Optimizing laparoscopic training efficacy by 'deconstruction into key steps': a randomized controlled trial with novice medical students.

BACKGROUND: Simulator training is an effective way of acquiring laparoscopic skills but there remains a need to optimize teaching methods to accelerate learning. We evaluated the effect of the mental exercise 'deconstruction into key steps' (DIKS) on the time required to acquire laparoscopic skills. METHODS: A randomized controlled trial with undergraduate medical students was implemented into a structured curricular laparoscopic training course. The intervention group (IG) was trained using the DIKS approach, while the control group (CG) underwent the standard course. Laparoscopic performance of all participants was video-recorded at baseline (t0), after the first session (t1) and after the second session (t2) nine days later. Two double-blinded raters assessed the videos. The Impact of potential covariates on performance (gender, age, prior laparoscopic experience, self-assessed motivation and self-assessed dexterity) was evaluated with a self-report questionnaire. RESULTS: Both the IG (n = 58) and the CG (n = 68) improved their performance after each training session (p < 0.001) but with notable differences between sessions. Whereas the CG significantly improved their performance from t0 -t1 (p < 0.05), DIKS shortened practical exercise time by 58% so that the IG outperformed the CG from t1 -t2, (p < 0.05). High self-assessed motivation and dexterity associated with significantly better performance (p < 0.05). Male participants demonstrated significantly higher overall performance (p < 0.05). CONCLUSION: Mental exercises like DIKS can improve laparoscopic performance and shorten practice times. Given the limited exposure of surgical residents to simulator training, implementation of mental exercises like DIKS is highly recommended. Gender, self-assessed dexterity, and motivation all appreciably influence performance in laparoscopic training.

[Making innovation in teaching measurable : Psychometric validation of the "Radio-Prak": a questionnaire using the example of a clinical practical seminar in interventional radiology]. / Innovationen in der Lehre messbar machen : Psychometrische Validierung des Messinstrumentes "Radio-Prak" am Beispiel eines klinisch-praktischen Seminars der interventionellen Radiologie.

BACKGROUND: As part of the reform of medical education with a stronger focus on clinical-practical skills, a restructured seminar on interventional radiology was evaluated using a newly developed questionnaire. OBJECTIVES: Because knowledge in medical education is increasingly transferred by means of application-based teaching formats, a suitable evaluation tool is essential to assess the quality of newly implemented teaching courses. The aim of this study was to evaluate the seminar on interventional radiology and to validate the "Radio-Prak" questionnaire psychometrically in the process. MATERIALS AND METHODS: In the summer semester of 2018, 123 students participating in the newly established seminar were asked to document their satisfaction using the "Radio-Prak" questionnaire with 23 items employing a 5-point Likert scale. We evaluated the questionnaire psychometrically by performing exploratory factor (EFA) and reliability analysis and examined differential validity by group differences. RESULTS: The newly structured seminar on interventional radiology was met with great approval by students (mean global rating = 1.31, on a grading scale where 1 = very good, 5 = insufficient). EFA revealed that the questionnaire consisted of two main factors "didactic quality" and "practical quality" (five items each, α = 0.68). The seminar was rated more positively when students perceived the time for practice as sufficient (p < 0.05). Furthermore, female students demonstrated significantly less self-esteem, identified by the item "I have improved my spatial ability through the seminar," (p < 0.05). CONCLUSION: The "Radio-Prak" questionnaire is both reliable and valid as an instrument to evaluate the quality of a clinical-practical seminar. The students assessed the didactic dimension, but also rated the practical component as important in the assessment.

Validation and educational impact study of the NANEP high-fidelity simulation model for open preperitoneal mesh repair of umbilical hernia.

