PubMed Health⌕ Search

Biomedical subjects

H W Duchna

Publications and source records attributed to H W Duchna.

At least 19 recordsLinked to original sources
PubMed2007

[Pulmonary diseases and heart function].

The most severe cardiac sequel to lung disease is the load on the right ventricle due to pulmonary hypertension with the development of a cor pulmonale. This is characterized by hypertrophy and/or dilatation of the right ventricle because of a primary impairment of lung function and/or lung structure. The most important pathomechanisms for the development of pulmonary hypertension are vessel obliteration, mechanical lesions, primary vascular or extra-vascular inflammation and hypoxic vasoconstriction. Chronic obstructive pulmonary disease (COPD) is one of the most important reasons for chronic cor pulmonale. A further very common reason is obstructive sleep apnea syndrome, especially if combined with a COPD. In this case, the prevalence of cor pulmonale can reach 80%. The development of a chronic cor pulmonale is the most striking negative prognostic factor for these patients. Only 30% of COPD patients with cor pulmonale survive longer than 5 years, and only early detection of the disturbances to respiration which might potentially lead to cor pulmonale and their subsequent therapy are able to improve the patient's prognosis. Furthermore, pulmonary diseases may also have an impact on the left heart side in terms of an impairment of left heart function or by inducing severe arrhythmias . Thus, lung diseases may have both a significant impact on right and left heart performance.

Arrhythmias, Cardiac↗
PubMed2004

[Acute severe asthma in older adults].

The underlying causes of acute severe or life threatening asthma are infections with respiratory viruses or Mycoplasma pneumoniae, rather than bacterial infections. In addition, exposure to various agents such as allergens, non-specific irritants or drugs, and inadequate long-term treatment may be responsible. High flow oxygen therapy, high dose topic beta(2)-agonists and systemic glucocorticosteroids should be used as baseline therapy in outpatients. In hospital, intravenous therapy-eventually including sedatives-can be administered under controlled or intensive care conditions. In patients with increasing respiratory pump weakness and alveolar hypoventilation, non-invasive and/or invasive mechanical ventilation may be required. In ventilated asthma patients permissive hypercarbia has been shown to reduce complications such as pneumothorax. Bronchoscopy and bronchial lavage are recommended for patients ventilated with increasing pressures or when atelectasis occurs.

Acute Disease↗
PubMed2002

Tuberculous involvement of the oesophagus with oesophagobroncheal fistula.

Tuberculous involvement of the oesophagus is a rare disease. Even if it is suspected, diagnosis is often difficult though dysphagia and chest pain are the most common symptoms without any other specific signs of tuberculosis. The diagnosis is based on oesophagography, oesophagoscopy, bronchoscopy, and computed tomographic scan. Suspected tuberculosis can be confirmed with histology, smear, and culture. The two most common differential diagnoses are Crohn's disease and carcinoma. The case is reported of a female patient with tuberculous involvement of the oesophagus, who developed an oesophagobroncheal fistula during steroid treatment started for suspicion of Crohn's disease. The patient was immunocompromised due to treatment with azathioprine that she was receiving for multiple sclerosis. The fistula was successfully treated by antituberculous chemotherapy alone.

Adult↗
PubMed2002

[Estimation of accident risk in obstructive sleep apnea syndrome (OSAS) by driving simulation].

