[Early Pulmonary Rehabilitation after Long Term Mechanical Ventilation]

Einleitung  Unter Frührehabilitation versteht man eine frühzeitig bei- oder nach akuter Erkrankung einsetzende, rehabilitationsmedizinische Behandlung die im § 39SGB V verankert ist. Ziel dieser Untersuchung ist es, die Ergebnisqualität der pneumologischen Frührehabilitation zu untersuchen und darzustellen.

Methoden  Prospektive Erhebung von funktionellen Parametern, Beatmungsstatus und Entlass-Disposition in einer spezialisierten Abteilung für pneumologische Frührehabilitation über den Zeitraum von einem Jahr.

Ergebnisse  Von den 190 Patienten waren 179 (94,2 %) zuvor invasiv beatmet. Während einer Behandlungsdauer von 39 ± 17 Tagen stieg der FAM-Index von 84,4 ± 19,8 auf 118,5 ± 23,3 (Ci 30,9 – 37,3, Cohen’s d 1,58; p < 0,001), der Barthel-Index von 30,5 ± 13,8 auf 58,3 ± 16,2 (Ci 25,4 – 33,8, Cohen’s d 1,4; p < 0,001) und die Wegstrecke von 12,9 ± 40,1 m auf 131,4 ± 85,2 m (Ci 105,6 – 131,4 m, Cohen’s d 1,78; p < 0,001). Die Patienten wurden weniger häufig in eine weitere Anschlussheilbehandlung verlegt, wenn sie beatmet waren.

Diskussion  Patienten in der pneumologischen Frührehabilitation sind bei Aufnahme schwer kompromittiert, es lässt sich aber eine sehr gute Ergebnisqualität erzielen, die unabhängig davon zu sein scheint, ob der Patient eigenständig atmet oder mittels nicht-invasiver oder invasiver Beatmung versorgt wird. Die weitere Disposition dieser Patienten ist vor allem dann schwierig, wenn eine Beatmung vorliegt.

[The Role of Air Pollutants for Health - A Reply to the Expert Opinion of the International Society for Environmental Epidemiology (ISEE) and the European Respiratory Society (ERS)]

In Deutschland gibt es regionale Fahrverbote für ältere Dieselfahrzeuge ohne SCR-Katalysator bei Überschreitung der Grenzwerte für NO2. Dies hat zu einer intensiven Diskussion über die Rolle der Luftschadstoffe für die Gesundheit geführt. In der Replik wird dargestellt, dass die Daten zur Wirkung von Stickstoffdioxid (NO2) und Feinstaub (PM10 und PM2,5) nicht ausreichen, um die Fahrverbote zu begründen.

Für NO2 gibt es passagere Reaktionen bei unbehandelten Asthmatikern ab 500 µg/m3. Die deutschen Grenzwerte (Jahresmittelwert 40 µg/m3) fußen im Wesentlichen auf einer Metaanalyse von 9 Studien aus Innenraumbelastungen wobei nur in 4 Studien NO2 gemessen wurde. In der großen europäischen Escape-Studie von 2014 wurde kein Einfluss von NO2 auf die Mortalität gefunden.

Als Surrogatparameter für andere Schadstoffe ist NO2 ebenfalls nicht mehr geeignet, da seit Einführung der Partikelfilter bei Dieselautos (etwa ab 2000) der KFZ-Anteil am Feinstaub an der Straße unter 10 % liegt. Der Feinstaub besteht im Wesentlichen aus Aufwirbelung von mineralischen, organischen Bodensubstanzen sowie Reifenabrieb und wird am stärksten durch Wetterphänomene, vor allen Dingen durch Sonneneinstrahlung beeinflusst.

Die Grenzwerte für NO2 und Feinstaub werden errechnet aus epidemiologischen Beobachtungsstudien. Es findet sich zumeist eine schwache Assoziation zwischen der Konzentra-tion und zahlreichen Erkrankung sowie der Mortalität. Epidemiologische Beobachtungsstudien erlauben nur die Bildung einer Hypothese. Permanente Wiederholungen der Beobachtungsstudien betätigen nur, dass manche gefundenen Phänomene nicht zufällig sind. Eine Kausalität kann daraus nicht abgeleitet werden, da es zahlreiche Erklärungsmodelle neben dem NO2 und Feinstaub gibt. Dazu wären Interventionsstudien im Niedrigdosisbereich sowie Tierexperimente erforderlich. Diese Daten fehlen nahezu komplett bzw. sind, soweit vorhanden, allesamt negativ.

