[Assurance of process-quality in pulmonary practice by means of a peer-review system--a pilot project]

Quality assurance and quality-management have been well anchored in social legislation for years. Peer-reviews to assure process-quality and quality of outcomes have been conducted repeatedly in centres for pulmonary medicine, facilities for pulmonary rehabilitation as well as centres for sleep-medicine. By means of a pilot study we wanted to investigate if assurance of process-quality is feasible and if a peer review system turns out to be a suitable method in pulmonary practice. Medical reports and/or diagnostic protocols of the investigational procedures such as pulmonary function tests, allergy-tests, induction test of bronchial hyperresponsiveness et cetera were randomly collected from nine patients with bronchial asthma or COPD in each of the 44 participating pulmonary practices and forwarded to three peer-reviewers respectively. 396 selected patient-datasets resulted in 1188 reviews. Peer review was conducted by means of a specially developed checklist of markers of process-quality accompanied by an explanatory manual. Measures of quality were determined for every pulmonary practice and a report of results was generated. The health economical efficacy of the therapy and the diagnostic process as well as an assessment of the overall process was evaluated by means of a visual analogue scale. No deficiencies could be detected in clearly more than half of the assessments. Major deficiencies or an unacceptable result in different items could be detected in every sixth assessment. For every item a graphic ranking in terms of benchmarking was generated for each individual report. Since peers were reviewers and subjects of review at the same time, they can now clearly improve and assure their diagnostic and therapeutic process-quality in patients with bronchial asthma and COPD by means of the experience they gained during the review process, as well as by the assessment they received. We were able to demonstrate that a peer-review-system is appropriate to assure process-quality in pulmonary practice and that it is feasible to achieve a continuous assurance and improvement of quality in the long run.

[Ethics of mechanical ventilation in end of life]

Invasiveness of interventions, complexity of diseases and patients' age are increasing in intensive care medicine. Ethical and legal issues are particularly challenging at the end of life of critically ill patients. At the borderline between intensive care and palliative medicine a significant amount of patients suffer from respiratory failure. Modern modes of mechanical ventilation may be able to improve ventilation and quality of life. On the other hand they may oppose a dignified death at the end of a long lasting chronic disease and e. g. prolong the suffering. In contrast to endotracheal intubation and invasive mechanical ventilation NIV enables patients to participate in the decision making process. While under normal circumstances, ethical standards dictate that patients themselves participate in the medical decision making process. For several reasons this is not always possible in intensive care medicine. However, chronically ill patients should get information from experts already at an early stage of the disease, go through a shared decision process and declare their will concerning interventions of intensive care medicine, e. g. mechanical ventilation. With respect to ethical and legal aspects of end of life this paper deals with chances of mechanical ventilation, including its withdrawal and withholding.

Pathophysiologische Grundlagen der mechanischen Beatmung

Mechanical ventilation is required if ventilatory insufficiency is present. This is typically indicated by hypercapnea. Hypoxemia occurs secondary to hypoventilation. Usually overload of the respiratory muscles (ventilatory pump) will be the underlying mechanism, for the most part caused by acute or chronic disease. In case of sole hypoxemia mechanical ventilation will only be indicated if the oxygen-content (equals oxygen saturation x haemoglobin x 1.39) drops below a critical threshold or if ventilatory pump failure is imminent on account of the underlying disease (eg. pneumonia). The background of our recommendations is to avoid potential damage caused by mechanical ventilation. Especially high inspiratory pressures and oxygen concentrations can be harmful to the lung. Therefore every case has to evaluated for individual target parameters of ventilation. The use of the oxygen-content instead of the arterial oxygen pressure as the target parameter will usually lead to a more careful ventilation. Cardiogenic pulmonary oedema is an exception to this rule since inspiratory positive pressure and PEEP will result in improved diffusion as well as reduction of preload and work of breathing. In recent years progress has been made on the field of ventilation access especially in severe and acute cases. Non-invasive ventilation is superior to invasive ventilation in patients with exacerbated COPD since it improves outcome effectively. This is being caused by a decline in ventilator associated pneumonias, most likely because non-invasive ventilation allows patients to clear their secretions by coughing, resulting in improved lung clearance. Controlled ventilation allows optimal unloading of the respiratory muscles which have been overloaded by the underlying disease. Application of a controlled ventilation mode in acute disease will usually require some kind of sedation. Assisted ventilation will result in improved gas exchange but only incomplete unloading of respiratory muscles and therefore delayed restitution. Permanent controlled ventilation under sedation for a prolonged period (days) requires intermittent periods of assisted- or spontaneous breathing in order to avoid atrophy of the respiratory muscles. This review summarizes background information on the nature of the derangement, the relation between oxygen supply and consumption under special consideration of respiratory muscle insufficiency and impact of different ventilation modes.

