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Biomedical subjects

C Ohmann

Publications and source records attributed to C Ohmann.

At least 73 records · Page 4Linked to original sources
PubMed1997

Prognostic modelling in peritonitis. Peritonitis Study Group of the Surgical Infection Society Europe.

OBJECTIVE: To develop and to evaluate a new score to aid management in peritonitis. DESIGN: Prospective, multicentre study. SETTING: 18 departments of surgery in Germany. Austria, and Switzerland. SUBJECTS: 355 patients with peritonitis confirmed at laparotomy. INTERVENTIONS: Computation of four different prognostic systems: APACHE II; APACHE II and successful operation; APACHE II, successful operation and Goris score on the first postoperative day: and multivariate analysis. Predictions were evaluated according to the following criteria: specificity with a fixed sensitivity at 80%, receiver operating characteristic (ROC-) curve, and predictive value. MAIN OUTCOME MEASURE: The ability to predict hospital death and infective complications. RESULTS: Multivariate analysis was superior to APACHE II: APACHE II and successful operation: and APACHE II, successful operation, and Goris score. From the analysis a new prognostic model was derived from which it was possible to identify patients early in the postoperative period who are at high risk of developing further complications (prognostic peritonitis model: PPM). CONCLUSIONS: None of the existing scores was of particular use for therapeutic decision making in peritonitis. The new prognostic model should be the focus of further trials in the management of peritonitis.

APACHE↗
PubMed1997

[Significance of lymph node metastases of differentiated thyroid gland carcinomas and C-cell carcinomas for prognosis--a meta-analysis].

Surgical therapy of differentiated thyroid cancer (DTC) includes thyroidectomy plus central lymph node dissection and postoperative radioiodine therapy. In cases of lymph node metastasis, T3/T4 tumors and C-cell-carcinoma (after thyroidectomy) uni- or bilateral modified radical lymph node dissection of the neck (neck dissection) and of the mediastinum is recommended. The importance of lymph node metastasis for prognosis of survival in papillary, follicular and C-cell-carcinoma is discussed controversial, however. Even the kind of surgical radicality is questioned. Thus a metaanalysis of 35 studies in 29 independent publications from a pool of 2186 studies was performed. Univariate analysis demonstrates lymph node metastasis as a negative prognostic factor in papillary carcinoma with a 3.25/2.97, in follicular carcinoma with a 7.62/4.0 and in C-cell-carcinoma with a 3.33/3.37 higher probability of mortality 5 and 10 years after operation. Modification of the present surgical therapy can therefore only be accepted after univariate and multivariate analysis of all prognostic factors (age, sex, cell type, tumor extent, lymph node- and distant metastasis) and after it has proven superiority to the present strategy in prospective randomised trials.

Adenocarcinoma, Follicular↗
PubMed1997

[Surgical epidemiology].

The application of epidemiological principles and methods to problems in surgery (Surgical Epidemiology) still plays a minor role in Germany. Different examples are presented, demonstrating that an increase of intellectual power can be achieved by applying epidemiological methods to surgery. Future developments in surgery can be estimated and the role of surgery in comparison with other clinical disciplines can be clarified and strengthened. Similar to foreign countries, support of Surgical Epidemiology by reference centers is required.

Bias↗
PubMed1997

[Is perforating appendicitis a separate disease picture?].

Large epidemiological studies recently published suggest that perforating appendicitis may represent a separate disease entity. To find out whether perforating and nonperforating appendicitis may be distinguished by clinical features (history and examination, lab tests) data from 519 cases of acute appendicitis (17.7% perforations) were analysed, and significant differences were recorded in various aspects of history and clinical examination. It was concluded that perforating and nonperforating appendicitis may clinically be distinguished reliably in the majority of cases.

Adult↗
PubMed1996

[Clinical standardization in acute abdominal pain].

The correct diagnosis in acute abdominal pain is necessary for adequate treatment. In several clinical studies it has been shown that, despite improvements in laboratory and technology medicine, errors occur in a considerable proportion of cases due to insufficient history-taking and clinical examination. By the introduction of a standardised and structured history and clinical examination, the diagnostic accuracy can be improved by at least 10%. The aim of this publication is to improve history-taking, clinical examination and diagnostic decision-making by exact definition of all relevant parameters. This was performed by a national clinical expert group, international standardisations were taken in consideration. The standardisation was based mainly on these existing international standardisations (World Organisation of Gastroenterology); however, revisions and corrections were necessary. In order to introduce the standardisation into clinical routine, a documentation form and a documentation program can be provided.

Abdomen, Acute↗
PubMed1996

Evaluation of automatic knowledge acquisition techniques in the diagnosis of acute abdominal pain. Acute Abdominal Pain Study Group.