Abstract. Patients with obstructive sleep apnea syndrome (OSAS) have an accident rate between two and seven times higher than normals. Investigations on accident frequency are based on case history, insurancy reports, and driving simulator investigations. The present controlled study was planned to test whether an increased accident risk could be demonstrated in patients with OSAS before and on CPAP (continuous positive airway pressure)-therapy using the driving simulator C.A.R. Driving simulator performance was investigated in 31 patients with polysomnographically confirmed OSAS (apnea-hypopnea-index 24.8 +/- 21.5/h) before, 2 and 42 days after initiation of CPAP and was compared to 10 healthy controls in whom OSAS was excluded by polysomnography. Driving simulator performance was significantly worse in OSAS as compared to normals especially in terms of accident frequency (OSAS: 2.7 +/- 2.0, controls: 1.3 +/- 1.5, p < 0.05) and concentration faults (OSAS: 12.4 +/- 5.1, controls: 7.1 +/- 3.2, p < 0.01). On CPAP accident frequency (OSAS before therapy: 12.4 +/- 5.1, 2 days CPAP: 1.5 +/- 1.4, p < 0.01; 42 days CPAP: 0.9 +/- 1.3, p < 0.001) and frequency of concentration faults (OSAS before therapy: 12.4 +/- 5.1, 2 days CPAP: 6.5 +/- 3.9, p < 0.001; 42 days CPAP: 4.9 +/- 3.3, p < 0.001) could be lowered significantly both in the short and medium term of therapy. The driving simulator C.A.R. is an adequate tool for the evaluation of an increased accident risk in OSAS-patients and demonstrates the efficiency of CPAP-therapy.

Accidents, Traffic↗
PubMed2001

[Obstructive sleep apnea syndrome: a cardiovascular risk factor?].

INTRODUCTION: Obstructive sleep apnea syndrome (OSAS) is frequently associated with cardiovascular disease. We investigated endothelium-dependent and endothelium-independent nitric oxide-mediated vasodilatory function in normotensive patients with OSAS using the hand vein compliance technique. PATIENTS AND METHODS: Dose-response curves to the endothelium-dependent vasodilator bradykinin were obtained in 23 male subjects with OSAS and 12 male control subjects of comparable age, height, and weight. RESULTS: Mean (+/- SD) maximum dilation (Emax) to bradykinin was significantly lower in OSAS patients than in controls (59.8 +/- 26.0 vs. 94.8 +/- 9.5%, p < 0.0001). Mean vasodilation with nitroglycerin was not diminished in the OSAS group (90.7 +/- 30.5 vs. 100.3 +/- 12.9% in controls; n.s.). In 11 OSAS patients, a follow-up investigation was performed after at least 2 months of treatment with nasal continuous positive airway pressure (CPAP): Emax to bradykinin rose from 54.5 +/- 19.2% to 111.5 +/- 25.1% after treatment (p < 0.001). Mean vasodilation to nitroglycerin was unchanged. CONCLUSIONS: These results suggest that endothelium-dependent nitric oxide-mediated vasodilation is impaired in patients with OSAS due to an impaired function in the endothelial cells. This impairment is reversible with CPAP treatment.

Bradykinin↗
PubMed2001

[The impact of different definitions of hypoxemia on the relation between awake pulmonary pressure and hypoxemia during sleep in patients with COPD].

BACKGROUND: Sleep related hypoxemia (SRH) in chronic obstructive pulmonary disease (COPD) can be easily detected by pulse-oximetry and may contribute to the development of pulmonary hypertension (PH). Since several parameters for the quantification of SRH are in use, we investigated which of these parameters has the strongest relation to the awake pulmonary arterial pressure (PAP) and is able to distinguish between patients without and with PH. PATIENTS AND METHODS: 44 COPD-patients (awake PaO2 > or = 60 mm Hg) were investigated. PAP at rest (PAP; pathological threshold > 20 mm Hg) and under physical exercise (PAPB; p.t. > 28 mm Hg) were determined during daytime by Swan-Ganz-catheter. To quantify the degree of SRH the following parameters of nocturnal pulse-oximetry were used: mean nocturnal oxygen saturation (SaO2 m; p.t. < 90%), nadir SaO2 (SaO2 min; p.t. < 85%), and mean time of SaO2 < or = 90% in relation to total time of registration (t90; p.t. > 30%). Linear correlations and regressions as Chi 2-respectively Fisher-test were used for statistical analysis (p < 0.05). RESULTS: Generally there was only a weak relation between PAP and SRH. The best linear correlation at rest respectively under physical exercise was found between PAP and SaO2 min (r = -0.529 resp. -0.541, p < 0.001). Using the above defined thresholds for PAP and SaO2 patients could be most precisely separated into those without and with PH using SaO2 min with a threshold for the pathological range of < 85% (p = 0.030 resp. 0.002). t90 with a threshold > 30%, however, had a much worse selectivity (p = 0.487 resp. 0.057). CONCLUSIONS: In COPD-patients with SRH the closest relation can be found between nadir SaO2 and PAP resp. PAPB. Furthermore nadir SaO2 (< 85%) could more precisely separate patients into those without and with pulmonary hypertension than t90. The overall weak relation between nocturnal oxygenation and pulmonary hypertension shows, however, that other factors such as daytime PaO2, hypercapnia or emphysema are involved in the development of pulmonary hypertension in COPD.

