medicine: exercise induced asthma, obesity, monitoring of rehabilitation or therapeutical interventions, preoperative risk stratification, and evaluation in occupational medicine.

Late outcomes after acute pulmonary embolism: rationale and design of FOCUS, a prospective observational multicenter cohort study

Acute pulmonary embolism (PE) is a frequent cause of death and serious disability. The risk of PE-associated mortality and morbidity extends far beyond the acute phase of the disease. In earlier follow-up studies, as many as 30 % of the patients died during a follow-up period of up to 3 years, and up to 50 % of patients continued to complain of dyspnea and/or poor physical performance 6 months to 3 years after the index event. The most feared ‘late sequela’ of PE is chronic thromboembolic pulmonary hypertension (CTEPH), the true incidence of which remains obscure due to the large margin of error in the rates reported by mostly small, single-center studies. Moreover, the functional and hemodynamic changes corresponding to early, possibly reversible stages of CTEPH, have not been systematically investigated. The ongoing Follow-Up after acute pulmonary embolism (FOCUS) study will prospectively enroll and systematically follow, over a 2-year period and with a standardized comprehensive program of clinical, echocardiographic, functional and laboratory testing, a large multicenter prospective cohort of 1000 unselected patients (all-comers) with acute symptomatic PE. FOCUS will possess adequate power to provide answers to relevant remaining questions regarding the patients’ long-term morbidity and mortality, and the temporal pattern of post-PE abnormalities. It will hopefully provide evidence for future guideline recommendations regarding the selection of patients for long-term follow-up after PE, the modalities which this follow-up should include, and the findings that should be interpreted as indicating progressive functional and hemodynamic post-PE impairment, or the development of CTEPH.

[Clinical classification and initial diagnosis of pulmonary hypertension: recommendations of the Cologne Consensus Conference 2016]

The 2015 European Guidelines on Diagnosis and Treatment of Pulmonary Hypertension are also valid for Germany. The guidelines contain detailed information about the clinical classification and diagnosis of pulmonary hypertension, and furthermore provide novel recommendations for risk stratification and follow-up assessments. However, the practical implementation of the European Guidelines in Germany requires the consideration of several country-specific issues and already existing novel data. This requires a detailed commentary to the guidelines, and in some aspects an update already appears necessary. In June 2016, a Consensus Conference organized by the PH working groups of the German Society of Cardiology (DGK), the German Society of Respiratory Medicine (DGP) and the German Society of Pediatric Cardiology (DGPK) was held in Cologne, Germany. This conference aimed to solve practical and controversial issues surrounding the implementation of the European Guidelines in Germany. To this end, a number of working groups was initiated, one of which was specifically dedicated to the clinical classification and initial diagnosis of PH. This article summarizes the results and recommendations of this working group.

[Noninvasive Mechanical Ventilation in Acute Respiratory Failure]

The non-invasive ventilation (NIV) is widespread in the clinical medicine and has attained meanwhile a high value in the clinical daily routine. The application of NIV reduces the length of ICU stay and hospitalization as well as mortality of patients with hypercapnic acute respiratory failure. Patients with acute respiratory failure in context of a cardiopulmonary edema should be treated in addition to necessary cardiological interventions with continuous positive airway pressure (CPAP) or NIV. In case of other forms of acute hypoxaemic respiratory failure it is recommended the application of NIV to be limited to mild forms of ARDS as the application of NIV in severe forms of ARDS is associated with higher rates of treatment failure and mortality. In weaning process from invasive ventilation the NIV reduces the risk of reintubation essentially in hypercapnic patients. A delayed intubation of patients with NIV failure leads to an increase of mortality and should therefore be avoided. With appropriate monitoring in intensive care NIV can also be successfully applied in pediatric patients with acute respiratory insufficiency. Furthermore NIV can be useful within palliative care for reduction of dyspnea and improving quality of life. The aim of the guideline update is, taking into account the growing scientific evidence, to outline the advantages as well as the limitations of NIV in the treatment of acute respiratory failure in daily clinical practice and in different indications.

