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Biomedical subjects

H Sitter

Publications and source records attributed to H Sitter.

At least 19 recordsLinked to original sources

[Clinical pathways in psychiatry and psychotherapy].

BACKGROUND: Implementing evidence-based clinical guidelines by means of clinical pathways is one of the key elements of continuous quality management at the University Hospital of Marburg. This paper explains how clinical pathways for suicidal ideation and suicide attempts were developed. METHODS: Based upon a review of existing guidelines and literature, optimal standards of care were defined. Step-by-step analysis of the process of care and results of a questionnaire were used to describe the actual processes. A problem-orientated comparison of the actual and the optimal process of care was the basis for developing these pathways. A consensus was achieved with all persons involved in the respective process of care taking into consideration local resources as well as barriers. The most important decisions and interventions were defined and presented as a patient-oriented process. RESULTS: The lack of explicit "how to do it"-recommendations of the guidelines for the entire care processes required specific, locally tailored adaptations. Potentials for improvement were identified in the following areas: transfer of patients, consultation, information and coordination within the team, and diagnosis of suicide risk. The pathways include care-oriented algorithms, checklists and assignments of responsibility. CONCLUSIONS: The development of clinical pathways as part of quality management and transsectoral integrated care in psychiatry and psychotherapy is feasible. The concept presented incorporates the potential of increasing transparency, efficiency and efficacy of care, and of improving satisfaction of those involved. It offers psychiatric hospitals the chance to guarantee optimal quality of care in face of increasing workload and costs.

Critical Pathways↗

[Development of a clinical guideline on medical rehabilitation of patients after lumbar disc surgery].

In cooperation with the Federation of German Pension Insurance Institutes (VDR) and with the VfR Norderney e. V., the university of Witten/Herdecke has developed a clinical guideline on medical rehabilitation for patients after lumbar disc surgery. Methodically, development of this guideline was based on the following three steps: (1) consideration of recent scientific literature, (2) analyses of structures and processes employed in rehab clinics, using consultations with clinic managers, with occupational groups involved in rehabilitation and analysis of patient files, as well as (3) the consensus process. One central result was the statement of substantial paucity of research on evidence for many therapeutic interventions used in orthopaedic rehabilitation of patients after lumbar disc surgery. Analyses and investigations in rehabilitation clinics showed a wide range of therapeutic interventions, used to very different extents. Development of the guideline therefore took place on the basis of consensus-based processes. Using formal consensus techniques according to recommendations of the Association of the scientific medical societies in Germany (AWMF), the guideline presented was developed in cooperation with the occupational groups involved in the rehabilitation process. Its structure focuses on the therapeutic targets, and it includes a clinical algorithm illustrating the orthopaedic rehabilitation process in a simple and understandable manner. The guideline presented is based on recent knowledge and corresponds to stage S2 of development. A further implementation project will evaluate practicability and acceptance of this guideline.

Germany↗

Single crystalline nature of para-sexiphenyl crystallites grown on KCl(100).

This work focuses on studies of the single crystal nature of para-sexiphenyl structures grown on freshly cleaved KCl(100) surfaces. Two different kinds of morphologies, namely terrace like structures and needle like structures, are found by atomic force microscopy as well as by electron microscopy. Regardless of the morphology the individual crystallites show highly regular shapes. The crystalline alignment and the degree of order of the crystallites on the surface are determined by X-ray diffraction. Several epitaxial alignments of para-sexiphenyl on KCl(100) are observed and all of them are perfectly aligned on the surface. The rocking curve widths of the organic crystallites do not exceed 800" which is approximately only the four fold of the substrates' ones. The single crystalline nature of para-sexiphenyl crystallites is proven by transmission electron microscopy, diffraction patterns, dark field imaging and high resolution techniques. Single crystalline terraced mounds reach diameters of several microns and heights of 50 nm. Single crystal needles show heights and breadths of more than 100 nm and lengths of several microns.

Crystallization↗

[A virtual reality simulator for objective assessment of surgeons' laparoscopic skill].

