Basic echocardiography for undergraduate students: a comparison of different peer-teaching approaches.

BACKGROUND: The aim of this study was to assess the impact of different teaching interventions in a peer-teaching environment on basic echocardiography skills and to examine the influence of gender on learning outcomes. METHODS: We randomly assigned 79 s year medical students (55 women, 24 men) to one of four groups: peer teaching (PT), peer teaching using Peyton's four-step approach (PPT), team based learning (TBL) and video-based learning (VBL). All groups received theoretical and practical hands-on training according to the different approaches. Using a pre-post-design we assessed differences in theoretical knowledge [multiple choice (MC) exam], practical skills (Objective Structured Practical Examination, OSPE) and evaluation results with respect to gender. RESULTS: There was a significant gain in theoretical knowledge for all students. There were no relevant differences between the four groups regarding the MC exam and OSPE results. The majority of students achieved good or very good results. Acceptance of the peer-teaching concept was moderate and all students preferred medical experts to peer tutors even though the overall rating of the instructors was fairly good. Students in the Video group would have preferred a different training method. There was no significant effect of gender on evaluation results. CONCLUSIONS: Using different peer-teaching concepts proved to be effective in teaching basic echocardiography. Gender does not seem to have an impact on effectiveness of the instructional approach. Qualitative analysis revealed limited acceptance of peer teaching and especially of video-based instruction.

Evaluation of phenotypic detection methods for metallo-ß-lactamases (MBLs) in clinical isolates of Pseudomonas aeruginosa.

Metallo-beta-lactamase (MBL) production in Pseudomonas aeruginosa is a growing issue across the globe. Fast and reliable diagnostic tools are needed for appropriate implementation of infection control measures. In this study we evaluated the performance of three commercial combined disk tests, two EDTA based in-house combined disk tests and the Carba NP test in comparison to molecular detection of MBL genes on 133 meropenem non-susceptible non-duplicate P. aeruginosa clinical isolates. The meropenem/DPA based commercial KPC + MBL-confirm ID kit (Rosco Diagnostica, Denmark) and the MASTDISCS™ ID carbapenemase (Enterobacteriaceae) detection disc set (MAST Diagnostics, UK) showed sensitivities of 31.1 % and 28.8 % and specificities of 69.3 % and 79.6 %, respectively. The total MBL confirm kit (Rosco Diagnostica, Denmark) contains imipenem/DPA and imipenem/EDTA combination disks. Evaluation of the single disk combinations revealed 84.4 % sensitivity and 81.8 % specificity for the imipenem/DPA assay and 86.7 % sensitivity and 51.1 % specificity for the imipenem/EDTA test. Applying both tests simultaneously resulted in a slightly higher sensitivity of 88.9 % but a lower specificity of 48.9 % when compared to the single tests alone. The Carba NP test showed 93.3 % sensitivity and 96.6 % specificity. All phenotypic combined disk tests lacked either sensitivity or specificity for the detection of MBL in P. aeruginosa. The Carba NP test showed excellent test properties, but suffers from drawbacks in handling and high costs. The optimal diagnostic approach needs to be chosen depending on the epidemiological situation, laboratory resources and availability of molecular confirmation tests.

Defecation mechanisms after anterior resection with J-pouch-anal and side-to-end anastomosis in dogs.

BACKGROUND: Colonic J-pouch-anal anastomosis or colonic side-to-end anastomosis is the reconstruction of choice after low anterior resection. However, the mechanisms of defecation after both reconstruction forms are still speculative. METHODS: Low anterior rectal resections were performed in 12 dogs with six colonic J-pouch-anal (pouch) and six coloanal side-to-end (SE) reconstructions. Four months postoperative stool frequency, intestinal transit time, and neorectal compliance were determined by radiography and barostat. Defecation mechanisms were evaluated radiographically during expulsion of artificial stool. RESULTS: One dog with pouch reconstruction could not be evaluated due to an anastomotic leak, while the others had uncomplicated course. Spontaneous stool frequency was significantly increased with both reconstruction methods (control 2.0+/-0.9, pouch 2.7+/-1.2, SE 3.3+/-0.9 day; p<0.05). Intestinal transit time was significantly higher with pouch reconstruction due to storage of stool in the pouch and the descending colon compared to SE (control 760+/-82, pouch 592+/-97, SE 550+/-87 min; p<0.05). Compliance and functional capacity were higher in pouch than in side-to-end reconstructions (pouch 5.0+/-0.7 ml/mmHg, 124+/-23 ml; SE 2.7+/-0.3 ml/mmHg, 92+/-24 ml; p<0.05). During defecation, there were no contractions of the pouch detectable. CONCLUSIONS: The colonic J-pouch reconstruction results in better functional outcome than side-to-end coloanal anastomosis. Our results show that pouch evacuation is passive and independent from pouch motility. The functional principle of the colonic J-pouch is not its reservoir function but a delay of colonic motility.

