Leopold Stiebellehner

Maxillomandibular advancement for treatment of obstructive sleep apnea syndrome: a systematic review.

PURPOSE To perform a systematic review of the published data concerning maxillomandibular advancement for the treatment of obstructive sleep apnea syndrome. MATERIALS AND METHODS A systematic literature search was performed in the PubMed database. Original articles in the English language were reviewed to obtain information about patient data, success rates, and outcome measures. RESULTS The systematic literature search yielded 1,113 citations, of which 101 articles met our inclusion criteria. After a review of the full text, 39 studies were included in the analysis. Most articles were classified as evidence level 4, and 5 met the inclusion criteria for level 2b. The only prospective randomized controlled study had been published in January 2010 and was assigned level 1b. CONCLUSIONS A recommendation grade of A to B was achieved with regard to the levels of evidence-based medicine. Our results have shown that maxillomandibular advancement is the most successful surgical therapy, and the postoperative polysomnography results are comparable to those under ventilation therapy.

Comparison of Plethysmographic and Helium Dilution Lung Volumes: Which Is Best for COPD?

BACKGROUND Theoretical considerations and limited scientific evidence suggest that whole-body plethysmography overestimates lung volume in patients with severe airflow obstruction. We sought to compare plethysmography (Pleth)-, helium dilution (He)- and CT scan-derived lung volume measurements in a sample containing many patients with severe airflow obstruction. METHODS We measured total lung capacity (TLC) in 132 patients at three hospitals, with monitored application of recommended techniques for Pleth and He measurements of lung volume and by thoracic CT scans obtained during breath hold at full inspiration. RESULTS Average TLC among 132 subjects was 6.18 L (+/- 1.69 L) by Pleth-derived TLC, 5.55 L (+/- 1.39 L) by He-derived TLC, and 5.31 L (+/- 1.47) by CT scan-derived TLC. Pleth-derived TLC was significantly greater than either He-derived TLC or CT scan-derived TLC (P < or = .001), whereas there was no significant difference between He-derived and CT scan-derived values. When examined separately, there were significant within-subject differences in TLC by measurement technique among subjects with airflow obstruction, but not among those without airflow obstruction. Plethysmographic overestimation of TLC was greatest among subjects with FEV(1) < 30% of predicted. CONCLUSIONS In the setting of airflow obstruction, Pleth systematically overestimates lung volume relative to He or thoracic imaging despite adherence to current recommendations for proper measurement technique.

T1 mapping of the entire lung parenchyma: Influence of respiratory phase and correlation to lung function test results in patients with diffuse lung disease.

The T1 values of lung parenchyma of 25 patients with fibrosis and emphysema were measured in the entire lung, and the effect of inspiration and expiration was investigated. T1 map acquisition was based on a snapshot‐fast low‐angle shot (FLASH) sequence. Lung function and blood gas tests were measured. The study documents reverse respiratory phase dependence of T1 measurements of the entire lung parenchyma in patients with emphysema and fibrosis. Furthermore, expiratory measurements showed higher and reverse differences between patient groups compared to inspiratory measurements. For the emphysema group, the average T1 value in inspiration was 1033 ± 74 ms. The average of the mean T1 values in expiration was 982 ± 56 ms. For the patients with fibrosis, the average T1 value in inspiration was 996 ± 103 ms. Compared to that, the average T1 value in expiration was 1282 ± 170 ms. Linear regression of T1 vs. lung function parameters showed the highest regression coefficients for total lung capacity (TLC) and residual volume (RV) in expiration, the values were inversely proportionally dependent on the pooled expiratory T1 values. These findings underline the strong but nonuniform influence of the inspirational status during T1 measurements of the lung. T1 maps in both emphysema and fibrosis should preferably be acquired at expiration if reliable data are to be obtained. Magn Reson Med 59:96–101, 2008.