The correlation between endothelin-1 levels and spirometry in dialysis patients compared to healthy subjects

Background and Aim. Several studies demonstrated a six-fold increase in plasma concentration of endothelin-1 (ET-1) in diaysis patients (hemodialysis and peritoneal dialysis) compared to healthy control subjects. However, the effects of ET-1 on respiratory function in these patients are less known. The aim of this study was to determine the potential differences in spirometric values in relation to ET-1 levels. Methods. The study included 28 patients (15 male, 13 female, mean age 55.9±16. 2 years) with end stage renal diseases (ESRD) receiving regular hemodialysis (HD), 23 patients (10 males, 13 females, mean age 55.8±15.8 years) with ESRD treated with continuous ambulatory peritoneal dialysis (CAPD) without any cardiovascular or respiratory diseases, and 30 healthy volunteers (14 male, 16 female, mean age 51.8±15.6 years) in control group. In each of the three groups the participants were divided into two additional sub-groups according to the serum levels of ET-1. The spirometry values were recorded before the onset of hemodialysis and prior to emptying the peritoneal cavity in CAPD patients. The results were analyzed using standard statistical methods (Student’s t-test). Results. Patients who were treated with HD or CAPD were found to have significant difference in values of most pulmonary function parameters between subjects with ET-1 levels lower than 6,6 pg/ml and subjects with ET-1 levels higher than 6,6 pg/ml. In the control group there was no difference in pulmonary function parameters in correlation with ET-1 levels. ET-1 values in patients of both dialysis groups were significantly higher compared to healthy subjects. Conclusions. Higher levels of ET-1 in dialysis patients over healthy subjects is associated with lower parameters of lung function tests. A possible pathophysiological mechanism for deterioration of pulmonary function might be explained by progression of inflammation, pulmonary oedema also known as “uraemic lung” or/and the progression of pulmonary hypertension.

Management of patients with idiopathic pulmonary fibrosis in clinical practice: the INSIGHTS-IPF registry

After introduction of the new international guidelines on idiopathic pulmonary fibrosis (IPF) in 2011, we investigated clinical management practices for patients with IPF according to physicians' diagnoses. A prospective, multicenter, noninterventional study with comprehensive quality measures including on-site source data verification was performed in Germany. 502 consecutive patients (171 newly diagnosed, 331 prevalent; mean±SD age 68.7±9.4 years, 77.9% males) with a mean disease duration of 2.3±3.5 years were enrolled. IPF diagnosis was based on clinical assessments and high-resolution computed tomography (HRCT) in 90.2%, and on surgical lung biopsy combined with histology in 34.1% (lavage in 61.8%). The median 6-min walk distance was 320 m (mean 268±200 m). The mean forced vital capacity was 72±20% pred and diffusing capacity of the lung for carbon monoxide was 35±15% pred. No drugs were administered in 17.9%, oral steroids in 23.7%, N-acetylcysteine in 33.7%, pirfenidone in 44.2% and other drugs in 4.6% of patients. Only 2.8% of the cohort was listed for lung transplantation. IPF patients were diagnosed in line with the new guidelines. They had more severe disease than those enrolled in recent randomised controlled trials. In addition to HRCT, the frequency of lung biopsies was surprisingly high. Treatment patterns varied substantially.

Relation of respiratory muscle strength, cachexia and survival in severe chronic heart failure

BACKGROUND

Respiratory muscle (RM) function predicts prognosis in non-cachectic patients with chronic heart failure (CHF). We hypothesized that weakness of RM (maximum inspiratory mouth occlusion pressure, Pimax) is a function of body mass index, and that outcome is more a function of BMI than of Pimax or ventilatory drive (P0.1).

