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Hospital Departments↗
Biomedical subjects
M Wendt
Publications and source records attributed to M Wendt.
[Assessment of the value of sedation and mobilization in the therapy concept of mechanically ventilated patients].
Continuous improvements in intubation technology have caused a substantial change in the treatment of intubated patients. Whereas, until a few years ago, patients requiring intubation were sedated and treated by muscular relaxation for technical reasons, today sedation is no longer technically indicated. The patient is sedated so that he may be spared the potentially traumatizing psychic experience of machine ventilation. Recent investigations have shown, however, that the emotional strain to which intubated patients are subjected cannot be specifically attributed to artificial ventilation, but rather that it may occur in any severe physical illness. This strain may be eased by a positive relationship between the patient and the ICU staff. Routine sedation of intubated patients thus seems unnecessary. Nevertheless, there are some indisputable medical and psychological arguments in favour of sedation of intubated patients, including insufficiently stabilized fractures, states of restlessness, tetanus, intentional reduction of oxygen consumption, etc. Among the objectives to be achieved by mobilizing intubated patients are the following: restoration of the patient's autonomy, prevention of impaired consciousness, improved oxygenation. A meaningful performance of mobilization under both medical and psychological aspects is also described.
Exercise Therapy↗
[A new modular system for respiratory therapy].
Diversification of respiratory therapy into humidification and secretolysis, oxygen therapy, augmentation of FRC, substitution of the work of breathing and changing inspiratory gas distribution is the basis of a modular device system. The basic unit of the modular system consists of an oxygen-air-mixer, a flow module and an emergency O2-supply for resuscitation bags. The system is preferably attached to the wall rail system and the modules locked into each other. The main advantages are: Reduction in the number of devices around the patient's bed, comprehensive setup; reduction of required storage capacity; cost reduction; easy integration at low cost of new therapeutical procedures; quick and easy change of therapy whilst maintaining basic parameters constant.
Respiratory Therapy↗
[Intensive care treatment as remembered by traumatological and surgical patients].
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Adolescent↗
[Analysis of contemporary and future respiratory therapy].
Up to now there are no systematics of respiratory therapy, although those procedures of "conservative" respiratory therapy are well known since the last century. As ventilation will take over a part or the whole work of breathing of a patient this kind of respiratory therapy must be separated from the conservative therapy procedure, which is the focal point of respiratory therapy. This has been demonstrated by an analysis of respiratory therapy made on two different ICU's. From this analysis a system has been developed encompassing the whole range of respiratory therapy.
Germany, West↗
[Nasotracheal intubation aid--cuff protection and intubation guard].
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Intubation, Intratracheal↗
[Post-traumatic pulmonary hematomas and pneumatoceles].
The x-ray morphology of posttraumatic intrapulmonary haematomas and pneumatoceles is described on the basis of 12 cases in a total of 211 patients with blunt thoracic traumas. The article also reports on the course of these haematomas and pneumatoceles. The problem of the development of a barotrauma through PEEP ventilation is discussed, taking the clinical courses into consideration. A characteristic feature of all the discussed cases was the tendency to spontaneous regression as well as continuous decrease in size roentgenologically; this enabled safe differential diagnosis against other cystic pulmonary changes.
Adult↗
[Specific stress of intensive therapy: its analysis and suggestions for changes].
Proceeding from studies which make the environment of an intensive care unit responsible for psychopathological disturbances in thoracic patients, we made investigations on an operative intensive care unit concerning its influence on the psychical state of surgical patients. For this purpose photometry and noise measurements were made at the patient's bedside; additionally the environment of a ventilated patient was recorded continuously by means of a cine-camera. The results we obtained from noise measurements showed that all patients were affected with both sensorial monotony and sensorial overstimulation. Overstimulation results from sudden and unexpected noise (for example due to emergency admissions) on an intensive care unit. The analysis of the illumination intensity showed a day and night turn; that means, the patient was able to distinguish between daytime and nighttime but due to missing bearings no further temporal orientation was possible. The filmings demonstrated that there were numerous contacts between the patient and his environment which, however, did not last longer than 105 s on an average. These findings refer to the problem of the patient's social isolation; others show the loss of sleeping and resting stages. So the "resting stages", that means stages without visible contact, last between 1-3 min. In the light of the results, psychopathological disturbances in the patients of this intensive care unit are connected with the situational conditions of the unit. Suggestions concerning the removal of situational load-factors are deducible from these findings.
Adolescent↗
[Traumatic right bundle branch block (author's transl)].
