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H Sitter

Publications and source records attributed to H Sitter.

At least 37 records · Page 2Linked to original sources
PubMed2001

Feasibility of MRI in the diagnosis of acute diverticulitis: initial results.

PURPOSE: The purpose of this study was to evaluate MRI as a diagnostic tool in patients with suspected acute sigmoid diverticulitis. Furthermore, we sought to develop an optimal imaging protocol in these patients. PATIENTS AND METHODS: Eleven patients with suspected acute diverticulitis were included in the study. All patients were imaged in a 1.0 T clinical scanner using a body-array coil. Imaging sequences were single-shot TSE, HASTE-, STIR- and TrueFisp- sequence. All were obtained in the frontal plane. The diagnosis was verified by a single experienced investigator, using ultrasound, and overall clinicopathological outcome. RESULTS: MRI enabled visualization of signs of an acute diverticulitis in all patients. However, the diagnosis of acute diverticulitis was obtained in 10 patients only. The mean imaging time was 17.5+/-5.5 min. STIR- and TrueFisp-sequences alone displayed all findings, e.g pericolonic exsudation, edema and segmental narrowing, whereas SSTSE and HASTE-sequences showed no additional information. Therefore, it appeared that the imaging protocol could be restricted to STIR- and TrueFisp-sequences. CONCLUSION: MRI is feasible as a fast, accurate and investigator-independent diagnostic tool in patients with suspected acute diverticulitis. To prove its value in comparison to computed tomography or ultrasound, further studies are needed.

Acute Disease↗
PubMed2001

Granulocyte-colony stimulating factor in the prevention of postoperative infectious complications and sub-optimal recovery from operation in patients with colorectal cancer and increased preoperative risk (ASA 3 and 4). Protocol of a controlled clinical trial developed by consensus of an international study group. Part one: rationale and hypothesis.

GENERAL DESIGN: Presentation of a novel study protocol to evalue the effectiveness of an immune modifier (rhG-CSF, filgrastim): prevention of postoperative infectious complications and sub-optimal recovery from operation in patients with colorectal cancer and increased preoperative risk (ASA 3 and 4). The rationale and hypothesis are presented in this part of the protocol of the randomised, placebo controlled, double-blinded, single-centre study performed at an university hospital (n = 40 patients for each group). OBJECTIVE: Part one of this protocol describes the concepts of three major sections of the study: Definition of optimum and sub-optimal recovery after operation. Recovery, as an outcome, is not a simple univariate endpoint, but a complex construction of mechanistic variables (i. e. death, complications and health status assessed by the surgeon), quality of life expressed by the patient, and finally a weighted outcome judgement by both the patient and the surgeon (true endpoint). Its conventional early assessment within 14-28 days is artificial: longer periods (such as 6 months) are needed for the patient to state: "I am now as well as I was before". Identification of suitable target patients: the use of biological response modifiers (immune modulators) in addition to traditional prophylaxes (i. e. antibiotics, heparin, volume substitutes) may improve postoperative outcome in appropriate selected patients with reduced host defence and increased immunological stress response, but these have to be defined. Patients classified as ASA 3 and 4 (American Society for Anaesthesiologists) and with colorectal cancer will be studied to prove this hypothesis. Choice of biological response modifier: Filgrastim has been chosen as an example of a biological response modifier because it was effective in a new study type, clinic-modelling randomised trials in rodents, and has shown promise in some clinical trials for indications other than preoperative prophylaxis. It has also enhanced host defence and has been anti-inflammatory in basic research. CONCLUSION: The following hypothesis will be tested in patients with operations for colorectal cancer and increased preoperative risk (ASA 3 and 4): is the outcome as evaluated by the hermeneutic endpoint (quality of life expressed by the patient) and mechanistic endpoints (mortality rate, complication rate, relative hospital stay, assessed by the doctor) improved in the group receiving filgrastim prophylaxis in comparison with the placebo group? Quality of life will be the first primary endpoint in the hierarchical, statistical testing of confirmatory analysis.

Bacterial Infections↗
PubMed2001

Granulocyte-colony stimulating factor in the prevention of postoperative infectious complications and sub-optimal recovery from operation in patients with colorectal cancer and increased preoperative risk (ASA 3 and 4). Protocol for a controlled clinical trial developed by consensus of an international study group. Part two: design of the study.

