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Biomedical subjects

R Lefering

Publications and source records attributed to R Lefering.

At least 19 recordsLinked to original sources
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

Base deficit development and its prognostic significance in posttrauma critical illness: an analysis by the trauma registry of the Deutsche Gesellschaft für unfallchirurgie.

This prospective, multi-center, observational study of 2069 multiple trauma patients evaluated the prognostic significance of the posttrauma base deficit (BD) on hospital and intensive care unit (ICU) admission to hemodynamic changes, volume and transfusion requirements, lactate and coagulation, as well as mortality. Furthermore, the importance of the BD development throughout a patient's course of critical illness from the time of injury to ICU admission is analyzed as a prognostic factor for fatal outcome. The data were obtained by the trauma registry of the 'Deutsche Gesellschaft für Unfallchirurgie.' The patients were subdivided into five categories of increasing BD values on hospital and ICU admission: Category I, BD < or = -2; Category II, -2 < BD < or = 2; Category III, 2 < BD < or = 6; Category IV, 6 < BD < or = 10; and Category V, BD > 10. A statistical analysis was performed by means of the ANOVA and chi-square tests. In 1264 (61.1%) of 2069 multiple trauma patients (age 39 +/- 19 years, 70.0% males, injury severity score 22 +/- 13, 18.6% mortality), the BD was documented on hospital and in 1536 (74.2%) patients on ICU admission. At both points in time, an increase in the BD category was associated with a significant decrease in systolic blood pressure and prothrombin time as well as increases in heart rate, lactate level and mortality (P < 0.0001). Also transfusion requirements (Category I: 4.5 +/- 7.7 and Category V: 13.7 +/- 13.0 packed red blood cells) increased significantly on hospital admission (P < 0.0001) with a worsening in the BD category. Mortality increased significantly (P < 0.0001) with a worsening of BD from hospital to ICU admission (from a mortality of 13% in patients with a hospital and an ICU admission BD of <6 to 45% in patients with a hospital and an ICU admission BD of >6). These data show that the base deficit is an early available important indicator to identify trauma patients with hemodynamic instability, high transfusion requirements, metabolic and coagulatory decompensation, as well as a high probability of death. The base deficit development may help to guide an early and aggressive therapy for the trauma/hemorrhage induced tissue hypoxia.

Acidosis↗
PubMed2000

Retrospective evaluation of the simplified Therapeutic Intervention Scoring System (TISS-28) in a surgical intensive care unit.

OBJECTIVE: To compare the simplified Therapeutic Intervention Scoring System (TISS-28) with its original version, to provide reference values of daily TISS-28 assessment and to describe its association with severity of illness in surgical patients. DESIGN: Retrospective evaluation of prospectively collected audit data; four documentation periods. SETTING: Ten-bed intensive care unit (ICU) in a surgical university hospital. PATIENTS: One thousand nine hundred eighty-six consecutive admissions (1,808 patients; 10,448 observation days) who stayed on ICU for at least 6 h. Patients were in hospital for abdominal, vascular or trauma surgery. The average age was 61.5 years, the mean APACHE II score on admission 10.3 points. INTERVENTIONS: None. MEASUREMENTS: Raw data for APACHE II score and TISS were recorded daily. TISS-28 was calculated retrospectively from the original TISS data. RESULTS: Average TISS-28 values (28.7 points; SD = 9.7) do not differ substantially from the original TISS values (28.2 points, SD = 10.9) and overall correlation is high (r = 0.935). Of the patients, 57.3 % left the ICU after 1-2 days as survivors with a mean daily TISS-28 of 20.0 points. Variability between documentation periods was higher with the original TISS. On average, patients with increasing severity of disease require an increasing amount of care. Survivors have lower TISS-28 values than non-survivors (27.6 vs 34.9). CONCLUSIONS: In a surgical ICU the simplified version of TISS with 28 items (TISS-28) sufficiently reflects the amount of intensive care provided and may provide useful additional information on severity of disease and prognosis. It should replace the original index, at least in these cases.

APACHE↗
PubMed1999

The pros and cons of evidence-based surgery.

INTRODUCTION: Evidence-based medicine (EBM) has been proposed as a new paradigm of practising medicine. However, an unproductive polarisation between supporters and opponents can make its unbiased assessment difficult. This review gives an overview of the arguments and discusses their surgeon-specific importance. DISCUSSION: As EBM claims a position in the centre of medicine, it borders with other highly debated topics as, for instance, rationing and equity of care, doctor-patient interaction, medical research and education. Most arguments against EBM relate to its role in reducing health expenses by rationing healthcare. We think that the principles of EBM can be applied to make the inevitable process of rationing fair and reproducible. In addition, evidence-based surgery is criticised for interfering with patient individuality and physician autonomy, although this is a misunderstanding. Furthermore, the evidence-basis of EBM, in particular the randomised controlled trial (RCT) and systematic review, has been subject of discussion. Additionally, surgical research has its own inherent difficulties and, ultimately, some clinicians have doubted the practical feasibility of applying EBM at the bedside, because searching and critically appraising the literature is too difficult and time consuming. CONCLUSIONS: We believe that most critics consider EBM to be a potentially dangerous tool, because they fear it will be used against themselves. Thus, these conflicts only prove that EBM as a methodology may have a strong impact on solving them. As EBM has already made discernible progress, surgeons should not stand aside from these activities, which are bound to strongly influence healthcare in the next century.