SUBJECTS AND METHODS

We enrolled 249 CHF patients (11.2 % female, median age 54.2 years) at the German Heart Institute Berlin. Patients were in NYHA classes I/II/III/IV by n = 16/90/108/35. All patients underwent tests of pulmonary function, RM (Pimax, P0.1), cardiopulmonary exercise testing (peakVO2, VE/VCO2-slope), and right heart catheterization.

RESULTS

Mean follow-up time was 18 (1-36) months, 47 patients (18.9 %) died or underwent cardiac assist implantation. Pimax correlated weakly with BMI (r = 0.19), peakVO2 (r = 0.15), and FEV1 (r = 0.34, all p < 0.02), and was lower in females compared to males (3.9 ± 1.7 vs. 6.6 ± 2.7 kPa; p < 0.001). P0.1 correlated with pulmonary pressure (rho = 0.2; p < 0.01) and peakVO2 (rho = -0.14; p < 0.02). Neither Pimax [hazard ratio (HR) 0.98; confidence interval (CI) 0.88-1.08] nor P0.1 (HR 0.52; 0.06-4.6) predicted survival. Multivariate regression analysis revealed gender, BMI, and FEV1 as cofactors of Pimax, with only BMI (HR 0.87; CI 0.80-0.95) predicting survival independently. The lowest quintile in BMI had the worst outcome (log-rank χ² = 13.5, p = 0.009). In CHF patients including cachexia and NYHA IV, Pimax does not predict survival. Pimax depends on gender, BMI, FEV1, and peakVO2, with only BMI and peakVO2 predicting survival. The impaired Pimax in CHF might be a result of catabolism and weight loss and is not a predictive factor in itself.

Performance of the high-resolution atmospheric model HRRR-AK for correcting geodetic observations from spaceborne radars

[1] Atmospheric phase delays are considered to be one of the main performance limitations for high-quality satellite radar techniques, especially when applied to ground deformation monitoring. Numerical weather prediction (NWP) models are widely seen as a promising tool for the mitigation of atmospheric delays as they can provide knowledge of the atmospheric conditions at the time of Synthetic Aperture Radar data acquisition. However, a thorough statistical analysis of the performance of using NWP production in radar signal correction is missing to date. This study provides a quantitative analysis of the accuracy in using operational NWP products for signal delay correction in satellite radar geodetic remote sensing. The study focuses on the temperate, subarctic, and Arctic climate regions due to a prevalence of relevant geophysical signals in these areas. In this study, the operational High Resolution Rapid Refresh over the Alaska region (HRRR-AK) model is used and evaluated. Five test sites were selected over Alaska (AK), USA, covering a wide range of climatic regimes that are commonly encountered in high-latitude regions. The performance of the HRRR-AK NWP model for correcting absolute atmospheric range delays of radar signals is assessed by comparing to radiosonde observations. The average estimation accuracy for the one-way zenith total atmospheric delay from 24 h simulations was calculated to be better than ∼14 mm. This suggests that the HRRR-AK operational products are a good data source for spaceborne geodetic radar observations atmospheric delay correction, if the geophysical signal to be observed is larger than 20 mm.

Exercise capacity affects quality of life in patients with pulmonary hypertension

BACKGROUND

The objective of this prospective study was to evaluate the impact of exercise capacity, mental disorders, and hemodynamics on quality-of-life (QoL) parameters in patients with pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH).

METHODS

Sixty-three patients with invasively diagnosed PAH (n = 48) or CTEPH (n = 15) underwent a broad panel of assessments, including cardiopulmonary exercise testing (CPET), 6-minute walking distance (6-MWD), World Health Organization functional class (WHO-FC), and assessment of hemodynamics. QoL was evaluated by the 36-item Medical Outcome Study Short Form Health Survey Questionnaire (SF-36). Exercise capacity, hemodynamics, age, gender, and mental disorders (anxiety and depression) were assessed for association with QoL subscores by uni- and multivariate regression analyses.

