Christian Ohmann

Risk factors associated with intraabdominal infections: a prospective multicenter study

Introduction and methods: A prospective observational multicenter study with 18 hospitals was performed to assess preoperative risk, therapeutic management and outcome of patients with peritonitis. Data collection was carried out according to standardized and recommended definitions. Included in the study were 355 patients with macroscopically confirmed peritonitis. Results: In the univariate analysis, the following factors influenced both the mortality and the incidence of postoperative complications: age, presence of certain concomitant disease, site of origin of peritonitis, type of admission and the ability of the surgeon to eliminate the source of infection. In addition, postoperative infective complications were related to the etiology of peritonitis and the exudate. In the multivariate analysis, APACHE II (P<0.001), successful operation (P<0.001), age (P<0.001), liver disease (P<0.03), malignant disease (P<0.04) and renal disease (P<0.05) turned out to be significant with respect to death. Escherichia coli was the predominant organism (51%), following by enterococci (30%) and bacteroides (25%). There was a significantly higher postoperative infection rate in patients with no adequate treatment of enterococci than patients with adequate treatment or no enterococci (P<0.05). Conclusion: The study demonstrated the important role of the physiological reserve of the patient and of the surgeon, which is not adequately reflected in existing scoring systems. Further investigations are needed to study the impact of enterococci on the outcome.

The Microbiology of Postoperative Peritonitis

Postoperative peritonitis carries a higher risk of complications and mortality than does community-acquired disease. Little, however, is known about the specific microbiology of this condition. To gain insight into this problem, the microbiological findings of 67 patients with postoperative peritonitis were compared with those of 68 patients with community-acquired peritonitis. In a comparison of postoperative peritonitis with community-acquired disease, the number of isolates of enterococci (23 versus 6) and Enterobacter species (13 versus 4) were increased and the number of isolates of Escherichia coli (21 versus 42) were reduced. Antibiotic therapy before reintervention increased the number of resistant organisms at relaparotomy (33% versus 8%). The in vitro efficacy of the primary antibiotic or combination of drugs did not affect mortality rates (40% versus 38% after effective and ineffective treatment, respectively). Thus, the microbiology of postoperative peritonitis differs significantly from that of community-acquired disease, and specific antibiotic therapy is required, despite the doubtful impact on survival.

Predicting Delirium After Vascular Surgery: A Model Based on Pre- and Intraoperative Data

Objective The aim of the study was to determine pre- and intraoperative risk factors for the development of postoperative delirium among patients undergoing aortic, carotid, and peripheral vascular surgery to predict the risk for postoperative delirium. Summary Background Data Although postoperative delirium after vascular surgery is a frequent complication and is associated with the need for more inpatient hospital care and longer length of hospital stay, little is known about risk factors for delirium in patients undergoing vascular surgery. Methods Pre-, intra-, and postoperative data were prospectively collected, including the first 7 postoperative days with daily follow-up by a surgeon and a psychiatrist of 153 patients undergoing elective vascular surgery. Delirium (Diagnostic and statistical Manual of Mental Disorders IV) was diagnosed by the psychiatrist. Multivariate linear logistic regression and a cross validation analysis were performed to find a set of parameters to predict postoperative delirium. Results Sixty patients (39.2%) developed postoperative delirium. The best set of predictors included the absence of supraaortic occlusive disease and hypercholesterinemia, history of a major amputation, age over 65 years, a body size of less than 170 cm, preoperative psychiatric parameters and intraoperative parameters correlated to increased blood loss. The combination of these parameters allows the estimation of an individual patients’ risk for postoperative delirium already at the end of vascular surgery with an overall accuracy of 69.9%. Conclusions Postoperative delirium after vascular surgery is a frequent complication. A model based on pre- and intraoperative somatic and psychiatric risk factors allows prediction of the patients risk for developing postoperative delirium.

Time-trends in the epidemiology of peptic ulcer bleeding

Objective. Despite the introduction of effective medical treatment of peptic ulcer disease, bleeding is still a frequent complication. The aim of this study was to investigate whether the incidence and the risk profile of peptic ulcer haemorrhage have changed within a 10-year period. Material and methods. In a prospective epidemiological and observational study the incidence and risk profile of peptic ulcer haemorrhage in Düsseldorf, Germany were compared between two time periods (period A: 1.3.89–28.2.90 and period B: 1.4.99–31.3.2000), involving nine hospitals with both surgical and medical departments. Patients with proven peptic ulcer haemorrhage at endoscopy or operation were included in the study; those with bleeding under defined severe stress conditions were excluded. Results. No differences in bleeding ulcer incidence were observed between periods A and B (51.4 per 100,000 person-years versus 48.7), or for duodenal ulcer (24.9 versus 25.7) or for gastric ulcer bleeding (26.5 versus 23.0). A marked increase in incidence rates was observed with increasing age. In period B, patients with bleeding ulcers were older (56% versus 41% 70 years or older), were usually taking non-steroidal anti-inflammatory drugs (NSAIDs) (45% versus 27%) and were less likely to have a history of ulcer (25% versus 59%) compared with patients in period A. Conclusions. The persisting high incidence of peptic ulcer disease is a superimposing of two trends: a higher incidence in the growing population of elderly patient with a higher intake of NSAIDs and a lower incidence among younger patients due to a decrease in incidence and improved medical treatment.

