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Biomedical subjects

M Walz

Publications and source records attributed to M Walz.

At least 19 recordsLinked to original sources
PubMed2000

3D norm data: the first step towards semiautomatic virtual craniofacial surgery.

When planning craniofacial surgical interventions, the ideal appearance of the patient is very important. The final appearance should be as close as possible to that which the patient would have if he/she were without defects. Our first step towards achieving this is to build a database containing sets of three-dimensional CT images that allows for comparison of the shape of a patient with defects to the typical shape of an age- and sex-matched "average" person without defects. We started to collect CT data from patients without pathologies and, in co-operation with two radiology institutes (in Mannheim and Heidelberg), over 100 CT data sets have now been collected and classified according to age and sex. It is necessary to choose an appropriate statistical method to calculate the norm data from the different data sets. Based on the statistical method, an age- and sex-matched "average" model of the anatomy will be created.

Adolescent↗
PubMed2000

[Does liberation of interleukin-12 correlate with the clinical course of polytraumatized patients?].

INTRODUCTION: Interleukin-12-p70 (IL-12-p70) is a potent immunoregulatory cytokine composed of a heavy chain (p40) and a light chain (p35). Contradicting results have been reported with regard to leukocyte release and systemic concentration of IL-12 after polytrauma. METHODS: We daily analyzed systemic concentrations of IL-12 in polytrauma patients (n = 37, mean ISS 33.9) in comparison to healthy donor values during intensive care course by ELISA. Patients were divided according to their mean IL-12 levels into those with elevated IL-12 (group 1, n = 7), those with decreased IL-12 (group 2, n = 4) and those with IL-12 in the normal range (group 3, n = 26). RESULTS: Patients in group 1 revealed elevated levels of IL-12 up to p70 > 1000 pg/ml and p40 > 2500 pg/ml. The common clinical feature of group 1 was a thorax trauma in combination with pneumonia (85% survivors). Patients with single thorax trauma or pneumonia without thorax trauma (group 3) showed normal IL-12 values. Patients with decreased IL-12 levels revealed also a thorax trauma and pneumonia but all patients succumbed. The groups significantly differ in their stay in the intensive care unit, in TISS, in MODS score and in respiratory ratio, but not in ISS, mean CRP values and leukocyte counts. Correlation analysis revealed no significant relation between systemically altered IL-12 values and clinical parameters, with the exception of a negative correlation of p70 and ISS (r = -0.785) or MODS score (r = -0.314) in group 1. CONCLUSIONS: After major injuries there is no overall suppression of IL-12 formation. Patients with normal or elevated IL-12 levels belong mainly to the survivors, whereas patients with decreased IL-12 levels are at high risk of succumbing to multi-organ failure.

Adolescent↗
PubMed2000

[Femoral neck fracture. Osteosynthesis or which endoprosthesis is indicated?].

Femoral neck fractures are frequent fractures of the elderly. They can be treated by the use of dynamic hip screws, lag screws, bipolar hemi-protheses or total hip replacement. The results are markedly influenced by the timing of the operation and the choice of the implant. Using the Garden classification of femoral neck fracture we demonstrate a different therapeutic approach according to Garden stadium I-IV.

Aged↗
PubMed2000

Teleradiology requirements and aims in Germany and Europe: status at the beginning of 2000.

Specific radiological requirements have to be considered for realization of telemedicine. In this article the goals and requirements for an extensive implementation of teleradiology are defined from the radiological user's point of view. Necessary medical, legal and professional prerequisites for teleradiology are presented. Superior requirements, such as data security and privacy or standardization of communication, must be realized. Application specific requirements, e. g. quality and extent of teleradiological functions as well as technological alternatives, are discussed. Each project must be carefully planned in relation to one's own needs, extent of functions and system selection. Topics like legal acceptance of electronic documentation, reimbursement of teleradiology and liability must be clarified in the future.

Europe↗
PubMed2000

Induction chemotherapy followed by concurrent chemotherapy and high-dose radiotherapy for locally advanced squamous cell carcinoma of the upper-thoracic and midthoracic esophagus.

