Biomedical subjects

M Pietsch

Publications and source records attributed to M Pietsch.

At least 19 recordsLinked to original sources

PubMed2006

[Intermittent compression devices for swelling reduction and thrombosis prophylaxis--a pilot study after total hip replacement. Is the 2 hour daily minimum application sufficient?].

BACKGROUND: The use of intermittent compression devices for thrombosis prophylaxis and the reduction of postoperative swelling are widely accepted. The recommended minimum application of 2 h daily has never been statistically verified. Without evidence based data, the benefit of this costly equipment cannot be maximized. PATIENTS AND METHODS: A randomized clinical trial on 41 patients after total hip replacement was performed. The A-V Impulse System was applied for 2 h a day during the first 5 postoperative days to observe whether this time was sufficiently effective. RESULTS: In the control group, two deep vein thromboses occurred postoperatively, but there were none in the treatment group. Even though two patients from the treatment group had to be excluded from the study because of severe pain, all other parameters including visual analogue pain scale results and limb circumferences were comparable in both groups. CONCLUSION: These preliminary results suggest that pump systems can prevent deep venous thrombosis after hip surgery even when applied for only short intervals over a short period of time. However, large scale confirmatory studies are needed.

Adult↗

PubMed2006

[Value of radiographic examination of the knee joint for the orthopedic surgeon].

Extended radiographic examinations offer excellent options for diagnosis and strategy for treatment of the knee joint. The whole-leg radiograph is indispensable in measuring alignment for osteotomy or total knee arthroplasty (TKA). Fluoroscopically assisted varus-valgus stress radiographs provide the possibility for verifying mechanical function of the implanted knee prosthesis. Ultrasound examinations have been widely replaced by magnetic resonance imaging (MRI). MRI is the golden standard to examine intra-articular structures of the knee (meniscus, ligaments, cartilage) and surrounding soft tissue. For evaluating femoral and tibial torsion and determining axial rotation of TKA, computed tomography (CT) is best qualified. Imaging of the patellofemoral joint (patella instability) is difficult; CT scans in combination with true lateral radiographs seem to be helpful.

Arthroplasty, Replacement, Knee↗

PubMed2006

[Bone marrow edema in the knee. Differential diagnosis and therapeutic possibilities].

The Bone marrow edema (BME) is a common finding when evaluating patients with knee pain by magnetic resonance imaging (MRI). The typical signal patterns of BME are unspecific and can be found with different diseases of the knee. Since different therapeutic approaches are mandatory, differential diagnosis of the several forms of BME is important. In this review, painful BME will be separated into three different etiological groups. Group 1 ischemic BME: osteonecrosis, osteochondritis dissecans, bone marrow edema syndrome and complex regional pain syndrome. Group 2 mechanical BME: bone bruises, microfracture, stress-BME und stress fracture. Group 3 reactive BME: inflammatory gonarthritis, degenerative gonarthrosis, postoperative and tumours. The typical MRI morphologies and differential diagnosis of these BME manifestations will be described. The different therapeutic consequences will also be briefly mentioned.

Arthralgia↗

PubMed2006

[Perioperative antibiotic prophylaxis. Use in orthopaedics].

Perioperative antibiotic prophylaxis in orthopaedics is only indicated if a foreign body such as a prosthetic joint remains in the operation site. For this indication first or second generation cephalosporins should be preferred. It is essential to administer the antibiotic within 30 min before incision. In the case of an extended intervention (more than 3 h) a repeated dose should be considered. It is evidence-based that prolonged perioperative antibiotic prophylaxis (more then 24 h) is not beneficial. To avoid the emergence of resistances or hygienic insufficiencies surveillance of surgical site infections should be enforced. Optimal conditions are necessary to achieve a rate of surgical site infection in orthopaedics below 1% in patients with normal infection risk profile.

Anti-Bacterial Agents↗

PubMed2006

Development and evaluation of different methods to assess download and display time of image web systems.