Ultrasonography for Diagnosis of Acute Appendicitis: Results of a Prospective Multicenter Trial

A prospective multicenter observational trial was performed to assess the performance and clinical benefit of ultrasonography of the appendix in the routine clinical examination. Included in the study were 2280 patients with acute abdominal pain from 11 surgical departments in Germany and Austria. Ultrasonography of the appendix was performed in 870 (38%) of the patients (range 16-85%). The overall sensitivity of ultrasonography of the appendix was 55% (13-90%), the specificity 95% (range 82-100%), positive predictive value 81% (50-100%), and negative predictive value 85% (68-96%). With respect to single ultrasound scan findings, adequate sensitivity (44%) was achieved only with the target phenomen, not with the other criteria. There were no correlations between the ultrasound findings of the appendix and the diagnostic accuracy of the clinician, the negative appendectomy rate, or the perforated appendix rate. From the study it can be concluded that there is no proven clinical benefit of ultrasound scanning of the appendix in the routine clinical diagnosis.

Evaluation of automatic knowledge acquisition techniques in the diagnosis of acute abdominal pain

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.

Relapse prevention in first-episode schizophrenia--maintenance vs intermittent drug treatment with prodrome-based early intervention: results of a randomized controlled trial within the German Research Network on Schizophrenia.

OBJECTIVE After acute treatment of the first illness episode in schizophrenia, antipsychotic maintenance treatment is recommended for at least 1 year. Evidence for the optimal subsequent treatment is still scarce. Targeted intermittent treatment was found to be less effective than continuous treatment at preventing relapse in multiple episode patients; however, a post hoc analysis of our own data from a previous study suggested comparable efficacy of the 2 treatment approaches in first-episode patients. The current study was therefore designed to compare prospectively the relapse preventive efficacy of further maintenance treatment and targeted intermittent treatment in patients with ICD-10-diagnosed first-episode schizophrenia. METHOD A randomized controlled trial was conducted within the German Research Network on Schizophrenia. Entry screening took place between November 2000 and May 2004. After 1 year of antipsychotic maintenance treatment, stable first-episode patients were randomly assigned to 12 months of further maintenance treatment or stepwise drug discontinuation and targeted intermittent treatment. In case of prodromal symptoms of an impending relapse, patients in both groups received early drug intervention, guided by a decision algorithm. The primary outcome measure was relapse (increase in the Positive and Negative Syndrome Scale positive score > 10, Clinical Global Impressions-Change score ≥ 6, and decrease in Global Assessment of Functioning score > 20 between 2 visits). RESULTS Of 96 first-episode patients, only 44 were eligible for the assigned treatment (maintenance treatment, n = 23; intermittent treatment, n = 21). The rates of relapse (19% vs 0%; P = .04) and deterioration (up to 57% vs 4%; P < .001) were significantly higher in the intermittent treatment group than in the maintenance treatment group, but quality-of-life scores were comparable. Intermittent treatment patients received a significantly lower amount of antipsychotics (in haloperidol equivalents; P < .001) and tended to show fewer side effects, particularly extrapyramidal side effects. CONCLUSIONS Maintenance treatment is more effective than targeted intermittent treatment in preventing relapse, even in stable first-episode patients after 1 year of maintenance treatment, and should be the preferred treatment option. However, about 50% of patients remain stable at a significantly lower drug dose and show fewer side effects, and a substantial proportion refuse maintenance treatment. Alternative long-term treatment strategies, including targeted intermittent treatment, should therefore be provided in individual cases. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00159120.

Long-term Biochemical Results after Operative Treatment of Primary Hyperparathyroidism Associated with Multiple Endocrine Neoplasia Types I and IIa: Is a More or Less Extended Operation Essential?

