Validation of the Brief Confusion Assessment Method for screening delirium in elderly medical patients in a German emergency department

Background Delirium is frequent in elderly patients presenting in the emergency department (ED). Despite the severe prognosis, the majority of delirium cases remain undetected by emergency physicians (EPs). At the time of our study there was no valid delirium screening tool available for EDs in German‐speaking regions. We aimed to evaluate the brief Confusion Assessment Method (bCAM) for a German ED during the daily work routine. Methods We implemented the bCAM into practice in a German interdisciplinary high‐volume ED and evaluated the bCAM's validity in a convenience sample of medical patients aged ≥ 70 years. The bCAM, which assesses four core features of delirium, was performed by EPs during their daily work routine and compared to a criterion standard based on the criteria for delirium as described in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Results Compared to the criterion standard, delirium was found to be present in 46 (16.0%) of the 288 nonsurgical patients enrolled. The bCAM showed 93.8% specificity (95% confidence interval [CI] = 90.0%–96.5%) and 65.2% sensitivity (95% CI = 49.8%–78.7%). Positive and negative likelihood ratios were 10.5 and 0.37, respectively, while the odds ratio was 28.4. Delirium was missed in 10 of 16 cases, since the bCAM did not indicate altered levels of consciousness and disorganized thinking. The level of agreement with the criterion standard increased for patients with low cognitive performance. Conclusion This was the first study evaluating the bCAM for a German ED and when performed by EPs during routine work. The bCAM showed good specificity, but only moderate sensitivity. Nevertheless, application of the bCAM most likely improves the delirium detection rate in German EDs. However, it should only be applied by trained physicians to maximize diagnostic accuracy and hence improve the bCAM's sensitivity. Future studies should refine the bCA

Pharmacology of the ADP receptors on human platelets

Die Thienopyridine Ticlopidin und Clopidogrel sind seit mehreren Jahren im klinischen Einsatz als Thrombozytenaggregationshemmer zur Sekundärprophylaxe bei arteriosklerotischen Erkrankungen der Herzgefäße, zerebralen Gefäße sowie der peripheren Arterien. Trotz ihrer nachgewiesenen klinischen Wirksamkeit war der Wirkmechanismus lange Zeit auf die Beschreibung als ADP-Rezeptorantagonist beschränkt. Im Zuge neuerer Erkenntnisse zum Mechanismus der Auslösung einer Aggregation, insbesondere der ADP-vermittelten Aggregation, sollte im Rahmen dieser Dissertation der Wirkmechanismus der Thienopyridine genauer untersucht werden sowie mögliche Auswirkungen auf intrazelluläre Kaskaden, die den aggregationshemmenden Effekt vermitteln. Zu diesem Zweck wurden die Effekte einer Thienopyridin-Einnahme auf die Thrombozytenfunktion gesunder Probanden untersucht. In unseren Versuchen bestätigte sich die gute Wirksamkeit der Substanzen hinsichtlich der deutlichen Reduktion der ADP-vermittelten Aggregation. Vor dem Hintergrund eines damals neu propagierten Drei-Rezeptoren-Modells für die ADP-vermittelte Aggregation konnten wir erstmals den Wirkmechanismus an humanen Thrombozyten auf eine Inhibierung des P2Yac-Rezeptors eingrenzen. Weiterhin konnten wir unter Thienopyridin-Einnahme eine Aufhebung der ADP-vermittelten Hemmung der PG-E1-vermittelten VASP-(VAsodilator-Stimulated Phosphoprotein) Phosphorylierung feststellen und somit einen wichtigen Beitrag zum Verständnis der Wirkung der Substanzen beitragen. Zum besseren Verständnis der zum damaligen Zeitpunkt bereits auf molekularer Ebene bekannten humanen thrombozytären ADP-Rezeptoren P2Y1 und P2X1 wurden diese aus humanen Thrombozyten kloniert und mit verschiedenen Tags versehen in einer Astrozytoma-Zelllinine transient und stabil exprimiert. Es wurden verschiedene zellbiologische Methoden wie Immunpräzipitation, Durchflusszytometrie und Immunfluoreszenz etabliert, die als Grundlage für weitere Untersuchungen der intrazellulären Signalkaskaden der Rezeptoren dienen können. Die stabil exprimierenden Zelllinien dienten zur Verifizierung des pharmakologischen Profils der Rezeptoren, weiterhin konnten bereits erste Versuche zu einer möglichen Regulation der Rezeptoren durch zyklische Nukleotide durchgeführt werden. Durch die Etablierung dieser Zelllininen wurde insgesamt eine gute Grundlage für eine weitere Charakterisierung dieser ADP-Rezeptoren unter besser standardisierbaren Bedingungen geschaffen.The thienopyridines Ticlopidine and Clopidogrel are clinically well known platelet antagonists. To uncover their mechanism of action, we conducted a study with healthy human volunteers to identify the ADP receptor, which is directly affected by these drugs. We found the P2Y12 receptor to be the only ADP receptor being impaired by Ticlopidine and Clopidogrel. Moreover we found that this specific inhibion of P2Y12 is sufficient to prevent platelet aggregation. This effect could occur due to the higher state of VASP phosphorylation in these platelets. To characterize the other two known ADP receptors on human platelets, P2Y1 and P2X1, stable expressing cell lines were created and analyzed. These cell lines may be valuable tools to futher characterize the pharmacology and signal transduction properties of these receptors