OBJECTIVE: The aim of the study was to develop, validate and analyze the educational impact of a high-fidelity simulation model for open preperitoneal mesh repair of an umbilical hernia. The number of surgical simulators available for training residents is limited. Primary for ethical reasons and secondary for the emerging pay-per-quality policies, practicing-on simulators rather than patients is considered gold standard. Validated full-procedural surgical models will become more and more important in training residents. Such models may assure that evidence-based standards regarding technical aspects of the procedures become integral part of the curriculum. Furthermore, they can be employed as a quality control of residents' skills (Fonseca et al. in J Surg Educ 70:129-137, 2013). METHODS: In a repeated measures design, medical students, residents in their last year of training and attending surgeons performed an open preperitoneal mesh repair on the NANEP model [NANEP stands for the German acronym Nabelhernien-Netzimplatation-Präperitonal (English: Umbilical hernia mesh implantation preperitoneal)]. Subjects were categorized as "Beginners" (internship students) or "Experts" (residents and surgeons). Content validity was analyzed by criteria of subject-matter-experts. Blinded raters assessed surgical skills by means of the Competency Assessment Tool (CAT) using the online platform "CATLIVE". Differential validity was measured by group differences. Proficiency gain was analyzed by monitoring the learning curve (Gallagher et al. in Ann Surg 241:364-372, 2005). Post-operative examination of the simulators shed light on criterion validity. RESULTS: The NANEP model-proofed content and construct-valid significant Bonferroni-corrected differences were found between beginners and experts (p < 0.05). Beginners showed a significant learning increase from the first to the second surgery (p < 0.05). Post-operative examination data confirmed criterion validity. CONCLUSION: The NANEP model is an inexpensive, simple and efficient simulation model. It has highly realistic features, it has been shown to be of high-fidelity, full-procedural and benchtop-model. The NANEP model meets the main needs of surgical educational courses at the beginning of residency.

Incisional hernia repair in a high-fidelity silicone model for open retro-muscular mesh implantation with preparation of the fatty triangle: validation and educational impact study.

BACKGROUND: Incisional hernia repair requires detailed anatomic knowledge. Regarding median subxiphoidal hernias, the proper preparation of the fatty triangle is challenging. To foster proficiency-based training, a cost-efficient model for open median retromuscular mesh repair resembling the human body was developed, including the main anatomical structures related to the procedure. The aim is to create and validate a high-fidelity model on open retromuscular mesh repair suitable for "training before doing". MATERIALS AND METHODS: Different types of fabrics for imitation of connective tissue and 2-component silicones were used to construct the incisional hernia model. Sample size for validation of the model was determined by a triangular testing approach. Operations from six beginners and six experts were assessed by three blinded-raters. Reliability and construct-validity were evaluated on a behaviorally anchored rating scale (highest score: 4) for the criteria: "instrument use", "tissue handling", "near misses and errors", and "end-product quality". RESULTS: The model authentically mimicked an open median retromuscular mesh repair. Participants considered the procedure realistic. Reliability was excellent, ranging from 0.811 to 0.974 for "end-product quality", and "tissue handling" respectively. Construct-validity was confirmed with experts significantly outperforming beginners in the "use of instruments" (Mbeg. = 2.33, Mexp. = 3.94, p < 0.001), "tissue handling" (Mbeg. = 2.11, Mexp. = 3.72, p < 0.001), "near misses and errors" (Mbeg. = 2.67, Mexp. = 3.67, p < 0.001), and "end-product quality" (Mbeg. = 2.78, Mexp. = 3.72, p < 0.001). Criterion-validity revealed a paradox effect: beginners performed significantly better than experts (p < 0.05) when preparing the fatty triangle. CONCLUSIONS: The model covers all relevant aspects involved in median-open retromuscular incisional hernia mesh repair. Performance differences between beginners and experts confirm construct-validity and thereby realism of the model. It enables to efficiently improve and practice technical skills of the demanding surgery.

Recycling food waste to clean water: the use of a biodigester's residual liquid inoculum (RLI) to decolourise textile azo dyes.

A residual liquid inoculum (RLI) was used to decolourise solutions of Acid Yellow 25 (AY25) and Direct Violet 51 (DV51) azo dyes. The RLI was obtained through anaerobic digestion of food waste from a university restaurant. The concentration of bacteria in the RLI was 8.45 × 107 CFU mL-1. Dye solutions (50 µg mL-1) were inoculated with the RLI (20% v/v) and incubated at room temperature. The decolourisation studies took place at microaerophilic and in-batch conditions and at pH = 2.50. Initially, the dyes were taken up from solution by biosorption; maximum colour removal was achieved after 3 hours of incubation, with 88.66% for AY25 and 77.65% of DV51. At prolonged incubation times (3-96 hours) decolourisation was mainly attributed to biodegradation of the azo solutions, with breakage of the azo bond, as detected by UV-VIS spectroscopy and Fourier transform infrared (FT-IR) analysis. Analysis of UV-VIS absorption rates of dyes showed, however, that AY25 was more readily biodegradable whereas DV51 was more recalcitrant to the action of the RLI.