Quantitative and O2 Enhanced MRI of the Pathologic Lung: Findings in Emphysema, Fibrosis, and Cystic Fibrosis

Purpose: beyond the pure morphological visual representation, MR imaging offers the possibility to quantify parameters in the healthy, as well as, in pathologic lung parenchyma. Gas exchange is the primary function of the lung and the transport of oxygen plays a key role in pulmonary physiology and pathophysiology. The purpose of this review is to present a short overview of the relaxation mechanisms of the lung and the current technical concepts of T1 mapping and methods of oxygen enhanced MR imaging. Material and Methods: molecular oxygen has weak paramagnetic properties so that an increase in oxygen concentration results in shortening of the T1 relaxation time and thus to an increase of the signal intensity in T1 weighted images. A possible way to gain deeper insights into the relaxation mechanisms of the lung is the calculation of parameter Maps. T1 Maps based on a snapshot FLASH sequence obtained during the inhalation of various oxygen concentrations provide data for the creation of the so-called oxygen transfer function (OTF), assigning a measurement for local oxygen transfer. T1 weighted single shot TSE sequences also permit expression of the signal changing effects associated with the inhalation of pure oxygen. Results: the average of the mean T1 values over the entire lung in inspiration amounts to 1199 +/− 117 milliseconds, the average of the mean T1 values in expiration was 1333 +/− 167 milliseconds. T1 Maps of patients with emphysema and lung fibrosis show fundamentally different behavior patterns. Oxygen enhanced MRT is able to demonstrate reduced diffusion capacity and diminished oxygen transport in patients with emphysema and cystic fibrosis. Discussion: results published in literature indicate that T1 mapping and oxygen enhanced MR imaging are promising new methods in functional imaging of the lung and when evaluated in conjunction with the pure morphological images can provide additional valuable information.

Abnormal pulmonary arterial pressure limits exercise capacity in patients with COPD

ZusammenfassungZIELE: Das Vorliegen einer pulmonalen Hypertension ist häufig bei Patienten mit chronisch obstruktiver Lungenerkrankung (COPD) anzutreffen. Der mittlere pulmonalarterielle Druck (mPAP) ist in Ruhe oft nur gering erhöht, zeigt aber einen pathologischen Anstieg unter Belastung. Das Ziel dieser Studie ist es, die Leistungsfähigkeit und den pulmonalen Gasaustausch bei COPD Patienten mit und ohne pulmonalarterieller Hypertension zu untersuchen. PATIENTEN UND METHODEN: Bei 42 Patienten mit COPD Grad II-IV (28 Männer, 14 Frauen) wurden eine Bodyplethysmographie, eine symptomlimitierte Fahrradergospirometrie sowie eine Rechtsherzkatheteruntersuchung durchgeführt. RESULTATE: 32 von 42 Patienten (76%) zeigten einen erhöhten mPAP in Ruhe (PH mPAP = 26,8 ± 5,9 mmHg), bei 10 Patienten war der mPAP in Ruhe im Normbereich (NPH, mPAP = 16,8 ± 2 mmHg). Es gab keinen signifikanten Unterschied hinsichtlich der lungenfunktionellen Parameter in beiden Gruppen. Die maximale Sauerstoffaufnahme (VO2max) war signifikant niedriger in der PH Gruppe (785 ± 244 ml/min) im Vergleich zur NPH Gruppe (1052 ± 207 ml/min, p = 0,004). Es zeigte sich in der PH Gruppe eine erhöhte Totraumventilation mit signifikant erhöhtem Atemäquivalent für CO2 (VECO2 47,3 ± 10 vs 38,6 ± 3,5, p = 0,025) und signifikant höherem arterio-endtidalen CO2 Partialdruck [p(a-ET)CO2]. Der pulmonalarterielle Widerstand (PVR) in Ruhe zeigte eine negative Korrelation hinsichtlich der VO2max, VE/VCO2 und dem arterio-endtidalen CO2 Partialdruck [p(a-ET)CO2]. ZUSAMMENFASSUNG: Patienten mit COPD und erhöhter pulmonalarterieller Druckwerte in Ruhe zeigen eine Verschlechterung des pulmonalen Gasaustausches unter Belastung, eine Beeinträchtigung der maximalen Sauerstoffaufnahme und somit eine limitierte Leistungsfähigkeit.SummaryOBJECTIVE: Pulmonary hypertension (PH) is common in patients with chronic obstructive pulmonary disease (COPD). Mean pulmonary artery pressure (mPAP) is often only slightly elevated at rest but is increased by exercise. The purpose of this study was to determine whether abnormal pulmonary artery pressure impairs exercise capacity in patients with COPD. PATIENTS AND METHODS: 42 patients with moderate-to-very-severe COPD (28 men, 14 women) underwent symptom-limited incremental cardiopulmonary exercise testing and also right-heart catheterization at rest. Abnormal pulmonary artery pressure was defined as mPAP > 20 mmHg at rest. RESULTS: Resting mPAP was elevated in 32 patients (PH, mPAP = 26.8 ± 5.9 mmHg) and normal in 10 non-hypertensive (NPH) patients (NPH, mPAP = 16.8 ± 2 mmHg). There were no significant differences in lung function between the PH and NPH groups. Maximum oxygen uptake during exercise (VO2max) was significantly lower in PH (785 ± 244 ml/min) than in NPH (1052 ± 207 ml/min, P = 0.004). Dead-space ventilation (Vd/Vt) was greater in PH (P = 0.05) with higher VE/VCO2 (ratio of minute ventilation to carbon dioxide output = 47.3 ± 10 vs 38.6 ± 3.5, P = 0.025) and significantly higher arterial-end-tidal pCO2 difference [p(a-ET)CO2]. Pulmonary vascular resistance measured at rest correlated significantly with VO2max, VE/VCO2 and p(a-ET)CO2. CONCLUSIONS: In patients with COPD, abnormal pulmonary artery pressure impairs gas exchange, decreases maximum oxygen uptake during exercise and impairs exercise capacity.

