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Biomedical subjects

T Bein

Publications and source records attributed to T Bein.

At least 19 recordsLinked to original sources
PubMed2005

Interhospital transportation of patients with severe lung failure on pumpless extracorporeal lung assist.

BACKGROUND: To describe the use of pumpless extracorporeal interventional lung assist (iLA) for transportation of patients with severe life-threatening acute lung failure from tertiary hospitals to a specialized centre. METHODS: Retrospective analysis in eight patients with severe lung failure requiring interhospital transport, in whom implementation of an iLA system at a tertiary hospital for air/ground transportation was performed. RESULTS: After implementation of iLA, a rapid increase in CO2-elimination (Pa(CO2) before iLA: 8.92+/-2.9 kPa, immediately after implementation: 5.06+/-0.93 kPa, 24 h after implementation: 4.53+/-1.20 kPa [mean+/-SD], P<0.05) was observed and a significant improvement in oxygenation (Pa(O2) before iLA: 6.66+/-2.26 kPa, immediately after implementation: 10.39+/-3.33 kPa, 24 h after implementation: 10.25+/-5.46 kPa, P<0.05) was noted. During transport, no severe complications occurred. Four patients died during further treatment due to multiple trauma or multiple organ failure. CONCLUSIONS: Due to ease of handling, high effectiveness and relatively low costs, iLA seems to be a useful system for treatment and transportation of patients with severe acute lung injury or ARDS suffering from life-threatening hypoxia and/or hypercapnia.

Adult↗
PubMed2005

Nondestructive identification of colloidal molecular sieves stabilized in water.

The encapsulation of small quaternary ammonium ions in zeolite frameworks could be used as a base for investigation of the crystallization process of colloidal (nanosized) molecular sieves stabilized in water with Raman and (13)C NMR spectroscopic methods. The organic-framework interactions in colloidal microporous materials with LTA, FAU, BEA, and MFI topology have been considered; the results show that the crystallinity of nanosized particles with monomodal particle size distribution stabilized in water can be examined using the vibrational and magnetic resonance spectral features of the organic template molecules occluded in the specific pores and cages in the zeolite framework. The molecular packing effect and restricted mobility due to specific organic/framework interactions result in shifts and substantial broadening of the (13)C NMR signals, as well as in changes of the positions and the relative intensities of the Raman peaks. The spectroscopic methods are very efficient for analyzing the crystalline structures of nanosized molecular sieves stabilized in aqueous suspensions due to no restrictions related to the particle size.

Journal Article↗
PubMed2005

Interlayer stacking disorder in zeolite beta family: a Raman spectroscopic study.

Raman spectroscopy has been applied to series of BEA- and BEC-type samples differing from each other in size, Si/Al ratio and polymorph percentage in order to analyse the effect of interlayer stacking arrangements on the vibrational modes of zeolite beta. The Raman peaks observed in the spectral range 250-550 cm-1 were assigned to the rings building the basic (001)-layer and to those linking the adjacent layers in zeolite beta. It is shown that the intensity ratio rho between the Raman signals at 314 and 343 cm-1 is most sensitive to the degree of periodicity faults along the c direction. A larger value of rho indicates a larger size of polymorph stacking sequence, i.e. improvement of the stacking faultlessness. The interlayer stacking disorder and the degree of connectivity point defects are higher in nanosized zeolite beta than in micron-sized crystals. The Al content influences the concentration of defected SiOH groups, but is less important for the interlayer stacking sequences in colloidal zeolite beta.

Microscopy, Electron, Transmission↗
PubMed2005

Ordered micro/mesoporous composite prepared as thin films.

A new synthesis method for preparation of thin films and powders consisting of zeolite beta nanocrystals embedded in ordered mesoporous silica matrix is described. The final structures possessing bimodal porosity, i.e., high degree of mesophase order and spatially defined microporous zeolite nanocrystals are obtained via simultaneous solvent evaporation of preformed silica/surfactant/ethanol/nanosized zeolite beta assemblies. The films were characterized with grazing-incident diffraction (GID), nitrogen sorption based on gravimetric measurements with quartz crystal microbalance (QCM) devices, and transmission electron microscopy (TEM). It is shown that the incorporation of beta nanocrystals in the mesoporous silica matrix and the mesophase order itself can be controlled through the variation of the fractional amounts of the zeolite nanoparticles and silica/surfactant solutions. The HR-TEM measurements showed that the nanosized Beta microporous crystals are separated and at the same time connected through an ordered mesostructured matrix.