Caspofungin infusion solutions (50 mg/100 mL): chemical stability and antifungal activity against Candida spp.

BACKGROUND: Ready to use caspofungin infusion bags are centrally prepared in the Hospital Pharmacy, University Hospital of Heidelberg, for economic reasons and possibly occurring problems with drug shortages. The aim of this study was a quality control of the in-house preparation of caspofungin infusion bags and the preparation process. Caspofungin concentration with regard to chemical stability and antifungal activity of caspofungin preparations were defined as quality parameters. METHODS: Three caspofungin infusion bags (50 mg in 100 mL 0.9% sodium chloride) were examined every seven days for a total of four weeks. Chemical stability of caspofungin solutions was analyzed using a validated high performance liquid chromatography (HPLC) method. Antifungal activity was assessed by microdilution tests according to the EUCAST protocol. Additionally, concentration and sterility were determined in returned caspofungin infusion bags. RESULTS: The amount of caspofungin in the infusion solutions still exceeded 90% after four weeks (2-8 °C). Antifungal activity was consistent over 28 days with a MIC ≤2 mg/L for different Candida spp. In returned infusion bags, caspofungin concentration was found to be ≥90% in 12 out of 13 bags and sterility was given in all preparations. CONCLUSION: These results show that chemical stability of caspofungin infusion solutions (50 mg/100 mL) can be guaranteed for four weeks at 2-8 °C and are confirmed by corresponding results regarding sterility and antifungal activity.

Psychological and neuroendocrine responses to social stress and to the administration of the alpha-2-receptor antagonist, yohimbine, in highly trained endurance athletes in comparison to untrained healthy controls.

INTRODUCTION: Several clinical studies suggest antidepressive and anxiolytic effects of regular endurance training. The mechanisms by which exercise exerts these effects are still unclear. It was hypothesized that athletes might show a diminished reaction to psychosocial stress and noradrenergic stimulation. METHODS: 12 male athletes and 12 healthy untrained male controls underwent a challenge paradigm on 3 separate days: the alpha-2-receptor antagonist yohimbine (0.4 mg/kg), placebo or a psychosocial stress test (SST) were administered. Responses were measured by psychometric scales, plasma cortisol, blood pressure and heart rate. RESULTS: Before testing, psychometric variables and cortisol levels were not different between the 2 groups. In comparison to placebo conditions, both the social stress test and the administration of yohimbine were followed by significant increases of anxiety symptoms, plasma cortisol, heart rate and blood pressure in both groups. However, these responses were not significantly different between the group of athletes and the control group. DISCUSSION: These results do not support the hypotheses that high aerobic fitness is associated with attenuated psychological and neuroendocrine responses to yohimbine or to psychosocial stress.

Application of mid-infrared molecular spectroscopy for assessment of biochemical parameters of blood serum.

The method of mid-infrared molecular spectroscopy allows precise measuring of the concentrations of a large number of biological molecules in a minimal sample volume. Method of projections on latent structures was used for plotting the calibration models. On the basis on mid-infrared spectral data we obtained calibration models for calculation of serum content of various substances: albumin, cholesterol, glucose, total protein, urea, 70 Da heat shock protein, and malonic dialdehyde.

Attenuated salivary cortisol secretion under cue exposure is associated with early relapse.