Blood Pressure↗
PubMed2000

Vascular reactivity in obstructive sleep apnea syndrome.

The obstructive sleep apnea syndrome (OSAS) is associated with cardiovascular disease and systemic hypertension. Because systemic arterial blood pressure is proportional to venodilation and venous return to the heart, we hypothesized that altered vascular responsiveness might exist in the veins of subjects with OSAS. We therefore investigated venodilator responses in awake, normotensive subjects with and without OSAS, using the dorsal hand vein compliance technique. Dose-response curves to bradykinin and nitroglycerin were obtained from 12 subjects with OSAS and 12 matched control subjects. Maximal dilation (E(max)) to bradykinin was significantly lower in the OSAS group (62.1% +/- 26.1%) than in the control group (94.3% +/- 10.7%) (p < 0.005). Vasodilation to nitroglycerin tended to be lower in the OSAS group (78.6% +/- 31.8%) than the control group (100.3% +/- 12.9%), but this effect did not reach statistical significance. When six of the OSAS subjects were retested after 60 d of treatment with nasal continuous positive airway pressure (CPAP), E(max) to bradykinin rose from 60.3% +/- 20. 3% to 121.4% +/- 26.9% (p < 0.01). Vasodilation to nitroglycerin also increased, but this effect did not reach statistical significance. These results demonstrate that a blunted venodilatory responsiveness to bradykinin exists in OSAS. This effect appears to be reversible with nasal CPAP therapy.

Blood Pressure↗
PubMed1998

Normative data on snoring: a comparison between younger and older adults.

Snoring is a common sleep-related behaviour. Increased body mass index (BMI), cranio-facial anatomical features, and older age have been linked to the occurrence of snoring. While mostly middle-aged populations have been studied for the occurrence of snoring and sleep-related breathing abnormality, this study was designed to assess the subjective report of snoring and the objective measurement of snoring at the two extremes of human age. The study design called for measurement of snoring in two age groups (college students; n=155 and older subjects; mean age 64.1 yrs n=134) with a mean age difference of 45 yrs. Snoring was assessed with a validated recording device. A validated questionnaire was used to subjectively assess snoring and obtain relevant sleep-related information. Students and older subjects differed in the self-report of snoring. While 83% of students reported "never" or "rarely" snoring only 35% of older subjects fell into these categories. Measurement of snoring during sleep revealed that students spent more time during sleep with continuous snoring than older subjects. In older subjects, a reduction in continuous snoring was accompanied by an increase in apnoeic snoring. Subjective snoring frequency correlated with continuous snoring in students only. A positive family history of snoring increased the odds ratio for self-reported snoring but not for recorded snoring. It has been shown that snoring frequency can vary depending on age and that the congruency between perceived snoring frequency and recorded snoring is influenced by the age of an individual.

Adult↗
PubMed1998

[Effect of salmeterol in obstructive sleep apnea syndrome].