Validation and perception of a key feature problem examination in neurology.

OBJECTIVE:To validate a newly-developed Key Feature Problem Examination (KFPE) in neurology, and to examine how it is perceived by students. METHODS:We have developed a formative KFPE containing 12 key feature problems and 44 key feature items. The key feature problems covered four typical clinical situations. The items were presented in short- and long-menu question formats. Third- and fourth-year medical students undergoing the Neurology Course at our department participated in this study. The students' perception of the KFPE was assessed via a questionnaire. Students also had to pass a summative multiple-choice question examination (MCQE) containing 39 Type-A questions. All key feature and multiple-choice questions were classified using a modified Bloom's taxonomy. RESULTS:The results from 81 KFPE participants were analyzed. The average score was 6.7/12 points. Cronbach's alpha for the 12 key-feature problems was 0.53. Item difficulty level scores were between 0.39 and 0.77, and item-total correlations between 0.05 and 0.36. Thirty-two key feature items of the KFPE were categorized as testers of comprehension, application and problem-solving, and 12 questions as testers of knowledge (MCQE: 15 comprehension and 24 knowledge, respectively). Overall correlations between the KFPE and the MCQE were intermediate. The KFPE was perceived well by the students. CONCLUSIONS:Adherence to previously-established principles enables the creation of a valid KFPE in the field of Neurology

Ultrasound-guided lumbar puncture with a needle-guidance system: A prospective and controlled study to evaluate the learnability and feasibility of a newly developed approach

<div><p>Objective</p><p>To evaluate the learnability and feasibility of a new technique comprising a needle-guidance-system (NGS) for ultrasound-assisted lumbar puncture.</p><p>Method</p><p>Using a randomized crossover study design, 24 medical students were asked to perform an ultrasound-assisted lumbar puncture on a gel phantom using two different techniques that each included a paramedian insertion site. Procedure 1 (P1) used a pre-procedural ultrasound scan to predetermine the ideal insertion point. Procedure 2 (P2) applied a new technique comprising an NGS for performing real-time ultrasound-guided lumbar puncture. Success rates and performance times for both procedures were compared. Participants were also asked to complete a post-study questionnaire, both to quantitatively assess the workload involved and state their personal preferences.</p><p>Results</p><p>In comparison to the pre-procedural scan (P1), the NGS (P2) was associated with a significant increase in the number of successful punctures per participant (5 (P2) [interquartile range: 3.3–5.0] vs. 3 (P1) [interquartile range: 1.3–4.0], p = 0.005), and led to a significant reduction in performance time (118 seconds vs. 80.6 seconds, p < 0.001). In terms of workload perception, NGS use was associated with significantly better performances and lower frustration levels, as rated by students in the post-study questionnaire. Finally, 23/24 participants stated their preference for P2.</p><p>Conclusion</p><p>Our newly-developed technique for real-time ultrasound-guided lumbar puncture proved to be learnable and feasible for novices, and only required a small amount of training. The use of an NGS therefore has the potential to serve as a key feature of the ultrasound-assisted lumbar puncture.</p></div