Myocardial contusion is a common, but often undiagnosed complication of a blunt chest trauma and is frequently accompanied by cardiac arrhythmias. Right bundle branch block is an arrhythmia that generally subsides spontaneously. The case of an adult patient is reported who sustained multiple facial fractures in a car accident. The admission ECG showed right bundle branch block without any haemodynamic effects. The patient was admitted to the intensive care unit. After 20 hours the right bundle branch block disappeared spontaneously and one month later, after two facial plastic operations, the patient could be discharged. Some of the clinical features and complications of myocardial contusion and diagnostic methods for its detection are reviewed.
Adult↗
Rupture of the aortic wall with compression of bronchial arteries.
A case of closed traumatic rupture of the aortic wall with compression of the bronchial arteries is described. No comparable case has been reported in the literature so far. The effect on pulmonary perfusion and gas exchange is demonstrated. The compression, displacement and transportation of the bronchial arteries (vasa privata) is shown is postmortem angiography.
Adult↗
[Therapeutic problems after massive blood transfusions].
The term of massive blood transfusion is still today not clearly defined. Through the introduction of microfilters, however, the clinical problems were decisively reduced. Nevertheless, a persistent shock may also today lead to acute respiratory disease. Further difficulties present the buffering, the slow activation of erythrocyte function in stored blood, the sufficient fluid and electrolyte substitution as well as the observation of renal function and coagulation disturbance. The problems of rewarming the patient and warming the stored blood before transfusion are discussed. Special regard must be paid to early and long enough ventilation during and after massive blood transfusion.
Acid-Base Equilibrium↗
[Interpretation of chest roentgenograms of intensive care patients. A comparison of pathoanatomical and roentgenographic findings (author's transl)].
Chest roentgenograms made within 24 hours of death were compared to the autopsy findings. Out of 150 unselected autopsy records of the years 1973/74 and 1976/77 50 and 91 cases respectively were suitable for evaluation. Since 1973/74 the radiographic technique has been considerably changed by the introduction of powerful condenser discharge equipment and the use of highly intensifying screens. Daily discussions with the physicians in charge of the intensive care unit and routine comparison of the pathological and radiological findings were also introduced. The success of these measures is reflected in the greater diagnostic accuracy in respect of the case material for the 1976/77 period. Comparison of the findings in cases of pulmonary embolism exposed the limitation of diagnostic radiology.
Humans↗
[Respiratory and hemodynamic parameters for evaluating the effect of artificial respiration].
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Acute Disease↗
[Haemodynamic effects during hypotension with sodium nitroprusside neurosurgery (author's transl)].
Haemodynamic effects during hypotension with sodium nitroprusside in the surgery of cerebral aneurysms were studied in 16 patients. Sodium Nitroprusside caused arterial hypotension by a direct vascular musculotropic effect and it was found to reduce peripheral vasculare resistance, and to lower the bloodpressure in the right atrium and pulmonary arteries. Stroke volume decreased in the presence of tachycardia while there was no change in cardiac output. Its evanescent action and easy regulation make sodium nitroprusside suitable for controlled hypotension during cerebral surgery, especially since there are no negative haemodynamic effects.
Adolescent↗
Remember true FISP? A high SNR, near 1-second imaging method for T2-like contrast in interventional MRI at .2 T.
Clinical requirements for interventional MRI (I-MRI) monitoring of needle placement or thermal ablation demand rapid (near-real-time) image acquisition rates, high spatial resolution, and T2 weighting. Experimental analysis performed earlier suggests that many sequences used for either rapid scanning or T2 weighting at high fields fail to meet both the speed (conventional spin echo [SE], turbo SE) or contrast (ie, fast low-angle shot [FLASH], fast imaging with steady state precession [FISP]) requirements when used at .2 T. In this work, we revisited a number of pulse sequences advocated primarily for higher field applications requiring T2 weighting and found that refocused steady state coherent pulse sequences, aka, true FISP sequences, performed superiorly in achieving both speed and T2 contrast requirements for I-MRI at .2 T. This work focuses on our experience with this new/old technique in the I-MRI setting and describes how one can take advantage of the low field strength and modest inhomogeneity of .2 T (and similar) systems to design pulse sequences that balance TE, TR (and hence T2 dephasing), and resonant offset frequency effects to provide images with the desired contrast and minimal artifactual field inhomogeneity "banding." At high flip angles (approximately 90 degrees ), reasonably short TEs (approximately 5 msec) and short TRs (approximately 10 msec), we have used this method in our last 25 I-MRI procedures (biopsies and/or radiofrequency [RF] thermal ablations) and found these sequences to be extremely useful in both needle localization phases of I-MRI biopsy procedures, RF thermal ablation electrode guidance, and posttherapy imaging assessment. Design methods and clinical I-MRI cases are presented that highlight these points.