Humans↗
PubMed1999

Cost analysis of laparoscopic cholecystectomy in children.

A detailed analysis of the hospital-related costs of laparoscopic cholecystectomy in children was performed. Data on 10 laparoscopic cholecystectomies were collected prospectively. Pre-, intra- and postoperative variables were assessed by standardized questionnaires. The hotel costs and costs for nursing, physicians, medicaments and equipment were calculated in detail. Reusable instruments were assumed to be used for 50 operations per year over 5 years and the costs for disposable instruments were calculated for comparison. In addition, the data of 10 children who underwent open cholecystectomy were analyzed retrospectively. The mean hospital costs for one laparoscopic cholecystectomy was 3685 DM. The costs for the operation itself represented 36.5% of the hospital costs and were mainly due to expenses for surgeons and nurses. The costs for laparoscopic equipment and instruments represented only 8.5% of the total costs. If an open procedure instead of a laparoscopic operation had been performed with a similar duration of hospital stay, the hospital costs would have been reduced by 425 DM (11.5%). In laparoscopic cholecystectomy the costs for medical treatment in addition to the operation were 32.8% of the total costs and were mainly due to expenses for nursing and physicians, which added up to 165 DM per day. The hotel costs represented 30.7% of the total costs and added another 189 DM per day. Therefore, potential savings in the operation theatre are limited and most effective savings may be achieved by shortening the hospital stay. The use of disposable instruments would have increased the costs by 844 DM and already 20 operations per year would have been cheaper performed with reusable compared to disposable instruments. Reusable instruments are recommended. Additional 60 minutes operating time cost 312 DM (5.20 DM/minute) and therefore, laparoscopic training courses for surgeons may be cost-effective in order to reduce the costs for training in the operation theatre.

Child↗
PubMed1999

Biostatistical aspects of outcome evaluation using TISS-28.

Quantification of therapeutic activities using the Therapeutic Intervention Scoring System (TISS) is an alternative approach to evaluate outcome of patients in intensive care. The reason for using cumulative TISS points is to integrate various adverse events (except mortality) according to the amount of therapeutic effort that they require. The reduced version of TISS with 28 items (TISS-28) allows a reliable assessment of therapeutic activities with limited observer variation, provided that an exact description of all items is given. Measurements can be validated by correlations with established severity of -disease classification systems such as APACHE II. Cumulative TISS-28 values correlate well with length of ICU stay (r = 0.98). On average, 27.2 points/day can be expected in an unselected mixed surgical ICU. Those who die can be included in non-parametric analyses of cumulative TISS values by allocation of arbitrary high values. Quantification of therapeutic interventions is a sensitive measure of outcome in patients who require intensive care but have a low risk of mortality. The usefulness of economic analysis further supports its clinical application.

APACHE↗
PubMed1999

Considerations on the statistical design of the ATMI study.

The ATMI study of prevention of mediastinitis after cardiac surgery uses the total amount of therapeutic interventions measured by the TISS-28 score as the primary endpoint. The study is designed as an adaptive group-sequential plan with three sequences, as experiences with the TISS-28 in cardiac intensive care units are scarce. According to the Bauer-Köhne method the sample sizes of the second and third sequences can be calculated in a data-driven manner after the results of the previous interim analyses are available. Thus the first trial phase can be considered as an internal pilot study.

APACHE↗
PubMed1999

Concept of and preliminary trial protocol for adjuvant treatment of mediastinitis with immunoglobulins after cardiac surgery (ATMI): response to comments and criticism.

During the consensus-based process of protocol development external experts were invited to comment on a proposal for a trial protocol on adjuvant immunotreatment of patients with wound infection after median sternotomy (ATMI). Controversies and arguments can be divided into five main areas: 1) rationale and objectives; 2) criteria for patient selection; 3) adjuvant treatment; 4) measures of efficacy; and 5) course and timetable of the study. We present and summarise the experts comments and criticism as well as the result of the final discussion of the study group with respect to these areas.

APACHE↗
PubMed1998

[Reduced neuromuscular blocking potency of atracurium in patients with purulent intrathoracic diseases].