RESULTS

Exercise capacity, WHO-FC, oxygen therapy, symptoms of right heart failure, right atrial pressure, and mental disorders were significantly associated with QoL (p < 0.05). In the stepwise backward selection multivariate analysis, depression remained an independent parameter in seven of eight subscales of the SF-36. Furthermore, peak oxygen uptake (peakVO2) during CPET, 6-MWD, anxiety, long-term oxygen therapy, right heart failure, and age remained independent factors for QoL. Hemodynamic parameters at rest did not independently correlate with any domain of the SF-36 QoL subscores.

CONCLUSIONS

Mental disorders, exercise capacity, long-term oxygen therapy, right heart failure, and age play important role in the quality of life in patients with PAH and CTEPH.

High-sensitive Troponin T increase after exercise in patients with pulmonary arterial hypertension

Background

The current study aimed to investigate the release of myocardial high-sensitive Troponin T (hsTnT) in patients with pulmonary arterial hypertension (PAH) in response to maximal physical exercise.

Methods

In 24 patients with PAH, symptom-limited cardiopulmonary exercise testing was performed. hsTnT was measured by the novel hsTnT assay with a lower limit of detection of 2 ng/L and a total imprecision of less than 10% at the 99^th percentile value. hsTnT was related to NT-proBNP, WHO functional class and right ventricular (RV) function. Serial measurement was performed before and 30 min, 180 min, and 300 min after exercise. Healthy volunteers served as a control group.

Results

In 21 PAH patients, hsTnT levels were detectable before exercise with a close correlation between hsTnT and NT-proBNP. hsTnT was detectable in all PAH patients after exercise and significantly increased from 7.5 ng/L at baseline to 14.62 ng/L after 300 min, whereas levels of NT-proBNP remained constant with time.

Conclusions

Using the novel hsTnT assay, the current study provides first evidence that hsTnT levels increase in PAH patients after maximal physical exercise, while levels of other biomarkers remain constant after exercise testing. This might provide new insights into pathophysiology and individual risk assessment in patients with PAH.

[Exercise testing in respiratory medicine]

This document replaces the DGP recommendations published in 1998. Based on recent studies and a consensus conference, the indications, choice and performance of the adequate exercise testing method in its necessary technical and staffing setting are discussed. Detailed recommendations are provided: for arterial blood gas analysis and right heart catherterization during exercise, 6-minute walk test, spiroergometry, and stress echocardiography. The correct use of different exercise tests is discussed for specific situations in respiratory medicine: exercise induced asthma, monitoring of physical training or therapeutical interventions, preoperative risk stratification, and evaluation in occupational medicine.

Osteopontin predicts adverse right ventricular remodelling and dysfunction in pulmonary hypertension

BACKGROUND

Osteopontin (OPN) was found upregulated in several heart failure models and appears to play an important role in myocardial remodelling. As we have previously demonstrated that OPN predicts mortality in patients with pulmonary hypertension (PH), we now evaluated whether OPN also predicts adverse right ventricular (RV) remodelling and dysfunction in PH.

METHODS

We prospectively included 71 patients with PH of different etiology in this study. OPN plasma level were determined by ELISA and assessed for correlation with RV dilatation and dysfunction determined by echocardiography.

RESULTS

OPN plasma values significantly correlated with RV end-diastolic diameter, Tricuspid Annular Plane Systolic Excursion (TAPSE) and Tricuspid Annular Systolic Velocity (TASV) (r = 0·43, P = 0·0002; r = -0·46, P = 0·0006; r = -0·31, P = 0·02). Furthermore, stratification of our study population according to RV end-diastolic diameter and RV dysfunction revealed that patients with enlarged and functionally impaired RV's display higher OPN levels (956 ng/mL vs. 628 ng/mL, P = 0·0005; 1108 ng/mL vs. 792 ng/mL; P = 0·02). Next, we determined OPN cut-off values for the detection of RV remodelling and dysfunction by receiver operating curve analyses and further stratified these parameters in a multivariate analysis. Here, OPN emerged as an independent predictor of RV dilatation and dysfunction. Finally, we demonstrate synergism of OPN and NT-proBNP in the prediction of RV dilatation and dysfunction by calculation of the Rothman Synergy Index.