Nie diskutiert wird eine starke Widerlegung der Hypothese der Gefährdung von NO2 und Feinstaub im Grenzwertbereich durch das Inhalationsrauchen. Die Raucher stellen quasi einen inhalationstoxikologischen Großversuch dar. Der Zigarettenrauch enthält sehr hohe Feinstaub-, Stickstoffmonoxid- (NO) und NO2-Konzentrationen, die vom Organismus erstaunlich gut toleriert werden. Das hängt damit zusammen, dass NO ein Naturstoff ist, der in den Zellen oder auch in den Nasennebenhöhlen in z. T. sehr hohen Konzentrationen (über 30 000 µg/m3) vorkommt. Eines der Abbauprodukte von NO ist NO2, was im Wasser zu Nitrat und Nitrit disproportioniert wird. Ein Teil von NO2 wird zur Synthese von Fettsäuren verwendet.

Zigaretten haben ein Kondensat von ca. 7 – 10 mg. Nimmt man als Vergleich eine lebenslange Dauerbelastung durch Feinstaub und NO2 in den Grenzwertkonzentrationen an, müssten alle Raucher nach wenigen Tagen bis Monaten zahlreiche Erkrankungen entwickeln, die dem Feinstaub und NOx angelastet werden. Auch die Mortalität müsste drastisch erhöht sein; nahezu alle Raucher müssten bereits nach 1 packyear verstorben sein. Der Unterschied wird noch größer, wenn man die nachgewiesene Toxizität und Kanzerogenität des Zigarettenrauchs im Vergleich zu dem i. d. R. deutlich weniger gefährlichen Feinstaub an der Straße ins Verhältnis setzt.

Therapeutic Chemical Screen Identifies Phosphatase Inhibitors to Reconstitute PKB Phosphorylation and Cardiac Contractility in ILK-Deficient Zebrafish

Patients with inherited dilated cardiomyopathy (DCM) often suffer from severe heart failure based on impaired cardiac contractility leading to increased morbidity and mortality. Integrin-linked kinase (ILK) as a part of the cardiac mechanical stretch sensor was found to be an essential genetic regulator of cardiac contractility. Integrin-linked kinase localizes to z-disks and costameres in vertebrate hearts and regulates the activity of the signaling molecule protein kinase B (PKB/Akt) by controlling its phosphorylation. Despite identification of several potential drug targets in the ILK signaling pathway, pharmacological treatment strategies to restore contractile function in ILK-dependent cardiomyopathies have not been established yet. In recent years, the zebrafish has emerged as a valuable experimental system to model human cardiomyopathies as well as a powerful tool for the straightforward high-throughput in vivo small compound screening of therapeutically active substances. Using the ILK deficient zebrafish heart failure mutant main squeeze (msq), which shows reduced PKB phosphorylation and thereby impaired cardiac contractile force, we identified here, in an automated small compound screen, the protein phosphatase inhibitors calyculin A and okadaic acid significantly restoring myocardial contractile function by reconstituting PKB phosphorylation in msq ILK-deficient zebrafish embryos.

Die überschätzte Beeinflussung der Exazerbationsrate bei COPD durch Inhalativa (LABA, LAMA, ICS)

Durch zahlreiche Studien ist belegt, dass inhalative, langwirksame Beta-2-Mimetika (LABA) und Anticholinergika (LAMA) sowie Steroide (ICS) die Exazerbationsrate bei COPD signifikant reduzieren. Allerdings konnte auch in aufwendigen und länger dauernden Studien nicht gezeigt werden, dass diese Reduktion der Exazerbation auch die Lebenserwartung reduziert. Im Gegensatz dazu zeigen zahlreiche Studien, dass die Lebenserwartung mit zunehmender Schwere und Häufigkeit der Exazerbation vermindert wird.

In dieser Übersicht werden diese Studien gegenübergestellt und die Relevanz der Reduktion der Exazerbationsraten durch LABA, LAMA und ICS durch Bewertung ihrer Effektstärke mittels Cohen’s d bewertet. Dabei zeigt sich in den Studien ein gleiches Muster. Die Reduktion der Exazerbationsrate zeigt nur bei den geringen Schweregraden einen kleinen Effekt (Cohen’s d max. 0,21). Bei Exazerbation mit höherem Schweregrad und bei Vergleich der Substanzen untereinander fällt Cohen’s d unter 0,1, was zeigt, dass die Wirkung der Medikamente klinisch praktisch bedeutungslos ist. Die Wirkung von LABA, LAMA und ICS auf die Exazerbationsrate bei COPD ist deutlich überschätzt.