Clinical diagnosis in acute abdominal pain is still a major problem. Computer-aided diagnosis offers some help; however, existing systems still produce high error rates. We therefore tested machine learning techniques in order to improve standard statistical systems. The investigation was based on a prospective clinical database with 1254 cases, 46 diagnostic parameters and 15 diagnoses. Independence Bayes and the automatic rule induction techniques ID3, NewId, PRISM, CN2, C4.5 and ITRULE were trained with 839 cases and separately tested on 415 cases. No major differences in overall accuracy were observed (43-48%), except for NewId, which was below the average. Between the different techniques some similarities were found, but also considerable differences with respect to specific diagnoses. Machine learning techniques did not improve the results of the standard model Independence Bayes. Problem dimensionality, sample size and model complexity are major factors influencing diagnostic accuracy in computer-aided diagnosis of acute abdominal pain.

Abdominal Pain↗
PubMed1996

[Ulcer surgery '96--choice of methods in an emergency].

Understanding of peptic ulcer disease has dramatically changed within the last years. Today ulcer disease can be considered as a chronic infection. Based on this new pathophysiological concept treatment policies for ulcer bleeding and perforation have to be revised. For ulcer bleeding the standard procedure consists of a diagnostic emergency endoscopy and endoscopic treatment based on the bleeding activity. Patients with recurrent bleeding during hospital stay carry an increased risk for death. More than 50% of these patients have to be operated, nearly 25% die during hospital stay. For that reason an early elective operation can be recommended in patients with a high risk for further bleeding. This includes patients with arterial bleeding (Forrest Ia) and with a vissible vessel (Forrest IIa) with an additional risk (e. g. posterior wall of the duodenum, lesser curvature). All other bleeding activities can primarily treated conservatively. Because of an effective medical treatment of the ulcer disease with eradication, the operation should be restricted to ulcer excision and ulcer oversewing in bleeding or perforated gastric ulcer and duodenotomy, ulcer ligation and extraluminal ligature in bleeding duodenum ulcer and excision and oversewing with pyloroplasty in perforated duodenal ulcer. More definite surgery is not reasonable and should be avoided. With treatment policies based on early elective operation in high risk groups and medical treatment in the other patients a mortality of 5% or less can be achieved.

Duodenal Ulcer↗
PubMed1996

[Ulcer hemorrhage in elderly patients: primary conservative or surgical therapy?].

Forty-six patients over 70 years admitted with a Forrest Ia-/IIa-peptic ulcer bleeding were prospectively recorded. Primarily surgical patients underwent early elective operations in 42% of cases with a mortality of 16% compared to 31% mortality in patients primarily treated conservatively in other departments. In our opinion even the older patient gains by a more aggressive surgical treatment of peptic ulcer bleeding.

Aged↗
PubMed1995

Planned relaparotomy vs relaparotomy on demand in the treatment of intra-abdominal infections. The Peritonitis Study Group of the Surgical Infection Society-Europe.

OBJECTIVE: To define the role of planned relaparotomy (PR) in the treatment of intraperitoneal infection, compared with that of relaparotomy on demand (RD). DESIGN: Case-control study on the basis of a prospective multicenter cohort analytic study. Statistical evaluation was done by the McNemar test for qualitative data and the Wilcoxon matched-pairs signed rank test for qualitative data. SETTING: Eighteen hospitals of different care levels in Austria, Germany, and Switzerland. PATIENTS: Thirty-eight of 42 patients with intra-abdominal infections who underwent PR were matched for APACHE II (Acute Physiology and Chronic Health Evaluation II) score, age, cause of infection, site of origin of peritonitis, and the ability of the surgeon to securely eliminate the source of infection with 38 patients taken from a cohort of 278 undergoing RD. INTERVENTIONS: Planned relaparotomy was defined as at least one relaparotomy decided on at the time of the first surgical intervention; RD, relaparotomy indicated by clinical findings. MAIN OUTCOME MEASURES: Mortality and incidence of postoperative multiple organ failure and infectious complications. RESULTS: There was no significant difference in mortality between patients treated with PR (21%) or RD (13%). Postoperative multiple organ failure as defined by a Goris score of more than 5 was more frequent in the group of patients undergoing PR (50%), compared with the group undergoing RD (24%) (P = .01), as were infectious complications (68% vs 39% [P = .01]). Infectious complications were due to more frequent suture leaks (16% vs 0% [P = .05]), recurrent intra-abdominal sepsis (16% vs 0% [P = .05]), and septecemia (45% vs 18% [P = .05]) in the PR vs the RD groups. The incidence of other complications was not different in the two groups. CONCLUSIONS: Until larger prospective studies are available, the indication for PR should be evaluated with caution.

