Different Learning Curves for Axillary Brachial Plexus Block: Ultrasound Guidance versus Nerve Stimulation

Little is known about the learning of the skills needed to perform ultrasound- or nerve stimulator-guided peripheral nerve blocks. The aim of this study was to compare the learning curves of residents trained in ultrasound guidance versus residents trained in nerve stimulation for axillary brachial plexus block. Ten residents with no previous experience with using ultrasound received ultrasound training and another ten residents with no previous experience with using nerve stimulation received nerve stimulation training. The novices' learning curves were generated by retrospective data analysis out of our electronic anaesthesia database. Individual success rates were pooled, and the institutional learning curve was calculated using a bootstrapping technique in combination with a Monte Carlo simulation procedure. The skills required to perform successful ultrasound-guided axillary brachial plexus block can be learnt faster and lead to a higher final success rate compared to nerve stimulator-guided axillary brachial plexus block

Exceptional preservation of palaeozoic steroids in a diagenetic continuum

The occurrence of intact sterols has been restricted to immature Cretaceous (~125 Ma) sediments with one report from the Late Jurassic (~165 Ma). Here we report the oldest occurrence of intact sterols in a Crustacean fossil preserved for ca. 380 Ma within a Devonian concretion. The exceptional preservation of the biomass is attributed to microbially induced carbonate encapsulation, preventing full decomposition and transformation thus extending sterol occurrences in the geosphere by 250 Ma. A suite of diagenetic transformation products of sterols was also identified in the concretion, demonstrating the remarkable coexistence of biomolecules and geomolecules in the same sample. Most importantly the original biolipids were found to be the most abundant steroids in the sample. We attribute the coexistence of steroids in a diagenetic continuum-ranging from stenols to triaromatic steroids-to microbially mediated eogenetic processes

Investigating the effect of intra-operative infiltration with local anaesthesia on the development of chronic postoperative pain after inguinal hernia repair. A randomized placebo controlled triple blinded and group sequential study design [NCT00484731]

<p>Abstract</p> <p>Background</p> <p>Inguinal hernia repair is one of the most frequently performed procedures in Switzerland (15'000/year). The most common complication postoperatively is development of chronic pain in up to 30% of all patients irrespective of the operative technique.</p> <p>Methods/Design</p> <p>264 patients scheduled for an inguinal hernia repair using one of three procedures (Lichtenstein, Barwell and TEP = total extraperitoneal hernioplasty) are being randomly allocated intra-operatively into two groups. Group I patients receive a local injection of 20 ml Carbostesin^®0.25% at the end of the operation according to a standardised procedure. Group II patients get a 20 ml placebo (0.9% Saline) injection. We use pre-filled identically looking syringes for blinded injection, i.e. the patient, the surgeon and the examinator who performs the postoperative clinical follow-ups remain unaware of group allocation. The primary outcome of the study is the occurrence of developing chronic pain (defined as persistent pain at 3 months FU) measured by VAS and Pain Matcher^®device (Cefar Medical AB, Lund, Sweden).</p> <p>The study started on July 2006. In addition to a sample size re-evaluation three interim analyses are planned after 120, 180 and 240 patients had finished their 3-months follow-up to allow for early study termination.</p> <p>Discussion</p> <p>Using a group sequential study design the minimum number of patients are enrolled to reach a valid conclusion before the end of the study.</p> <p>To limit subjectivity, both a VAS and the Pain Matcher^®device are used for the evaluation of pain. This allows us also to compare these two methods and further assess the use of Pain Matcher^®in clinical routine.</p> <p>The occurrence of chronic pain after inguinal hernia repair has been in focus of several clinical studies but the reduction of it has been rarely investigated. We hope to significantly reduce the occurrence of this complication with our investigated intervention.</p> <p>Trial Registration</p> <p>Our trial has been registered at ClinicalTrials.gov. The trial registration number is: [NCT00484731].</p

Cardiovascular Response to Beta-Adrenergic Blockade or Activation in 23 Inbred Mouse Strains

We report the characterisation of 27 cardiovascular-related traits in 23 inbred mouse strains. Mice were phenotyped either in response to chronic administration of a single dose of the β-adrenergic receptor blocker atenolol or under a low and a high dose of the β-agonist isoproterenol and compared to baseline condition. The robustness of our data is supported by high trait heritabilities (typically H2>0.7) and significant correlations of trait values measured in baseline condition with independent multistrain datasets of the Mouse Phenome Database. We then focused on the drug-, dose-, and strain-specific responses to β-stimulation and β-blockade of a selection of traits including heart rate, systolic blood pressure, cardiac weight indices, ECG parameters and body weight. Because of the wealth of data accumulated, we applied integrative analyses such as comprehensive bi-clustering to investigate the structure of the response across the different phenotypes, strains and experimental conditions. Information extracted from these analyses is discussed in terms of novelty and biological implications. For example, we observe that traits related to ventricular weight in most strains respond only to the high dose of isoproterenol, while heart rate and atrial weight are already affected by the low dose. Finally, we observe little concordance between strain similarity based on the phenotypes and genotypic relatedness computed from genomic SNP profiles. This indicates that cardiovascular phenotypes are unlikely to segregate according to global phylogeny, but rather be governed by smaller, local differences in the genetic architecture of the various strains

Rollenerwartungen unterschiedlicher Berufsgruppen im OP

Hintergrund: Ausdifferenzierte Rollenstrukturen haben den Vorteil, dass sie den Teammitgliedern vorgeben, welches Verhalten von ihnen erwartet wird bzw. welches Verhalten sie von den anderen Mitgliedern erwarten können. Die Entstehung einer solchen Rollenstruktur erfordert jedoch eine Vielzahl an Interaktionen der betreffenden Menschen und somit eine Mindestkontaktdauer. Im OP-Saal arbeiten die Teams meist in wechselnder Zusammensetzung. In diesen kurzfristig zusammengestellten Teams kann sich eine Rollenstruktur nicht ausdifferenzieren. In der vorliegenden Untersuchung wird der Frage nachgegangen, ob die Zugehörigkeit zu einer bestimmten Berufsgruppe die fehlende Möglichkeit zur häufigen Interaktion im OP-Bereich substituiert. Methode: Anhand eines 9-Item-Fragebogens zur sozialperspektivischen Imagepositionierung (Kurzform von SYMLOG) wurden in einer schriftlichen Befragung OP-Saal-Mitarbeiter aus zwei Krankenhäusern zu ihrer Einschätzung von professionsspezifischen Verhaltensmerkmalen bezüglich Einfluss, Sympathie und Zielorientierung befragt (n=179). Ergebnisse: Die jeweiligen Berufsgruppen beurteilen sich selbst in der Eigenbewertung in jeder der 3Dimensionen höher, als sie die beiden anderen Professionen in der Fremdbeurteilung bewerten. Die Fremdbewertungen können jedoch den Wert der Eigenbewertung übersteigen. Die Analyse der Rollenwahrnehmung zeigt auf, dass sich beide akademischen Berufsgruppen einen großen Einfluss und eine große Zielorientierung zuschreiben. Hieraus kann ein Führungsanspruch abgeleitet werden, der ein Konfliktpotenzial beinhalten könnte. Diskussion: Die Datenanalyse zeigt, dass im untersuchten Kollektiv eine ausdifferenzierte Rollenstruktur im OP-Saal nicht vorhanden war. Hieraus lassen sich Optimierungsmöglichkeiten ableiten, wie beispielsweise der verstärkte Einsatz eingespielter Teams oder die Implementierung Konflikt reduzierender Methode