Journal Article↗
PubMed2005

Impact of the AEP-Monitor/2-derived composite auditory-evoked potential index on propofol consumption and emergence times during total intravenous anaesthesia with propofol and remifentanil in children.

BACKGROUND: The composite auditory evoked potential index (cAAI), derived from the AEP Monitor/2 (version 1.6; Danmeter A/S, Odense, Denmark) is a measure of the hypnotic component of general anaesthesia. The purpose of this study was to evaluate the impact of cAAI guidance on propofol consumption and emergence times in children receiving total intravenous anaesthesia (TIVA) with propofol and remifentanil. METHODS: Twenty children, aged 3-11 years, scheduled for strabismus repair under TIVA with propofol and remifentanil were enrolled. Remifentanil was given to all patients at a constant infusion rate of 0.3 microg kg(-1) min(-1) throughout the anaesthesia. Patients were randomly allocated to receive a continuous propofol infusion adjusted either according to a conventional clinical practice (Group C, n = 10) or guided by cAAI-monitoring (Group G, n = 10, target cAAI 25-35). All patients were connected to the AEP Monitor/2, but in group C the anaesthetist was blinded to cAAI values. Propofol consumption (mgkg(-1)h(-1)) and emergence times (min) were the primary and secondary outcome measures. RESULTS: Propofol consumption and emergence times (mean +/- SD) were significantly lower in group G compared to group C (Propofol: G: 4.2 +/- 1.7 vs. C 6.4 +/- 1.3 mg kg(-1) h(-1); P < 0.01; emergence times: G: 5.1 +/- 3.7 vs. C 13.2 +/- 8.2 min; P < 0.01). Intraoperative cAAI values (median [interquartile range]) were significantly higher in group G (23.9 [18-29.7]) than in group C (18.4 [16.0-22.1]; P < 0.01). Haemodynamic variables remained stable within age-related limits, and there were no observations of adverse events, especially no clinical signs of intraoperative awareness in any patient. CONCLUSION: Composite auditory evoked potential index monitoring during propofol/remifentanil-TIVA in children results in reduced propofol consumption and faster emergence.

Analysis of Variance↗
PubMed2004

Nanosized gismondine grown in colloidal precursor solutions.

A colloidal molecular sieve with GIS-type structure was prepared from aged aluminosilicate precursor solutions containing tetramethylammonium (TMA) hydroxide under hydrothermal treatment at 100 degrees C. The nucleation and the development of the GIS zeolite structure were studied by dynamic light scattering, scanning electron microscopy, X-ray diffraction, Raman and infrared spectroscopies, and liquid-state NMR spectroscopy. It is shown that the aging at room temperature leads to the formation of subcolloidal particles that incorporate TMA cations and form larger aggregates. After an extended heating of 13 days, a complete transformation from amorphous precursor material to crystalline GIS-type colloidal particles is observed. The mean hydrodynamic radius of the crystalline GIS particles is in the range of 30-50 nm. The specific template-framework interactions influence the spectral features of the TMA cations incorporated in the zeolite structure, thus making possible the use of the corresponding Raman spectra and 13C NMR data for the examination of the crystallinity of GIS-type colloidal particles stabilized in water.

Journal Article↗
PubMed2004

Quality of life after decompressive craniectomy in patients suffering from supratentorial brain ischemia.

BACKGROUND: Decompressive craniectomy in patients suffering from severe ischemic stroke in the middle cerebral artery territory (MCA) decreases mortality to near 30%. Additionally functional outcome in patients after early craniectomy seems to be better than in patients without surgery. The aim of this study was to investigate the quality of life of patients who were treated with a decompressive craniectomy for severe ischemic stroke. METHODS: We retrospectively investigated the patient records of 48 patients (26 men, mean age 48 years) suffering from ischemic strokes who underwent craniectomy since 1993. We registrated the preoperative neurological status, the diagnostic data as well as the operative procedure. The outcome was assessed using the Barthel Index, the Glasgow outcome score and a questionnaire to assess the quality of life according to Blau consisting of eleven items at follow-up. FINDINGS: The mortality rate was 26%, age correlated to mortality (44.5 versus 60.3 years GOS 1, mean, p<0.0006). Craniectomy without dura patch correlated to mortality (58% versus 14% GOS 1 with dura patch, p<0.005). The quality of life index was 6 points mean. The quality of life index did neither differ significantly between patients with left or right sided lesions nor in patients with and without aphasia. 83% of the surviving patients and/or dependents would agree to surgery in the future. CONCLUSION: Despite the fact that some patients remain in a poor neurological condition, quality of life after decompressive surgery for ischemic stroke seems to be acceptable to the patients.