GENERAL DESIGN: Presentation of a new type of a study protocol for evaluation of the effectiveness of an immune modifier (rhG-CSF, filgrastim): prevention of postoperative infectious complications and of sub-optimal recovery from operation in patients with colorectal cancer and increased preoperative risk (ASA 3 and 4). This part describes the design of the randomised, placebo controlled, double-blinded, single-centre study performed at an university hospital (n = 40 patients for each group). OBJECTIVE: The trial design includes the following elements for a prototype protocol: * The study population is restricted to patients with colorectal cancer, including a left sided resection and an increased perioperative risk (ASA 3 and 4). * Patients are allocated by random to the control or treatment group. * The double blinding strategy of the trial is assessed by psychometric indices. * An endpoint construct with quality of life (EORTC QLQ-C30) and a recovery index (modified Mc Peek index) are used as primary endpoints. Qualitative analysis of clinical relevance of the endpoints is performed by both patients and doctors. * Statistical analysis uses an area under the curve (AUC) model for improvement of quality of life on leaving hospital and two and six months after operation. A confirmatory statistical model with quality of life as the first primary endpoint in the hierarchic test procedure is used. Expectations of patients and surgeons and the negative affect are analysed by social psychological scales. CONCLUSION: This study design differs from other trials on preoperative prophylaxis and postoperative recovery, and has been developed to try a new concept and avoid previous failures.

Clinical Protocols↗
PubMed2001

Granulocyte-colony stimulating factor in the prevention of postoperative infectious complications and sub-optimal recovery from operation in patients with colorectal cancer and increased preoperative risk (ASA 3 and 4). Protocol of a controlled clinical trial developed by consensus of an international study group. Part three: individual patient, complication algorithm and quality manage.

GENERAL DESIGN: Presentation of a new type of a study protocol for evaluation of the effectiveness of an immune modifier (rhG-CSF, filgrastim): prevention of postoperative infectious complications and of sub-optimal recovery from operation in patients with colorectal cancer and increased preoperative risk (ASA 3 and 4). A randomised, placebo controlled, double-blinded, single-centre study is performed at an University Hospital (n = 40 patients for each group). This part presents the course of the individual patient and a complication algorithm for the management of anastomotic leakage and quality management. OBJECTIVE: In part three of the protocol, the three major sections include: The course of the individual patient using a comprehensive graphic display, including the perioperative period, hospital stay and post discharge outcome. A center based clinical practice guideline for the management of the most important postoperative complication--anastomotic leakage--including evidence based support for each step of the algorithm. Data management, ethics and organisational structure. CONCLUSIONS: Future studies with immune modifiers will also fail if not better structured (reduction of variance) to achieve uniform patient management in a complex clinical scenario. This new type of a single-centre trial aims to reduce the gap between animal experiments and clinical trials or--if it fails--at least demonstrates new ways for explaining the failures.

Algorithms↗
PubMed2001

[Outcome of minimally invasive surgery. Qualitative analysis and evaluation of the clinical relevance of study variables by the patient and physician].

INTRODUCTION: Mechanistic study endpoints, evaluated exclusively by the physician, are mostly used in clinical studies evaluating new treatment modalities (e.g. laparoscopic cholecystectomy). Those endpoints often lack clinical relevance. The patient's opinion concerning the importance of a study endpoint is particularly important in the evaluation of minimally invasive procedures, which place special emphasis on patient comfort. METHODS: In a first step it was evaluated by meta-analysis, which clinical endpoints have been used for comparison of laparoscopic and conventional cholecystectomy. Furthermore, using a qualitative analysis it was investigated how important the individual study endpoints are for patients and physicians. Ten patients and five surgeons were questioned in a structured interview. RESULTS: Of all outcome variables used world-wide, approximately one third were hermeneutic study endpoints, depending on the quality of the study, but often the method of evaluation was insufficient. Only three of 215 endpoints (< 2%) were quality of life scores, an integrated concept of outcome was missing completely. The qualitative analysis confirms the claimed difference between isolated and integrated evaluation of treatment goals. The importance of postoperative death is underestimated by patients and physicians; postoperative pain is overestimated. Patients ranked the outcome variable "restoration of full physical fitness" as the most important study endpoint after avoidance of complications and death. It is underestimated in isolated evaluation and has not been used in the world literature at all. CONCLUSION: The analysis of clinical relevance of study endpoints should be the first and not the last step of studies to evaluate surgical technology. It cannot be based purely on intuition; it must make use of scientifically accepted techniques (e.g. qualitative analysis).

Attitude of Health Personnel↗
PubMed2001

Clinical decision-making, ultrasonography, and scores for evaluation of suspected acute appendicitis.