The purpose of this study was to evaluate the efficacy and toxicity of an induction chemotherapy schedule followed by high-dose radiotherapy and concurrent chemotherapy for locally advanced squamous cell carcinomas of the upper and midthoracic esophagus. Patients were treated with three courses of fluorouracil, leucovorin, etoposide, and cisplatin-containing induction chemotherapy followed by high-dose external beam radiotherapy to 65 Gy in 6 weeks for T4 and obstructing T3 tumors. Transversable T3 tumors received 60 Gy in 6 weeks by external radiotherapy, followed by two high-dose-rate esophageal brachytherapy fractions of 4 Gy in 5-mm tissue depth. Concurrent to radiotherapy, cisplatin and etoposide were given. Long-term survival of 22 patients was 41% and 31% at 2 and 3 years, respectively, with a median follow-up of 39 months. The probability of locoregional tumor recurrence was 60% at 3 years for all patients and 30% for those with a partial or complete response to induction chemotherapy. Acute toxicity of this schedule was moderate. Long-term survivors had a good swallowing function. This schedule offers a considerable chance of long-term survival for patients with locally advanced squamous cell carcinomas of the upper and midthoracic esophagus. Local in-field recurrences are the main risk after definitive radiochemotherapy. Dose escalation of radiotherapy is possible because of the observed low late toxicity.

Adult↗
PubMed1999

[In Process Citation]

Mechanical ventilation is a well-established strategy in intensive care medicine. ICU trauma patients require analgesia, and sedation mostly consists of benzodiazepines and opioids with increasing doses over time. The weaning period is complicated by the withdrawal syndrome, showing tachycardia, hypertonia, tachypnea and restlessness. Although treatment with clonidine can influence these symptoms, tachypnea still remains the main problem in weaning patients from mechanical ventilation. Adding sufentanil, an opioid with greater effects on analgesia than on respiratory depression compared with fentanyl, tachypnea can be reduced to normal frequency. In this way weaning management can be managed more easily for the benefit of both, the patient and physician. In comparison with a group of 50 patients treated with clonidine alone, 72 patients treated with clonidine/sufentanil showed a shorter period from the start of spontaneous ventilation until extubation (4.8 vs 7.6 days) and until discharge from the ICU (7.7 vs 12.4 days). The number of reintubations caused by respiratory exhaustion decreased from 16.0 to 2.8%.

Journal Article↗
PubMed1999

[Transport-fixator for reconstructive surgery of the extensor apparatus of the knee joint].

Operative repair in ruptures of the extensor mechanism of the knee joint mostly requires additional external or internal fixation by plaster, transfer of tendons or encircling wires. Reconstruction of initially undiagnosed ruptures has to solve the problems of fixed proximal or distal migration of the patella and tendenous shortening. This can be performed with a tibiopatellar external fixator which allows gradually reduction of the patella in an anatomical position before operative reconstruction by suturing or reinsertion. During this period as well as a post-operative protection this fixator enables patients to maintain motion of the knee joint and full weightbearing. This technique can avoid poor functional results caused by long periods of immobilisation and is helpful in patients with marked displacement of the patella and inability to manually reduce the patella distally when delayed repair is necessitated.

Adult↗
PubMed1999

Dental print media and their value in forensic odontology.

Teeth are one of the most important factors in the identification of unknown cadavers. One of the most efficient methods the police have of publicizing a case is to publish the victim's dental x-rays of treatment records in the dental print media which dentists will often recognize and thus be able to contribute to the identification. To evaluate the efficiency of this procedure, 177 cases published between 1975 and 1995 were reviewed. The results show that only 3% of the cases were identified from recognition in the dental print media. A survey of 500 dentists was carried out to gauge the efficacy of the presentation of identification cases in their dental print media. According to these results a revised method of presentation needs to be developed to improve the efficiency of this odontoforensic publicity medium. New technologies could also open new avenues for forensic identification such as digital x-raying or online data transfer. The Internet itself could be useful regarding international cooperation of forensic odontologists in the identification of unknown corpses.

Dental Records↗
PubMed1999

Economic analysis of teleradiology applications with KAMEDIN.

The teleradiology system KAMEDIN (German Telekom), installed on HP-Unix- and NT-Workstations, was evaluated in different scenarios and a cost-benefit-analysis was performed. CT examinations were transferred from a PACS workstation (GE) to KAMEDIN using DICOM-3 protocol. Teleconferences were realized with an intensive care unit by LAN, with a radiology department at 5 km. distance by ISDN, and with an on duty radiologist 22 km. away by ISDN. On average, 36 CT slices per patient were transferred. Overall costs (costs for hardware, software, support, ISDN-fees, and staff) were compared to possible cost reduction, mainly concerning transportation and films. These three scenarios could be realized during daily routine work. Differing in their amount of transportation cost reduction, two applications (intensive care unit, radiologist on duty) showed a break-even at 1817, respectively 528 teleconferences/year. Improvement of cost-effectiveness can be obtained on the conditions that existing hardware will be used and that the automatic data transfer will be improved. Combining all optimisation factors, the break-even decreased to a minimum of 167, respectively 77 teleconferences/year. The optimisation of patient management is an additional--but in this study, not yet counted--advantage of teleradiology.

Computer Communication Networks↗
PubMed1998

[Nonbacterial osteomyelitis of the clavicle].