AIMS: To test whether the risk of relapse in alcohol dependence is predicted by the subjective experience of cue exposure (CE) and/or cortisol reactivity to alcohol cues. METHODS: Salivary cortisol and self-ratings of 'tension' and 'desire to drink' were measured in 32 detoxified alcohol-dependent inpatients during CE sessions conducted in the first and third week of motivation enhancement therapy. Subjects completed the Toronto Alexithymia Scale (TAS-20) and the Abbreviated Alcohol Expectancy Questionnaire (B-AEQ) towards the end of the inpatient treatment to measure emotional self-awareness and the expected positive effects of alcohol. RESULTS: Six weeks after the end of the inpatient treatment, 15 patients were abstinent. Relapse was verified or was presumed for 17 patients. Those who had relapsed had shown an attenuated response to CE in the third week as an inpatient but did not differ from abstainers in terms of subjective reaction to cues. Subjective ratings of CE were not related to salivary cortisol or relapse but showed several associations with factors one and two of the TAS-20. The expectancy of enhanced social contacts by using alcohol (factor 1 of the B-AEQ) correlated negatively with the decline in salivary cortisol during the CE session in the third week of treatment. Subjective ratings of CE correlated with Alexithymiascores. CONCLUSIONS: Alcoholic patients who use alcohol to enhance their social contacts typically lack hypothalamo-hypophysical-pituitary-adrenocortical (HPA) reactivity in the early period of abstention. They are at an increased risk of early relapse and perhaps use alcohol to increase cortisol secretion again.

Impaired serum cortisol stress response is a predictor of early relapse.

AIMS: to investigate a possible association of cortisol stress response during early abstention with relapse. METHODS: Thirty-six alcohol-dependent males, half of them with a comorbid anxiety disorder, and 15 healthy controls were exposed to a standardized psychosocial stress test. Thirty-one of the patients were assessed for relapse 6 weeks after discharge. RESULTS: The relapsers showed almost no cortisol responses in the stress test. Comorbid anxiety disorder influenced neither stress response nor relapse. CONCLUSIONS: During early abstention from alcohol, reduced stress-responsivity of the hypothalamo-pituitary-adrenocortical axis seems to be connected to early relapse.

[Addiction in the elderly - an underestimated diagnosis in clinical practice?]. / Sucht im Alter Ein unterschätztes Problem in der klinischen Versorgung älterer Menschen?

According to several studies in the USA, alcohol abuse is common among elder people, particularly among those admitted to hospital. Corresponding data for Germany are lacking as yet. In this study, the frequency of addiction problems in the elderly admitted to hospital was investigated using the data from 1990 to 1998 of the psychiatric department at the General University Hospital of Lübeck, Germany. Furthermore, the documentations of all consultations in that period were reevaluated. The psychiatric consultation service covers two general hospitals providing inpatient treatment for about 200,000 inhabitants. Diagnoses were made according to the ICD-10 criteria. In 17.7% of the males older than 64 years and in 4.2% of the elderly females admitted to the psychiatric department, alcohol dependency was diagnosed, while 5.8% of the elderly patients showed substance abuse, most often of benzodiazepine. Among the patients visited in the psychiatric consultation service, 10.8% of the elderly males and 3.2% of the elderly females were alcohol addicts and 3.9% substance abusers. The frequency of alcohol-induced neuropsychiatric complications, particularly withdrawal delirium and amnestic syndrome, increased with age. Also, benzodiazepine withdrawal delirium most frequently occurred in older patients. These results underscore that, although the prevalence rate seems to be lower than among the younger population, in the elderly population substance abuse still is a relevant medical problem, since the rate of neuropsychiatric complications increased with age.

[Diagnosis and therapy of sleep disorders. Early assessment--prompt treatment]. / Diagnostik und Therapie von Schlafstörungen. Frühzeitig nachfragen--rechtzeitig behandeln.

Effective medications, as well as other effective options, are available for the treatment of insomnia. Since many patients do not inform their family doctors that they have sleep-related problems, the physician should himself question his patients on this point, with the aim of initiating specific treatment early enough to prevent such a condition becoming chronic.

A double-blind, randomized and placebo-controlled study on the polysomnographic withdrawal effects of zopiclone, zolpidem and triazolam in healthy subjects.

