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Background The aim of our study was to describe the anatomic relationships in internal jugular (IJV), subclavian (SCV), and femoral (FV) vein sites. Methods One hundred and forty-two children had a two-dimensional (2D) ultrasound (US) evaluation of IJV, SCV, and FV sites. They were enrolled according to their age: 0–1 month old ( n =9), 1 month old to 2 yr old ( n =61), 2–6 yr old ( n =22), 6–12 yr old ( n =32), and 12–18 yr old ( n =18). Results We found about 7.7% variation for the IJV. The most common anatomic variations were a lateral (nine children) or anterior (nine children) position of the IJV to the carotid artery. Regardless of the age category, about 9.8% of the anatomic variations were found for the FV. The most common anatomic variation in our study was that the FV ran anteromedially to the femoral artery (17 children). Anatomic variation of the SCV, regardless of age category, was about 7.4%. The most common anatomic variation was the SCV, which ran medially (10 children) to the subclavian artery. Conclusions The relevant percentages of anatomic variations obtained for all these areas support at least a systematic US screening before attempting to obtain central venous access, ideally using a US-guided technique.

Resume Objectifs Conception et evaluation d'un programme d'aide a la prescription en nutrition artificielle, NutriPDA ® , dedie a la reanimation et a la periode peri-operatoire, fonctionnant avec le systeme d'exploitation Palm OS. Type d'etude Etude prospective de type avant–apres. Methodes Soixante et un patients admis en reanimation apres chirurgie cardiovasculaire et thoracique ont ete etudies (âge superieur a 17 ans, duree de nutrition artificielle superieur a trois jours, duree de sejour superieur a huit jours). Les patients ont ete repartis historiquement en deux groupes (avant et apres utilisation de NutriPDA) : groupe A : 32 patients (quatre mois en 2005) ; groupe B : 29 patients (quatre mois en 2006). Resultats Il n'y avait pas de difference significative concernant les caracteristiques demographiques et les scores de gravite entre les deux groupes. Les apports caloriques etaient inferieurs a 80 % des depenses energetiques de base chez 21 % des patients du groupe A, contre seulement 1 % des patients du groupe B ( p p Conclusion L'aide a la prescription de la nutrition artificielle par le logiciel NutriPDA ® a permis d'ameliorer les apports nutritionnels au lit du malade.

Resume Objectifs. – Concevoir, realiser, valider et evaluer un site Internet pedagogique d'anesthesie–reanimation destine aux etudiants inscrits aux formations universitaires organisees par les professeurs des universites, praticiens hospitaliers du service. Type d'etude. – Analyse des besoins constituee de deux etapes : enquete aupres des etudiants inscrits (91 etudiants) et recherche sur Internet des sites pedagogiques en anesthesie–reanimation. Methodes. – Apres la definition de la cible, etudiants inscrits aux formations universitaires dont nous avons la charge, nous avons construit le referentiel. Nous avons elabore un referentiel d'enseignement fonde sur les donnees actualisees de la science, assorti d'une selection bibliographique, puis redige une liste d'objectifs operationnels specifiques. La construction du support, un site Internet, a fait l'objet d'une reflexion prealable prenant en compte le public concerne, les objectifs poursuivis et les conditions materielles disponibles. Ce site pedagogique en anesthesie–reanimation a ete concu pour etre utilise en complement des cours magistraux. Apres la validation interne et externe, nous avons soumis le site a une evaluation par les etudiants. Resultats. – Le site a obtenu un score total, apres analyse de toutes les reponses, de 76 sur 100, selon la grille d'analyse de sites Internet proposee par la regie regionale de la sante et des services sociaux de Montreal. Conclusion. – A partir de cette analyse, le site peut etre considere comme satisfaisant. Notre etude a demontre que les outils adaptes de multimedia peuvent ameliorer l'enseignement en anesthesie–reanimation.

