PubMed Health⌕ Search

Biomedical subjects

T T Bauer

Publications and source records attributed to T T Bauer.

At least 19 recordsLinked to original sources
PubMed2005

Relevance of human metapneumovirus in exacerbations of COPD.

BACKGROUND AND METHODS: Human metapneumovirus (hMPV) is a recently discovered respiratory virus associated with bronchiolitis, pneumonia, croup and exacerbations of asthma. Since respiratory viruses are frequently detected in patients with acute exacerbations of COPD (AE-COPD) it was our aim to investigate the frequency of hMPV detection in a prospective cohort of hospitalized patients with AE-COPD compared to patients with stable COPD and to smokers without by means of quantitative real-time RT-PCR. RESULTS: We analysed nasal lavage and induced sputum of 130 patients with AE-COPD, 65 patients with stable COPD and 34 smokers without COPD. HMPV was detected in 3/130 (2.3%) AE-COPD patients with a mean of 6.5 x 10(5) viral copies/ml in nasal lavage and 1.88 x 10(5) viral copies/ml in induced sputum. It was not found in patients with stable COPD or smokers without COPD. CONCLUSION: HMPV is only found in a very small number of patients with AE-COPD. However it should be considered as a further possible viral trigger of AE-COPD because asymptomatic carriage is unlikely.

Adult↗
PubMed2005

[Driving simulator performance in patients with obstructive sleep apnea syndrome: what consequences for driving capability?].

BACKGROUND AND OBJECTIVE: Patients with obstructive sleep apnea (OSA) have an increased accident risk. The German Society of Sleep Research and Sleep Medicine (DGSM) recommends for patients with OSA and daytime sleepiness that their driving ability should be re-established 6 weeks after the initiation of CPAP (continuous positive airway pressure), with documentation of therapeutic effects on daytime symptoms and performance. The present study was conducted to investigate whether an improvement of driving ability can be documented in neuropsychological tests and a simulated driving situation 14 days after the initiation of CPAP. PATIENTS AND METHODS: Driving simulation and neuropsychological tests of vigilance were conducted in 36 patients (36 males, aged 54 9 years) with OSAS before and 2 (n=23), 14 (n=18) and 42 days (n=17) after initiation of CPAP. RESULTS: Vigilance tests showed only slight changes under CPAP. Frequency of accidents during driving simulation was reduced after 14 days of CPAP, but a statistically remarkable decrease was achieved only on day 42. In contrast, concentration faults were reduced after 2 and 14 days of CPAP. CONCLUSIONS: In OSA-patients improvement of daytime performance in a simulated driving situation can be documented 14 days after initiation of CPAP. There is need for investigating larger cohorts of patients so that current recommendations for driving licensing can be modified and permission to drive can be given earlier.

Automobile Driving↗
PubMed2005

[Prospective randomized trial of a modified standard multislice CT protocol for the evaluation of multiple trauma patients].

PURPOSE: To evaluate whether modification of a standard multislice CT (MSCT) protocol might improve the diagnostic work flow in patients with multiple trauma without relevant loss of image quality. MATERIALS AND METHODS: Between September 2002 and September 2003, 80 multiple trauma patients underwent 4-slice CT encompassing head, thorax, abdomen/pelvis and spine. All patients were randomly assigned to either protocol A or B: Protocol A included serial scanning of the head (collimation 1 mm, 350/380 mAs/120 kV) and spiral scans of thorax, abdomen/pelvis and spine (collimation 2.5 mm, 220 mAs/120 kV) with gantry angulation and arm elevation; protocol B included spiral scanning of all body regions (collimation 2.5 mm, 300/150 mAs/120 kV) without gantry angulation or arm elevation. Time intervals, radiation exposure and results of the initial and final analysis were documented. RESULTS: In the investigated 64 male and 16 female patients (mean age 41.7 years), 88.7 % of the 407 pathologic findings were correctly identified on the initial images. Protocol B revealed a significant decrease in scan time (6.4 vs. 16.8 min., p < 0.001), time in the CT examination room (22.9 vs. 32.8 min.; p < 0.001), time until initial (25.3 vs. 35.8 min.; p < 0.001) and final image analysis (93.7 vs. 112.9 min; p < 0.005). No significant difference was found for patient transport time and image reconstruction time. Protocol B has a significantly lower effective radiation dose compared to protocol A (10.2 vs. 12.7 mSv, p < 0.001). CONCLUSIONS: Applying a modified MSCT protocol without gantry angulation and arm elevation can significantly decrease radiation exposure and examination time in multiple trauma patients without relevant loss of diagnostic image information and, consequently, has the potential of improving the diagnostic process and prognosis in multiple trauma patients.