OBJECTIVES: The aim of this study was to develop and verify different methods of measuring time-to-display (TTD) for radiological images with image web systems (IWS). The process should be automatable in order to repeatedly perform a large number of measurements without human interaction. MATERIALS AND METHODS: Three methods were defined and compared with respect to usability, stability, and quality of results. Method 1 was based on Windows 2000 Performance Monitor, whereas method 2 employed phototransistors taped to the screen and connected to a separate PC. A software tool developed for method 3, which used Windows application programming interface (API) function, calls to read the color code assigned to specific pixels on the screen. RESULTS: Method 3 proved to be the most reliable and easy to automate. The accuracy is practically equivalent to method 2, but it proved to be far more automatable. Method 1 produced the largest mean error, was easily disturbed, but was also easy to set up and provided additional insights into the system's architecture especially if combined with method 3. CONCLUSIONS: To measure the performance of image distribution systems, any of these methods can be used, but method 3 proved to be superior.

Data Compression↗

PubMed2003

Upload capacity and time-to-display of an image Web system during simultaneous up- and download processes.

The aim of this study was to assess the up- and download performance of an image Web system (IWS) during simultaneous up- and download procedures. Following preparatory tests, the upload capacity (UC) with and without simultaneous download and the time-to-display (TTD) with and without simultaneous upload were determined for different image, server and compression types, and with up to 16 concurrent clients. The UC varied between 1.7-5.5 Gigabyte per hour (GB/h) and was slightly influenced by a simultaneous download; however, the TTDs were substantially prolonged during an upload and only below 5 s with up to four to six concurrent clients. The choice of image and server type had a strong impact on UC and TTD. Lossy primary compression proved slightly superior. An effective UC of approximately 4.0 GB/h or 96 Gigabyte per day (GB/day) can be achieved, which appears suitable even for large institutions. Because of its substantial influence on UC and TTD during simultaneous up- and download, the server hardware should be equipped with two processors and 1 GB RAM. Lossy primary compression may be used with slight performance benefits when full-resolution images are not required. The upload is a time-demanding process, and it is possible that during peak hours the waiting times are unacceptable for clinicians.

Data Compression↗

PubMed2003

Performance of Web-based image distribution: server-oriented measurements.

The aim of this study was to assess the performance of Web-based image distribution when multiple personal computers (PCs) are downloading images simultaneously for different server hardware configurations. Using specially developed software, the time-to-display (TTD) of different image types was measured with up to 16 concurrent PCs for various combinations of processor, random access memory (RAM), network connection and image compression. The TTD increased linearly with the number of concurrent PCs but remained under 5 s in most of the cases, even with 16 concurrent PCs. Only with a 10-Mbit/s network connection or with lossy compression were TTDs above 5 s obtained. Two processors instead of one led to a slight and constant improvement of the TTD. Reducing the amount of RAM increased the TTD mainly for computed radiography (CR) images. There was no difference between a 200- and 100-Mbit/s network, but 10 Mbit/s proved significantly worse. When increasing the number of clients lossless compression performed substantially better than lossy. A standard off-the-shelf server provides an appropriate download performance even with 16 concurrent clients. Processor speed and RAM amount are of minor importance, but it is highly recommended to use a 100-Mbit/s network connection and to avoid the application of on-demand lossy compression in a local area network.

Internet↗

PubMed2003

Performance of Web-based image distribution: client-oriented measurements.

The aim of this study was to define a clinically suitable personal computer (PC) configuration for Web-based image distribution and to assess the influence of different hard- and software configurations on the performance. Through specially developed software the time-to-display (TTD) for various PC configurations was measured. Different processor speeds, random access memory (RAM), screen resolutions, graphic adapters, network speeds, operating systems and examination types (computed radiography, CT, MRI) were evaluated, providing more than half a million measurements. Processor speed was the most relevant factor for the TTD; doubling the speed halved the TTD. Under processor speeds of 350 MHz, TTD mostly remained above 5 s for 1 CR or 16 CT images. Here Windows NT with lossy compression were superior. Processor speeds of 350 MHz and over delivered TTD <5 s. In this case Windows 2000 and lossless compression were preferable. Screen resolutions above 1280 x 1024 pixels increased the TTD mainly for CR images. The RAM amount, network speed and graphic adapter did not have a significant influence. The minimum threshold for clinical routine is any standard off-the-shelf PC better than Pentium II 350 MHz, 128 MB RAM; hence, high-end PC hardware is not required.

