An observer tool to enhance learning of incoming anesthesia residents' skills during simulation training of central venous catheter insertion: a randomized controlled trial.

BACKGROUND: Central venous catheter (CVC) insertion using simulation is an essential skill for anesthesiologists. Simulation training is an effective mean to master this skill. Given the large number of residents and the limited duration of training sessions, the active practice time is limited and residents remain observers of their colleagues for much of the session. To improve learning during observation periods, the use of an observer tool (OT) has been advocated but its educational effectiveness is not well defined. METHODS: Incoming anesthesia residents were randomized to use an OT (i.e. procedural skill-based checklist) (OT+) or not (OT-) when observing other residents during a simulation bootcamp. The primary outcome was a composite score (total 60 points) evaluating CVC procedural skills rated immediately after the training. This score covers theoretical knowledge explored by multiple choice questions (MCQs) (/20), perceived improvement in knowledge and skills (/20), perceived impact on future professional life (/10) and satisfaction (/10). Measurements were repeated 1 month later. Residents in each group recorded the number of CVCs placed and their clinical outcomes (attempts, complications) during the first month of their clinical rotation using a logbook. RESULTS: Immediately after training, the composite score was similar between the two groups: 45.3 ± 4.2 (OT+, n = 49) and 44.4 ± 4.8 (OT-, n = 42) (p = 0.323). Analysis of sub-items also showed no difference. Results at 1 month were not different between groups. Analysis of the logbook showed no difference between groups. No serious complications were reported. CONCLUSIONS: The use of a procedural task-based OT by incoming anesthesia residents and used during CVC insertion simulation training was not associated with better learning outcomes, neither immediately after the session nor when re-evaluated 1 month later. The training at least once on simulator of all residents could limit the impact of OT. Further studies are necessary to define the place of OT in simulation training.

A new murine model of endovascular aortic aneurysm repair.

Endovascular aneurysm exclusion is a validated technique to prevent aneurysm rupture. Long-term results highlight technique limitations and new aspects of Abdominal aortic aneurysm (AAA) pathophysiology. There is no abdominal aortic aneurysm endograft exclusion model cheap and reproducible, which would allow deep investigations of AAA before and after treatment. We hereby describe how to induce, and then to exclude with a covered coronary stentgraft an abdominal aortic aneurysm in a rat. The well known elastase induced AAA model was first reported in 1990(1) in a rat, then described in mice(2). Elastin degradation leads to dilation of the aorta with inflammatory infiltration of the abdominal wall and intra luminal thrombus, matching with human AAA. Endovascular exclusion with small covered stentgraft is then performed, excluding any interactions between circulating blood and the aneurysm thrombus. Appropriate exclusion and stentgraft patency is confirmed before euthanasia by an angiography thought the left carotid artery. Partial control of elastase diffusion makes aneurysm shape different for each animal. It is difficult to create an aneurysm, which will allow an appropriate length of aorta below the aneurysm for an easy stentgraft introduction, and with adequate proximal and distal neck to prevent endoleaks. Lots of failure can result to stentgraft introduction which sometimes lead to aorta tear with pain and troubles to stitch it, and endothelial damage with post op aorta thrombosis. Giving aspirin to rats before stentgraft implantation decreases failure rate without major hemorrhage. Clamping time activates neutrophils, endothelium and platelets, and may interfere with biological analysis.