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Resume Objectifs : Preciser les habitudes en matiere de prescription de bilan de coagulation preoperatoire et evaluer l’impact sur les habitudes de prescription de la prise de connaissance des resultats de la premiere partie de l’enquete et d’une information medicale repetee. Type d’etude : Etude epidemiologique descriptive et comparative. Patients et methodes : L’etude a ete menee en deux temps sur deux journees au cours de deux annees consecutives (1998 et 1999). Elle concernait 22 cliniques privees de la region Nord-Pas-de-Calais. Un questionnaire facile et bref etait a completer par les anesthesistes des cliniques participantes pour chacun des patients admis au bloc operatoire. Celui-ci s’interessait notamment a la presence ou non d’un bilan d’hemostase, a son prescripteur eventuel et aux examens biologiques demandes. Les resultats de la premiere partie de l’enquete (1998) ont ete presentes a plusieurs reprises aux anesthesistes concernes. Ils ont ete discutes et confrontes aux recommandations d’experts avant que la meme enquete ne soit repetee en 1999. Resultats : En 1998, un bilan a ete prescrit pour 81 % des patients ( n = 662) et plus d’une fois sur deux a l’initiative d’un anesthesiste. Dans moins de 5 % des cas il existait une ou plusieurs anomalies dont la moitie etaient previsibles au vu des antecedents des patients. Un seul des patients enrole dans l’enquete a presente un probleme hemorragique alors qu’il avait un bilan de coagulation normal. Un an apres, la prescription d’un bilan de coagulation preoperatoire concernait 75 % des patients ( n = 400), ce qui represente une diminution faible mais significative du nombre de prescriptions par rapport a 1998 ( p Conclusions: Dans cette etude, l’information medicale repetee des praticiens entre les deux temps de l’enquete n’a pas permis de diminuer de facon importante le nombre de prescriptions de bilan de coagulation preoperatoire. Ces resultats plaident en faveur d’une approche differente de l’expose des connaissances scientifiques pour esperer modifier les comportements.

Certain remnants of a quantum spacetime foam can be modeled by a distribution of defects embedded in a flat classical spacetime. The presence of such spacetime defects affects the propagation of elementary particles. In this article, we show explicitly that both topology and differential structure of the defects are important for the particle motion. Specifically, we consider three types of spacetime defects which are described by the same topological manifold $\mathbb{R}\times\big(\mathbb{R}P^3-\{\text{point}\}\big)$ but which are not diffeomorphic to each other. We investigate the propagation of a massless scalar field over the three different manifolds and find different solutions of the \mbox{Klein--Gordon} equation., Comment: 24 pages; v5: published version

A model in which pointlike defects are randomly embedded in Minkowski spacetime is considered. The distribution of spacetime defects is constructed to be Lorentz-invariant. It does not introduce a preferred reference frame, because it is based on a sprinkling process. A field-theoretic action for the photon and a fermion is set up, in which the photon is assumed not to couple to the defects directly, but via a scalar field. We are interested in signs for Lorentz violation caused by the spacetime defects, which are expected to reveal themselves in the photon sector. A modification of the photon dispersion relation may result as a quantum effect and we compute it at leading order perturbation theory. The outcome of the calculation is that the photon dispersion law remains conventional, if the defect distribution is dense, homogeneous, and isotropic. This result sheds some new light on Lorentz violation in the framework of a small-scale structure of spacetime. It shows that Lorentz invariance can be preserved even in the presence of a spacetime structure that is supposed to emerge at the Planck scale. This conclusion has already been drawn on general grounds in other publications, where the current paper delivers a demonstration by a direct computation in a simple model., 40 pages, 9 figures

Resume Une etude a ete effectuee chez 42 enfants pesant moins de 10 kg et beneficiant d'une intervention de plus d'une heure, randomisee en deux groupes : 21 ont ete operes avec un rechauffeur de perfusion Hotline™ et 21 sans rechauffeur. Tous avaient un matelas chauffant et un rechauffeur de gaz frais. Entre le debut et la fin de l'intervention, la baisse de temperature etait significativement plus importante chez ceux operes sans rechauffeur (1,1 ± 1,4 °C vs 0,1 ± 0,3 °C). La parfaite stabilite des temperatures des enfants du groupe avec Hotline™ demontre l'efficacite de cet appareil pour les faibles debits de perfusion qu'exige la chirurgie du nouveau-ne et du nourrisson.

This study aimed at: i) stating what the routines are regarding ordering of preoperative coagulation test; ii) evaluating the impact on the use of pre-operative orders from the data obtained during the first and the second parts of the study.Descriptive and comparative epidemiologic study.This study was performed twice, and lasted for one day each during two consecutive years (1998 and 1999). It concerned 22 private clinics in the French region 'Nord-Pas-de-Calais'. The anaesthesiologists who took part in the project had to fill out an easy and brief questionnaire concerning each patient who had been admitted to the operating area. It dealt mainly with the presence or the absence, of a preoperative laboratory screening, and with who ordered the test and which tests. The results of the first part of the study (1998) have been evaluated several times with the involved anaesthesiologists. Before repeating the study in 1999, the results were first discussed and compared to the recommendations of the experts.In 1998, preoperative coagulation tests were ordered for 81% of the patients (n = 662), which in more than half the cases were ordered by an anaesthesiologists. In less than 5% of the cases, one or more abnormalities were detected out of which half were predictable because of the patients previous medical history. Only one of the patients in the study suffered from an haemorrhagical problem although he had a normal coagulation screening. A year after, the ordering of a preoperative coagulation check included 75% of the patients (n = 400), which represents a small but nonetheless significant decrease of the number of orders compared to 1998 (p0.05). The proportion of preoperative laboratory screening prescribed by an anaesthesiologist remained the same. There were one or more abnormalities in 1% of the screening tests that were obtained. A patient had a haemorrhagical problem while she had a normal coagulation screening.In this study, repeated feed-back to the writers of the preoperative orders in the time interval between the two parts of the study did not induce a noticeable decrease in the number of preoperative coagulation tests ordered. The results show the necessity of a different approach to present scientific knowledge in order to modify medical behaviour.

The size 1 laryngeal mask (LMA1) was studied prospectively in a series of 37 infants (weight less than 6.5 kg) undergoing 42 routine surgical procedures. LMA1 insertion was successful at first attempt in 80.9% of all cases and a good airway control was obtained in 93%. The most frequent cause of insertion failure was an insufficient depth of anaesthesia. Only one incident occurred peroperatively. The recovery incidents rate, higher than in other studies, was mainly due to the laryngeal hyperreactivity of infants. LMA1 provides high safety for infant anaesthesia woith food working conditions for bot anaesthetist and surgeon. However, an accurate determination of the anaesthesia level and a close monitoring of recovery are strongly recommended.

A series of 251 anaesthesias with a laryngeal mask (LM) in a paediatric surgery unit is studied retrospectively. After some short training, using LM is most often easy and allows a good airway control without any frequent or severe complications. Therefore this technique should quickly supplant the facial mask and many endotracheal intubations.

This randomized study assessed the efficacy of the Hotline fluid warner in 42 children under 10 kg, undergoing surgery of more than 1 h of duration. In all a heating mattress and a heating humidifier were also used. The decrease in core temperature was more important in children without warner (1.1 +/- 1.4 degrees C vs 0.1 +/- 0.3 degrees C in those with a warner). Efficiency of this device is demonstrated even at the low perfusion flows requested for surgery in newborns and infants.