Dissociation between systemic and pulmonary anti‐inflammatory effects of dexamethasone in humans

Aims The local pulmonary inflammatory response has a different temporal and qualitative profile compared with the systemic inflammatory response. Although glucocorticoids substantially downregulate the systemic release of acute‐phase mediators, it is not clear whether they have comparable inhibitory effects in the human lung compartment. Therefore, we compared the anti‐inflammatory effects of a pure glucocorticoid agonist, dexamethasone, on bronchoalveolar lavage and blood cytokine concentrations in response to bronchially instilled endotoxin. Methods In this randomized, double‐blind and placebo‐controlled trial, 24 volunteers received dexamethasone or placebo and had endotoxin instilled into a lung segment and saline instilled into a contralateral segment, followed by bronchoalveolar lavage. Results Bronchially instilled endotoxin induced a local and systemic inflammatory response. Dexamethasone strongly blunted the systemic interleukin (IL) 6 and C‐reactive protein release. In sharp contrast, dexamethasone left the local release of acute‐phase mediators in the lungs virtually unchanged: bronchoalveolar lavage levels of IL‐6 were only 18% lower and levels of IL‐8 were even higher with dexamethasone compared with placebo, although the differences between treatments were not statistically significant (P = 0.07 and P = 0.08, respectively). However, dexamethasone had inhibitory effects on pulmonary protein extravasation and neutrophil migration. Conclusions The present study demonstrated a remarkable dissociation between the systemic anti‐inflammatory effects of glucocorticoids and its protective effects on capillary leak on the one hand and surprisingly low anti‐inflammatory effects in the lungs on the other.

Dexamethasone inhibits endotoxin-induced coagulopathy in human lungs.

Essentials Glucocorticoids are associated with an increased risk of thrombosis. Healthy volunteers received dexamethasone or placebo in an endotoxin lung instillation model. Dexamethasone suppressed thrombin generation in bronchoalveolar lavage. Glucocorticoids inhibit endotoxin induced pulmonary coagulopathy.

Empfehlungen zur ambulanten Polygraphie der Österreichischen Gesellschaft für Pneumologie