OBJECTIVE: Based on personal observations the neuromuscular blocking potency of atracurium was supposed to be diminished in purulent intrathoracic diseases. This hypothesis was tested in a prospective clinical trial. METHODS: 52 adult patients undergoing general anaesthesia (methohexitone, sufentanil, flunitrazepam, N2O, enflurane) for elective thoracic surgery were investigated. After the intubation dose of 0.6 mg/kg atracurium was applied continuously to maintain a 90% suppression of the evoked compound electromyogram. According to the intraoperatively established diagnosis patients were allocated to three categories: 1) non-malignant tumor as the control group (n = 15), 2) lung cancer (n = 22), 3) purulent intrathoracic process without tumor (n = 15). The groups were compared regarding onset time, DUR 10% and maintenance dose of atracurium. RESULTS: Patients with lung cancer did not differ significantly from the controls regarding efficiency of atracurium. In contrast, patients with a purulent intrathoracic process showed a significantly longer onset time (6.3 +/- 2.5 vs. 2.9 +/- 0.8 min, p < 0.001), and a significantly shorter DUR 10% (23 +/- 6 vs. 36 +/- 10 min, p < 0.001) compared to the control group. Mean infusion rate of atracurium to maintain a 90% suppression of the evoked compound electromyogram was significantly higher in patients with a purulent process compared to the controls (10.5 +/- 3.2 vs. 6.0 +/- 1.2 micrograms/kg.min, p < 0.001). CONCLUSION: Our results support the hypothesis that patients with a purulent intrathoracic disease show a clear reduction in neuromuscular blocking potency of atracurium.

Adult↗
PubMed1998

[Prospective randomized pilot study of ambulatory prevention of thromboembolism. 2 times 500 mg aspirin (ASS) vs. clivarin 1750 (NMH)].

From March 1994 to March 1996, 287 patients, presenting with lower extremity injuries, who required immobilizing bandages or casts, where included in a prospective, randomized study. These patients received either low-molecular heparin or acetylsalicylic acid for thrombosis prophylaxis. In all patients a clinical examination and a colour-coded duplex sonography were performed after removal of the cast for detection of lower extremity venous thrombosis. A plebography was performed when thrombosis was suspected. A subcutaneous injection of divarin 1750 was given once daily in 143 patients. Thrombosis prophylaxis with Aspirin 2 x 500 mg administered orally was performed in 144 patients. Deep vein thrombosis occurred in 9 patients (6.3%) with clivarin prophylaxis and in 7 patients (4.8%) treated with Aspirin. In both groups, no clinically significant side effects of the medications were observed.

Adult↗
PubMed1998

Prevalence of fecal incontinence: what can be expected?

Fecal incontinence is a serious problem especially for the elderly. The epidemiology of incontinence is not well described in the literature although it is often used as an endpoint for treatment evaluation in clinical trials. Complete continence is often assumed to be the "normal" standard. The goals of this study were to establish detailed prevalence rates for fecal incontinence in a standard population and to identify differences due to age and sex. A questionnaire about fecal incontinence and its consequences with predefined answers was filled out anonymously by 500 volunteers. The study population was selected to meet the respective age and sex distribution of the German adult population. The data indicated that 4.8% of the persons were unable to control solid stools, while 19.6% had problems at least with one type of incontinence (solid, pasty, or lipid stools, winds). Problems with pasty or liquid stools are more frequent in women. The ability to control wind is decreased in elderly persons. The time needed to reach a toilet is shorter for women, and generally decreases in the elderly. Men more often describe soiling the underwear. Persons with signs of incontinence show decreased levels of social activities. A global incontinence rate of 5% fits well with some previously published results. Soiling of the underwear is not well suited for defining incontinence. The increased rate in women may in part be explained by morphological differences. The reduced time to hold stools especially in the elderly in combination with a reduced mobility may result in a higher rate of incontinence, which is correlated with reduced social activities.

Adolescent↗
PubMed1998

Clinical relevance of sepsis scores.

In this article sepsis scoring systems commonly used are presented as regards their results and shortcomings. Furthermore, in a more general context, the direct and indirect effect on the individual patients is discussed and recommendations are given on how to use scoring systems.

Critical Care↗
PubMed1998

Laparoscopic vs conventional appendectomy--a meta-analysis of randomised controlled trials.

AIM: To compare the effectiveness and safety of laparoscopic and conventional "open" appendectomy in the treatment of acute appendicitis. METHODS: Meta-analysis of randomised controlled trials available by May 1998 that compared both techniques. Within each trial and for each outcome an effect size was calculated; the effect sizes were then pooled by a random-effects model. RESULTS: We summarised outcome data of 2877 patients included in 28 trials. Operating time was +16 min (95% confidence interval +12-20 min) longer for laparoscopic appendectomy. Overall complication rates were comparable, but wound infections were definitely reduced after laparoscopy [rate difference -4.2%, (-2.3% to -6.1%)]. Intra-abdominal abscesses, however, occurred slightly more frequently [+0.9%, (-0.4% to +2.3%)]. Hospital stay after laparoscopic appendectomy was 15 h (8-23 h) shorter, and patients returned to full fitness or work 7 days (5-9 days) earlier. Pain intensity on day 1 was slightly less. Heterogeneity was present for some outcome measures due to methodological differences among the primary studies. CONCLUSION: Laparoscopic appendectomy reduces wound infections and eases postoperative recovery. Nevertheless, the various differences among the primary studies and their partly flawed methodology make it difficult to generalise from these findings.