Osteomyelitis can be subdivided into a bacterial exogenic (post-traumatic/postoperative), bacterial endogenic (hematogenous) and an abacterial type, including the rare group containing primary chronic sclerosing osteomyelitis, which is typically localized in the clavicle. In a review of the literature, the criteria for the various types of chronic sclerosing osteomyelitis are analyzed. Out of a group of 17 patients with osteomyelitis of the clavicle treated between 1978 and 1996, three cases of primary chronic sclerosing osteomyelitis are demonstrated. In the differential diagnosis, primary chronic sclerosing osteomyelitis of the clavicle has to be taken into consideration despite its rareness. After establishing a diagnosis by biopsy, in contrast to the other forms, drug therapy will be the treatment of choice and not an operation.

Adolescent↗
PubMed1998

[CPAP-augmented spontaneous respiration in thoracic trauma. An alternative to intubation].

Intubation and Positive End Expiratory Pressure Ventilation (PEEP) is a well established therapeutic strategy for impaired lung function, particularly following blunt chest trauma. Complications of this regime are however also well known and pose the question why non-invasive forms of respiratory assistance such as Continuous Positive Airway Pressure (CPAP) have only gained minor popularity. In a prospective study, 30 patients who had suffered blunt chest trauma were treated with CPAP administered by mask. The regime consisted of continuous administration of CPAP by a face-mask, with gradually increasing periods of spontaneous breathing. Initially a FiO2 of 0.33 (range 0, 28-0, 33) proved necessary. The initial CPAP level was 7 mbar (range 5-8) with an (Assisted Spontaneous Breathing) ASB of 15 mbar (range 13-8). FiO2 and CPAP/ASB levels were subsequently gradually reduced until no longer necessary. In all patients intubation and ventilation was avoided by this regimen. The treatment was well accepted by all patients and common ventilation associated complications such as pneumonia did not occur. In comparison with the former standard method of treatment the average ICU stay was dramatically reduced, principally due to not having to gradually wean patients from ventilation and sedation. Other positive benefits include normal communication and feeding with active early mobilisation leading to faster recovery, both physical and psychological. We conclude that non-invasive respiratory techniques should be used more frequently and recommend further studies are undertaken to define the indications.

Adult↗
PubMed1998

Teleradiology: results of a questionnaire of German radiologists.

A questionnaire was sent by mail to 4400 radiologists (i.e. to at least 1000 radiological institutions). The response rate was about 5%. The results showed that 47% of respondents felt well informed about teleradiology, 49% not enough and 3% not at all. Image and report transfer as well as interfaces to reference databases, educational applications, technical quality surveillance and product support (maintenance) were considered to be increasingly important areas. Smaller institutions (1-3 doctors) judged expert consultation as more important than bigger institutions. Standardization, system stability and data security were demanded as well as guidelines, for example concerning the linking of report and image, correct documentation and required image quality. Technically most demands can be fulfilled today but this technology is not yet commonly included in teleradiology systems.

Attitude of Health Personnel↗
PubMed1997

[Possible applications of the KAMEDIN teleradiology system with special reference to an economic analysis].

INTRODUCTION: Different concepts and applications of teleradiology systems have been realised. However, their cost-effectiveness is still questionable. Therefore, a cost-benefit analysis of three different scenarios of the new teleradiology system Kamedin (Kooperatives Arbeiten und rechnergestützte Medizinische Diagnostik auf innovativen Netzen der Deutschen Telekom) was performed. METHODS: CT examinations were transmitted from an Advantage Windows (GE) workstation to a Kamedin workstation using DICOM 3 protocol. Afterwards a teleconference was established with a Kamedin workstation in the intensive care unit within the hospital via FDDI/Ethernet, with an external workstation in a radiology department 6 km away via ISDN and with a Kamedin PC located with radiologist on duty 22 km away via ISDN. On average, 36 CT slices per patient were transferred. A break-even analysis was performed with respect to costs of hardware, software, support, use of ISDN and staff, as well as benefits like the decrease in transportation or film documentation costs. RESULTS: Owing to the different reductions in transportation costs, two applications (intensive care unit and external PC) showed a break-even of 1817 and 528 teleconferences/year, respectively. Further optimisation of cost-effectiveness is possible on condition that existing hardware can be used and an automatic data transfer without staff control is available. When all optimisation factors were combined, the break-even decreased to a minimum of 167 and 77 teleconferences/ year, respectively. CONCLUSION: Teleconferences with high image quality can be set up between workstations and PCs using the Kamedin system. Depending on the possible decrease in transportation costs, teleconferencing is cost-effective under certain conditions. Teleradiology has additional advantages, such as the acceleration and optimisation of patient management.

Computer Communication Networks↗