CONCLUSION

In summary, OPN predicts adverse RV remodelling and dysfunction in PH. Together with our previously published data regarding OPN's value for the prognostication of death in PH, we believe that OPN can improve risk stratification in patients with PH beyond current assessment standards.

Local anaesthetic surgical treatment of severe objective pulsatile tinnitus: a useful technique

Objective pulsatile tinnitus is a rare condition with an often dramatic presentation. We present the case of a 70-year-old woman who presented with over two years' history of unilateral distressing objective pulsatile tinnitus. Carotid arteriography revealed a highly tortuous internal carotid artery. Computed tomography of the ipsilateral temporal bones showed a large jugular bulb. Internal jugular vein ligation under local anaesthetic yielded immediate resolution of her symptoms.

[The first 24 hours: acute dyspnea]

Acute dyspnea is a common presentation in the emergency department. Immediate diagnostic strategy and efficient management is crucial. Therefore, a diagnostic work up consisting of a brief medical history, physical examination and technical investigations, including laboratory tests, is presented. Identification of the cardio-vascular, pulmonary or other etiology enables the initiation of adequate therapy. This is outlined in detail for three common entities.

Changes in spirometry over time in uremic patients receiving long-term hemodialysis therapy

Complications of respiratory system in patients suffering from chronic renal failure who are treated with regular haemodialysis are well known. However, the influence of the duration of haemodialysis on pulmonary function is less understood. The aim of this study was to determine spirometry changes in patients on chronic haemodialysis over a five-year period. We tested 21 patients, out of which 11 female and 10 male, mean age of 50 (+/- 11) years. The mean duration of haemodialysis was 52.2 (+/- 44.7) months at the time of the inclusion. We performed spirometry testings in all patients, one hour before start and one hour after completion of haemodialysis. All parameters of spirometry recorded one hour after completion of haemodialysis (FVC, FEV1, FEF75, 50, 25, % of predicted), improved significantly (p < 0.01). After five years, only FVC demonstrated significant decline and none of the recorded spirometry parameters improved significantly one hour post haemodialysis compared to pre-haemodialysis period. Analysis of post-dialysis parameters of spirometry at the study onset and following five years of haemodialysis showed that all parameters, except FEF50 (p > 0.05), significantly deteriorated (p < 0.01). Patients who are on long-term haemodialysis show a significant decline in FVC following five years of treatment. Although the spirometry changes in observed population treated with chronic haemodialysis have reversible character during the first years of renal replacement therapy, five years after these changes become irreversible.

A purging procedure for pantoprazole and 4-lumen catheters to prevent IV drug incompatibilities

OBJECTIVE OF THE STUDY

The purpose of this prospective intervention study was to assess the number of patients with Y-site incompatibilities before and after implementation of quality improvement measures to prevent incompatibilities consisting of a focused instruction for pantoprazole as a drug frequently involved in incompatible drug pairs and of a recommendation to use 4-lumen instead of 3-lumen catheters to increase the number of available central infusion lines.

SETTING

Cardiovascular intensive care unit where several standard operating procedures (SOPs) dealing with compatibility were already in place.

METHOD

In a prospective intervention study, patients' IV medication was assessed for potential incompatibilities using a database containing compatibility information on approximately 60,000 drug pairs. In a first period, routine administration was monitored in 53 consecutive patients (control group). Then, quality improvement measures were implemented recommending a purging procedure before and after bolus administration of pantoprazole as a drug frequently causing incompatibilities in this setting. Additionally, the use of 4-lumen instead of 3-lumen catheters was suggested whenever considered useful by the responsible physicians. The monitoring was repeated during a second period in another 58 patients consecutively admitted to the same unit (intervention group).