Effects of additional team-based learning on students’ clinical reasoning skills: a pilot study

Abstract Background In the field of Neurology good clinical reasoning skills are essential for successful diagnosing and treatment. Team-based learning (TBL), an active learning and small group instructional strategy, is a promising method for fostering these skills. The aim of this pilot study was to examine the effects of a supplementary TBL-class on students’ clinical decision-making skills. Methods Fourth- and fifth-year medical students participated in this pilot study (static-group comparison design). The non-treatment group (n = 15) did not receive any additional training beyond regular teaching in the neurology course. The treatment group (n = 11) took part in a supplementary TBL-class optimized for teaching clinical reasoning in addition to the regular teaching in the neurology course. Clinical decision making skills were assessed using a key-feature problem examination. Factual and conceptual knowledge was assessed by a multiple-choice question examination. Results The TBL-group performed significantly better than the non-TBL-group (p = 0.026) in the key-feature problem examination. No significant differences between the results of the multiple-choice question examination of both groups were found. Conclusions In this pilot study participants of a supplementary TBL-class significantly improved clinical decision-making skills, indicating that TBL may be an appropriate method for teaching clinical decision making in neurology. Further research is needed for replication in larger groups and other clinical fields

Successful punctures and time required.

<p>Successful punctures and time required.</p

Procedure 2 –Real-time puncture using a needle-guidance-system.

<p>Steps taken for Procedure 2: <b>A</b>. Schematic overview of the approach to Procedure 2. Both the transducer and the needle are positioned paramedially (P), approximately 1 cm lateral to the midline (M) and with medial angulation. The needle is shown to meet the ultrasound beam near the anatomical midline. <b>B</b>. Depiction of Procedure 2 under study-like conditions. The needle is held and introduced with the dominant hand while controlling for its advancement in real-time on the ultrasound screen <b>(C)</b>. The solid line in <b>C</b> represents the actual advancement of the needle in line with the calculated trajectory, which is represented by the dotted line. The red square embodies the target, namely, the intersection between the ultrasound beam with the needle trajectory. Thus, the target should directly lie beneath the ligamentum flavum/dura mater complex (LF/DM) in the spinal canal (SC) between the two adjacent laminae (L). As soon as the needle (solid line) meets the ultrasound beam, the red square turns green, indicating that the tip of needle is theoretically lying inside the spinal canal.</p

Procedure 1—Puncture with pre-procedural scanning.

<p><b>A</b>. PSO view of spinal canal before procedure. <b>C</b>. Marking the paramedian insertion point. <b>D</b>. Needle insertion at pre-marked insertion point. Steps taken for Procedure 1: The transducer is held in the right (dominant) hand and a paramedian sagittal oblique (PSO) scan is performed by placing the transducer approximately 1 cm lateral to the midline (M) and angling it medially (<b>A</b>) until a clear view of the spinal canal (SC) is obtained (<b>B</b>). The ligamentum flavum/dura mater complex (LF/DM) is represented by a sharp hyperechoic line in between two adjacent laminae (L). The midpoints of the four borders of the probe can then be marked (<b>C</b>). The probe is then set aside and the 4 marks are connected in a cross-wise fashion, thereby defining the needle insertion point. Finally, the needle is inserted with the same angulation used to hold the probe (<b>D</b>).</p

Baseline characteristics of participants.

<p>Baseline characteristics of participants.</p