Computers↗

PubMed2003

[Temporary articulating spacer with antibiotic-impregnated cement for an infected knee endoprosthesis].

Two-stage reimplantation remains the gold standard in the treatment of late infected total knee arthroplasties. The reported disadvantages include difficult exposure at the time of reimplantation and less functional outcome by using static spacers. Patients who receive an articulating spacer retain a functional joint before second-stage reimplantation. This may reduce the disadvantages of static spacers (ligament contracture, extensor lag, arthrofibrosis). There is no difference in the success rates of eradicating infection (range: 90-96%). In a prospective study 24 consecutive patients were treated with an articulating spacer. The articulating spacer is made by cleaning and autoclaving the removed femoral component and the tibial polyethylene insert. These are reinserted during the same operation with antibiotic-loaded cement. The average time during which the spacer was in place was 16 weeks (range: 7-28 weeks). During an average follow-up period of 14.8 months (range: 5-33 months) one patient had a secondary reinfection. Use of an articulating spacer is economical and decreases the risk of complications in reimplantation with good functional outcome.

Anti-Bacterial Agents↗

PubMed2003

Standardized reprocessing of reusable colonoscopy biopsy forceps is effective: results of a German multicenter study.

BACKGROUND AND STUDY AIMS: National and international guidelines recommend that a standardized protocol consisting of cleaning, ultrasound cleaning, and sterilization should be used for the reprocessing of endoscopic accessories in order to reduce the risk of transmission of microorganisms. This German multicenter study investigated the efficacy of standardized reprocessing of reusable biopsy forceps used during colonoscopy. MATERIALS AND METHODS: Ten endoscopy centers (eight hospitals and two private practices) used 330 biopsy forceps during routine colonoscopy. The forceps were used once, five times, or 20 times for colonoscopy, based on a randomization plan. The reprocessing protocol consisted of manual cleaning with an enzymatic agent, ultrasound cleaning with an enzymatic agent (30 min, 40 degrees C, 47 Hz), neutralization, drying, and sterilization (5 min, 134 degrees C). Aldehydes were not used, and the protocol did not include a disinfection step. The biopsy forceps were sent to three microbiological institutes, based on a randomization plan, to have them tested for the presence of organisms, including identification of bacteria. RESULTS: A total of 318 of the 330 forceps were evaluable; 314 forceps (98.74 %) were sterile after use once, five times, or 20 times. Four forceps were contaminated with Staphylococcus epidermidis (n = 2), Bacillus licheniformis (n = 1) and Corynebacterium aquaticum (n = 2). All of 25 forceps were sterile after being used 20 times. CONCLUSION: Colonoscopy biopsy forceps can be reliably reprocessed following this standardized protocol, even without aldehydes.

Bacteria↗

PubMed2002

Evaluation of a "no-cost" Internet technology-based system for teleradiology and co-operative work.

The aim of this study was to assess the suitability of a no-cost system based on standard Internet technology components for teleradiology. The system was composed of free software (communication, DICOM viewer, compression) and standard off-the-shelf hardware components. For different image (CR, CT, MR) and network types (LAN and ISDN) the File Transfer, Audio and Video Conference, and Co-operative Work properties were examined and compared with the literature referring to standard complete packages and dedicated teleradiology systems. The main advantages of the no-cost system are: price; ease of use; independence from specific hardware; and potential connection to any possible partner. The performance of the File Transfer and the Audio and Video Conference was comparable to the other system groups with slight disadvantages in the usability. For Co-operative Work the employed "application sharing" technology does not meet the clinical requirements, which applies identically to the standard complete packages. Here the specialized systems prove superior, although they are proprietary. With minimal restraints the evaluated no-cost solution can be used for File Transfer and Conference scenarios. The usage for Co-operative Work with ISDN is not recommended, unless for the purpose of gaining experience or when dealing with small amounts of cases or images.