The effect of inhaled long-acting beta 2-agonists on obstructive sleep apnoea syndrome (OSAS) is unknown, though from the pharmacological point of view both therapeutic and adverse effects might be discussed. The purpose of this study was to obtain data on the efficacy and safety of Salmeterol in patients with OSAS. In a randomised, double-blind, placebo-controlled, crossover study effects of Salmeterol were investigated in 20 patients with OSAS: 4 female, 16 male; age 53.0 +/- 7.8 years, body mass index (BMI) 28.0 +/- 3.0 kg.m-2; apnoea hypopnoea index (AHI) 35.6 +/- 17.8 h-1. Patients with asthma, chronic obstructive pulmonary disease (COPD), and left heart failure were excluded. Placebo or verum (50 micrograms Salmeterol) were administered at 7 p.m. by metered dose inhaler and spacer device. All patients underwent full polysomnography during baseline, placebo, and verum night. Statistical analysis was performed by Student's t-test (p < 0.05). Between placebo and verum there were no differences in total sleep time, sleep stages, apnoea index (AI), AHI, and nadir SaO2. There was, however, a significant deterioration of mean SaO2 (placebo 93.1 +/- 2.0 vs Salmeterol 92.5 +/- 2.2%) and of relative time spent with SaO2 < or = 90% (placebo 13.1 +/- 14.5 vs Salmeterol 19.5 +/- 20.8%), as well as a significant increase in heart rate (placebo 63.1 +/- 9.2 vs Salmeterol 65.6 +/- 9.3 h-1). Thus, in patients with OSAS Salmeterol had no adverse effect on quality of sleep, AI or AHI. The slight increase in heart rate and the deterioration of oxygen saturation are clinically irrelevant. The latter might be due to ventilation-perfusion-mismatch. This study demonstrates that Salmeterol has no influence on obstructive sleep apnoea and hypopnoea, but on the other hand provides an acceptable safety profile in OSAS. This might be of special importance in patients suffering from both OSAS and obstructive airway disease.

Adrenergic beta-Agonists↗
PubMed1998

[Prospective study of the significance of contact sensitization caused by metal implants].

INTRODUCTION: Allergies caused by metallic implants are often thought to be a reason for postoperative complications like bone necrosis or loosening of the prosthesis. PATIENTS AND METHODS: In a prospective study, we investigated allergic sensitivity against components of stainless steel implants, including titanium, in 112 patients shortly before surgical operation. The same tests were then repeated in 100 of these patients exactly one year after operation. There were three different kinds of procedures: 1. titanium implants, mainly total hip replacements, 2. regular steel implants, 3. surgery without any implants (control group). Any differences from the process of regular healing were regarded as postoperative complications. RESULTS: A sensitivity against nickel (Ni) was diagnosed in three of these 100 patients (3%) before surgery. These patients, of whom two received a nickel-containing implant and one a titanium arthroplasty, did not show any postsurgical complications. Furthermore, three patients (3%) acquired a new sensitivity against metals during the study-interval of one year. Two of these three patients were women, who developed a postsurgical sensitivity against nickel or chrome but got titanium arthroplasties, which did not contain any nickel. These two women wore metal-containing jewelry, which might be the reason for the newly acquired metal-sensitivities, and both showed postsurgical complications. The third patient, who has developed a postsurgical sensitivity against components of his steel arthroplasty, did not reveal any complications. DISCUSSION: We conclude that the rate of allergic sensitization against metal-components of arthroplasties is low in our patients. Additionally, skin-sensitivity against components of alloys and platings was not associated with a higher rate of postsurgical complications in our patients. We did not see any sensitivity against titanium. In conclusion, metallic implants are not a cause of allergies to a relevant extent, nowadays.

Adult↗
PubMed1997

[Stress test blood gas analysis in chronic obstructive lung diseases].