Evaluation of anastomotic microcirculation after low anterior rectal resection: an experimental study with different reconstruction forms in dogs.

BACKGROUND: Data on anastomotic microcirculation of coloanal anastomoses are contradictory. Therefore, it was the aim of the present study to investigate perianastomotic blood perfusion in a standardized experimental setting comparing three forms of reconstruction using laser fluorescence videography, a new method for the evaluation of microcirculation. METHODS: After a standardised rectal resection in dogs, reconstruction was performed as straight end-to-end (n = 6), side-to-end (n = 6), or J-pouch (n = 6) coloanal anastomosis. Bowel perfusion was evaluated using IC-View laser fluorescence videography. RESULTS: The perfusion index was significantly reduced in all three groups compared to the reference regions: endto-end anastomosis, median, 93% (range, 63%-136%); side-to-end-anastomosis, 65% (35%-138%); colonic-J-pouch anal anastomosis, 52% (32%-72%); p < 0.001). CONCLUSIONS: Straight coloanal anastomoses provide better anastomotic microcirculation after rectal resections than colonic-J-pouch anal anastomoses or side-to-end anastomoses. However this effect does not seem to be decisive for the prevention of anastomotic leaks.

[Effect of biofeedback and electrostimulation on sphincter function in fecal incontinence]. / Stellenwert von Biofeedback-Training mit kombinierter analer Elektrostimulation bei idiopathischer Stuhlinkontinenz.

UNLABELLED: The following study reports on the effect of biofeedback and transanal electric stimulation as a conservative method in the therapy of idiopathic fecal incontinence. 22 consecutive patients in whom the diagnosis "idiopathic incontinence" was established after endoscopy, endoanal ultrasound and measurement of pudendal nerve terminal motor latency underwent combined sphincter training for 3 months. The results were evaluated prospectively by clinical classification using a modified Kelly-Holschneider-score and anal manometry before and after treatment. Combined biofeedback led to a significant increase of the continence score in 18 of 22 patients (7.7 +/- 3.8 vs. 9.3 +/- 3.0, p = 0.004). Both squeeze (77 +/- 28 mmHg vs. 92 +/- 32 mmHg, p = 0.047) and resting pressures (40 +/- 19 vs. 52 +/- 23 mmHg, p = 0.015) increased significantly during the training period. There were no significant differences in squeeze and resting asymmetry indexes, sensory and urge thresholds and maximal tolerable volumes. The prolongation of biofeedback training from 3 to 6 months in 9 patients did not change clinical or manometric results significantly. CONCLUSIONS: The combination of biofeedback training with anal electrostimulation increases anal squeeze and resting pressures, thus leading to an improvement of clinical incontinence symptoms. Therefore it should be the first choice in the therapy of idiopathic fecal incontinence. A training period of 3 months seems to be sufficient.

Does botulinum type-A toxin affect motor activity after proctocolectomy and ileal pouch-anal anastomosis? An experimental study in dogs.

AIM OF THE STUDY: The use of anticholinergic drugs has provided a useful therapeutic approach to reduce stool frequency in patients with proctocolectomy and ileal pouch-anal anastomosis (IPAA). Botulinum type-A (BTA) toxin has been shown to specifically block acetylcholine release in the intestinal wall. Therefore this study investigated the effect of BTA on small intestinal and J-pouch motility after IPAA. MATERIAL AND METHODS: Proctocolectomy and IPAA were performed in 4 dogs. The motility of the small intestine and the ileal pouch was recorded by serosal electrodes and strain gauge transducers. The intestinal transit time was determined radiologically and pouch compliance was determined manometrically. Multiple measurements were performed before and after endoscopic injection of BTA into the pouch wall. RESULTS: This treatment did not significantly influence stool frequency, intestinal transit time or pouch compliance. Intrinsic pouch motility was characterized by irregular contractions, the amplitudes and frequencies of which remained unchanged after BTA administration. With the exception of lower contraction amplitudes directly proximal to the pouch, there were no significant differences in the characteristics of the migrating myoelectric complex or in the fed pattern of the small intestine and ileal pouch. CONCLUSIONS: BTA does not significantly affect ileal pouch motility. The beneficial effects of anticholinergic drugs therefore seem to be due to their multifactorial mode of action and not to the inhibition of cholinergic neurons in the pouch.