Adult↗
PubMed2004

[Pumpless extracorporeal lung assist using arterio-venous shunt in severe ARDS. Experience with 30 cases].

BACKGROUND: Extracorporeal lung assist has been proposed as an invasive measure in patients with acute respiratory distress syndrome (ARDS) when oxygenation is critically impaired. However, this technique generally requires high personnel and technical resources. We report on a new system, which is characterised by a short circuit arterio-venous shunt using arterio-venous pressure gradient as driving force (pumpless extracorporeal lung assist [pECLA]). PATIENTS AND METHODS: In 30 patients with ARDS due to multitrauma, pneumonia or after surgery (p(a)O(2)/F(I)O(2)-ratio 67+/-23 mmHg) pECLA was established by insertion of cannulae to the femoral artery and vein followed by connection with a membrane gas exchanger. For this system, only "low dose" continuous heparin infusion is required. RESULTS: Arterial oxygenation was acutely and significantly increased by pECLA (p(a)O(2)/F(I)O(2)=103+/-56 mmHg 2 h after begin) and carbon dioxide removal was markedly enhanced in 25 out of 30 patients (87%) allowing a lung protective ventilation strategy. The mean duration of pECLA therapy was 6.5 days, 15 patients (50%) died due to ARDS or non-ARDS related reasons. CONCLUSION: pECLA represents a feasable and effective treatment in patients with severe ARDS. Compared with pump-driven systems pECLA is characterised by low costs and reduced personnel requirements. However, mortality remains high in patients suffering from severe ARDS despite newer treatment modalities.

Adult↗
PubMed2004

[Comparison of incomplete (135 degrees ) and complete prone position (180 degrees ) in patients with acute respiratory distress syndrome. Results of a prospective, randomised trial].

BACKGROUND: Ventilation in the prone position is carried out for improvement of pulmonary gas exchange in patients with acute respiratory distress syndrome (ARDS). We compared the effects of an incomplete prone position (IPP, 135( degrees )) with a complete prone position (CPP, 180( degrees )) in patients with ARDS. PATIENTS AND METHODS: For this trial 59 patients with ARDS were randomly assigned and were positioned in a "cross-over" design: patients of group A were placed in IPP for 6 h and then immediately positioned in CPP for another 6 h. Patients in group B were positioned in reverse order. Blood gases, hemodynamic measurements, quasistatic respiratory compliance and assessments of side effects were performed before begin, 30 min and 6 h after first positioning, then 30 min and 6 h after second positioning and 2 after repositioning. RESULTS: Turning patients in IPP and CPP resulted in a significant increase in the arterial oxygenation index (p(a)O(2)/F(I)O(2)), but this effect was more pronounced in the CPP (before: 142+/-46 mm Hg, 6 h: 253+/-107 mm Hg) than in the IPP (before: 139+/-54 mm Hg, 6 h: 206+/-75 mm Hg), and compliance was improved only in CPP. The improvement in arterial oxygenation persisted 2 h after repositioning in the supine position in both groups. The oxygenation responder rate was lower during the IPP (70.3%) in comparison with the CPP (84.0%, p<0.05). The incidence of side effects tended to be increased during the CPP. CONCLUSION: Incomplete prone position improves oxygenation in ARDS patients, but less effectively than a "classic" CPP. In these patients the use of a CPP should be preferred.

Aged↗
PubMed2003

Pure silica BETA colloidal zeolite assembled in thin films.

Pure silica nanoscale zeolite BETA with monomodal particle size distribution was synthesized from a colloidal precursor solution and successfully applied for the preparation of hydrophobic ultrathin films on silicon wafers via spin coating.

Journal Article↗
PubMed2003

[Hb 1.1 g/dl: successful treatment of a polytraumatized patient in hemorrhagic shock].

We report on the successful treatment of a seriously traumatized patient (injury severity score=59) who presented with exsanguinating hemorrhage in the emergency room. Preclinical and emergency room management included "small volume" hypertonic resuscitation as well as massive transfusion, C-clamp stabilization of a pelvic ring instability, and attachment of external fixators to multiple bone fractures. During the intensive care period,we started enteral immunonutrition immediately after an abdominal compartment syndrome was removed by laparotomy and a jejunal catheter had been inserted. Multiple fractures were stabilized rapidly and the soft tissue wounds were covered by split skin grafts. Additionally, we provided sufficient analgesia with few side effects using an epidural catheter for continuous application of local anesthetics. In summary, an effective synthesis of up-to-date strategies for preclinical, emergency room, and intensive care management prevented multiple organ failure and achieved survival with good quality of life after a "fatal" multiple trauma.