Rebound effects after withdrawal from hypnotics are believed to trigger their chronic use and to enhance the risk of tolerance and dependence. It was the purpose of this study to investigate the acute polysomnographic withdrawal effects after a 4 week treatment with standard doses of the non-benzodiazepine hypnotics zopiclone and zolpidem compared with triazolam and placebo. Healthy male subjects between 22 and 35 years of age participated in a parallel study design. They received either zopiclone 7.5 mg (n=11), zolpidem 10 mg (n=11), triazolam 0.25 mg (n=10) or placebo (n=7) over 4 weeks in randomized and double-blind order. Sleep EEG was registered during 2 nights before treatment under placebo, on days 1, 27 and 28 of treatment and on days 29,30,41 and 42 under placebo. Total sleep time and sleep efficiency were lower in the 1st night after discontinuation of triazolam (p < 0.05, t-test). After withdrawal from zopiclone or zolpidem slight but not significant rebound effects concerning sleep continuity were observed. Self-rating scales showed minimal rebound insomnia after discontinuation of all three hypnotics. In the placebo group no changes of sleep parameters were observed. Assuming that rebound insomnia is part of a withdrawal reaction, this study indicates that the risks of tolerance and dependency are low when administering zopiclone or zolpidem at the recommended doses.

Long-term effectiveness of a short-term cognitive-behavioral group treatment for primary insomnia.

The long-term effectiveness of a short-term cognitive-behavioral therapy was evaluated. The structured group treatment consisted of six weekly sessions and included progressive muscle relaxation, cognitive relaxation, modified stimulus control with bedtime restriction, thought stopping and cognitive restructuring. Twenty patients with chronic primary insomnia took part in the study. All patients were referred by physicians for diagnosis and therapy of insomnia. During a waiting period of six weeks prior to treatment, patients did not experience any change of their sleep parameters. After therapy, patients improved their total sleep time and sleep efficiency and reduced their sleep latency and negative sleep-related cognitions. Furthermore, depression scores decreased. Most of the treatment effects were significant at the end of the treatment and remained stable over the long-term follow-up, which was evaluated after a mean of almost three years (35 +/- 6.7 months). The subjective estimated total sleep time improved from 298 +/- 109 min prior to therapy to 351 +/- 54 min at the end of treatment, to 376 +/- 75 min at the 3-month follow-up, to 379 +/- 58 min at the 12-month follow-up and to 381 +/- 92 min. at the long-term follow-up.

How to preserve the antidepressive effect of sleep deprivation: A comparison of sleep phase advance and sleep phase delay.

Total sleep deprivation (TSD) leads to an immediate amelioration of depressed mood in approximately 70 % of patients with the melancholic subtype of depression. The clinical utility of this procedure is limited, as the improvement usually subsides after the next night of sleep. In the present study, 40 depressed inpatients, being free of psychoactive medication for at least 7 days and who had responded to a TSD were then distributed (according to a matched-pair design) to a sleep phase advance (SPA = time in bed scheduled from 1700-2400 hrs) or a sleep phase delay (SPD = time in bed from 0200-0700 hrs) with a succeeding shift back (for one hour in the SPA group per day) respectively shift forward (for 30 minutes in the SPD group per day), until the initial sleep phase (2300-0600 hrs) was reached after seven days again. Based on previous observations it was hypothesized that a phase advance of the sleep period should prevent responders to TSD from relapsing. Whereas 75% of the TSD responders were stabilized by the phase advanced condition and did not relapse over a period of seven days, only 40% of the patients in the phase delayed condition did not relapse. Polysomnography during the course of the study gave no evidence that the unusual sleep schedules caused prolonged sleep deprivation. Abnormalities of REM sleep persisted both in the clinical responders and non-responders after the sleep wake manipulation. It is concluded that the clinical effectiveness of TSD can be significantly improved by combining TSD with a following phase advance of the sleep period.

The tryptophan depletion test. Impact on sleep in healthy subjects and patients with obsessive-compulsive disorder.