Acute Disease↗
PubMed1997

[Analysis of the publication spectrum of 4 German-language medical specialty periodicals "Der Chirurg", "Der Unfallchirurg", "Langenbecks Archiv für Chirurgie" and "Medizinische Klinik"].

All 1994 publications of four leading journals in surgery, orthopedics and internal medicine in Germany (Der Chirurg, Der Unfallchirurg, Langenbecks Archiv für Chirurgie, Medizinische Klinik) were reviewed by means of a structured analysis. The type of article, authorship, number of references, geographical location, quality, and main conclusion (positive; neutral; negative) of each article were documented. The journals focused on clinical studies (32.2-59.6%), case reports (11.0-26.1%) and reviews (6.4-40.9%). Articles about surgical techniques were mainly found in Der Chirurg (16.9%), experimental studies in Der Unfallchirurg (14.7%) and Langenbecks Archiv für Chirurgie (25.7%). Most articles were written by university clinic personnel (62.6-81.4%). In 11.0-22.6% of all articles, the head of a clinic was the first author and the co-author in 36.5-58.7%. Women were found to be first author in 4% in surgery, and in 10.4% in internal medicine. Of a total of 495 publications, 53.9% were written in Northrhine-Westphalia, Bavaria or Baden-Württemberg and only 1.6% in the five new federal states. Of all articles 16.4% were by foreign authors, with 10.5% originating from German-speaking countries. The portion of controlled randomized trials ranged between 4.9% (Der Unfallchirurg) and 11.3% (Der Chirurg) of all published studies. Studies and case reports with negative results were found to be more evident in Der Chirurg and Langenbecks Archiv für Chirurgie (ca. 20%) as compared to Der Unfallchirurg and Medizinische Klinik (ca. 6%). All journals provided good general information about the actual developments in a variety of topics to the reader. However, some improvement concerning international contributions, participation of the new federal states, and the quality of studies is recommended.

Authorship↗
PubMed1997

The impact of risk factors and pre-existing conditions on the mortality of burn patients and the precision of predictive admission-scoring systems.

Clinical experience has shown that concomitant diseases and risk factors have a significant influence on the patient's outcome. Since none of the currently available score systems consider the impact of concomitant diseases or risk factors on burn trauma mortality, the present study was planned to further evaluate the role of these factors. Four hundred and ninety-eight patients could be included in this retrospective analysis of prospectively collected data. Parameters documented were: sex, age, weight, height, laboratory data, TBSA, inhalation trauma (IHT), full thickness (3 degrees) burn and pre-existing conditions. Single-variable analysis (SVA), logistic regression and CART analysis were performed. The data confirm the role of age and TBSA as the strongest prognostic variables. Chronic alcohol abuse and smoking, IHT and pre-existing cardiac and neurologic conditions were also found to be significant. Borderline groups could be identified in the ABSI score (7-10), where the risk factors cause 'mortality-shifting'. It can be concluded that risk factors and pre-existing conditions have a significant impact on the prognosis of burn mortality and should be incorporated into further refinements of burn admission scores.

Adolescent↗
PubMed1997

Trauma score systems: Cologne Validation Study.

BACKGROUND: Most standard trauma score systems have been developed and validated in the United States. However, trauma differs between the United States and Germany. This prospective study tested the validity of eight current trauma scoring systems (Glasgow Coma Scale, Trauma Score, Revised Trauma Score, Injury Severity Score, TRISSTS, TRISSRTS, Prehospital Index, Polytraumaschluessel) in 612 patients in Cologne. METHODS: Between January 1, 1987, and December 31, 1987, 2,136 trauma related emergencies were seen by emergency physicians in the field. All trauma patients with a Trauma Score below 16 and a random sample of 10% of patients with a Trauma Score of 16 were included in the study (n = 625). Follow-up was successfully completed for 612 patients (97%). Their hospital outcome was correlated with their individual score result. RESULTS: All trauma score systems under study showed high accuracy rates. TRISSRTS and TRISSTS performed best with values of above 0.97 for the area under the receiver operating characteristics curve. CONCLUSION: We conclude that the standard trauma score systems are valid tools for patient classification and support TRISSRTS as the international reference score system for the assessment of injury severity. This validation will allow comparisons between different trauma care systems.

Adolescent↗