BACKGROUND: The aim of this study was to validate computed virtual reality simulation as a tool to assess laparoscopic skills and to establish whether the simulator allows differentiating between surgeons with different laparoscopic experience. METHODS: 27 physicians at the surgical department of the University of Marburg, Germany, with different experience in laparoscopic surgery were divided into three groups: experienced (group I), intermediate (group II), and novices (group III). Following a brief introduction to the virtual reality simulator (LapSim), each participant performed twice a training program consisting of seven tasks (examinations I and II). RESULTS: Comparison of experienced surgeons with less experienced laparoscopic physicians showed a significant (P<0.05) superiority of group I at examinations I and II in most exercises. The groups' difference was more obvious in examination II, since the technique was new for all participants during examination I. Tasks of low complexity in virtual reality such as camera navigation, which are performed by young, not yet responsible surgeons in real surgery, did not show significantly different results between the three groups. CONCLUSION: Differences in laparoscopic experience can be visualised with a virtual reality simulator, and thus a simulator is helpful for assessing surgeons' laparoscopic skills.

Clinical Competence↗

A problem solving and decision making toolbox for approaching clinical problems and decisions.

In this paper, we begin by presenting three real patients and then review all the practical conceptual tools that have been suggested for systematically analyzing clinical problems. Each of these conceptual tools (e.g. Evidence-Based Medicine, Clinical Practice Guidelines, Decision Analysis) deals mainly with a different type or aspect of clinical problems. We suggest that all of these conceptual tools can be thought of as belonging in the clinician's toolbox for solving clinical problems and making clinical decisions. A heuristic for guiding the clinician in using the tools is proposed. The heuristic is then used to analyze management of the three patients presented at the outset.

Biomedical Research↗

Classification of perioperative histamine-related reactions.

OBJECTIVE: Histamine release may cause anaphylactoid reactions. However, during anaesthesia and surgery especially cardiovascular effects may not be regarded as histamine-related. Therefore, we adapted the classical concept of histamine release reactions to the perioperative situation and validated the new paradigm. METHODS: Elevated plasma histamine (diagnostic gold standard) was correlated to potentially related intraoperative signs and symptoms. The validity, repeatability and sensitivity of the 'gold standard' was tested by ROC analysis in volunteers, who also received H1-/H2-histamine antagonists. Additionally, a dose-response relationship was determined in dogs using the histamine releaser compound 48/80. RESULTS: The 'gold standard' had a sensitivity of 96% (90%-100%) and a specificity of 93% (85%-100%). The reproducibility was proven by repeated injections of histamine. Skin reactions, tachycardia and hypertension were identified as histamine-related diagnostic variables. A dose-response curve of plasma histamine release was created. CONCLUSIONS: The defined 'gold standard' is valid for the diagnosis of histamine-related reactions during anaesthesia and surgery. It may help to identify patients, who could benefit from pre-anaesthetic antihistamine prophylaxis.

Animals↗

[Haemorrhoidectomy: conventional excision versus resection with the circular stapler. Prospective, randomized study].

BACKGROUND AND OBJECTIVE: The goal of this study was to compare two surgical methods of treating for haemorrhoids that aim at closure of the wound: resection with a circular stapler and a conventional, closed haemorrhoidectomy. PATIENTS AND METHODS: 80 patients (41 males, mean age 47,1 years) with haemorrhoids stage 3 were randomized and treated with stapler haemorrhoidectomy (test group; n = 40) or had an haemorrhoidectomy according to Fansler and Anderson (control group; n = 40). Following a standardized study protocol we compared postoperative results on the operating day and one week, six weeks, six months and one year afterwards uni- and multivariate analysis and we also calculated the costs. RESULTS: The stapler haemorrhoidectomy proved to be the method causing significantly reduced pain in the early postoperative period so that the patients needed less pain relief. They were able to return to work earlier. One year after stapler haemorrhoidectomy there were three episodes of postoperative bleedings that required intervention, one in the control group. Six patients still had haemorrhoids stage 3, six patients over the age of 65 had persistent anal incontinence (I degrees according to Parks) with proven sphincter dysfunction and disturbances in voiding their bowel with resulting deterioration of quality of life, significantly more frequent than in the control group. CONCLUSIONS: Stapler haemorrhoidectomy cures stage 3 haemorrhoids on a long term basis in 84.2 % of patients, costing less than all alternative treatments. In some cases, it can be associated with postoperative complications.

