Biomedical subjects
Publications and source records attributed to T Schreiber.
We describe a method to suppress maternal and noise contaminations in single-lead fetal ECG recordings. A nonlinear state space projection technique originally developed for noise reduction in deterministically chaotic signals is used. The method is successfully applied to recordings with fetal components and noise of comparable amplitude.
The diagnostic value of endotracheal aspirates with quantitative assessment and bronchoalveolar lavage (BAL) was investigated in 104 mechanically ventilated patients in an anaesthesiologic/surgical intensive care unit. Patients were either considered as "pneumonia positive" (77 patients) according to clinical, radiological or laboratory criteria or "pneumonia negative" (27 patients). Using a threshold of 10(5) colony forming units (cfu) per ml for endotracheal aspirates and 10(4) cfu/ml for BAL-fluid, the results were similar for both techniques (sensitivity 74% and 77% respectively; specifity 63%). In our investigation, in 80% of the cases microbial growth was observed in either both or neither of the techniques. Therefore 20% of the patients had positive results in only one of the two diagnostic procedures. As a consequence of the presented study, quantitative assessment of endotracheal aspirates as a cost-effective, low-invasive and simple technique could be helpful in diagnosing nosocomial pneumonia in mechanically ventilated patients. Performance of BAL is indicated in patients with clinical signs of nosocomial pneumonia and negative results in endotracheal aspirates (< 10(5) cfu/ml). Nevertheless, diagnostic uncertainty will remain in about 15% of all cases, even when both techniques are applied. The primary use of invasive bronchoscopic techniques, such as BAL, in diagnosis of nosocomial pneumonia has to be considered critically.
Although percutaneous transluminal coronary angioplasty (PTCA) has been an effective treatment for primary reperfusion in acute myocardial infarction, patients with thrombolytic ineligibility, thrombolytic failure, cardiogenic shock, and vein graft occlusion remain at high risk for complications with PTCA treatment. The transluminal extraction catheter may be useful for treatment for such patients owing to its ability to aspirate thrombus. At 2 clinical centers, extraction atherectomy was prospectively evaluated in 100 patients (age 62 +/- 10 years). High-risk features included thrombolytic failure in 40%, postinfarct angina in 28%, presence of angiographic thrombus in 66%, presence of cardiogenic shock in 11%, and a saphenous vein graft occlusion in 29%. Procedural success, defined as a final residual stenosis <50% and Thrombolysis in Myocardial Infarction 2 or 3 grade flow, was seen in 94%. Events during the hospitalization included death in 5%, bypass surgery in 4%, and blood transfusion in 18%. In a substudy, patients enrolled at William Beaumont Hospital (n = 65) underwent elective predischarge angiography, which revealed a patent infarct-related vessel in 95%. These patients were also followed for 6 months with angiographic follow-up in 60%. Target vessel revascularization was necessary in 38%, and 6-month mortality was 10%. Although long-term vessel patency was 90%, angiographic restenosis occurred in 68%. Acute myocardial infarction patients can be treated with extraction atherectomy with a high technical success rate and a low incidence of complication. Infarct artery patency at 1 week and 6 months was excellent; however, angiographic restenosis remains a problem. Extraction of thrombus in this high-risk group of patients is associated with low in-hospital mortality and a high rate of vessel patency at 6 months.
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OBJECTIVES: The purpose of this retrospective study was to compare the results of transluminal extraction coronary atherectomy in saphenous vein graft lesions with and without angiographic thrombus. BACKGROUND: Percutaneous interventions in lesions with thrombus are associated with reduced procedural success and increased risk of complications. Use of the transluminal extraction catheter, which cuts and aspirates atheroma and thrombus, has been advocated as a potential revascularization strategy for lesions with thrombus. METHODS: Baseline patient characteristics, lesion morphology, immediate angiographic results, in-hospital complications and follow-up were prospectively entered into an interventional cardiology data base. The results of transluminal extraction coronary atherectomy in saphenous vein bypass grafts with angiographic thrombus were compared with results in similar grafts without angiographic thrombus. RESULTS: Transluminal extraction coronary atherectomy was performed in 175 patients with 183 vein graft lesions, including 59 lesions (32%) with thrombus (Group 1) and 124 (68%) without thrombus (Group 2). Compared with lesions in Group 2, lesions in Group 1 were associated with a higher incidence of baseline total occlusion, diffuse disease and abnormal Thrombolysis in Myocardial Infarction (TIMI) grade flow (p < 0.05); more severe diameter stenosis at baseline, after atherectomy and after final angiography (p < 0.05); a lower rate of clinical success (69% vs. 88%, p < 0.01); and more angiographic and clinical complications, including no reflow (p < 0.05), vascular repair (p < 0.05) and Q wave myocardial infarction (p = 0.09). CONCLUSIONS: In transluminal extraction coronary atherectomy of saphenous vein bypass grafts, the presence of thrombus is associated with more baseline lesion complexity, reduced clinical success and increased risk of no reflow, Q wave myocardial infarction and vascular repair.