MAIN OUTCOME MEASURE

Overall number of patients with at least one incompatible drug pair and number of patients receiving incompatible pantoprazole combinations.

RESULTS

The number of patients receiving incompatible pantoprazole combinations decreased from 15 of the 15 patients receiving pantoprazole (100.0%) in controls to 9/16 (56.2%) in the intervention group (P < 0.01). The overall number of patients with incompatibilities was not influenced by the intervention with 36/58 (62.1%) compared to controls with 38/53 (71.7%, P = 0.28). The fraction of central lines contributed by four lumen central catheters was larger due to the intervention (80/168 lines, 47.6%) compared to controls (16/184, 8.7%, P < 0.001). Only sporadically there were incompatible combinations of drugs governed by the already existing SOPs.

CONCLUSION

In an intensive care setting with good SOP adherence, purging before and after administration decreased the respective incompatibility rate whereas the use of 4-lumen instead of 3- lumen catheters had not the expected benefit on separating drug pairs.

Riociguat for chronic thromboembolic pulmonary hypertension and pulmonary arterial hypertension: a phase II study

We assessed the therapeutic potential of riociguat, a novel soluble guanylate cyclase stimulator, in adults with chronic thromboembolic pulmonary hypertension (CTEPH; n = 42) or pulmonary arterial hypertension (PAH; n = 33) in World Health Organization (WHO) functional class II/III. In this 12-week, multicentre, open-label, uncontrolled phase II study, patients received oral riociguat 1.0-2.5 mg t.i.d. titrated according to systemic systolic blood pressure (SBP). Primary end-points were safety and tolerability; pharmacodynamic changes were secondary end-points. Riociguat was generally well tolerated. Asymptomatic hypotension (SBP <90 mmHg) occurred in 11 patients, but blood pressure normalised without dose alteration in nine and after dose reduction in two. Median 6-min walking distance increased in patients with CTEPH (55.0 m from baseline (390 m); p<0.0001) and PAH (57.0 m from baseline (337 m); p<0.0001); patients in functional class II or III and bosentan pre-treated patients showed similar improvements. Pulmonary vascular resistance was significantly reduced by 215 dyn·s·cm(-5) from baseline (709 dyn·s·cm(-5); p<0.0001). 42 (56%) patients were considered to have experienced drug-related adverse events (AEs; 96% mild or moderate). Dyspepsia, headache and hypotension were the most frequent AEs. Study discontinuation because of AEs was 4%. These preliminary data show that riociguat has a favourable safety profile and improves exercise capacity, symptoms and pulmonary haemodynamics in CTEPH and PAH. Randomised controlled trials are underway.

Strain and strain rate echocardiography for evaluation of right ventricular dysfunction in patients with idiopathic pulmonary arterial hypertension

Optimizing the non-invasive imaging of right ventricular (RV) function is of increasing interest for therapy monitoring and risk stratification in patients with idiopathic pulmonary hypertension (IPAH). Therefore, this study evaluated strain and strain rate echocardiography as a tool for comprehensive assessment of RV function and disease severity in IPAH patients. In 30 IPAH patients [WHO functional classes II-IV; mean pulmonary artery pressure (mPAP) 48.8 +/- 12.5 mmHg; pulmonary vascular resistance (PVR) 7.9 +/- 5.3 Wood units] and in 10 matched healthy control subjects' two-dimensional echocardiography, 6-MWD and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels were obtained. In IPAH patients when compared with controls, RV systolic strain (-18.8 +/- 4.3 vs. -34.5 +/- 3.8%, p = 0.0016) and strain rate (-1.6 +/- 0.6 vs. -2.7 +/- 0.5 s(-1), p = 0.018) were significantly altered and correlated significantly with elevated NT-proBNP levels (r = 0.73 and r = 0.62; p < 0.001, respectively) and reduced 6-MWD (r = -0.76 and r = -0.81; p < 0.001). In IPAH patients, reduced strain correlated with both mPAP (r = 0.61, p = 0.01 for strain; and r = 0.55, p = 0.04 for strain rate, respectively), and PVR (r = 0.84, p < 0.001 for strain; and r = 0.67, p < 0.001 for strain rate, respectively). This study gives first comprehensive evidence that strain echocardiography allows accurate non-invasive assessment of RV function and disease severity in patients with IPAH.