Abdomen↗
PubMed1995

[Prognostic factors in curative resection of stomach carcinoma. A uni- and multivariate analysis].

The TNM system, including tumor infiltration (T category), lymph node infiltration (N category) and metastasis (M category), is a well-established system of prognostic factors. To evaluate the prognostic importance of patient characteristics and tumor parameters 5 clinical and 13 pathological factors were analyzed. Data on 200 consecutive patients with histologically verified stomach cancer were prospectively recorded using a standardized form. In the subgroup with curative resection (R0, n = 108) a uni- and multivariate analysis was performed with respect to 5-year survival. In the univariate analysis statistical significance was demonstrated for the following factors: tumor size, tumor localization, T category, N category, number of infiltrated lymph nodes infiltrated, lymph node compartments, tumor stage, lymph node ratio: infiltrated/inspected. Multivariate analysis, taking into consideration the interaction between prognostic factors, revealed only two factors as statistically significant: number of infiltrated lymph nodes and tumor size. Our results and those in the literature indicate that the infiltration of lymph nodes is the most relevant prognostic factor. In addition to the TNM system the number of infiltrated lymph nodes seems to be of prognostic importance.

Adult↗
PubMed1995

Evaluating four diagnostic methods with acute abdominal pain cases.

Contemporary work in medical decision support is characterized by a multitude of methods. To investigate their relative strengths and weaknesses, we built four diagnostic expert systems based on different methods (Bayes, case-based classification, heuristic classification) for analysis of the same set of 1254 cases of acute abdominal pain previously documented in a prospective multicenter study. The results of the comparative evaluation indicate that differences in overall performance are relatively small (statistically not significant). The performance depends more on the quality of the knowledge base and the case data than on the inference methods of the expert systems. Methods relying exclusively on empirical knowledge (Bayes, case-based classification) tend to have slightly higher overall performance scores due to a diagnostic bias toward ordinary and common diseases. By contrast, methods operating with expert knowledge (e.g., heuristic classification) perform slightly worse overall, but are more sensitive toward uncommon (serious) diseases.

Abdominal Pain↗
PubMed1995

[Surgical therapy of uncomplicated ulcer: results of a prospective epidemiologic study. DUSUK Study Group].

In a prospective, multicenter and interdisciplinary study (DUSUK I) the present position of elective surgery in uncomplicated peptic duodenal and gastric ulcers was evaluated. Ten Düsseldorf hospitals (surgery and internal medicine) participated in the study. The investigation focussed on the proportion of operated patients related to hospitals and clinical disciplines, the operative procedure and results and possible selection criteria for the indication of operation. In the study period a total of 1030 patients with uncomplicated peptic ulcer was documented, an incidence of indoor patients with uncomplicated peptic ulcers of 180/100,000 inhabitants/year and an incidence of elective ulcer surgery of 7.5/100,000 inhabitants/year was calculated. Patients primarily admitted to surgical units were operated in 27% of cases (39/146) in contrast to 0.5% (4/884) of patients primarily admitted to internal units. The majority of hospitals perform rare or no elective peptic ulcer surgery at all. There is a considerable difference between the hospitals and clinical disciplines. The collective of operated patients concentrated on young patients with positive ulcer history. In the long run a negative effect on surgical training and results is apprehended.

Adult↗
PubMed1995

Diagnostic scores for acute appendicitis. Abdominal Pain Study Group.

OBJECTIVE: To assess the value of predictive scores in the diagnosis of acute appendicitis. DESIGN: Multicentre evaluation with a prospective database. SUBJECTS: 1254 patients with acute abdominal pain. SETTING: 6 departments of surgery, Germany. INTERVENTIONS: To measure the performance of 10 scores on one database using standardised criteria and to compare the results with published data. MAIN OUTCOME MEASURES: The ability of a score to fulfill standardised criteria: an initial negative appendicectomy rate of 15% or less, a potential perforation rate of 35% or less, an initial missed perforation rate of 15% or less, and a missed appendicitis rate of 5% or less. RESULTS: Reevaluation of the published data showed that the Alvarado score fulfilled all four criteria and the Lindberg, the Fenyö and the Christian scores fulfilled two criteria each. If applied to our database (acute abdominal pain, suspected appendicitis), none of the scores fulfilled any of the given criteria, even if the cut-off point was varied systematically. There were significant differences among the scores. CONCLUSIONS: The original published data seemed to comply with our standardised criteria but evaluation of the scores on our database resulted in poor performances for all of them. Published data seem to be optimistically biased whereas our evaluation gives more realistic estimates of the routine performance in different clinical environments. Further well designed large scale trials are needed to investigate the clinical benefit of diagnostic scoring in acute appendicitis.