[Recommendations for the treatment of respiratory complications in case of a viruspandemic]

In case of a viral pandemic without availability of effective vaccination, one can expect to be faced with additional 250 to 300 new admissions per hospital per week given the worst case scenario. Major complications are expected to occur in the respiratory system with the focus on viral pneumonia often complicated by bacterial superinfection. Frequently these patients will require artificial ventilation. The present infrastructure will not be capable of dealing sufficiently with such high numbers of casualties. These recommendations of the German Society for Pneumonology are based on the successful application of non-invasive ventilation for acute respiratory failure in recent years. It is of importance to achieve effective treatment by the use of relative simple means. The recommendation proposes to use a separate building in order to realize quarantine. In terms of diagnostic tools, a simple x-ray apparatus should be available. To monitor patients pulsoxymetry and ECG devices should be sufficient in most cases. For the treatment of acute respiratory insufficiency a sufficient number of ventilators, masks, tubing systems and filters should be kept in stock. In terms of medical treatment antibiotics to treat superinfections are of major importance. Analgesics, sedatives and intravenous fluids will also be needed. Oxygen should be available for every single patient. The recommendation gives detailed advise for the enforcement of hygiene control, diagnostic as well as therapeutic steps for in hospital treatment of high numbers of casualties of a viral pandemic.

Die CT-gestützte perthorakale Punktion von peripheren Lungenrundherden mit Hilfe einer speziellen Punktionsnadel

Peripheral pulmonary nodules are difficult to reach bronchoscopically, so for a long time it has been tried, by the use of imaging techniques like X-ray, ultrasound and computed tomography, to aspirate these nodules for exact histological diagnosis. The computed tomography offers the best spatial orientation for methodical reasons, thus this technique is performed increasingly and with great accuracy in pulmonary lesions. Complications like bleeding into lung parenchyma or small pneumothorax after aspiration can be detected easier by computed tomography. In this study we evaluated the use of a special bioptic technique with the AUTOVAC(R) needle in 30 cases. Causing low parenchymal damage to the lung, this bioptic needle enables extraction of representative tissue samples for further pathological examination. In 21 of 30 (70 %) cases the histological specimen led to the diagnosis of malignancy, but 8 of those malignant specimen could have been verified as primary or secondary malignancy by using additional immunocytochemical techniques. In 2 of 30 cases (7 %) harmless hemorrhage into lung parenchyma occured after aspiration. In another 4 of 30 (13 %) cases pneumothorax occurred, requiring chest tube placement. The ct-guided lung biopsy with the AUTOVAC(R) needle represents a safe, low resilient diagnostic tool to obtain large tissue samples of specimen in good quality. Even in patients with compromised lung function because of severe chronic obstructive lung disease and/or emphysema, the described aspiration technique can be performed, if at the moment of aspiration procedure a pneumologist with corresponding equipment and trained medical staff is present, in order to place a chest tube in case of pneumothorax.

[Inhalation therapy with Respimat soft inhaler in patients with COPD and asthma]

Developing more effective and convenient inhalation devices for the treatment of obstructive pulmonary diseases is at least as important as designing new drugs. In recent years, existing inhalation systems have undergone many technical modifications and there have also been many new developments. All of these systems have their own particular attributes and characteristics. Two fundamentally different modes of operation are represented by propellant-driven metered-dose inhalers (pMDI) on the one hand and dry powder inhalers (DPI) on the other. However, none of the systems developed so far can be considered ideal. The Respimat Soft Inhaler (Respimat SI) was developed in the light of experience with previous systems and was launched in Germany at the beginning of 2004. The aim in developing this new type of inhaler was to avoid the well-known drawbacks typically associated with pMDI and DPI. The Respimat SI requires neither a chemical propellant nor batteries. The active ingredients are dissolved in water and the solution is atomised using mechanical energy only imparted by a spring which, when released, provides the power to force the solution through an extremely fine nozzle system. Two fine jets of liquid are produced. They converge at an optimised angle and the resulting impact generates a fine mist which is slow-moving and lasts for about 1.5 seconds; moreover, a high proportion of the droplets fall into the fine particle fraction. All of these features allow excellent lung deposition and reduced oropharyngeal deposition. Coordination between actuation and inhalation is less critical as compared with pMDI due to the fact that the mist is both slow-moving and long-lasting. A further advantage is that the mist is generated independently of the patient's inspiratory flow. The Respimat SI meets the requirements for an ideal inhaler better than any other previous device and must therefore be regarded as a significant new development.

