Biomedical subjects

T T Bauer

Publications and source records attributed to T T Bauer.

42 records · Page 3Linked to original sources

PubMed1997

[Correlation of radiologic and pathologic-anatomical findings in dust-induced pneumoconiosis in former coal miners].

The ILO classification of small and large opacities is the basis for the compensation of patients with pneumoconiosis. In order to validate the radiological findings, we compared the ILO classification with the gradings of pneumoconiosis in the post mortem investigation (n = 126). An ILO classification of 1/0 used as the threshold value for accepting the diagnosis of a pneumoconiosis was 100% sensitive with a specificity of 2%. With a value of 2/3 the sensitivity decreased to 60% and specificity increased to 74%. The grading of large opacities in the radiograph correlated well with the post mortem findings (rs = 0.71; p < 0.001). For accepting the diagnosis pneumoconiosis from the radiograph alone a threshold value of 1/0 is not specific. The ROC-plot revealed that specificity reached acceptable levels with an ILO classification of at least 2/3.

Coal↗

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↗

PubMed1992

Dietary calcium blocks lithium toxicity in hamsters without affecting circadian rhythms.

Lithium can be toxic to rodents at plasma concentrations (0.6-1.2 mmol/L) that also phase delay circadian rhythms. In hamsters, raising the concentration of calcium in the diet from 0.1%-3% reduced weight loss and polydipsia caused by 0.4% lithium carbonate. Calcium ingestion did not affect plasma lithium concentration or the phase of the circadian wheel-running rhythm in lithium-treated animals. Calcium ingestion did not alter weight gain, salt or water intake, or circadian rhythms in hamsters not receiving lithium. Dietary calcium supplementation may prevent some toxic effects of lithium without interfering with other central nervous system actions.

Animals↗