Adult↗
PubMed2005

[Evaluation of multiple trauma victims with 16-row multidetector CT (MDCT): a time analysis].

PURPOSE: Description and time analysis of a 16-row MDCT protocol in the evaluation of multiple trauma patients considering transport, time of scanning, patient positioning, image reconstruction, and image interpretation. MATERIALS AND METHODS: Between May and December 2004, 60 multiple trauma patients underwent 16-row MDCT (Sensation, Siemens, Erlangen, Germany). The protocol included serial scanning of the head, spiral scanning of the cervical spine and contrast-enhanced spiral scanning of the thorax/abdomen with multiplanar reformations (MPR) of the thoracic/lumbar spine and the pelvis. All time intervals including transport, patient positioning, scanning, duration of MPR, total time in the examination room, and time to first and final image interpretation were prospectively evaluated. Furthermore, patient characteristics, trauma profiles, and mortality rates were recorded. RESULTS: 46 male and 14 female patients (mean age 43.6 years) were enrolled in the study. Time analysis of 16-row MDCT revealed the following results (mean time standard deviation): Emergency room treatment and transport 19.2 +/- 6.7 min, patient positioning 16.5 +/- 6.5 min, scan duration 8.0 +/- 3.3 min, total time in examination room 24.5 +/- 7.2 min, image reconstruction including MPR 32.0 +/- 16.4 min, and time of first (16.4 +/- 4.7 min) and final image interpretation (82.5 +/- 30.4 min). Trauma profiles revealed thoracic injuries in 35/60 patients (58.3 %), head injuries in 23/60 patients (38.3 %), abdominal injuries in 15/60 patients (25.0 %), injuries of the cervical (9/60 patients, 15.0 %), thoracic (12/60 patients, 20.0 %), and lumbar spine (19/60 patients, 31.7 %), pelvic injuries in 13/60 patients (21.7 %), and injuries of extremities in 39/60 patients (65.0 %). The mortality rate was 21.7 %. CONCLUSION: MDCT provides fast and all-inclusive imaging of multiple trauma patients. With the use of 16-row MDCT technology scanning times of 8 minutes are realistic and first image interpretation can be performed 16 minutes after arrival of the patient in the examination room and 35 minutes after admission in the emergency room, respectively. The duration of all procedures done in the examination room is strongly influenced by positioning maneuvers, whereas final image interpretation depends on image reconstructions including MPR. Beside technical improvements, these circumstances provide the potential to further accelerate the diagnostic process in multiple trauma victims.

Abdominal Injuries↗
PubMed2005

[Non-passable tumor-associated stenosis of trachea and stent-implantation -- an indication for Virtual CT-bronchoscopy].

We report about a male 50-year-old patient with known non-small cell lung cancer and tumor-associated stenosis of the right main bronchus already treated with Neodym-YAG-laser coagulation. Eight months later the patient was readmitted to hospital and revealed complete occlusion of the right main bronchus and subtotal stenosis of the distal trachea and the left main bronchus. Conventional tracheobronchoscopy failed to visualize the post-stenotic parts of the left main bronchus due to the length and degree of stenosis. Multidetector-CT-generated virtual tracheobronchoscopy was able to demonstrate complete intraluminal tumor extent thus making precise pre-interventional measurements for stent implantation possible. Furthermore, post-interventional re-evaluation by virtual tracheobronchoscopy confirmed correct position and patency of the stent located within the distal trachea and the left main bronchus. Our case report demonstrates a non-invasive and easy approach for evaluating the tracheobronchial system in a patient with tumor-associated airway stenosis including the possibility for viewing beyond post-stenotic segments.

Bronchoscopy↗
PubMed2005

Driving simulator and neuropsychological [corrected] testing in OSAS before and under CPAP therapy.