Diagnosing acute appendicitis (aA) remains difficult. This study evaluated the utility of ultrasonography (US) compared to clinical decision-making alone and scoring systems to establish the indication for laparotomy in patients in whom aA was suspected. The prospectively documented data of 2209 patients admitted for suspicion of aA, who underwent US by one of 12 surgeons, formed a database in which the diagnostic and procedural performance of clinical decision-making, US, two scoring systems (Ohmann and Eskelinen scores), and clinical algorithms taking account of clinical and either US findings or score results, were retrospectively evaluated. The results of either modality were correlated with final diagnoses obtained by laparotomy in 696 patients, of whom 540 had aA (prevalence 24.45%) and follow-up data in the remainder. US had the highest specificity (97%, compared to 93% for the Ohmann and Eskelinen scores and 94% for the clinical evaluation and algorithms) and lowest overall rate of false-positive findings (negative laparotomy rate 7.6%). The scores were accurate in refuting the diagnosis of aA but otherwise not superior to US. The best overall diagnostic and procedural results were obtained with the algorithms that combined the results of either US or the Ohmann score with clinical evaluation, which produced the most favorable numbers of negative laparotomies, potential perforations, and missed cases of aA. US is the diagnostic standard of reference for patients with a possible diagnosis of aA. It yields diagnostic results superior to those of scoring systems and provisional clinical evaluation. However, the benefits of US by ultrasonographically trained surgeons are only fully appreciated within the context of clinical algorithms. The joint evaluation of score results and clinical evaluation may deliver information of similar accuracy.

Acute Disease↗
PubMed2000

[Is a general pharmacologic thromboembolism prophylaxis necessary in ambulatory treatment by plaster cast immobilization in lower limb injuries?].

Selected patients with minor lower limb injuries and low risk for deep vein thrombosis (DVT), who required cast immobilizing and did not receive medical thrombosis prophylaxis, were included in a prospective study. The decision to give not medical thrombosis prophylaxis depended on an concept of individualised prophylaxis for patients at risk for thromboembolism. From March 1994 to March 1996 in 178 outpatients (118 men, 60 women, mean age 25.8 [16-39] years) a clinical examination and a colour-coded duplex sonography were performed after removal of the cast for detection of DVT of the lower limb. A phlebography was performed when thrombosis was suspected. Two patients developed a one bundle thrombosis of the calf. Clinical appearance of lung embolism was not observed. These results suggest, that low risk patients with minor injuries of the lower limb and plaster cast immobilisation do not need a medical thrombosis prophylaxis.

Adolescent↗
PubMed2000

How asymptomatic is asymptomatic primary hyperparathyroidism?

We observed several cases of patients who believed they were free of symptoms or signs of primary hyperparathyroidism (pHPT) preoperatively. reported a change of complaints following parathyroidectomy (PTX). We, therefore, decided to examine a larger group of patients to discover if these findings were incidental or of more general significance. The role of PTX in these patients with asymptomatic pHPT remains controversial. In 1991 criteria were defined at a NIH-consensus conference, according to which patients qualify for either operative therapy or long term medical surveillance. Until now, it was generally believed that the majority of asymptomatic patients would never develop symptoms. In a epidemiological cohort-study, the perioperative data of 582 consecutive patients with pHPT, including 116 asymptomatic patients (20.9%), who underwent parathyroidectomy between 1987 and 1998 were evaluated by uni- and multivariate analysis. At a median of 72 months postoperatively, all patients underwent a planned follow-up which included a standardised, validated questionnaire, physical examination and laboratory investigations. Eighty-six patients who were asymptomatic preoperatively were available for follow-up. Only eight (9.3%) were definitely asymptomatic, 4.6% of the entire, representative cohort. Postoperative improvement was reported in 81.4% of the "asymptomatic" patients. Multivariate analysis did not reveal a single or a set of preoperative measurements, that would allow to predict the retrospectively definitely asymptomatic patient. PTX resulted in normocalcaemia in 98.8% of preoperatively asymptomatic patients, with an operative morbidity of 1.2% and no mortality. Many apparently asymptomatic patients with pHPT will only realise that they did in fact have preoperative symptoms in retrospect, following PTX. This study suggests that using an up-to-date definition of asymptomatic pHPT, there are only a small number of truly asymptomatic patients and that these cannot be predicted preoperatively, as their symptoms may become apparent only after PTX. "Asymptomatic" patients with pHPT may share the same objective and subjective benefits from PTX as symptomatic patients. They should be operated as soon as the diagnosis is established.