Adult↗
Shifted rotated keyhole imaging and active tip-tracking for interventional procedure guidance.
The tools and devices used for patient treatment during interventional procedures must be accurately and safely localized. Recently, procedure guidance has been performed increasingly with MRI, but tool localization has been performed primarily by analyzing the lack of signal caused by displaced excited tissue and/or susceptibility artifacts. In this investigation, a new technique was developed to actively detect and visualize interventional tools using receive coils mounted on the tip of the interventional devices. Unlike earlier methods, in which images from small device-mounted coils are super-imposed on a previously acquired image data set, our localization method uses similar tip-mounted tools in combination with a radiofrequency (RF) switching circuit, standard imaging coils, and specially modified sequences to toggle between the standard and tip-mounted receive coil within a single fluoroscopic mode sequence. With this technique, the misregistration between the reported anatomic location and true location of interventional devices is minimized.
Animals↗
Fast "real time" imaging with different k-space update strategies for interventional procedures.
Interventional procedures under MR guidance require the images to be acquired with a fast acquisition strategy, a rapid reconstruction algorithm for "real-time" imaging (ie, high temporal resolution), acquisition of at least three adjacent slices to track a tool reliably, and high tissue contrast to ensure safe positioning of interventional devices. Often times, the field strength for interventional MR-imaging units is limited by the open magnet design. This complicates the trade-off between scan time and image quality, particularly when applied during low field interventional MRI procedures. To minimize the impact of some of these trade-offs, a combination of keyhole techniques or modified k-space trajectories, in conjunction with a fluoroscopic (ie, continuous acquisition) mode and a real time reconstruction, permits rapid imaging in a low field system using standard (speed optimized) reconstruction hardware and standard gradient electronics. The purpose of this study was to design and describe different keyhole strategies that can be used in a real time mode to increase the image frame rate by a factor of up to 16. By updating the entire raw data space with our strategies, even small changes of the object could be recognized. Our results using these new strategies on two commercially available open magnet MR-imaging units (Siemens Magnetom Open 0.2T resistive magnet, Toshiba Access 0.064T permanent magnet) and a 1.5T superconductive solenoidal magnet design imager (Siemens SP) are presented to show the potential of these acquisition strategies in interventional MRI. Furthermore, these strategies may also be helpful for several other medical applications requiring high temporal resolution like contrast-enhanced breast imaging or functional brain imaging.
Algorithms↗
Intrathecal local anesthetic distribution with the new spinocath catheter.
BACKGROUND AND OBJECTIVES: Microcatheters have been linked in some cases to the development of cauda equina syndrome, which may be further traced to the maldistribution of the local anesthetic. A long injection time via the microcatheters contributes to the inadequate mixing. With the new Spinocath catheter, considerably shorter injection times can be achieved due to larger internal size. This study examined whether this leads to more homogeneous intrathecal distribution without causing greater trauma to the dura. METHODS: In an in vitro model of the spinal canal, the distribution of hyperbaric and isobaric 0.5% bupivacaine (2.5 mL) as well as 5% lidocaine (2.5 mL) was examined after injection via the 28-gauge CoSpan catheter (Kendall, Healthcare, Mansfield, MA), the 22-gauge Spinocath catheter (Braun, Melsungen, Germany), and a 29-gauge Quincke needle (Becton Dickinson, Rutherford, NJ). The local anesthetic concentration in the vertebral interspaces T12-L1 to L5-S1 was measured via gas chromatography 3 and 10 minutes after injection. In addition, the morphologic puncture characteristics of human dura were examined with the halftone electron microscope, after puncture with the catheters and needle. RESULTS: After injection through the 28-gauge CoSpan catheter, caudal segments of the spinal canal showed peak concentrations up to a maximum of 1,147 microg/mL bupivacaine or 8.5 mg/mL lidocaine with hyperbaric solutions, which did not decrease over the 10 minutes of measurement. After injection through the Spinocath catheter, there was a homogeneous distribution with data peaks of approximately 350 microg/mL bupivacaine or 4.2 mg/mL lidocaine similar to the data found after injection through the spinal needle. CONCLUSIONS: The new Spinocath catheter allows a better mixing of the local anesthetic with the cerebrospinal fluid. Because of significantly shortened injection times, hyperbaric solutions also show a more homogeneous distribution. Although the Spinocath catheter has a larger inner diameter than the other microcatheters, it appeared to cause less trauma to the dura.
Anesthesia, Spinal↗