Patients with obstructive sleep apnoea syndrome (OSAS) have an increased car accident rate. Investigations on accident frequency are based on case history, insurance reports and driving simulator studies. The present study combines neuropsychological testing of different attention aspects engaged in driving a car and driving simulation to evaluate a suitable instrument for assessing therapeutic effects of continuous positive airway pressure (CPAP). Driving simulator investigation and neuropsychological testing of alertness, vigilance and divided attention were performed in 31 patients with polysomnographically confirmed OSAS (apnoea-hypopnoea index 24.8+/-21.5.h(-1)) before, and 2 and 42 days after initiation of CPAP. Divided attention and alertness improved significantly during CPAP, whereas vigilance remained unchanged. However, accident frequency (OSAS before therapy: 2.7+/-2.0; 2 days after CPAP: 1.5+/-1.4; 42 days after CPAP: 0.9+/-1.3) and frequency of concentration faults (OSAS before therapy: 12.4+/-5.1; 2 days after CPAP: 6.5+/-3.9; 42 days after CPAP: 4.9+/-3.3) decreased in the simulated driving situation after 2 and 42 days of therapy. There was no relation between accident frequency, concentration faults and daytime sleepiness, as measured by the Epworth Sleepiness Scale, and polysomnographic or neuropsychological findings, respectively. In conclusion, the present results suggest that driving simulation is a possible benchmark parameter of driving performance in obstructive sleep apnoea syndrome patients.

Accidents, Traffic↗
PubMed2004

[Treatment for viral respiratory infections: Principles of action, strategies, and future prospects].

Pulmonary viral infections are associated with substantial morbidity and socioeconomic costs. Rhinovirus, influenza A and B, adenovirus, parainfluenza, respiratory syncytial virus (RSV), and coronavirus are etiologies most often associated with infections of the upper and lower respiratory tract. Therapy of viral infections in nonimmunocompromised hosts has only developed slowly during recent years, despite the enormous socioeconomic impact. This is in part due to the complex virus/host interactions and numerous and varying mechanisms of infection. Neuraminidase inhibitors have produced notable progress in the therapeutic approaches to influenza-associated pulmonary infections and are at least able to shorten the duration of symptoms in selected patients. However, neuraminidase inhibitors can only be applied in specific infections and the spectrum of agents with antiviral activity is broad. This article summarizes major principles of antiviral efficacy and reviews recent clinical trials.

Antiviral Agents↗
PubMed2004

[Does nCPAP-therapy change the lung function of patients with obstructive sleep apnea syndrome?].

BACKGROUND: nCPAP-therapy is standard for patients with obstructive sleep apnea syndrome (OSAS). This study investigated, if nCPAP changed the patients lung function. PATIENTS AND METHODS: Lung function of 228 OSAS patients without co-prevalent lung disease, who received nCPAP for the first time, was examined (whole body plethysmography, spirometry, and blood gas analysis). After 1, 2, and 3 years the results of the re-examined patients were compared with their individual starting results. RESULTS: The results of the patients in the basic and in the follow-up examinations was within standard range. During reexamination, an improvement of inspiratory vital capacity was registered repetitively, especially in smokers. On the other hand, MEF 50 decreased within the first two years and FEV (1) %VC, but not FEV (1), decreased after 2 and 3 years of reexamination. CONCLUSIONS: Neither obstructive nor restrictive lung diseases were diagnosed under nCPAP-therapy within three years. This study with a retrospective design showed significant improvements of vital capacity (VC) in patients with OSAS, especially in smokers, under nCPAP-therapy. This increase can be explained by an effect of practice in the examination and by recruitment of formerly hypoventilated lung areas. As MEF 50 and FEV (1) %VC depend on VC, the decrease of both parameters may be caused by the increase of VC. In summary, nCPAP did not cause negative effects of lung function in the investigated patients over a period of 3 years.

Continuous Positive Airway Pressure↗
PubMed2003

[Virtual multislice-CT-bronchoscopy as a diagnostic tool in patients with endobronchial tumors: case report of a carcinoid tumor].

BACKGROUND: Bronchial carcinoids are rare neuroendocrine tumors of the lung. Diagnosis is established by computed tomography (CT) and bronchoscopy-guided biopsy. Imaging features of carcinoids are highly characteristic including contrast enhancement and central intraluminal growth. Multislice-CT generated three-dimensional virtual bronchoscopy enables non-invasive and detailed view of the tracheobronchial system. CASE REPORT: A 70-year-old male with known silicosis and chronic cough with hemoptysis showed hypertransparency of the left lung on conventional images. Axial CT scans revealed a solid tumor in the left lower lobe. Virtual CT-bronchoscopy based on surface rendering depicted an intraluminal mass occluding the bronchus of the anterobasal segment that was confirmed by conventional endoscopy. Conventional and virtual bronchoscopy showed almost identical imaging features. Histopathological evaluation of the bioptic specimen revealed a typical carcinoid tumor. The patient successfully underwent resection of the left lower lobe with mediastinal lymphadenectomy. CONCLUSIONS: Virtual Multislice-CT-bronchoscopy can add important information about an intraluminal tumor and its relation to surrounding structures. Further studies have to be undertaken to evaluate the potentials of this promising method as a tool to determine endoluminal growth in tumorous lung lesions.