Adult↗
PubMed2002

Lung recruitment maneuver in patients with cerebral injury: effects on intracranial pressure and cerebral metabolism.

OBJECTIVE: To investigate the effects of a lung recruitment maneuver on intracranial pressure (ICP) and cerebral metabolism in patients with acute cerebral injury and respiratory failure. DESIGN: Prospective investigation. SETTING: Ten-bed intensive care unit of a university hospital. PATIENTS: Eleven patients with acute traumatic or non-traumatic cerebral lesions, who were on mechanical ventilation with acute lung injury. INTERVENTIONS: Hemodynamics, ICP, cerebral perfusion pressure (CPP), jugular venous oxygen saturation (SJO(2)), and arterial minus jugular venous lactate content difference (AJDL) were measured before, during and after a volume recruitment maneuver (VRM), which included a 30-s progressive increase in peak pressure up to 60 cmH(2)O and a sustained pressure at the same level for the next 30 s. RESULTS: At the end of VRM, ICP was elevated (16+/-5 mmHg vs 13+/-5 mmHg before VRM, P<0.05) and mean arterial pressure was reduced (75+/-10 vs 86+/-9 mmHg, P<0.01), which resulted in a decrease of CPP (60+/-10 vs 72+/-8 mmHg, P<0.01). SJO(2) deteriorated at the end of the procedure (59+/-7 vs 69+/-6%, P<0.05), AJDL was not altered. In the following period all parameters returned to normal values. An improvement in arterial oxygenation was observed at the end, but not in the period after the maneuver. CONCLUSIONS: Our VRM reduced cerebral hemodynamics and metabolism. We conclude that our VRM with high peak pressure effects only a marginal improvement in oxygenation but causes deterioration of cerebral hemodynamics. We therefore cannot recommend this technique for the ventilatory management of brain-injured patients.

Adult↗
PubMed2002

[ARDS and severe brain injury. Therapeutic strategies in conflict].

The development of adult respiratory distress syndrome (ARDS) complicates the treatment of patients with severe head injury, since special therapeutic strategies for both conditions might lead to a "conflict of interest". We report on the intensive care treatment of a young man who suffered severe brain injury (Glasgow Coma Scale = 3) due to a traffic accident and simultaneously developed ARDS from the aspiration of gastric content. We performed extensive monitoring of cerebral hemodynamics and metabolism (intracranial pressure measurement, jugular bulb oxymetry, estimation of arterial-jugular bulb lactate concentration difference) to prevent cerebral hypoxia and to control cerebral hyperemia. The application of a "lung protective strategy" with "permissive hypercapnia" led to a conflict, since the development of cranial hyperemia combined with cranial hypertension a few days after trauma, warranted the concept of controlled, temporary hyperventilation. Therefore, we applied a pumpless extracorporeal lung assist to improve carbon dioxide elimination. Furthermore, we started the ventilation in the prone position, since arterial oxygenation continued to deteriorate, although there is a lack of data describing the effect of a prone position on acute cerebral injury. Positioning the patient prone, we observed a prompt increase in intracranial pressure, which resulted in pharmacological intervention (mannitol). Treating the patient by intermittent prone position, by continuous extracorporeal lung assist and aerosolized prostacyclin administration in the following period, lung function improved and ARDS was treated successfully. After withdrawing the analgo-sedation the patient's vigilance rose continuously. The patient was transferred to a rehabilitation ward 33 days after admission to the intensive care unit. The combination of ARDS and severe brain injury needs special treatment, which includes extensive monitoring techniques to find a solution for therapeutic conflicts.

Adult↗
PubMed2002

["Simplified Acute Physiology Score" (SAPS II) ina the assessment of severity of illness in surgical intensive care patients].

INTRODUCTION: In 1993, Le Gall proposed a new Simplified Acute Physiology Score (SAPS II) to assess the severity of illness in intensive care patients and to predict the risk of hospital mortality using a large data base of more than 13,000 patients of different intensive care units. Up to the present time, no satisfactory form of validation for surgical intensive care patients has been available. We investigated the prognostic quality of this score system for the assessment of the severity of the illness in surgical intensive care patients. METHODS: Between October 1997 and December 1998, 310 consecutive patients were included in our study. We calculated the SAPS II score according to the published guidelines. Additionally, we calculated the risk of mortality by referring to the score. We used a receiver operating characteristics (ROC) analysis for statistical evaluation. RESULTS: The median duration of stay on our intensive care unit was 8.4 days. In all patients, the mean SAPS II was 29.9 +/- 12.7. In the survivors, calculation of mean SAPS II was 27.7 +/- 11.4. In the non-survivors, mean SAPS II was 45.7 +/- 11.2. The predicted risk of mortality was 15.7%, the actual risk of mortality was 15.8%. CONCLUSION: The SAPS II score has proved to be a good prognostic instrument in surgical intensive care patients. SAPS II is particularly effective in providing an exact estimation of the risk of death, classifying patient groups in clinical studies, epidemiological investigations, and quality assessment.