Adult↗

[Lateral, partial sphincter myotomy as therapy of chronic anal fissue. Long-term outcome of an epidemiological cohort study].

AIM: We observed a relatively high rate of severe forms of anal incontinence in patients who had undergone lateral, partial, internal, open sphincterotomy for chronic fissure in ano years ago in our clinic. An explicit investigation of pre- and postoperative data for a representative patient group was undertaken to find out whether this incidental finding proved to be meaningful. PATIENTS AND METHODS: The perioperative data from 523 patients who underwent sphincterotomy (Parks) between 1986 and 1997 were analyzed by uni- and multivariate analysis. RESULTS: Of 209 patients included in the study, 94.7% could be considered healed after operation. Up until the 12th postoperative week, 14.8% of patients were incontinent in stage I and II (Parks). This increased up to 21% at the time of follow-up, mainly in stage II and III, which significantly differed from a healthy control group. CONCLUSION: Lateral sphincterotomy leads in most cases to quick healing of the chronic fissure in ano with a low recurrence rate. The added effect of degenerative changes was observed to be linked, however, with a higher long-term rate of anal incontinence.

Adult↗

Functional parameters before and after parathyroidectomy: a prospective, randomized long-term trial on different rat strains.

For clinical controls before and after parathyroidectomy and for evaluation of the function of transplants of parathyroid tissue, it is necessary to establish standard values of relevant laboratory parameters for donor and recipient animals as well as for different types of nutrition. Since no such data are yet available, it was the purpose to define such standards. In a prospective randomized trial on 400 rats of the Dark Agouti (DA) and Lewis strain, different functional laboratory parameters such as total calcium, intact parathyroid hormone, phosphate, 1.25-dihydroxyvitamin D, and alkaline phosphatase were measured under a standard and low calcium diet over a period of 40 weeks. Two hundred of these animals underwent a parathyroidectomy four weeks after the beginning of the study and specimens were evaluated histologically. For all eight different study groups normal values could be defined within tight limits for parameters which describe the function of the parathyroid gland or elements of calcium metabolism under different conditions. The optimal conditions for a transplantation model of parathyroid glands were established. Lewis-rats were identified as the ideal donor and DA rats as the better recipient animals. These data can serve as reference values for future studies on transplantation of the parathyroid without immunosuppression.

Alkaline Phosphatase↗

Diagnostic score in appendicitis. Validation of a diagnostic score (Eskelinen score) in patients in whom acute appendicitis is suspected.

BACKGROUND AND AIM: At times, the diagnosis of acute appendicitis may be difficult. However, for minimum morbidity to be obtained, early and accurate diagnosis is essential. This study aimed to validate a scoring system proposed by Eskelinen et al. as an aid in making the diagnosis of appendicitis. PATIENTS AND METHODS: The prospectively documented data of a consecutive series of 2,359 patients admitted for suspicion of appendicitis were used for validation. Accuracy and positive predictive value were defined as the main overall performance parameters, as was the rate of unnecessary operations to assess changes of patient management. Overall performance was assessed by receiver-operator characteristics (ROC) analysis. RESULTS: Of 2,359 patients, 662 were proven to have acute appendicitis (prevalence of 28%). The overall sensitivity, specificity, positive and negative predictive value, and accuracy of the score were 0.79, 0.85, 0.68, 0.91 and 0.835 at a cut-off value of 55. Calibration of the score's cut-off value to 57 yielded more favourable results (0.72, 0.91, 0.76, 0.9 and 0.86), and the rate of unnecessary operations declined from 26.6% to 15.4% ( P<0.05, chi2). ROC analysis revealed an area index of 0.91. CONCLUSION: The Eskelinen score delivered acceptable clinical results only after calibration to a cut-off value of 57. The data from this study suggest the investigation of whether a calibrated score might be particularly instrumental in the pre-admission evaluation of the patient in whom appendicitis is suspected.