Endothelin receptor antagonist and airway dysfunction in pulmonary arterial hypertension

BACKGROUND

In idiopathic pulmonary arterial hypertension (IPAH), peripheral airway obstruction is frequent. This is partially attributed to the mediator dysbalance, particularly an excess of endothelin-1 (ET-1), to increased pulmonary vascular and airway tonus and to local inflammation. Bosentan (ET-1 receptor antagonist) improves pulmonary hemodynamics, exercise limitation, and disease severity in IPAH. We hypothesized that bosentan might affect airway obstruction.

METHODS

In 32 IPAH-patients (19 female, WHO functional class II (n = 10), III (n = 22); (data presented as mean +/- standard deviation) pulmonary vascular resistance (11 +/- 5 Wood units), lung function, 6 minute walk test (6-MWT; 364 +/- 363.7 (range 179.0-627.0) m), systolic pulmonary artery pressure, sPAP, 79 +/- 19 mmHg), and NT-proBNP serum levels (1427 +/- 2162.7 (range 59.3-10342.0) ng/L) were measured at baseline, after 3 and 12 months of oral bosentan (125 mg twice per day).

RESULTS AND DISCUSSION

At baseline, maximal expiratory flow at 50 and 25% vital capacity were reduced to 65 +/- 25 and 45 +/- 24% predicted. Total lung capacity was 95.6 +/- 12.5% predicted and residual volume was 109 +/- 21.4% predicted. During 3 and 12 months of treatment, 6-MWT increased by 32 +/- 19 and 53 +/- 69 m, respectively; p < 0.01; whereas sPAP decreased by 7 +/- 14 and 10 +/- 19 mmHg, respectively; p < 0.05. NT-proBNP serum levels tended to be reduced by 123 +/- 327 and by 529 +/- 1942 ng/L; p = 0.11). There was no difference in expiratory flows or lung volumes during 3 and 12 months.

CONCLUSION

This study gives first evidence in IPAH, that during long-term bosentan, improvement of hemodynamics, functional parameters or serum biomarker occur independently from persisting peripheral airway obstruction.

[Diagnostic value of peak flow variability in patients with suspected diagnosis of bronchial asthma in general practice]

BACKGROUND

National guidelines advice self measurement of peak flow variability as a diagnostic tool for asthma. However, its actual value for this purpose remains controversial.

PATIENTS AND METHODS

219 persons were recruited by 14 general practitioners after they presented themselves for the first time with symptoms suspicious of obstructive airway disease. They were asked to measure and record peak expiratory flow (PEF) three times daily for two weeks. PEF variability was calculated with three different indices and compared to the post bronchodilator FEV (1) response or methacholine inhalation challenge.

RESULTS

132 (60.3 %) patients completed the peak flow diary. 60 (45.5 %) of them were found to have asthma. But the sensitivity, specificity and predictive values of PEF variability were low. The number of daily measurements did not enhance diagnostic accuracy. Variation of the cut-off value (PEF variability > 25 %) increased the probability for asthma to 77.8 %. However, only one out of six had PEF variability > 25 %. None of the three methods sufficed to rule out asthma.

CONCLUSION

The diagnostic accuracy of PEF variability was low. Thus, in case of inconclusive spirometric results in general practice bronchial provocation remains an essential tool for diagnosing asthma. Diagnostic algorithms, as recommended by national guidelines, should be reconsidered in relation to the diagnostic value of peak flow variability.