RNA splicing regulated by RBFOX1 is essential for cardiac function in zebrafish

Alternative splicing is one of the major mechanisms through which the proteomic and functional diversity of eukaryotes is achieved. However, the complex nature of the splicing machinery, its associated splicing regulators and the functional implications of alternatively spliced transcripts are only poorly understood. Here, we investigated the functional role of the splicing regulator rbfox1 in vivo using the zebrafish as a model system. We found that loss of rbfox1 led to progressive cardiac contractile dysfunction and heart failure. By using deep-transcriptome sequencing and quantitative real-time PCR, we show that depletion of rbfox1 in zebrafish results in an altered isoform expression of several crucial target genes, such as actn3a and hug. This study underlines that tightly regulated splicing is necessary for unconstrained cardiac function and renders the splicing regulator rbfox1 an interesting target for investigation in human heart failure and cardiomyopathy.

Summary: The zebrafish splicing regulator rbfox1 is necessary for tightly regulated splicing and unconstrained cardiac function, making it an interesting candidate for targeting during human cardiomyopathy.

[Standardization of spirometry: 2015 update. Published by German Atemwegsliga, German Respiratory Society and German Society of Occupational and Environmental Medicine]

Spirometry is a simple test and considered the gold standard in lung function. An obstructive ventilatory defect is a disproportionate reduction of maximal airflow from the lung in relation to the maximal volume that can be displaced from the lung. It implies airway narrowing and is defined by a reduced FEV1/FVC ratio below the 5th percentile of the predicted value (lower limit of normal, LLN). A restrictive disorder may be suspected when vital capacity (FVC) is reduced and FEV1/FVC is normal. It is definitely proven, however, only by a decrease in TLC below the 5th percentile of predicted value (LLN). The measurement of TLC by body plethysmography is necessary to confirm or exclude a restrictive defect or hyperinflation of the lung when FVC is below the LLN. 2012 a task force of the ERS published new reference values based on 74,187 records from healthy non-smoking males and females from 26 countries. The new reference equations for the 3-95 age range are now available that include appropriate age-dependent mean values and lower limits of normal (LLN). This presentation aims at providing the reader with recommendations dealing with standardization and interpretation of spirometry.

Crucial role of Plexin C1 for pulmonary inflammation and survival during lung injury

Acute pulmonary inflammation during lung injury is initiated by the migration of neutrophils into the alveolar space. The severity of these inflammatory changes within the pulmonary tissue determines the severity of lung injury and ultimately patient outcome. Recent work has demonstrated that the guidance protein Semaphorin 7A propagates the infiltration of neutrophils into an hypoxic tissue site, yet the role of its target receptor Plexin C1 (PLXNC1) during lung injury is to date unknown. We demonstrate here that PLXNC1(+) neutrophils are present within the alveolar space and that PLXNC1 is induced in vitro and in vivo during lung injury. In a model of high-pressure ventilation PLXNC1(-/-) animals show decreased signs of alveolar inflammation and improved survival compared with wild-type controls. Studies employing chimeric animals identified the hematopoietic expression of PLXNC1 to be of crucial importance for the observed results. Functional inhibition of PLXNC1 resulted in improved survival and ameliorated the signs of inflammation within the lung. Furthermore, the injection of a peptide binding to PLXNC1 resulted in improved survival and attenuated pulmonary inflammation. As such we demonstrate here, that previously unknown PLXNC1 holds significant importance for degree of pulmonary inflammation and determines outcome during experimental lung injury.

Right ventricular failure and pathobiology in patients with congenital heart disease - implications for long-term follow-up

Right ventricular dysfunction represents a common problem in patients with congenital heart defects, such as Tetralogy of Fallot or pulmonary arterial hypertension. Patients with congenital heart defects may present with a pressure or volume overloaded right ventricle (RV) in a bi-ventricular heart or in a single ventricular circulation in which the RV serves as systemic ventricle. Both subsets of patients are at risk of developing right ventricular failure. Obtaining functional and morphological imaging data of the right heart is technically more difficult than imaging of the left ventricle. In contrast to findings on mechanisms of left ventricular dysfunction, very little is known about the pathophysiologic alterations of the right heart. The two main causes of right ventricular dysfunction are pressure and/or volume overload of the RV. Until now, there are no appropriate models available analyzing the effects of pressure and/or volume overload on the RV. This review intends to summarize clinical aspects mainly focusing on the current research in this field. In future, there will be increasing attention to individual care of patients with right heart diseases. Hence, further investigations are essential for understanding the right ventricular pathobiology.