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Mucociliary clearance represents an important protective mechanism of the upper and lower respiratory tracts whereby inhaled particles and micro-organisms are removed from the tracheobronchial system. In incubated intensive care unit (ICU) patients, impaired ciliary function and mucus transport are associated with pulmonary complications [9]. Some authors have shown that theophylline increases mucus transport in healthy subjects and patients with chronic bronchitis [8, 16, 31, 36]. However, other investigators have found unconvincing or conflicting results [4, 20, 25]. Therefore, we studied the influence of theophylline on bronchial mucus transport velocity (BTV) in ventilated ICU patients. METHODS. The study was approved by the ethnics committee of our hospital. In a placebo-controlled double-blind study, the effect of therapeutic serum concentrations (10-20 micrograms/ml) of theophylline on BTV in ventilated patients in a surgical ICU was investigated. Group 1 (n = 10) served as controls and received placebo. The patients of group 2 (n = 10) were given intravenous infusions of 5 mg/kg body weight theophylline over 20 min, followed by 1 mg/kg per hour. Before administration of theophylline and 1 h after starting the infusion BTV, serum theophylline concentrations, and arterial blood gases were measured. Heart rate and blood pressure were registered every 5 min. In an additional study, the effect of theophylline on BTV at subtherapeutic serum concentrations (5 micrograms/ml) was investigated. BTV was measured with a small volume (0.05-0.08 ml) of albumin microspheres labeled with technetium-99m, which was deposited on the dorsal surface at the lower ends of the right and left main bronchi via a catheter placed in the inner channel of a fibre-optic bronchoscope. The movement of the microspheres towards the trachea was visualised and recorded using a scintillation camera [10]. RESULTS. The theophylline treatment induced a significant improvement in BTV from 3.8 to 7.6 mm/min in the left main bronchus and from 0.5 to 5.4 mm/min in the right, while placebo was inactive. The increase in BTV, however, was associated with an increase in heart rate; in 3 patients the theophylline infusion had to be stopped because of severe tachycardia. Blood gases and blood pressures did not change. Theophylline at subtherapeutic concentrations had no effect on either BTV or heart rate. CONCLUSIONS. Theophylline at therapeutic concentrations improves bronchial mucus transport in intubated ICU patients. The increase in BTV may be associated with severe tachycardia, and therefore routine application cannot be recommended.
OBJECTIVES: The objectives of this study were to determine the bronchial mucus transport velocities in ventilated ICU patients and to study the possible role of impaired mucus transport in the development of retention of secretion and pneumonia. DESIGN: The patients were studied prospectively in a convenience sample trial. SETTING: The study took place at a university hospital. PATIENTS: Thirty-two ventilated patients in a surgical ICU were included in the study. The study was approved by the Ethics Committee of the University of Ulm. INTERVENTIONS: Bronchial mucus transport velocity (BTV) was measured with a small volume of technetium 99m-labeled albumin microspheres within the first 3 days of mechanical ventilation. The radiolabeled bolus was deposited at the distal end of the right and left main bronchus via flexible bronchoscopy. The movement of the microspheres toward the trachea was visualized and recorded using a scintillation camera. After determination of BTV, the patients were examined daily for 4 days to record pulmonary complications (defined as retention of secretion and nosocomial pneumonia). MAIN MEASUREMENTS AND RESULTS: The median BTV in the right primary bronchus was 0.8 mm/min and in the left it was 1.4 mm/min. In nine patients both radioactive drops remained at the application site. In 14 patients, a total of 19 pulmonary complications occurred (10 times retention of secretion, 9 times pneumonia). Patients with pulmonary complications had statistically significant lower BTV compared with patients without pulmonary complications; in the left bronchus 0 (0 to 6.5) mm/min (median with range) vs 3.5 (0 to 10.5) mm/min (p < 0.01) and in the right bronchus 0 (0 to 3.0) mm/min vs 4.7 (0 to 11.7) mm/min (p < 0.01). CONCLUSIONS: Ventilated patients in the ICU frequently have impaired mucus transport, which is associated with the development of retention of secretion and pneumonia.