Computer Systems↗

PubMed2002

[Influence of information campaigns on the vaccination immunity among the population of a small town area - seroepidemiological results of the 'Wittlich Vaccination Study'].

In the course of the three-phase 'Wittlich Vaccination Study' the population immunity against tetanus, diphtheria and poliomyelitis was controlled in all age groups of the regional population. Antibody measuring was done in specific validated enzyme immunoassays and neutralisation tests. After performing several campaigns for training and informing medical staff and the population about vaccinations the effect of these campaigns was checked in an additional control of the population immunity. The part of not or only partially protected participants decreased for tetanus from 36.7 % to 2.8 % and for diphtheria from 61 % to 51 %. The gap in population immunity was reduced for polio virus type 1 from 6.7 % to 3.1 %, for polio virus type 2 from 6.2 % to 2.5 % and for polio virus type 3 from 13.2 % to 3.6 %. The study design can be transferred to regions with comparable structure of their population.

Adolescent↗

PubMed2002

[Studies on the importance of tick-borne encephalitis in Rhineland-Pfalz].

Within the scope of a prospective clinical study during 2001 in Rhineland-Palatinate specimen from sera and cerebrospinal fluids of 163 patients with suspected meningitis were controlled in an enzyme immunoassay concerning a TBE infection. Questionable results were checked via a neutralisation test. In no case such an infection was confirmed. No virus specific nucleic acids could be detected in 998 nymphs and adults of Ixodes ricinus in an additional investigation in 2000. Therefore Rhineland-Palatinate has to be considered as a region with low virus prevalence. A general recommendation for vaccination is not necessary.

Adolescent↗

PubMed2001

[Control of low Legionella concentrations in pool water].

The Legionella proof is necessary in pool water according to DIN 19 643 in case of possible aerosol formation. In lab tests it was proven that the direct spatulation of 1 ml water offers high-grade proof with high correlation of the determined concentration to the actual germ content. With very small germ concentrations, however, preceding filtration of larger sample volumes is necessary. During the investigation of routine samples a Legionella proof was possible thereby in individual cases, whereas direct spatulation remained negative.

Bacteriological Techniques↗

PubMed2001

Normal clinical outcome in untreated subjects with mild hyperphenylalaninemia.

ABSTRACT There is international consensus that patients with phenylalanine (Phe) levels <360 microM on a free diet do not need Phe-lowering dietary treatment whereas patients with levels >600 microM do. Clinical outcome of patients showing Phe levels between 360 and 600 microM in serum on a free nutrition has so far only been assessed in a small number of cases. Therefore, different recommendations exist for patients with mild hyperphenylalaninemia. We investigated in a nationwide study 31 adolescent and adult patients who persistently displayed serum Phe levels between 360 and 600 microM on a normal nutrition with a corresponding genotype. Because of limited accuracy of measurements, Phe levels should be looked on as an approximation, but not as an absolute limit in every instance. In addition to serum Phe levels, the assessment program consisted of comprehensive psychological testing, magnetic resonance imaging of the head, (1)H magnetic resonance spectroscopy, and genotyping. We found a normal intellectual (intelligence quotient, 103 +/- 15; range, 79-138) and educational (school performance and job career) outcome in these subjects as compared with healthy control subjects (intelligence quotient, 104 +/- 11; range, 80-135). Magnetic resonance imaging revealed no changes of cerebral white matter in any patient, and (1)H magnetic resonance spectroscopy revealed brain Phe levels below the limit of detection (<200 microM). In the absence of any demonstrable effect, dietary treatment is unlikely to be of value in patients with mild hyperphenylalaninemia and serum Phe levels <600 microM on a free nutrition, and should no longer be recommended. Because of a possible late-onset phenylketonuria, Phe levels of untreated patients should be monitored carefully at least during the first year of life. Nevertheless, problems of maternal phenylketonuria should still be taken into account.