Abdominal Pain↗
PubMed1995

[The intensive care gallbladder--a transient phenomenon or a problem requiring therapy?].

Acute acalculous cholecystitis (AAC) is a well-known complication in postoperative and severely traumatized patients. Existing data of AAC originate from retrospective analyses and episodic case reports. In a prospective study 45 polytraumatized patients admitted to our intensive care unit between January 1, 1989 and June 30, 1990 were clinically and sonographically screened for this condition at defined time-intervals. A clinical and sonographical follow-up was performed annually (1991-1993). Trauma scoring was performed according to the Injury Severity Score (ISS) and Polytrauma Score (PTS). AAC was defined as a combination of hydrops of the gallbladder, an increased mural thickness (> 3.5 mm) and the demonstration of sludge. We were able to demonstrate this diagnostic triad in 8 out of 45 patients (18%). As a consequence early elective cholecystectomy was performed in one patient. The remaining patients were treated conservatively. Incidence of AAC in severely traumatized patients is probably higher than figures so far published suggest. The systematic search for this condition using serial sonographic examinations and defined sonomorphological criteria may select individual cases for elective cholecystectomy. Ultrasound is a reliable method of early detection and follow-up of this complication. Trauma and following intensive care therapy induce a lithogenetic factor, developing gallstone disease in 27% of patients within an 2-3-year interval.

Acute Disease↗
PubMed1995

[Quality assurance from the theoretical viewpoint].

The process of quality assurance is related to all measures and actions used to achieve the required quality. There is agreement about the aim and benefit of quality assurance, but the appropriate way is a matter of discussion. This paper deals from a theoretical viewpoint with basic problems of quality assurance that have not been evaluated adequately so far: a) criteria for measuring quality, b) measuring quality with adjustment for case-mix and c) evaluation of the effects of quality assurance. During the last years tools and study designs have been developed, which could contribute to the solution of these problems by a more sensible analysis, more complete and quality-controlled data and more useful evaluation studies. Further improvements in external quality assurance in surgery are to be expected, if these aspects are taken into consideration.

Diagnosis-Related Groups↗
PubMed1995

[Diagnostic score for acute appendicitis].

Scoring systems seem to be ideal for supporting diagnosis of acute appendicitis because they are non invasive, require no special equipment and can be used in clinical routine. Several scores for appendicitis have been developed with good results in the original publications. Unfortunately these good results could not be reproduced on a German data base. Therefore we developed a new score using multivariate statistics and a quality controlled prospective data base. The score covers 8 variables: tenderness, rebound tenderness, micturition, type of pain, leucocytes, age, relocation of pain, rigidity. Independent evaluation of the score on a Dutch database resulted in a negative appendicectomy rate of 21% and a missing appendicitis rate of 2%. The results are encouraging, so that further testing and clinical application can be recommended.

Acute Disease↗
PubMed1995

Transhiatal oesophagectomy compared with transthoracic resection and systematic lymphadenectomy for the treatment of oesophageal cancer.

OBJECTIVE: To compare the results of transhiatal oesophagectomy with those of transthoracic resection with systematic two field en bloc lymphadenectomy in the treatment of carcinoma of the oesophagus. DESIGN: Prospective open (non-random) study. SETTING: University hospital, Germany. SUBJECTS: 87 patients with carcinoma of the oesophagus of whom 46 underwent transhiatal, and 41 transthoracic resection. MAIN OUTCOME MEASURES: Morbidity and short and long term mortality. RESULTS: The type of operation was chosen on clinical grounds, and the groups were comparable except for site and type of tumour, and nodal stage. The hospital mortality was 7/46 (15%) in the transhiatal group and 4/41 (10%) in the transthoracic group. The most common complication was anastomotic leak (23/46, 50%, compared with 10/41, 24%, p = 0.014), followed by major pulmonary complications (16/46, 35%, compared with 12/41, 29%), and cardiac complications (12/46, 26% compared with 11/41, 27%). Median survival was 350 days in the transhiatal group and 378 days in the transthoracic group. The percentage survival after one, two, and three years in the two groups was 48 and 55, 26 and 18, and 21 and 17, respectively. There were no significant differences in short or long term mortality. CONCLUSION: We have been unable to show that the oncologically more radical procedure (transthoracic resection with systematic two field en bloc lymphadenectomy) results in longer survival, but we have shown that it can be done with similar morbidity and short term mortality. Because it is possible to stage the disease exactly with a transthoracic resection, and because published reports from other centres have hinted at improved prognosis after it, we shall continue to do the operation for suitable patients.

Adult↗