Calcium↗
PubMed1999

[Can diagnostic scoring systems help decision making in primary care of patients with suspected acute appendicitis?].

BACKGROUND AND OBJECTIVE: To assess two recently developed scoring systems with respect to making or excluding the diagnosis of acute appendicitis. PATIENTS AND METHODS: Data on 2359 patients with typical signs of acute appendicitis (AA) were analysed, the results of two diagnostic scoring systems being compared with the diagnosis made by an experienced surgeon. RESULTS: AA was confirmed in 662 of the 22,359 patients (prevalence 28%). Sensitivity, specificity, positive and negative predictive values and overall accuracy for diagnosis with the Ohmann scoring system were 0.63, 0.93, 0.77, 0.86 and 0.84; with the Eskelinen score the values were 0.79, 0.85, 0.68, 0.81 and 0.835; and by the surgeon they were 0.90, 0.94, 0.85, 0.96 und 0.93. The negative appendectomy or laparotomy rate was 14.3 an 12.3 respectively with the Ohmann score, 29.5 and 26.6 with the Eskelinen score. The numbers of potential and of nondiagnosed perforations were 41% and 37% respectively with the Ohman score and 26.6% and 16.3% with the Eskelinen score. The number of missed cases of AA was lowest with the Ohman scoring system, compared with 1.8% for the surgeon. After excluding AA, both scoring systems had a specificity of -0.99, with a positive probability rate of at least 27 (Eskelinen score) up to 87 (Ohman score). CONCLUSION: Both diagnostic scoring systems are better for excluding than correctly diagnosing AA; the decision to exclude could be made with a high degree of accuracy. Either scoring system may therefore be used in primary care of patients suspected of AA to help decide on referral to hospital.

Acute Disease↗
PubMed1999

[Validation of a diagnostic scoring system (Ohmann score) in acute appendicitis].

A diagnostic scoring system, recently published by Ohmann et al. in this journal, was validated by analyzing the clinicopathological data of a consecutive series of 2,359 patients, admitted for suspicion of acute appendicitis. The results of the scoring system were compared to the results of clinical evaluation by junior (provisional) and senior surgeons (final clinical diagnosis). To assess the diagnostic ability of the score, the accuracy and positive predictive value were defined as the major diagnostic performance parameters; the rate of theoretical negative laparotomies and that of diagnostic errors served as the major procedural performance parameters. Of 2,359 patients admitted for suspected acute appendicitis, 662 were proven to have acute appendicitis by histology, for a prevalence of 28%. The overall sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the provisional clinical diagnosis were 0.50, 0.94, 0.77, 0.83, and 0.82; 0.93, for the score 0.63, 0.93, 0.77, 0.86 and 0.84, and for the final clinical diagnosis 0.90, 0.94, 0.85, 0.96, and 0.93, respectively. Of the main diagnostic performance parameter, the accuracy of the score was significantly better than that of provisional clinical diagnosis (P < 0.05, chi 2 test). The score yielded a rate of negative appendecomies and laparotomies of 14.3 and 12.3%. With respect to the rate of overlooked cases of acute apendicitis, the score demonstrated a superior performance, with only 6 cases missed (0.9%). However, the number of patients with acute appendicitis, including those with perforated disease, who were not identified by the score, was almost four times that of the final clinical diagnosis (245 vs 63). With regard to the main procedural performance parameter, the score resulted in a significantly smaller number of diagnostic errors than the provisional clinical investigator (P < 0.05, chi 2 test). The results of this study indicate that the diagnostic scoring system might be helpful when experienced investigators or additional diagnostic modalities such as ultrasonography are not available. It may therefore be of value in the preclinical evaluation of patients with suspected acute appendicitis and may be instrumental as a quality control tool and in clinical guidelines.

Acute Disease↗
PubMed1999

[Formal decision aids in surgery--results of a survey].