[Respiratory therapist: introduction of a new profession]

Respiratory therapists are healthcare professionals taking care of patients with pulmonary disorders. They are an allied health specialty, practicing under medical direction. The professionalism of nurses and therapists must grow up to act successfully in new fields of medicine, where evidence-based independent action is necessary. Specialized therapists can help us coordinate separated processes (diagnoses, therapy and nursing). The profession "Respiratory Therapist" was created in the United States 50 years ago. We intend to introduce this profession also in Germany. We follow many other countries who have already taken this step. We hope that we can reach yet a higher quality of patient care.

Anti-GM-CSF antibodies in paediatric pulmonary alveolar proteinosis

BACKGROUND

Auto-antibodies against granulocyte-macrophage colony stimulating factor (GM-CSF) may be central to the pathogenesis of adult sporadic pulmonary alveolar proteinosis (PAP). The role of anti-GM-CSF auto-antibodies in paediatric forms of PAP is as yet unclear.

METHODS

Anti-GM-CSF auto-antibodies were determined with the help of an antigen capture assay using serum and/or bronchoalveolar lavage (BAL) fluid from 27 patients with PAP (nine adults, 15 children, three neonates) and from 185 children with different diseases as disease controls (various pulmonary conditions and patients with malignancies).

RESULTS

Anti-GM-CSF auto-antibodies were detected in the serum of five of seven adult PAP patients. They were not found in the serum of any of the children or neonates with PAP nor in any of the disease control patients. Raised anti-GM-CSF titres were found in BAL fluid from three of four adult patients with PAP. Anti-GM-CSF auto-antibodies were detected in BAL fluid of only one of the 15 children (age at diagnosis 11 years, age at BAL 24 years) and in none of the neonates with PAP, nor in any of the disease control patients.

CONCLUSIONS

The presence of anti-GM-CSF auto-antibodies seems to define an autoimmune disease underlying most of the adult sporadic type of PAP, but age at diagnosis may cause an overlap with children in some rare instances. In most of the children and all of the neonates the anti-GM-CSF titres were not significantly increased, indicating that alternative explanations are needed for the pathogenesis of the disease in these patients.

Is the rhesus monkey (Macaca mulatta) comparable to humans? Histomorphology of the sphincteric musculature of the lower urinary tract including 3D-reconstruction

The physiology of the muscle systems of the human lower urinary tract is still not known in detail. To study the functional basics of this complex organ system, experiments are often performed in animal models including rhesus monkeys. To apply the results of animal model studies to the humans, a clear knowledge of the comparative anatomy of both species is necessary. However, detailed comparative studies of the lower urinary tract of the rhesus monkey and the humans are lacking. Accordingly, a detailed study on the sphincteric musculature of the lower urinary tract of the rhesus monkey was performed in order to demonstrate anatomical correspondences and differences between both species. The lower urinary tract anatomy was investigated in 18 male and female rhesus monkeys (Macaca mulatta) by serial sections. Immunohistochemical staining methods were used to differentiate striated and smooth musculature. Three-dimensional reconstructions were performed in order to demonstrate the topographical anatomy of the different muscle systems. In both man and male rhesus monkeys, a urethral sphincter muscle exists independent of the pelvic floor musculature, with a smooth and a striated muscular part. A urinary diaphragm (diaphragma urogenitale) does neither exist in the rhesus monkey nor in the human. In contrast to women, a striated muscle encircles the urethra and vagina together in the female rhesus monkey. A vesical sphincter muscle, found in the human bladder outlet, does not exist in the rhesus monkey.

Long-term oxygen therapy stops the natural decline of endurance in COPD patients with reversible hypercapnia

BACKGROUND

Respiratory muscle weakness is one of the most important causes of hypercapnia in patients with COPD. There is evidence that stable hypercapnic patients will benefit from long-term oxygen therapy (LTOT).

OBJECTIVES

The prognostic role of reversible hypercapnia in COPD is still unclear. Early implementation of LTOT in these patients may influence endurance time and mortality.

METHODS

In this pilot study, we investigated 28 patients (26 males, 49-74 years) with COPD, advanced airflow limitation [forced expiratory volume in 1 s (percentage of predicted value) 40.8 +/- 10.2] and mild hypoxaemia (pO(2) 66.5 +/- 6.3 mm Hg). All patients had developed a moderate reversible hypercapnia during an acute exacerbation or during exercise testing (peak pCO(2) 48.0 +/- 2.5 mm Hg). Patients were allocated randomly to a control group (n = 14) or an LTOT group (n = 14). The two groups were well matched in terms of physiological data. Lung function, endurance time (cycle ergometer), dyspnoea score, blood gases and LTOT compliance were measured at baseline and every 6 months over a period of 3 years.