OBJECTIVE To analyse our long term results in patients operated on for primary hyperparathyroidism associated with multiple endocrine neoplasia types I and IIa. DESIGN Retrospective (data collection) and prospective (follow-up) analysis. SETTING University hospital, Germany. SUBJECTS 39 patients with MEN type I-associated and 7 patients with MEN-type-IIa-associated primary hyperparathyroidism. INTERVENTIONS Subtotal parathyroidectomy (n = 25 with MEN I and 1 with MEN IIa), total parathyroidectomy and autotransplantation (one in each group) and removal of only enlarged glands (13 with MEN type I and 5 with MEN type IIa). MAIN OUTCOME MEASUREMENTS Recurrence rate of hyperparathyroidism and permanent hypocalcaemia postoperatively. RESULTS Subtotal parathyroidectomy in patients with MEN type I gave a significantly lower recurrence rate than removal of only enlarged glands (3/25 compared with 3/13, log rank, p = 0.04). Permanent hypocalcaemia developed in 3/25 compared with 3/13, respectively. 2/5 patients with MEN type IIa developed recurrences after removal of only enlarged glands and the rate was higher than expected. CONCLUSIONS A more extensive operation is essential for patients with MEN type I; the rate of permanent hypocalcaemia is not increased, but the recurrence rate is reduced. Patients with MEN type IIa should be treated by excision of enlarged glands alone, but this may be extended to subtotal parathyroidectomy in patients with severe symptoms.

Simple data from history and physical examination help to exclude bowel obstruction and to avoid radiographic studies in patients with acute abdominal pain

OBJECTIVE To assess the value of plain abdominal radiographs and of data from the medical history and physical examination in the diagnosis of acute abdominal pain in general and of bowel obstruction in particular. DESIGN Prospective study. SETTING 4 university and 2 community hospitals, Germany. SUBJECTS 1254 patients with acute abdominal pain lasting less than 7 days, and with no history of abdominal injury including surgery. INTERVENTIONS Standardised and structured medical history and physical examination, study of results of plain abdominal radiographs. MAIN OUTCOME MEASURES Positive predictive value and sensitivity of clinical variables and abdominal film with respect to the diagnosis at discharge. RESULTS 48 patients (3.8%) had bowel obstruction. 704 patients (56.1%) had plain abdominal films taken at the time of initial presentation. 111 studies (15.8%) showed important findings leading to diagnosis or immediate treatment, 455 (64.7%) showed unimportant or no findings. In 138 (19.6%) results of films were not reported. 16 of 45 single variables were of help in diagnosing bowel obstruction. The six with the highest sensitivity were distended abdomen, increased bowel sounds, history of constipation, previous abdominal surgery, age over 50, and vomiting. If only patients presenting with any two of these symptoms had had radiographs taken, 300 (42.6%) could have been avoided without loss in diagnostic accuracy. CONCLUSION A considerable number of plain abdominal films taken for patients with acute abdominal pain could be avoided by focusing on clinical variables relevant to the diagnosis of bowel obstruction.

Short-term treatment with risperidone or haloperidol in first-episode schizophrenia: 8-week results of a randomized controlled trial within the German Research Network on Schizophrenia

Patients with first-episode schizophrenia appear to respond to lower doses of neuroleptics, and to be more sensitive to developing extrapyramidal side-effects. The authors therefore compared in such patients the efficacy and extrapyramidal tolerability of comparatively low dosages of the atypical neuroleptic risperidone and of the conventional neuroleptic haloperidol. Risperidone was hypothesized to have better extrapyramidal tolerability and efficacy in treating negative symptoms. Patients were randomly assigned under double-blind conditions to receive risperidone (n=143) or haloperidol (n=146) for 8 wk. The primary efficacy criterion was the estimated difference in the mean change in the Positive and Negative Symptom Scale (PANSS) negative score between treatment groups; secondary efficacy criteria were changes on the PANSS total score and other PANSS subscores, and several other measures of psychopathology and general functioning. The primary tolerability criterion was the difference in baseline-adjusted occurrence rates of extrapyramidal side-effects measured with the Simpson-Angus Scale (SAS) compared between treatment groups. The main hypothesis was that risperidone would be superior in terms of improving negative symptoms and lowering the risk of extrapyramidal symptoms. Secondary tolerability criteria were the other extrapyramidal symptoms, measured with the Hillside Akathisia Scale (HAS) and the Abnormal Involuntary Movement Scale (AIMS). The average mean daily doses were 3.8 mg (s.d.=1.5) for risperidone and 3.7 mg (s.d.=1.5) for haloperidol. There were similar, significant improvements in both treatment groups in the primary and secondary efficacy criteria. At week 8 nearly all scores of extrapyramidal side-effects indicated a significantly higher prevalence of extrapyramidal side-effects with haloperidol than with risperidone [SAS: risperidone 36.5% of patients; haloperidol 51.5% of patients; likelihood ratio test, chi2(1)=7.8, p=0.005]. There were significantly fewer drop-outs [risperidone n=55, drop-out rate=38.5%; haloperidol n=79, drop-out rate=54.1%, chi2(1)=7.1, p=0.009] and a longer non-discontinuation time [risperidone: average of 50.8 d to drop-out; haloperidol: average of 44.0 d to drop-out; log rank test, chi2(1)=6.4, p=0.011] in the risperidone group. Risperidone and haloperidol appear to be equally effective in treating negative and other symptoms of first-episode schizophrenia. Risperidone has better extrapyramidal tolerability and treatment retention rate than the equivalent dose of haloperidol in these patients.