Adolescent↗

PubMed2001

[Hemodynamics of the lower extremity with pneumatic foot compression. Effect on leg position].

External pneumatic compression of the foot is being used more and more to increase the venous blood flow in the lower limbs and thus reduce the risk of postoperative deep venous thrombosis. We have investigated the efficacy of the foot pump pneumatic compression device (A-V Impulse, Novamedix, Andover, England) in 10 healthy subjects and in 10 patients undergoing total hip arthroplasty. The velocity of venous blood flow in the common femoral artery was measured in the horizontal, Trendelenburg (head-down, foot-up) and reverse Trendelenburg (head-up and foot-down) positions using a duplex ultrasound unit (Sonoline Elegra, Siemens, Erlangen, Germany) with a 5 MHz linear array probe. Application of the foot pump produced an increase in venous blood flow velocity in all healthy subjects and in all patients. In healthy subjects the mean increase in the horizontal position was 31.18% (SD = 15.86%), and in the Trendelenburg position 20.72 (SD = 15.69%) (right limb). In the reverse Trendelenburg position, the foot pump produced a mean increase of 94.08% (SD = 55.00%). The difference is statistically significant (p < 0.005). In patients with a total hip arthroplasty, the mean increase in the horizontal position was 28.67% (SD = 9.95%), and in the Trendelenburg position 20.34% (SD = 17.85%) (operated limb). In the reverse Trendelenburg, the foot pump produced a mean increase of 91.55% (SD = 42.38%). The difference is statistically significant (p < 0.005). There was no noteworthy difference in results between the controls and patients. Pneumatic compression devices designed to reduce venous stasis are effective in decreasing the rate of deep venous thrombosis after surgery on the lower limb. The results of the present study show that the efficiency of the foot pump in increasing venous return is improved by adopting the reverse Trendelenburg position. This may increase its thromboprophylactic effect.

Adult↗

PubMed2000

[Long-term follow up of bile duct injury by laparoscopic cholecystectomy and reconstruction with jejunum interposition].

The follow-up of patients with severe bile duct lesions after laparoscopic cholecystectomy often shows secondary complications. We report on a female patient suffering from long-lasting complications after bile duct injury and early reconstruction by end-to-end anastomosis via a T-tube drainage. More than 5 years later and after multiple dilatation and stenting of the bile duct stenosis the patient was treated with an expanding metal stent. The severe cholangitis persisted. So the patient was operated on: bile duct and connected stent were resected. The reconstruction was performed with an isoperistaltic jejunal conduit. More than 24 months later the patient is healthy and at work again.

Cholangitis↗

PubMed2000

[Internet technology for clinical applications in a digital radiography department].

PROBLEM: To provide an overview and to assess the clinical feasibility of Internet technology-based systems for hospital-wide image and report distribution as well as for video conferencing. METHODS: The paper describes the theoretical concept behind, the various technical approaches and the experience gained from different systems. RESULTS: Image and report distribution: Advantages include the universal availability of images and reports inside and outside hospitals; ease of use; security features; image and report integration; cost savings by reducing support and training efforts and by optimising available hardware. The main critical issues are performance and workflow integration with RIS and PACS. Video conferencing: main advantages are the standardised, software-based approach and the low investments for hard- and software. Depending on the desired usage the communication performance can be seen as inappropriate. CONCLUSION: Today, Internet technology-based systems appear to satisfy the main clinical needs in radiology. The mentioned drawbacks could be eliminated by means of modified software implementation and focused standardisation efforts. Considering the numerous advantages of these systems a further distribution can be expected for the future.

Communication↗