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OBJECTIVES: The objectives of this study were to evaluate a method for measuring BTV in ventilated patients and to study the short-term effect of general anesthesia with midazolam, Fentanyl, pancuronium and O2:N2O on BTV. DESIGN: The study included phantom measurements on a bronchoscopy model and the determination of BTV in patients in a convenience sample trial. SETTING: The study took place in a university hospital. PATIENTS: Fourteen patients undergoing major abdominal surgery with planned postoperative mechanical ventilation were included in the study. All patients gave their written informed consent to participate in the study. INTERVENTIONS: Bronchial mucus transport velocity was measured with a small volume (0.05 to 0.08 ml) of technetium 99m-labeled albumin microspheres with an activity of 3 MBq. The radiolabeled bolus was deposited on the dorsal mucosal surface at the distal end of the right and left main bronchus via flexible bronchoscopy. The movement of the microspheres toward the trachea was visualized and recorded using a scintillation camera; quantitative evaluation utilized the condensed image. MAIN MEASUREMENTS AND RESULTS: The technique was validated in a bronchoscopy model and in an intubated patient by moving a radioactive drop in a catheter through the main bronchi at velocities from 0 to 20 mm/min. The velocities determined by the image processing technique correlated well with the data by the model and patient determination (right bronchus, r = 1.0; left bronchus, r = 1.0). In seven ventilated patients, mechanical irritation by the fiberscope produced no significant effect on BTV. The BTV was measured preoperatively in seven conscious patients one day before surgery while they received local anesthesia with 10 ml of 1 percent lidocaine and postoperatively while they received intubation anesthesia. The preoperative and postoperative BTV values showed no significant differences (10.5; 5.7 to 13.7 mm/min; vs 9.7 (3.7 to 15.3) (median with range). CONCLUSION: By this method, bronchial transport velocity can be determined in a relatively short time in ventilated patients. General anesthesia with midazolam, Fentanyl, pancuronium and O2:N2O does not influence BTV.
The incidence of retained hardware components in the coronary artery tree is likely to parallel the growing number and types of percutaneous coronary revascularization procedures being performed. Management has extended from the conservative option of simply leaving behind the retained components to the more aggressive approach of surgical removal. A percutaneous method is described herein which offers the interventional cardiologist an alternative method of managing patients with retained wire fragments contained entirely in the coronary artery.
A total of 161 cases of choroidal metastases are reviewed. Breast or bronchial carcinomas are the most frequent primary tumors. One-third of the patients develop bilateral choroidal metastases. In 67% of all cases metastatic choroidal lesions were found in the posterior pole. Eighty-nine percent of all patients had a history of malignant tumor, in 11% of all patients choroidal metastasis was the first sign of a primary carcinoma elsewhere in the body. Sixty percent of all patients with choroidal metastases had additional other distant metastases at the time of diagnosis of choroidal involvement. The survival rate is poor: 50% of all patients with choroidal metastasis had died 1 year later. In 35% of all patients, choroidal metastases occurred despite prior systemic therapy with cytotoxic drugs or hormone therapy. In many cases the spontaneously course leads to irreversible loss of central visual acuity due to tumor growth, tumor necrosis or the complications of an exudative retinal detachment. Early fractionated external beam in radiation may prevent this outcome. The clinical course in 71 eyes following irradiation is reported. In 80% radiation therapy led to regression or eradication of the tumor, and a vision of at least 0.4 was maintained in 61% of the treated eyes.
Numerous complications have been associated with cardiopulmonary resuscitation. Acute purulent staphylococcal mediastinitis and sternal osteomyelitis are, however, unusual and do not appear to have been reported previously in association with closed chest resuscitation. Sternal fracture during chest compressions and subsequent hematogenous seeding of the resultant retrosternal hematoma with Staphylococcus aureus led to purulent mediastinitis and sternal osteomyelitis in our patient. The source of bacteremia may have been a resolving phlebitis at an intravenous catheter insertion site. Early diagnosis, aggressive surgical debridement, and antibiotic therapy were key to a successful outcome.
Four benign esophagorespiratory fistulas, three secondary to granulomatous disease and one presumed to be congenital, have been diagnosed in adults at the authors' institution in the past year. The patients had symptoms of chronic or recurrent pulmonary infections, and two experienced coughing after swallowing. Chest radiographs demonstrated refractory consolidation, with or without cavitation and frequently accompanied by an air-distended esophagus. Barium studies were diagnostic. All patients responded well to antibiotic and surgical therapy.