Aged↗
PubMed2003

Respiratory viruses in exacerbations of chronic obstructive pulmonary disease requiring hospitalisation: a case-control study.

BACKGROUND: Acute exacerbations of chronic obstructive pulmonary disease (AE-COPD) are a common cause of hospital admission. Many exacerbations are believed to be due to upper and/or lower respiratory tract viral infections, but the incidence of these infections in patients with COPD is still undetermined. METHODS: Respiratory syncytial virus (RSV), influenza A and B, parainfluenza 3, and picornaviruses were detected by nested reverse transcription polymerase chain reaction (RT-PCR) in upper (nasal lavage) and lower respiratory tract specimens (induced sputum). In a 2:1 case-control set up, 85 hospitalised patients with AE-COPD and 42 patients with stable COPD admitted for other medical reasons were studied. RESULTS: Respiratory viruses were found more often in sputum and nasal lavage of patients with AE-COPD (48/85, 56%) than in patients with stable COPD (8/42, 19%, p<0.01). The most common viruses were picornaviruses (21/59, 36%), influenza A (15/59, 25%), and RSV (13/59, 22%). When specimens were analysed separately, this difference was seen in induced sputum (exacerbation 40/85 (47%) v stable 4/42 (10%), p<0.01) but was not significant in nasal lavage (exacerbation 26/85 (31%) v stable 7/42 (17%), p=0.14). In patients with AE-COPD, fever was more frequent in those in whom viruses were detected (12/48, 25%) than in those in whom viruses were not detected (2/37, 5%, p=0.03). CONCLUSION: Viral respiratory pathogens are found more often in respiratory specimens of hospitalised patients with AE-COPD than in control patients. Induced sputum detects respiratory viruses more frequently than nasal lavage in these patients. These data indicate that nasal lavage probably has no additional diagnostic value to induced sputum in cross-sectional studies on hospitalised patients with AE-COPD and that the role of viral infection in these patients is still underestimated.

Adolescent↗
PubMed2002

Intrapulmonary neutrophil apoptosis in a pig model of pneumonia.

BACKGROUND: Apoptosis and necrosis are two distinct cell death modalities. Polymorphonuclear leukocytes (PMNL) play an important role in pneumonia and little information is available on whether these cells are cleared by necrosis or apoptosis. We therefore compared the proportion of apoptotic PMNL in lung tissues with and without pneumonia. In addition, the association of PMNL apoptosis and mechanical ventilation (MV) was investigated. METHODS: Samples obtained from a pig model developed to tracheobronchial stenting were analysed. Pneumonia was induced with that model in 10 animals (white-Landrace piglets, Pittman-Moore or Göttingen minipigs). Animals were sacrificed when clinical parameters of pneumonia became evident and 17 lung samples could be analysed for histologic evidence of pneumonia, growth of micro-organisms, and the apoptotic index (proportion of apoptotic PMNL over all PMNL in a 400-power field). In addition, lung samples (n = 7) from two pigs without stent implantation on mechanically ventilated for more than 48 h were studied. RESULTS: A total of 9/17 samples (53%) showed histologic evidence of pneumonia, 11/17 (65%) had significant bacterial growth (> 10(3) cfu/g), and 7/17 (41%) fulfilled both criteria. The apoptotic index was not significantly different in samples with and without histologic evidence of pneumonia (pneumonia: 25.3 +/- 6.1% vs. No pneumonia: 25.2 +/- 11.9%; 95%CI: -9.7 - 9.5, p = 0.989) or in samples with and without significant bacterial growth (significant bacterial growth: 23.5+/-9.3% vs. No significant bacterial growth: 28.5+/-8.2%; 95%CI: -4.6 - 16.7; p = 0.284). However, the apoptotic index was higher in samples of pigs, mechanically ventilated for more than 48 h, compared to the stent group (MV: 36.9+/-10.7% vs. Stent: 25.2 +/- 9.0%; 95% CI: -20.5 - -2.9; p = 0.012). CONCLUSION: In an animal model, the proportion of apoptotic PMNL was not different in lung samples with and without histologic or bacterial pneumonia. However, MV for more than 48 h was associated with a higher proportion of apoptotic PMNL in lung tissue. This study may be helpful for the understanding of the evolution of lung tissue damage induced by bacterial pneumonia and MV.