This study was conducted to investigate the clinical value of blood gas analysis during exercise in patients with COPD and healthy controls using the new criteria of the Deutsche Gesellschaft für Pneumologie (DGP) for performance and interpretation of blood gas analysis during exercise. A total of 64 patients with COPD (age: 63.7 +/- 10.1 years) and 35 healthy controls (age: 35.0 +/- 14.3 years) exercised on a bicycle ergometer to their submaximal capacity under steady state conditions (patients: 44.4 +/- 24.6 watt vs. 102.4 +/- 32.1 watt; p < 0.01). A pathological response for PaO2 occurred in 3 of 35 controls (8.6%) and 14 of 64 patients (21.9%; p < 0.01). A decrease in PaO2 yielded a sensitivity of 28% and a specificity of 92% in respect of patients with emphysema. Significant associations of lung function parameters at rest and blood gases under exercise were found by linear regression analysis (airway resistance (Rt): beta = -0.48; p < 0.001) and PaCO2 (FEV1: beta = -0.27; p < 0.05). This study demonstrates that in patients with COPD parameters of lung function and blood gas analysis at rest are already good predictors of gas exchange under exercise conditions. In individual cases, however, prediction may not be possible. This underlines the importance of the exercise test to investigate gas exchange under diagnostic (i.e. dyspnoea, medical opinion) and therapeutic aspects (i.e. therapy control). For COPD patients, the rule of the DGP yielded a poor sensitivity, but an excellent specificity in the diagnosis of emphysema, which yields confirmation of the diagnosis only in conjunction with, and complementary to, other methods.

Adult↗
PubMed1997

[Incidence of cutaneous sensitization to environmental allergens in obstructive sleep apnea syndrome].

A skin prick test was performed in 75 patients with an obstructive sleep apnea syndrome (OSAS) to test allergic skin reactivity to 18 common inhalant allergens. Additionally, anterior rhinomanometry was performed. Results were compared with a group of 21 patients with chronic obstructive pulmonary disease and with 198 workers of the chemical industry. A positive (> or = 4 mm wheal diameter) skin test to at least one allergene was present in 49 per cent of the OSAS patients, compared to 14 per cent in COPD patients and 28 per cent in industrial workers (p < 0.05; chi 2-test)-33 per cent (n = 25) of the OSAS patients with a sleep apnea syndrome showed skin reactivity to house dust mite (D. ph., D. f.) compared to 9.5 per cent in COPD patients and 12.6 per cent in industrial workers (p < 0.05 chi 2-test). No difference was found between anthropometric, polysomnographic, or rhinomanometric data comparing OSAS patients with positive skin reactions against house dust mites (n = 25) and those without any allergic skin reactivity (n = 38).

Adult↗
PubMed1996

[Incidence of chronic obstructive respiratory tract disease in patients with obstructive sleep apnea].

Data concerning the occurrence of chronic-obstructive pulmonary disease (COPD) in patients with obstructive sleep apnea syndrome (OSAS) vary between 11 and 20% due to the underlying definition of COPD. We investigated the frequency of COPD in 202 patients with OSAS. The obstructive pattern was defined by bodyplethysmography (Rt > 0.35 kPa x 1(-1) x s(-1)), flow-volume-curve (MEF50 < 50% pred.), Tiffeneau-index (FEV1/IVC < 70% pred.) and anamnesis (cough and/or sputum). Prevalence of COPD in our 202 patients with OSAS was 16.3%. Patients with OSAS and COPD had a higher body-mass-index (BMI), lower PaO2 and spent more time in an oxygen saturation < or = 90% in relation to total recording time (t90). Polysomnographically there was no difference between the two groups with regard to the ventilatory parameters apnea-index (AI) and apnea-hypopnea-index (AHI). As there is a high risk of developing hypercapnia, pulmonary arterial hypertension and cor pulmonale in patients with OSAS and COPD there is need for early diagnosis of the combination of both diseases.

Adult↗
PubMed1996

[Anamnestic and polygraphic parameters in obstructive sleep apnea syndrome patients with reduced nasal respiration during the day in comparison with obstructive sleep apnea patients with normal nasal respiration].