[Weaning from long-term mechanical ventilation: data of a single weaning center from 2007 to 2011]

INTRODUCTION

Regional weaning centers play a more and more important role in the weaning process of long-term ventilated patients. The medical center Kloster Grafschaft is one of the oldest and largest centers in Germany. There is very little published data from larger weaning centers in Europe.

METHODS

From 2007 to 2011 all weaning patients were registered in a database. Additional information of the transferring hospitals was inquired. Prolonged weaning was defined by a period of at least 7 days of mechanical ventilation as well as three unsuccessful weaning trials.

RESULTS

Data from 867 of 916 registered patients could be analyzed. 71.1% could be successfully weaned from mechanical ventilation. All patients were suffering from a hypercapnic insufficiency as well as a variety of secondary diagnoses, on average 15.1 per patient. The median of age was 70 years, 62 % were male. Prior to hospital transfer patients had been ventilated for a median of 41 days. Time to successful removal of the artificial airway was 8 days according to the DRG code directive and 13.4 days when non-invasive ventilation (NIV) time was included. Of the 616 patients who could be successfully weaned, 42 % were discharged on NIV. Out of the 251 patients who could not be weaned, 107 were discharged. The remaining 144 (16.7 %) patients died, 33 % due to the primary underlying disease or a complication. 66 % of the deceased patients received palliative care. Patients with successful and unsuccessful weaning did not differ by age, by duration of mechanical ventilation or time until tracheostomy. Postoperative patients could be weaned more often than medical patients (p < 0.05). Discrimination between patients with successful and unsuccessful weaning was not possible by the point in time of the first spontaneous breathing trial in regard to the duration of ventilation but only by the duration of this trial after transfer to our unit (150 vs. 60 min; p < 10-6). The TISS-28 and the SAPS-II-Score did not differ between the two groups. Patients with successful weaning had less agitation according to the RASS-Score (0.47 vs. 0.15; p < 0.005).

CONCLUSION

It becomes apparent that in a specialized weaning center the majority of difficult to wean patients can be liberated in short time from mechanical ventilation.

Alterations in cardiac DNA methylation in human dilated cardiomyopathy

Dilated cardiomyopathies (DCM) show remarkable variability in their age of onset, phenotypic presentation, and clinical course. Hence, disease mechanisms must exist that modify the occurrence and progression of DCM, either by genetic or epigenetic factors that may interact with environmental stimuli. In the present study, we examined genome-wide cardiac DNA methylation in patients with idiopathic DCM and controls. We detected methylation differences in pathways related to heart disease, but also in genes with yet unknown function in DCM or heart failure, namely Lymphocyte antigen 75 (LY75), Tyrosine kinase-type cell surface receptor HER3 (ERBB3), Homeobox B13 (HOXB13) and Adenosine receptor A2A (ADORA2A). Mass-spectrometric analysis and bisulphite-sequencing enabled confirmation of the observed DNA methylation changes in independent cohorts. Aberrant DNA methylation in DCM patients was associated with significant changes in LY75 and ADORA2A mRNA expression, but not in ERBB3 and HOXB13. In vivo studies of orthologous ly75 and adora2a in zebrafish demonstrate a functional role of these genes in adaptive or maladaptive pathways in heart failure.

Alterations in cardiac DNA methylation in human dilated cardiomyopathy

Dilated cardiomyopathies (DCM) show remarkable variability in their age of onset, phenotypic presentation, and clinical course. Hence, disease mechanisms must exist that modify the occurrence and progression of DCM, either by genetic or epigenetic factors that may interact with environmental stimuli. In the present study, we examined genome-wide cardiac DNA methylation in patients with idiopathic DCM and controls. We detected methylation differences in pathways related to heart disease, but also in genes with yet unknown function in DCM or heart failure, namely Lymphocyte antigen 75 (LY75), Tyrosine kinase-type cell surface receptor HER3 (ERBB3), Homeobox B13 (HOXB13) and Adenosine receptor A2A (ADORA2A). Mass-spectrometric analysis and bisulphite-sequencing enabled confirmation of the observed DNA methylation changes in independent cohorts. Aberrant DNA methylation in DCM patients was associated with significant changes in LY75 and ADORA2A mRNA expression, but not in ERBB3 and HOXB13. In vivo studies of orthologous ly75 and adora2a in zebrafish demonstrate a functional role of these genes in adaptive or maladaptive pathways in heart failure.