Resume Objectif. – Faire une revue de l’etat actuel des connaissances sur la variabilite de la frequence cardiaque et de la pression arterielle. Sources des donnees. – Recherche des donnees dans la banque de donnees Medline® des articles de langue francaise ou anglaise. Les articles originaux et les observations cliniques ont ete retenus. Extraction des donnees. – Les articles ont ete analyses de facon a extraire toutes les informations disponibles sur la variabilite de la pression arterielle et de la frequence cardiaque (ou de l’intervalle RR), en mettant l’accent sur l’analyse spectrale. La non stationnarite est abordee, cas ou les analyses temps–frequence et temps–echelle sont d’un interet particulier. Synthese des donnees. – En raison de sa capacite a moduler rapidement les niveaux de pression et la frequence cardiaque, l’activite du systeme nerveux autonome peut etre evaluee par la mesure de la variabilite de la pression arterielle et de la frequence cardiaque. Le baroreflexe appartient au systeme nerveux autonome, et est l’un des principaux mecanismes de controle a court terme de la pression arterielle. En faisant varier la frequence cardiaque et les resistances systemiques, le baroreflexe tend a maintenir le niveau de la pression arterielle. La variabilite de la pression arterielle et de la frequence cardiaque a aide a la comprehension des mecanismes physiopathologiques de certaines affections. Un nombre croissant de travaux suggere que les composantes spectrales de ces signaux, notamment la balance sympathovagale, peuvent avoir une valeur pronostique. Les differents types d’analyse spectrale des signaux biologiques, en particulier la transformee de Fourier rapide, peuvent etre utilises d’une facon facilement lisible et interpretable, en particulier en clinique. L’analyse spectrale des signaux non stationnaires a conduit a developper des outils specifiques adaptes a ces signaux, parmi lesquels emergent les methodes temps–frequence et temps–echelle qui prennent explicitement en compte une possible evolution temporelle du contenu frequentiel d’un signal.

BACKGROUND Lateral wall pressure may cause tracheal injury by affecting tracheal capillary blood flow. Damage to the trachea is less severe when lateral wall pressure exerted by the endotracheal tube cuff does not exceed the mean capillary perfusion pressure of the mucosa. The purpose of this study was to determine the effects of hypothermic and normothermic cardiopulmonary bypass (CPB) on tracheal tube cuff pressure dynamics. METHODS Twenty-two patients were studied during normothermic CPB (pulmonary artery blood temperature in the CPB period between 36 and 35 degrees C), and 22 patients during hypothermic CPB (pulmonary artery temperature in the CPB period between 32 and 28 degrees C). A Mallinckrodt Medical Lo-Contour Murphy tracheal tube, with high-volume, low-pressure cuff was used without lubricant. Intracuff pressure (ITCP) was recorded at end-expiration before, during and after cardiopulmonary bypass. RESULTS ITCP measurements were different between groups during CPB at aortic cross-clamping (13.9 +/- 0.8 mmHg in the normothermic group versus 11.3 +/- 0.4 mmHg in the hypothermic group, P < 0.05), and respectively during CPB after aortic declamping (15.3 +/- 0.8 mmHg and 12.6 +/- 0.8 mmHg, P < 0.05) and after CPB at the end of surgery (16.8 +/- 0.7 mmHg and 18.6 +/- 0.3 mmHg, P < 0.05). CONCLUSION We conclude that the ITCP is higher in normothermic CPB than in hypothermic CPB; however, the clinical significance of this observation needs further investigation.

A 62-year-old patient was scheduled for coronary artery bypass surgery because of tritroncular coronary artery disease. The early postoperative period was uncomplicated until the 10th postoperative day when purulent fluid appeared from the sternal wound. Cultures of blood, wound and mediastinal tissues yielded Streptococcus pneumoniae with decreased susceptibility to penicillin G. Despite prompt surgical debridement and appropriate antibiotics, a septic shock with multiorgan failure occurred and the patient died on the 19th postoperative day. Although Streptococcus pneumoniae is uncommonly implicated in postoperative mediatinitis, it frequently leads to multiple organ failure and death.