UNLABELLED: The tryptophan depletion test is a research tool to study the functional consequences of decreasing the brain serotonin metabolism. Since serotonin is involved in sleep regulation and assumed to be of high importance in the etiology of psychiatric disorders, the acute polysomnographic effects of tryptophan depletion were studied in healthy subjects and patients with obsessive compulsive disorder (OCD). According to the reciprocal interaction model of non-REM and REM-sleep regulation we expected that tryptophan depletion in healthy controls should provoke alterations of sleep similar to depression, whereas we assumed that these effects would be more pronounced in patients with OCD. METHODS: 12 healthy subjects with a mean age of 34 years and 12 patients suffering from OCD with a mean age of 30 years had 4 polysomnographic investigations. After 1 adaption and 1 baseline night subjects received a low protein diet on day 3 and 4 until midday. On day 4 at 18.00 h subjects ingested an aminoacid mixture devoid of tryptophan. This procedure resulted in a decrease of 85% in healthy subjects and 80% in OCD patients at 22.00 h. RESULTS: The tryptophan depletion led to more pronounced disturbances of sleep continuity in OCD patients than in healthy subjects in terms of an increase of wake time and a decrease of total sleep time. In both groups a decrease of sleep stage 2 could be observed. Healthy subjects showed significant alterations of phasic REM parameters as REM density and total number of rapid eye movements, what was not the case for OCD patients. CONCLUSIONS: Our results indicate the important role of the serotonergic system for sleep maintainance and the phasic aspects of REM sleep. Furthermore our data demonstrate that the tryptophan depletion test is a useful tool to evaluate the hypothesis of a serotonergic involvement in sleep regulation and the etiology of psychiatric disorders.

A 19-h spontaneous sleep period in idiopathic central nervous system hypersomnia.

Reports of prolonged sleep periods in idiopathic central nervous system hypersomnia, as shown by ad libitum sleep recordings, are rare. A patient with idiopathic hypersomnia with extremely long sleep periods and sleep drunkenness after awakening is described. Polysomnographic recordings showed a spontaneous sleep period of 19.4 h and a normal Multiple Sleep Latency Test. These polysomnographic findings are clearly abnormal but essentially different form those of narcolepsy. Unlike narcolepsy, 'idiopathic hypersomnia' does not seem to be a distinct clinical entity but a category for different heterogenous subtypes.

Impact of experimentally induced serotonin deficiency by tryptophan depletion on sleep EEG in healthy subjects.

The tryptophan depletion test is a research strategy to investigate the functional consequences of decreasing the brain serotonin metabolism. Because serotonin is involved in sleep regulation and the regulation of affective states, we studied the acute polysomnographic effects of tryptophan depletion and expected to induce similar changes of sleep EEG as observed in depressed patients. A total of 12 healthy subjects (mean age 34 +/- 3 years) had eight polysomnograms, divided in two blocks of 4 consecutive nights. After one adaptation and 1 baseline night, subjects received a low-protein diet on day 3 and 4 until midday. On day 4 at 18.00 h, they drank an amino acid mixture either devoid of tryptophan or containing 2.3 g of tryptophan (placebo control) in randomized and double-blind order, resulting in an 85% decrease (tryptophan depletion) and a 144% increase (placebo control) of serum tryptophan at 22.00 h. After tryptophan depletion but not placebo, significant effects on sleep EEG were observed in terms of decreased non-rapid eye movement (non-REM) stage 2, increase of wake %, and of rapid eye movement (REM) density compared with baseline. REM latency was not altered, however the first and second REM period interval were significantly shorter after tryptophan depletion. This study underlines the impact of the serotonergic system on sleep maintenance and on REM sleep.

Sleep and the cholinergic rem sleep induction test in patients with primary alcoholism.

Sleep disturbances of alcoholics while actively drinking and at the beginning of, and during, abstinence were frequently reported. Recently, Gillin et al. (1994) showed that a high "REM sleep pressure" at the time of admission to a 1-month inpatient alcohol treatment program predicted the relapse in nondepressed patients with primary alcoholism at 3 months following hospital discharge. We investigated 24 patients with primary alcoholism after 2-3 weeks abstinence in the sleep laboratory; in 15 of these patients the cholinergic REM sleep induction test (CRIT) with 10 mg galanthamine was performed additionally. In comparison with an age- and sex-matched healthy control group, patients had a heightened "REM sleep pressure" including shortened REM latency and increased REM density. A decrease of serotonergic neurotransmission is proposed as being the neurochemical mechanism to explain the results in alcoholic subjects. Follow-up investigations will clarify whether the sleep abnormalities in alcoholism are state- or trait-markers and whether they are suitable to predict the relapse risk.