[Scope and limitations of the median nerve mouse model in research on peripheral nerve regeneration]

INTRODUCTION

Peripheral nerve regeneration is usually studied in rat animal models (N. medianus or N. ischiadicus). In this article, we further evaluate the mouse median nerve model with its advantages and possible pitfalls.

MATERIALS AND METHODS

24 mice (C57BL/6) were operated. The median nerve was exposed in the left axilla. After transection, immediate microsurgical repair followed using 11/0 sutures. In the contralateral axilla, 1 cm of median nerve was resected. After the operation, functional regeneration of the median nerve was assessed using the grasping test. Histological analysis was performed after staining with toluidine blue.

RESULTS

All animals survived the procedure. Grip strength increased starting at day 10 and reached its maximum at day 35. Myelinated fibres in the regenerated nerves showed a smaller diameter and a thinner myelin sheath and the typical microfasciculation of regenerated nerve fibres in comparison to the uninjured nerve.

CONCLUSION

The mouse median nerve model is technically demanding but opens a wide field of possible research options using genetically modified mice.

Body plethysmography--its principles and clinical use

Body plethysmography allows to assess functional residual capacity (FRC(pleth)) and specific airway resistance (sRaw) as primary measures. In combination with deep expirations and inspirations, total lung capacity (TLC) and residual volume (RV) can be determined. Airway resistance (Raw) is calculated as the ratio of sRaw to FRC(pleth). Raw is a measure of airway obstruction and indicates the alveolar pressure needed to establish a flow rate of 1 L s(-1). In contrast, sRaw can be interpreted as the work to be performed by volume displacement to establish this flow rate. These measures represent different functional aspects and should both be considered. The measurement relies on the fact that generation of airflow needs generation of pressure. Pressure generation means that a mass of air is compressed or decompressed relative to its equilibrium volume. This difference is called "shift volume". As the body box is sealed and has rigid walls, its free volume experiences the same, mirror image-like shift volume as the lung. This shift volume can be measured via the variation of box pressure. The relationship between shift volume and alveolar pressure is assessed in a shutter maneuver, by identifying mouth and alveolar pressure under zero-flow conditions. These variables are combined to obtain FRC(pleth), sRaw and Raw. This presentation aims at providing the reader with a thorough and precise but non-technical understanding of the working principle of body plethysmography. It also aims at showing that this method yields significant additional information compared to spirometry and even bears a potential for further development.

[Polycythemia]

Polycythemia is defined by the increase of hematocrit and haemoglobin respectively. Possible causes might be neoplastic diseases like polycythemia vera with proliferation of a cell clone. More often one will find reactive forms resulting from chronic hypoxemia. A physiologic form of polycythemia can be found in highlanders and athletes training at high altitude. With increasing frequency erytrhopoetin and it's analoga are being used as doping substances to induce Polycythemia. Red cell proliferation induced by chronic hypoxemia is the most common form in patients. In this instance the lung itself can be the cause (hypoxemia with hypocapnea in blood gas analysis) or hypoventilation caused by an insufficient respiratory pump (hypercapnea with hypoxemia in blood gas analysis) induces a compensatory Polycythemia. The former form can be treated with long term oxygen therapy and the latter by non-invasive ventilation, either approach corrects hypoxemia and reduces Polycythemia within some weeks.

[Protracted respiratory insufficiency - epidemiology and network on respiratory weaning after prolonged ventilation]

The prevalence of difficult or prolonged weaning from the ventilator is increasing due to a growing number of multi-morbid, elderly and pulmonary deficient patients being mechanically ventilated. Intensive care units (ICU) tend to refer difficult to wean patients to specialised weaning facilities. A survey of 38 centres - performed in 2006 - included a total number of 2718 patients with difficult or prolonged weaning. Almost three quarters of the patients were transferred to a weaning centre from an external ICU. The weaning success rate was 66.3 %. After weaning in 31.9 % of the patients, home mechanical ventilation was started. The overall hospital mortality rate was 20.8 %. Recently the task force "WeanNet" - a network of weaning units - was founded under the auspices of the German Thoracic Society. The main aim of WeanNet is to improve cooperation among the weaning centres and the quality of patient management. Important tools of WeanNet are (i) the register of weaning patients and (ii) accreditation of the weaning centres. To develop the register an intensive cooperation between the task force and the Institute for Lung Research (ILF) was necessary. The finished register is now logistically run by ILF. In less than 1 year after the official start, already 70 weaning units with ca. 3000 patients are registered. In future "WeanNet", in particular in terms of the register and the accreditation, will stand for the quality of weaning centres in Germany.