Randomized clinical trial of folate supplementation in patients with peripheral arterial disease

BACKGROUND

The aim was to determine whether folate supplementation improved arterial function in patients with peripheral arterial disease (PAD).

METHODS

Individuals with PAD were randomly assigned to receive 400 microg folic acid (45 patients) or 5-methyltetrahydrofolate (5-MTHF) (48) daily, or placebo (40) for 16 weeks. Primary endpoints were changes in plasma total homocysteine (tHcy), ankle : brachial pressure index (ABPI) and pulse wave velocity (PWV). Secondary outcomes were changes in plasma inflammatory markers.

RESULTS

Plasma tHcy was significantly reduced in folic acid and 5-MTHF groups compared with controls: median difference: - 2.12 (95 per cent confidence interval - 3.70 to - 0.75) micromol/l (P = 0.002) and - 2.07 (-3.48 to - 0.54) micromol/l (P = 0.007) respectively. ABPI improved significantly: median difference 0.07 (0.04 to 0.11) (P < 0.001) and 0.05 (0.01 to 0.10) (P = 0.009) respectively. Brachial-knee PWV (bk-PWV) decreased significantly in individuals receiving 5-MTHF and tended to be reduced in those taking folic acid compared with controls: median difference: - 1.10 (-2.20 to - 0.20) m/s (P = 0.011) and - 0.90 (-2.10 to 0.00) m/s (P = 0.051) respectively. Plasma levels of inflammatory markers were not affected.

CONCLUSION

Folate administration reduced plasma homocysteine, and slightly improved ABPI and bk-PWV.

Low levels of prothrombin time (INR) and platelets do not increase the risk of significant bleeding when placing central venous catheters

BACKGROUND AND PURPOSE

Central venous catheters are frequently placed in intensive care medicine for multiple indications. The risk of severe bleeding after cannulation is considered to be increased in patients with abnormal coagulation, common in critically ill patients.

PATIENTS AND METHODS

This open prospective trial, performed at two medical intensive care units and one hematology intermediate care ward, investigated whether insertion of a central venous catheter in patients with coagulopathy (prothrombin time <or= 50% [International Normalized Ratio, INR, >or= 1.5] and/or platelets <or= 50 x 10(9)/l) bears an increased risk of bleeding.

RESULTS

In 196 patients with and without severe disorders of hemostasis, no significant difference in decrease of hemoglobin after catheter placement was observed. In addition, no correlation between a significant drop in hemoglobin and increased levels of creatinine or urea was seen. Mechanical complications were similar in frequency compared to previous publications.

CONCLUSION

These findings demonstrate that coagulation disorders with altered prothrombin time (INR) or platelets do not increase the risk of significant bleeding when inserting a central venous catheter. Therefore, the prophylactic correction of coagulation by transfusion of blood products or coagulation factors is not necessary before central venous catheter insertion.

[The heart and weaning]

The initiation of and weaning from mechanical ventilation with extubation cause significant changes in intrathoracic pressures and have profound consequences for the cardiovascular function. However, in spite of the known pathophysiological relationships, frequently little attention is paid to the cardiovascular situation during the weaning period. The currently available guidelines concerning weaning and extubation/reintubation are based on only limited evidence and are thus rather general. Moreover, recommendations for the cardiovascular management during weaning reflect mainly the pathophysiological rationale. In patients with known cardiac disease, studies have demonstrated the necessity for a prolonged weaning process. On the contrary, many intensive care patients have subclinical or undiagnosed cardiac disease, and cardiovascular compensation mechanisms are frequently hampered by the underlying critical illness. Therefore, in a significant proportion of patients, weaning and extubation attempts fail due to the patient's limited cardiovascular reserves. This review summarises the relevant information for a successful weaning and extubation with special respect to the cardiovascular function.