RESULTS

Endurance time increased from 6.4 +/- 2.7 min at baseline to 7.1 +/- 2.7 min after 1 year in the LTOT group and decreased from 6.1 +/- 3.0 to 4.9 +/- 3.8 min in the controls (p < 0.05). After 1 year, the end-exercise dyspnoea score was significantly lower in the LTOT group (4.5 +/- 1.5) than in the controls (5.7 +/- 1.9).

CONCLUSION

COPD patients with reversible hypercapnia and mild hypoxaemia benefit from LTOT in terms of endurance time and a reduction of exertional dyspnoea after 1 year.

The use of APACHE II prognostic system in difficult-to-wean patients after long-term mechanical ventilation

BACKGROUND AND OBJECTIVE

To examine the calibration of the prognostic system Acute Physiology and Chronic Health Evaluation Score (APACHE II) regarding hospital mortality and predicting weaning outcome after long-term mechanical ventilation of the lungs.

METHODS

Prospective observational cohort study performed in a respiratory intensive care unit including 246 patients whose lungs were ventilated for 42.1+/-37.8 (median 30) days in the referring hospital. APACHE II (24 h after admission to our respiratory intensive care unit) and the cause of respiratory failure, underlying disease, prior duration of mechanical ventilation and gender were recorded. The predictive power was evaluated with sensitivity and specificity for different cut-off points and summarized in a receiver operating characteristic curve.

RESULTS

No difference was found between survivors (APACHE II 16.0+/-4.3) and non-survivors (APACHE II 16.9+/-5.1). In a mean time of 8.0+/-10.3 days, 146 patients (59.3%) were successfully weaned (APACHE II 15.2+/-3.5). One-hundred patients (40.7%) were considered unweanable (APACHE II 17.7+/-5.3). Recalibration of APACHE II to predict weaning failure was possible, resulting in an area under the receiver operating characteristic curve (AUC) of 0.638. Furthermore the AUC improved to 0.723 by changing the weights of selected APACHE items and introducing external factors. Diagnostic accuracy fell from group with mechanical ventilation < or =25 days (AUC 0.770) to group with mechanical ventilation >50 days (AUC 0.517).

CONCLUSIONS

APACHE II did not predict hospital mortality after long-term mechanical ventilation of the lungs. Not the original APACHE II but a recalibrated and adapted APACHE II can be useful to predict weaning outcome in patients with less than 25 days of prior lung ventilation.

[Powder inhalation systems]

Inhalation of bronchodilators and corticosteroids is the mainstay treatment for patients with obstructive lung diseases. Many dry powder inhaler devices and drug combinations are now available, and competing promotional claims can confuse both prescribers and patients. The appropriate dose of a given drug may be different for a pressurized metered dose inhaler (pMDI) and a dry powder inhaler (DPI). DPIs create aerosols by drawing air through an aliquot of dry powder. The powder contains either micronized (< 5 micro m in diameter) drug particles bound into loose aggregates, or micronized drug particles that are loosely bound to large (> 30 micro m in diameter) lactose or glucose particles. Usually, the drug particles are bound to carrier particles and are stripped form the carrier particles by the energy provided by the patientacute;s inhalation. The release of respirable particles of the drug requires inspiration at relatively high flow rates (30 - 120 L/min). Other important factors influencing aerosol generation and lung deposition are device design (resistance to airflow) and environmental conditions (humidity, temperature). Preferably, patients should employ only one type of aerosol-generating device for inhalation therapy. The technique of use varies among devices, and repeated instruction is highly advisable, to ensure that the patient uses the device appropriately. At present, DPIs are recommended for prophylactic and maintenance therapy in patients with asthma and chronic obstructive pulmonary disease, but not for patients with acute severe bronchoconstriction or children less than 5 years of age.

Multizentrische Studie: „Nicht-invasive Beatmung bei Patienten mit schwerer chronisch obstruktiver Bronchitis und Emphysem (COPD)”

Non-invasive ventilation is applied with increasing frequency in patients with chronic hypercapnic COPD and insufficiency of the ventilatory pump. In the few existing clinical trials on long-term use of NIV, no significant improvement on survival could be proven, mainly due to methodical reasons. The "National Task Force for Non-invasive ventilation and weaning" plans to study patients with severe COPD and hypercapnic ventilatory pump insufficiency in a prospective, randomised, multicentre clinical trial over one year. In the intervention group, NIV will be applied for at least six hours per day in addition to standard COPD-treatment. The target of mechanical ventilation is a reduction of PCO (2) during spontaneous breathing by at least 20 %, or into the normal range. The main outcome parameter is all-cause mortality, secondary outcome parameters are course of the disease, exercise capacity, quality of life and consumption of medical resources. The sample size is estimated on 300 patients (150 control group, 150 intervention group). The whole study will take approximately three years.