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A recent survey among French anesthesiologists revealed that monitoring of curarization is used in approximately in 50% of cases after a unique dose of curare and in 75% of cases after repeated doses of curare. In this survey, a majority of clinicians used a quantitative monitor based on acceleromyography, i.e. that the majority of clinicians used a device from the TOF-watch(®) product line. Results obtained by these monitors depends on the model used, TOF-Watch(®), TOF-Watch S(®) or TOF-Watch SX(®), as well as if it is used for a single point measurement at the end of the operation or continuously throughout the operation, with or without calibration, and if a calibration is used, should we used Cal 1 or Cal 2? Technical specifications and their impact on results will be developed in this technical note. This will help clinicians to better interpret results obtained by TOF-watch(®) monitors in order to improve clinical decisions based on monitoring of neuromuscular transmission., (Copyright © 2012 Société française d’anesthésie et de réanimation (Sfar). Published by Elsevier SAS. All rights reserved.)

Introduction: Few information are available regarding the learning curve in ultrasonography and even less for ultrasound-guided regional anesthesia. This study aimed to evaluate in a training program the learning curve on a phantom of 12 residents novice in ultrasonography., Material and Methods: Twelve trainees inexperienced in ultrasonography were given introductory training consisting of didactic formation on the various components of the portable ultrasound machine (i.e. on/off button, gain, depth, resolution, and image storage). Then, students performed three trials, in two sets of increased difficulty, at executing these predefined tasks: adjustments of the machine, then localization of a small plastic piece introduced into roasting pork (3 cm below the surface). At the end of the evaluation, the residents were asked to insert a 22 G needle into an exact predetermined target (i.e. point of fascia intersection). The progression of the needle was continuously controlled by ultrasound visualization using injection of a small volume of water (needle perpendicular to the longitudinal plane of the ultrasound beam). Two groups of two different examiners evaluated for each three trials the skill of the residents (quality, time to perform the machine adjustments, to localize the plastic target, and to hydrolocalize, and volume used for hydrolocalization). After each trial, residents evaluated their performance using a difficulty scale (0: easy to 10: difficult)., Results: All residents performed the adjustments from the last trial of each set, with a learning curve observed in terms of duration. Localization of the plastic piece was achieved by all residents at the 6th trial, with a shorter duration of localization. Hydrolocalization was achieved after the 4th trial by all subjects. Difficulty scale was correlated to the number of trials. All these results were independent of the experience of residents in regional anesthesia., Discussion: Four trials were necessary to adjust correctly the machine, to localize a target, and to complete hydrolocalization. Ultrasonography in regional anesthesia seems to be a fast-learning technique, using this kind of practical training.

Lepirudin is an alternative anticoagulant therapy in heparin-induced thrombocytopenia (HIT) during cardiopulmonary bypass (CPB). We report a case of a female patient with HIT referred for aortocoronary bypass graft despite persistence of antibodies to platelet factor 4-heparin complexes. Anticoagulation management is described. Whole blood hirudin concentration attempted during CPB was above 4 microg ml(-1). To obtain this concentration, lepirudin administration was managed as follows: 0.1 mg kg(-1) h(-1) lepirudin during preoperative course, 0.2 mg kg(-1) bolus just before CPB and 0.2 mg kg(-1) in the priming solution, complementary boluses of 5 and 10 mg during procedure (according to whole blood ecarin clotting time). Aprotinin was administered simultaneously according to Royston protocol. Anticoagulation was monitored with whole blood ecarin time performed in the operation room (patient's whole blood was diluted one half and one third with normal whole blood; in vitro calibration curve was constructed using normal whole blood spiked with lepirudin). CPB duration was 73 min. When measured, whole blood hirudin concentration was 3.8-5.8 microg ml(-1). Total lepirudin administration was 44 mg. No haemorrhagic or thrombotic events were observed during surgical procedure and postoperative course. Despite lepirudin administration is not yet clearly precise for CPB procedure, its use seems adapted and safe in subjects without renal insufficiency but requiring precise coordination for anaesthesiological, surgical and biological teams.

Objective: Our study was to assess the validity of SAPS II (New Simplified Acute Physiology Score) to predict the probability of in hospital mortality, in a cohort of patient admitted to a medical intensive care unit., Study Design: Prospective study., Patients and Methods: Out of 467 the 525 patients admitted were included. SAPS score and in hospital mortality prediction were calculated for each of them., Results: In this group, SAPS II offered a satisfactory discrimination power with an area under the curve of 0.843. However, calibration showed a lack of fit (chi 2 = 28.5, P < 0.001), with an overall under prediction of mortality (observed versus expected ratio of 1.12)., Conclusion: This SAPS II lower predicting accuracy in a specific population and for individual outcome prediction may reduce its interest in clinical decision-making.

Objective: To assess whether the pressure gauges at the downstream part of pressure regulators are accurate enough to ensure that pressure in O2 pipeline is always higher than in Air pipeline and that pressure in the latter is higher than pressure in N2O pipeline. A pressure difference of at least 0.4 bar between two medical gas supply systems is recommended to avoid the reflow of either N2O or Air into the O2 pipeline, through a faulty mixer or proportioning device., Study Design: Prospective technical comparative study., Material and Methods: Readings of 32 Bourdon gauges were compared with data obtained with a calibrated reference transducer. Two sets of measurements were performed at a one month interval., Results: Pressure differences between Bourdon gauges and reference transducer were 8% (0.28 bar) in average for a theoretical maximal error less than 2.5%. During the first set of measurements, Air pressure was higher than O2 pressure in one place and N2O pressure higher than Air pressure in another. After an increase in the O2 pipeline pressure and careful setting of pressure regulators, this problem was not observed at the second set of measurements., Discussion: Actual accuracy of Bourdon gauges was not convenient enough to ensure that O2 pressure was always above Air pressure. Regular controls of these pressure gauges are therefore essential. Replacement of the faulty Bourdon gauges by more accurate transducers should be considered. As an alternative, the increase in pressure difference between O2 and Air pipelines to at least 0.6 bar is recommended.