Acute Disease↗

[Influence of processing and sterilization on the mechanical properties of pins made from bovine cortical bone].

In a biomechanical study pins made of xenogenous cortical bone were tested in vitro. Forty pins of 3 mm diameter and 60 mm length were made of eight different cattle tibiae and allocated to five different treatment groups. Freeze-dried pins served as control group. Pins of the second group were preserved in concentrated sodium chloride solution and defatted with acetone (Tuto-plast processing). Pins of groups three to five were treated with sodium chloride and acetone and afterwards sterilized by different means (ethylene oxide, autoclavation, or gamma radiation). All pins were subjected to a three-point-bending test and a shear test. We found that bending strength and shearing strength were most increased after sodium chloride and acetone treatment, whereas after sterilization with ethylene oxide or autoclaving, the stability of the pins was similar to the control group. The stability was considerably diminished after gamma radiation. Taking into account possible toxic side effects of ethylene oxide, we conclude that Tutoplast processing followed by autoclavation presents a reliable preparation method for the clinical use of implants made of bovine cortical bone.

Acetone↗

Skeletal growth and long-term bone turnover after enterocystoplasty in a chronic rat model.

OBJECTIVE: To investigate skeletal growth and bone metabolism in a chronic animal model of urinary diversion. MATERIALS AND METHODS: Young male Wistar rats (120) were allocated randomly to four groups undergoing: ileocystoplasty, ileocystoplasty and resection of the ileocaecal segment, colocystoplasty, and controls. All animals received antibiotics for 1 week after surgery; half of each group remained on oral antibiotics. Bone-related biochemistry was measured in serum and urine. Dual-energy X-ray absorptiometry and peripheral quantitative computed tomography (pQCT) were used to determine bone mass ex vivo. RESULTS: Most (90%) of the rats survived the study period (8 months); six rats died from bowel obstruction at the level of the entero-anastomosis and four had to be killed because of persistent severe diarrhoea. Vital intestinal mucosa was found in all augmented bladders. There were no differences in bone length and volume. Loss of bone mass was almost exclusively in rats with ileocystoplasty and resection of the ileocaecal segment (-37.5%, pQCT, P < 0.01). There was no hyperchloraemic metabolic acidosis or gross impairment of renal function. Hypomagnesaemia, hypocalcaemia and decreased insulin-like growth factor-binding protein 3 were the only significant findings on blood analysis. Deoxypyridinoline crosslinks in urine were higher in rats with an enterocystoplasty than in controls. CONCLUSIONS: Enterocystoplasty in rats neither impairs skeletal growth nor bone quantity, but leads to significant loss of bone mass when combined with resection of the ileocaecal segment. Rarefaction of the trabecular network is confined to the metabolically highly active cancellous compartment, most likely as a consequence of intestinal malabsorption.

Absorptiometry, Photon↗

[Analysis of factors affecting the prognosis of vertebral metastases].

The goal of this study was to evaluate factors for the prognosis of patients with metastatic spinal tumors. 139 patients with vertebral metastases were studied. The modified Tokuhashi Score (a preoperative score composed of six parameters) and single factors were analysed with statistical methods. The modified Tokuhashi Score showed a significant correlation (p = 0,0019) with survival time of patients. Additionally, only the Karnofsky Index as single parameter showed statistically significant correlation(p = 0.0016). Regarding the logistic regression, primary tumor, age, sex and Karnofsky Index were identified as prognostic factors for survival time. This trial could demonstrate that the Tokuhashi Score is a successful predicting tool for the assessment of prognosis of patients with vertebral metastases.

Adult↗