Defecation mechanisms after proctocolectomy and ileal pouch--anal anastomosis in dogs.

BACKGROUND AND AIMS: The role of intrinsic pouch motility after ileal pouch-anal anastomosis (IPAA) during defecation is still speculative. MATERIALS AND METHODS: IPAA was performed in 12 dogs. Defecation mechanisms were evaluated by motility recordings during spontaneous defecation and during expulsion of an endoluminal balloon and by radiography with sequential sector-related gray scale analysis. RESULTS: Spontaneous defecations appeared without significant changes in electrical or mechanical activity of the pouch. Sequential filling of the pouch led to defecation in only seven dogs while the others did not succeed in emptying their pouch even with maximal balloon inflation. Neither strain gauge measurements nor electromyography demonstrated peristaltic contractions of the pouch during defecation while sector-related gray scale analysis revealed strong contractions of the abdominal wall during pouch emptying. CONCLUSION: Pouch emptying is independent of intrinsic pouch motility. The ileoanal pouch acts as a functionally passive reservoir, and its evacuation is initiated by a rise of the intra-abdominal pressure.

[Functional results and quality of life after proctocolectomy and ileal J-pouch-anal anastomosis for ulcerative colitis]. / Funktionelle Langzeitergebnisse und Lebensqualität nach Proktokolektomie und Ileumpouch-analer Anastomose bei Colitis ulcerosa.

BACKGROUND: Ileal pouch-anal anastomosis is the surgical standard in the therapy of ulcerative colitis. It was the aim of the present study to evaluate functional long-term results and correlate them with quality of life. PATIENTS AND METHODS: 37 patients with a follow-up of more than 5 years were included. Functional results and quality of life were assessed by standardised questionnaires (modified Kelly-Hohlschneider-Score, EORTC QLQ-C30). RESULTS: 24 of 37 patients could be evaluated. Median follow-up was 8 (5-13) years. Postoperative stool- frequency was 5.5 +/- 1.7/d. When compared with the preoperative situation, patients suffered less from urgency. Stool-frequency and -consistency, soiling and sensibility remained unchanged. 83 % of patients had a subjective increase of life quality with the ileoanal pouch. The quality of life index was almost normal with 83 (28-100) %. Patients with postoperative complications had a significant decrease of life quality when compared to patients with uneventful course. There was no statistically significant correlation of life quality with age, gender or stool continence. CONCLUSIONS: Ileal pouch-anal anastomosis leads to a long-term increase of stool frequency with partially impaired stool continence. Patients with uneventful course have a significantly better life quality.

[In vitro analysis and animal experiment study of surface modified biodegradable polylactide ureteral stents]. / In-vitro-Analytik und tierexperimentelle Untersuchung oberflächenmodifizierter biodegradierbarer Polylactidureterstents.

With the objective of developing a biodegradable ureteric stent, various polylactides were analyzed and grafted with a clinically adapted surface. Stent moulding was performed by CESP technology (Controlled Expansion of Saturated Polymers), which is not based on high temperature but gas-loading under high pressure which induces a foamy bulk structure. The hydrolytically biodegradable, synthetic homo- and copolymers poly(D,L-lactide) (PDLLA), poly(D,L-lactide-co-trimethylene-carbonate) (PDLLA-co-TMC), poly(D,L-lactide-co-glycolide) (PDLLA-co-Gly) as derivatives of lactic acid or glycolic acid and surface modifications with hydroxyethylene-methacrylate (HEMA) and oligoethyleneoxidemonomethacrylate (OEOMA) were analyzed with regard to cytotoxicity and cell adhesion. Methacrylates have minimized protein and cell adhesion and degradation of non-toxic products. All polymers exhibited a high degree of biocompatibility and cell adhesion was markedly reduced following HEMA grafting. A 3 cm and 7 Charrière prototype of the stent was moulded from PDLLA-co-TMC by CESP-technology, and grafted with HEMA by means of plasma-induced polymerization. Finally, the stents were implanted into female sheep, following unilateral ureterotomy. Regular blood and urine analysis as well as ultrasound and the final autopsy revealed no pathological findings. Histopathological analysis exhibited a regular epithelium without any changes being determined by contact to the stent, and a good regeneration of all layers in the area of anastomosis.