Animals↗
PubMed2002

Biofilm formation in endotracheal tubes. Association between pneumonia and the persistence of pathogens.

Nosocomial pneumonia is still a common problem, especially in intubated and mechanically ventilated patients. The endotracheal tube contributes substantially to the pathogenesis of pneumonia in these patients, because it facilitates microaspiration and impairs host defences. Common nosocomial pathogens like Pseudomonas aeruginosa are known to produce exopolysaccharide and generate the complex biofilm structure, which allows adhesion to abiotic surfaces and protection against antibiotic action. Multiple studies have identified bacterial biofilm on the inner lumen of endotracheal tubes, which represents a permanent source of infectious material. Endotracheal tubes, removed from patients with ventilator-associated pneumonia are covered more frequently with biofilm than those of uninfected controls. It remains unclear whether this represents a source of infection or contamination. Bacterial biofilm, however, may play an important role in recurrent pulmonary infections of the intubated and mechanically ventilated patient.

Biofilms↗
PubMed2001

Effects of bronchoalveolar lavage volume on arterial oxygenation in mechanically ventilated patients with pneumonia.

OBJECTIVE: To assess the effect of bronchoalveolar lavage (BAL) volume on arterial oxygenation in critically ill patients with pneumonia. DESIGN: Randomized clinical comparison. SETTING: Six-bed respiratory intensive care unit of a 850-bed tertiary care university hospital. PATIENTS: Thirty-seven intubated and mechanically ventilated patients with clinical suspicion of pneumonia. INTERVENTIONS: Bronchoscopically guided protected specimen brush (PSB) followed by either a "high volume" BAL (n = 16, protected catheter, mean volume: 131 +/- 14 ml) or a "low volume" BAL (n = 21, protected double-plugged catheter, 40 ml volume for all patients). MEASUREMENTS: Arterial oxygen tension/fractional inspired oxygen (PaO2/FIO2) and mean arterial pressure (MAP) before and up to 24 h after the intervention. Bacterial growth in quantitative cultures. Analysis of variance for repeated measurements with inter-subject factors. RESULTS: All patients showed a lower PaO2/FIO2 ratio and higher MAP after the diagnostic procedure, without differences between the study arms (p = 0.608 and p = 0.967, respectively). Patients with significant bacterial growth (p = 0.014) and patients without preemptive antibiotic (p = 0.042) therapy showed a more profound and longer decrease in arterial oxygenation after the diagnostic procedure. CONCLUSIONS: A decrease in the PaO2/FIO2 ratio was observed in all patients after a combined diagnostic procedure, independent of the BAL volume used. A significant bacterial burden recovered from the alveoli and no preemptive antibiotic therapy were associated with a larger and longer-lasting decrease in arterial oxygenation.

Analysis of Variance↗
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↗
PubMed2001

Functional variables associated with the clinical grade of dyspnoea in coal miners with pneumoconiosis and mild bronchial obstruction.

OBJECTIVES: Dyspnoea is a common symptom in coal miners with pneumoconiosis. Among others, gas exchange disturbances due to airway obstruction or mismatch between ventilation and perfusion may be underlying mechanisms. The validation of dyspnoea by the degree of airway obstruction is controversial, because the extent of airway obstruction often does not correlate with the clinical grade of breathlessness. METHODS: The association was investigated between breathlessness (self reported, on a six point scale) and indices of submaximal spiroergometry in 66 coal workers with radiographically confirmed pneumoconiosis (International Labour Organisation (ILO) grade of profusion > or =1/0, mean (SD) age 64 (5.5) years, mean (SD) forced expired volume in 1 second (FEV(1)) 77.5 (22.9) % predicted). RESULTS: The clinical degree of breathlessness was independently associated with minute ventilation/oxygen consumption (VE/VO(2)) ratio (beta 0.423, 95% confidence interval (95% CI) 0.18 to 0.67, p=0.001) and smoking (beta 0.318, 95% CI 0.21 to 1.79, p=0.014) in a multiple linear regression analysis. The VE/VO(2) ratio (beta 0.556, 95% CI 0.20 to 0.90, p=0.003) was also the best predictor of breathlessness when only coal miners with airway obstruction (FEV(1) < 80% predicted) were analyzed. CONCLUSION: The VE/VO(2) ratio as a measurement of mismatch between ventilation and perfusion predicted the clinical grade of breathlessness better than measurements of bronchial obstruction at rest in coal workers with pneumoconiosis.

Aged↗