Nasal obstruction is a predictive factor for snoring and may contribute to the development of an obstructive sleep apnea syndrome (OSAS). The aim of this study was to further evaluate the impact of nasal obstruction in OSAS. Therefore, we investigated 2 groups of OSAS-patients, matched pairs concerning gender, age, and BMI: OSAS-patients with nasal obstruction (N, n = 28), total nasal airflow < 500 ccm/s (referred to 150 pa pressure of difference or unilateral nasal resistance > 1 pa/ccm/s), and 28 OSAS-patients without nasal obstruction (control-group K, total nasal airflow > 700 ccm/s [referred to 150 pa pressure of difference or unilateral nasal resistance > 1 pa/ccm/s]). We performed anterior rhinomanometry, lung-function testing, cardio-respiratory polygraphy, and patients answered a standardized questionnaire. We found the following significant differences: 1) N complained more often (n = 17) about dyspnea at night than K (n = 7, p < 0.05, Chi2-test). 2) N had a higher apnea index (20.4 +/- 19.0/h) than K (9.6 +/- 10.0/h, p < 0.05, Student's t-test). There were, however, no significant differences concerning lung function, number of nocturnal hypopneas, nocturnal SaO2 and heart rate. Our results underline the importance of nasal ventilation in the pathogenesis of OSAS. At least in moderate cases of OSAS a therapy of nasal obstruction might be of success in order to abolish nCPAP-therapy or might reduce nasal problems during nCPAP-therapy and thus ameliorate patient's therapy compliance.

Airway Resistance↗
PubMed1996

[Signs of right heart stress in diurnal normoxemic patients with chronic obstructive lung disease and nocturnal hypoxemia].

Nocturnal hypoxemia in daytime normoxemic patients with COPD may lead to an increased right ventricular afterload due to pulmonary hypertension. We investigated the frequency of clinical, electrocardiographical, and radiological signs of right cardiac insufficiency (SRCI) in 178 consecutive COPD-patients [71 bronchitis, 25 emphysema, 82 bronchitis plus emphysema; PaO2 = 60 mm Hg]. Patients with asthma, left ventricular impairment, obstructive sleep apnea syndrome, primary pulmonary hypertension, and neuromuscular diseases were excluded. Polysomnography was performed in all patients. They were divided into 3 groups concerning SRCI: missing, doubtful, and secure SRCI. Parameters of nocturnal pulse oximetry were analyzed within the three groups (Student's t-Test. Chi2-Test. p < 0.05). 25.8% of the patients had secure SRCI without a significant frequency difference between patients with bronchitis and/or emphysema. Patients with secure SRCI had a significant lower mean nocturnal SaO2 than those with missing SRCI (92.7 +/- 2.5 vs. 90.3 +/- 3.5%). With regard to the high prevalence of SRCI in association with nocturnal hypoxemia routine control of nocturnal oxygenation is recommended in daytime normoxemic COPD-patients for the early decision for nocturnal oxygen therapy.

Adult↗
PubMed1996

[Sex-specific sleep anamnesis in obstructive sleep apnea syndrome?].

Although the prevalence of obstructive sleep apnea syndrome (OSAS) is about 4% in men and 2% in women, women are underrepresented in clinical routine. The aim of this study was to determine whether differences in clinical features of OSAS may in part explain the bias observed. 224 men and 24 women with polysomnographically confirmed OSAS filled in a symptom-focussed multiple-choice questionnaire. Polysomnographical results were comparable in both groups. With regard to snoring, daytime sleepiness and tendency of falling asleep there were no differences between both groups. Women more frequently complained about difficulties of initiating and maintaining sleep and about apneas. Further investigations have to concentrate on the pathomechanisms of OSAS in women which may in part explain the gender differences in sleep apnea associated symptoms.

Adult↗