Schlafassoziierte Atemstörungen stellen aufgrund ihrer hohen Prävalenz und den mit dieser Erkrankung verbundenen Auswirkungen auf gesundheitliche, soziale und ökonomische Faktoren sowohl für den betroffenen Patienten als auch für das gesamte Gesundheitssystem ein beträchtliches Problem dar. T. Young et al. berichtete bereits 1993 für über 40-Jährige eine Prävalenz obstruktiver Schlafapnoe (definiert durch einen Apnoe/Hypopnoe-Index – AHI – von mehr als 5/Stunde) von 24% für Männer und 9% für Frauen. Die Prävalenz einer höhergradigen schlafassoziierten Atemstörung mit einem AHI von zumindest 15/h betrug für über 40-Jährige bei Männern 9,1% und bei Frauen 4,0% [1]. In einer rezenten Zusammenfassung epidemiologischer Daten dreier großen Studien von insgesamt über 2700 untersuchten Personen betrug die Prävalenz für die Gruppe mit einem AHI > 15/h bei Männern 7–14%, bei Frauen 2–7% [2]. Die Prävalenz jener Patienten mit einem AHI > 15/Stunde und gleichzeitig bestehender Tagesmüdigkeit beträgt etwa 5% der erwachsenen Bevölkerung (> 40 Jahre). Schlafassoziierte Atemstörungen – insbesondere deren häufigste Form, die obstruktive Schlafapnoe – führen zu teils dramatischen pathophysiologischen Abläufen, die nachts für den Patienten meist unbemerkt ablaufen. Neben der vom Patienten nicht selten bagatellisierten Tagesmüdigkeit, intellektuellem Leistungsverlust und hoher Unfallgefährdung [3] sind unbehandelte schlafassoziierte Atemstörungen klar mit einer erhöhten kardiovaskulären Mortalität assoziiert [4–6]. Die obstruktive Schlafapnoe stellt demnach einen unabhängigen, durch Therapie beeinflussbaren kardiovaskulären Risikofaktor dar [7, 8]. Es besteht international Einigkeit, dass insbesondere ein symptomatisches Schlafapnoe-Syndrom rasch erkannt und behandelt werden sollte. Die Abklärung und Therapie dieser Erkrankungen sind – sowohl im niedergelassenen als auch im stationären Bereich – mit beträchtlichem zeitlichem, personellem und apparativem Aufwand verbunden. Die American Thoracic Society und die American Sleep Society verwendet ein 4-stufiges Konzept (Stufe 1 und 2: überwachte und nicht überwachte Polysomnographie, Stufe 3: nicht überwachte ambulante und stationäre Polygraphie und Stufe 4: 1oder 2-Kanal-Monitoring) [9]. In ähnlicher Weise schlägt der Arbeitskreis folgende Einteilung von Gerätesystemen zur apparativen Diagnostik schlafassoziierter Atemstörungen vor:

An 83-year-old female with worsening dyspnoea and bleeding from a cavernostomy

An 83-yr-old female presented with a history of worsening dyspnoea. In 1952, the patient had undergone surgical treatment for progressive pulmonary tuberculosis (TB) of the left-upper lobe. Treatment had consisted of an artificial pneumothorax and a cavernostomy via incision and drainage of a tuberculous cavity. Since surgery, the patient had cared for the cavernostomy herself by occasionally draining secretions using a plastic tube prescribed by a general practitioner. There had been no other post-surgical surveillance over almost 50 yrs. The patient had no history of smoking. On admission, the patient was in reduced general condition and reported recurrent local bleedings from the cavernostomy. Physical examination revealed that the cavernostomy was occluded by a polypoid mass, presumably located within the cavity. Both the mass and the cavernostomy were bleeding slightly. There was no palpable local lymphadenopathy. Auscultation was unremarkable. The serum level of C-reactive protein was markedly raised at 81 mg·L−1 (normal: <10 mg·L−1). The blood serum levels of alkaline phosphatase (228 U·L−1; normal: <170 U·L−1) and γ-glutamyltransferase (23 U·L−1; normal: 4–18 U·L−1) were slightly elevated, as was the blood serum level of uric acid (81 mg·L−1; normal: 25–60 mg·L−1). All other laboratory tests, including haematocrit, were within the normal ranges. The chest radiograph obtained on admission is shown in figure 1⇓. Contrast-enhanced computed tomography (CT) performed on the same day, before and after drainage of fluid from the cavity, is shown in figures 2⇓ and 3⇓, respectively. Figure 4⇓ shows a CT section taken while the cavernostomy was drained by the patient using the plastic tube, as described above. Fig. 1— Postero-anterior chest radiograph obtained at admission. Fig. 2— Contrast-enhanced computed tomography sections at the level of the pulmonary arteries before drainage of fluid from the cavernostomy. …