Even though many decision-aids have been developed in the past, the application of these systems in clinical practice is still rare. There are many reasons for this, including the reservations of potential users. A survey in three university surgery clinics was conducted to assess the experience and attitudes towards decision-aids among physicians. Seventy-two of the 102 physicians approached (71%) filled out and returned the short questionnaire that was sent to them. More than half of the 72 survey participants already use decision-aids. Among them, guidelines are used most often (46%), whereas other instruments (algorithms, scores, decision trees) are used less frequently (10-17%). Computer-based decision-aids are hardly used at all (7%). These results are in contrast to the strong request for more decision-aids, especially for computer-based systems (40%). Physicians who already use decision-aids are more interested in additional systems. More than 70% of all participants are interested in more information about the topic. The standardized question about attitudes towards computer-based decision-aids reveals more positive than negative appraisal, whereas the answers to open questions focus more on objections. The substantial differences between the three survey locations in parts of the survey results show that attitudes towards decision-aids are influenced by the way the instruments are introduced and the way the users are informed and involved in the process of implementation. A successful implementation of decision-aids in clinical practice should therefore try to integrate the future users as much as possible.

Academic Medical Centers↗
PubMed1999

Second step: testing-outcome measurements.

Despite worldwide enthusiasm for endoscopic surgery, this new technology is now on the top of McKinlay's "product life circle curve." Critical questions are being asked about its benefits and burdens, but the concepts applied and the methodologies used for technology assessment are in a similar position as endoscopic surgery and need a critical evaluation. (1) There are incorrect and outdated concepts for the scientific basis of surgery (surgical theory) including the basic sciences involved; biomedicine still dominates, but assessment of outcome after operations is no longer possible without clinical epidemiology and social psychology. (2) Based on an outdated scientific theory for surgery, an outdated concept of disease is still propagated. It is denoted as mechanical and is based solely on biomedicine. Human subjects are reduced to biologic machines, and outcomes measurement excludes most dimensions of functioning and well-being. To achieve a valid result for outcome measures, a hermeneutic approach must be combined with the mechanical approach. (3) Based on an outdated model of disease, the outcomes used in endoscopic surgery rely too much on traditional measures, such as mortality rate, complication rate, hospital stay, and especially an endless list of biochemical mediators. Their alterations during the perioperative period have not yet been shown to be related to clinical or hermeneutic outcomes. A new method of assessment for clinical trials in endoscopic surgery and for other surgical problems is outlined, such as for surgical infections and for surgical oncology. It includes an index of recovery and objective health status assessed by the doctor, a quality-of-life self-report by the patient, and the true endpoint concept as a critical weighting of both types of outcome by patients and doctors.

Endoscopy↗
PubMed1999

Effect of active compression-decompression resuscitation (ACD-CPR) on survival: a combined analysis using individual patient data.

Active compression decompression resuscitation (ACD-CPR) has been developed as an alternative to standard cardiopulmonary resuscitation (S-CPR). To determine the effect of ACD-CPR on survival and neurologic outcome in patients with out-of-hospital cardiac arrest, this combined analysis involved individual patient data from 2866 patients from seven separate randomized prospective prehospital studies who had received ACD-CPR or S-CPR after out-of-hospital cardiac arrest in seven international sites. Significant improvement in 1-h survival (odds ratio (OR) = 0.83; confidence interval (CI): 0.695-0.99; P < 0.05) was found with ACD-CPR (n = 1410) versus S-CPR (n = 1456). The odds ratio for hospital discharge after ACD-CPR was similar (OR = 0.82; CI: 0.609-1.107, P = NS), but this finding was not statistically significant. Using the chi2-test for trend, there was a significant improvement in overall survival with ACD-CPR (P < 0.05) versus S-CPR. This improvement was largely due to the influence of results from one study site. Neurological outcome and complication rates were comparable between groups. Further study is needed to determine which emergency medical services systems may benefit from out-of-hospital use of ACD-CPR.

Aged↗
PubMed1999

[Clinical guidelines as part of total quality management. Analysis of heterogenous treatment concepts of sepsis in various clinics with computer assisted generation, logical testing and complexity assessment of clinical algorithms].

Generation, local tailoring, implementation and evaluation of clinical guidelines is an integral part of quality management. Clinical guidelines are intimately related to the independency of physicians' decisions. By this the physicians should be responsible for guideline development and guarantee the use of adequate methods of total quality management and outcome assessment. Formal consensus finding and transparency of evidence are necessary to guarantee the use of guidelines. Clinical algorithms are highly formalized and they are well suited for generation and analysis by the software ALGO. Determination of complexity and comparison of the clinical contents of algorithms is done by the scores CASA (Clinical Algorithm Structural Analysis) and CAPA (Clinical Algorithm Patient Abstraction). In a study of 22 clinical departments on treatment management concepts in sepsis following anastomotic insufFiciency in colorectal carcinoma a considerable heterogeneity was shown using this program.

Algorithms↗