Adult↗
PubMed2002

[Thoracic computed tomography in intensive care patients - evaluation of clinical usefulness].

PURPOSE: Computed tomography of intensive care patients requires transportation of the patient to the radiology department. This study analyses, whether this consumption of resources is justified by therapeutical and diagnostic consequences derived from helical computertomography of the chest. METHODS: 558 CT studies of the chest were compared with current bedside chest radiographs. The additional information of CT scans and their consequences were evaluated retrospectively. RESULTS: 388 (69.5 %) of these computed tomographies provided additional information compared with projection radiographs. 374 therapeutical procedures resulted from 266 (68.6 %) out of these 388 CT examinations. These therapeutical interventions were significantly more invasive than those 144 procedures derived from 170 (30.5 %) CT studies which did not show any additional findings compared with bedside chest radiographs. CONCLUSION: In more than two thirds (69.5 %) additional diagnoses were found with computertomography. Nearly one half of the CT studies resulted in additional findings and therapeutical consequences. Invasive therapeutical consequences were based on CT studies significantly more frequently than on bedside chest radiographs.

Adolescent↗
PubMed2001

Alternative shift models and the quality of patient care. An empirical study in surgical intensive care units.

UNLABELLED: On 1 January 1996, the German Arbeitszeitgesetz (working-time regulation) came into effect for hospital physicians. It states that working hours must not exceed 8 h per day, even for physician in hospitals. As a consequence, the prevalent two-shift model is legally inadmissible. The intention of this law is to protect the physician and to create better conditions for the patients. However, a systematic evaluation of the postulated benefits is still lacking. AIM: The aim of our study was to analyze the influence of the length of daily working hours on the quality of patient care by measuring the outcome of patients in intensive care units (ICUs), comparing the two-shift model (2-SM)--two 12-h shifts--with the three-shift model (3-SM)--three 8-h shifts. MATERIALS AND METHODS: In a prospective multicenter study, we compared the outcome of patients in six ICUs (organized by surgeons) with different models of working hours. The health status of each patient and the course on ICU [described by hospital mortality, number of complications, readmission to the ICU, reinterventions, duration of the stay in an ICU and hospital, the course of the Acute Physiology and Chronic Health Evaluation (APACHE) II score] were uni- and multivariately analyzed. In addition, the technical and personnel resources of the ICUs and the hospitals were documented. RESULTS: Three hundred and forty seven patients (103 2-SM, 244 3-SM) were included. The epidemiological and the health status on admission to the ICU were comparable. Patients in the 3-SM stayed 1.6 days longer on ICU and 2.3 days longer in the hospital than the 2-SM patients. The frequency of complications, reinterventions, and readmissions to ICU was higher in the 3-SM. The median of the APACHE-II score decreased more for 2-SM than for 3-SM patients. This means a significantly quicker recovery of the patients in 2-SM (P < 0.05). The multivariate analysis with individual outcome measures as dependent variables revealed a significant positive effect of the 2-SM on the physicians' assessment of postoperative course, on the relative frequency of therapeutic procedures, and to a lesser extent on the duration of stay in the ICU.

APACHE↗
PubMed2000

[Ventilation in prone position in a 5-year-old child after multiple trauma. Effective treatment of persistent atelectasis].

We report on the ventilation in prone position in a 5-year-old traumatized child with severe thoracic and abdominal injuries (lung contusion, rib fractures, rupture of liver and spleen). Under continuous analgesic sedation, the young patient was ventilated in prone position for 6 h, since acute lung injury and atelectasis persisted despite various therapeutic measures (artificial ventilation in the pressure controlled mode, fiberoptic bronchoscopy, reexpansion maneuver). After initiation of the prone position, we observed a rapid increase in arterial oxygenation, which persisted in the following period. The hemodynamic situation remained stable. The complete disappearance of atelectasis was demonstrated radiologically after supine repositioning. After cessation of analgesic sedation, the extubation was performed 2 days later. Furthermore, we found no side effects of the prone position on the injured abdomen, and the liver function improved rapidly. Although there is a lack of experience with ventilation in prone position in pediatric intensive care, our report might be a recommendation for the indication of this technique in children.

Abdominal Injuries↗