Background: The low (LF) vs. high (HF) frequency energy ratio, computed from the spectral decomposition of heart beat intervals, has become a major tool in cardiac autonomic system control and sympatho-vagal balance studies. The (statistical) distributions of response variables designed from ratios of two quantities, such as the LF/HF ratio, are likely to non-normal, hence preventing e.g., from a relevant use of the t-test. Even using a non-parametric formulation, the solution may be not appropriate as the test statistics do not account for correlation and heteroskedasticity, such as those that can be observed when several measures are taken from the same patient. Objectives: The analyses for such type of data require the application of statistical models which do not assume a priori independence. In this spirit, the present contribution proposes the use of the Generalized Linear Mixed Models (GLMMs) framework to assess differences between groups of measures performed over classes of patients. Methods: Statistical linear mixed models allow the inclusion of at least one random effect, besides the error term, which induces correlation between observations from the same subject. Moreover, by using GLMM, practitioners could assume any probability distribution, within the exponential family, for the data, and naturally model heteroskedasticity. Here, the sympatho-vagal balance expressed as LF/HF ratio of patients suffering neurogenic erectile dysfunction under three different body positions was analyzed in a case-control protocol by means of a GLMM under gamma and Gaussian distributed responses assumptions. Results: The gamma GLMM model was compared with the normal linear mixed model (LMM) approach conducted using raw and log transformed data. Both raw GLMM gamma and log transformed LMM allow better inference for factor effects, including correlations between observations from the same patient under different body position compared to the raw LMM. The gamma GLMM provides a more natural distribution assumption of a response expressed as a ratio. Conclusions: A gamma distribution assumption intrinsically models quadratic relationships between the expected value and the variance of the data avoiding prior data transformation. SAS and R source code are available on request.

The aim of our study was to assess the effect of NutriPDA, a personal digital assistant (PDA)-based clinical decision-support system (CDSS) for the management of artificial nutrition. A CDSS was developed and implemented on a handheld computer for use in the ICU after cardiovascular and thoracic surgery.System impact was assessed in a prospective "before/after" cohort trial.After informed consent we studied 61 patients in the postcardiovascular and thoracic surgery ICU (age17 years, duration of artificial nutrition3 days, length of stay8 days). Patients were divided into two groups (before and after the use of NutriPDA: Group A: 32 patients (4-month period in 2005); group B: 29 patients (4-month period in 2006).There were no significant differences in anthropometric and clinical parameters between the 2 groups. Energetic intakes were80% of basal energetic expenditures in 21% and 1% of patients, respectively (P0.01). Caloric and nitrogen intakes were below international recommendation in Group A: 20+/-4 kcal/kg/d (mean+/-SD), 104+/-30 mg/kg/d, but not in Group B: 26+/-5 kcal/kg/d, 196+/-41 mg/kg/d (P0.01).NutriPDA was found to be able to optimize artificial nutrition by improving caloric intake in ICU. This new software has potential clinical applications.

Heart-rate variability (HRV) is an interesting tool for assessing cardiac autonomic system control, but nonstationarities raise problematic issues. The objective of this paper is to show that adapted signal processing tools may cope with nonstationary situations and improve the analysis of HRV.We propose to use the recent method of Empirical Mode Decomposition (EMD), so as to analyze the cardiac sympatho-vagal balance on automatically extracted modes. The method, which is fully data-adaptive, consists in an iterative decomposition based on the idea that any signal can be locally represented as an oscillation superimposed to a more regular trend. When a signal is composed of distinct nonstationary components, EMD therefore achieves a time-varying filtering which effectively separates them.The method has been applied to situations where postural changes occur, provoking instantaneous changes in heart rate as a result of autonomic modifications. In the considered application where the sympatho-vagal balance is quantified by comparing the low-frequency (LF) and high-frequency (HF) components of RR intervals, EMD automatically achieves a separation of these components upon which further processing can be carried. Visualizing the decomposition in the time-frequency plane, we can identify local events due to the postural changes, and we can assess a (time-varying) HF vs. LF discrimination without resorting to some fixed high-pass/low-pass filtering.Assessing cardiovascular autonomic control by resorting to LF/HF measurements may prove difficult in nonstationary situations where the use of a priori fixed filters can be questioned. Because it is both local and fully data-adaptive, EMD appears as an appealing and versatile pre-processing technique for overcoming some of the limitations that conventional spectral methods are faced with in nonstationary situations.

To review current data on the heart rate and blood pressure variability.Search through Medline databases of articles in french or english.Original articles and case reports were selected according to their quality and main advances. The articles were analysed in order to obtain current data about the methods of study and clinical application of blood pressure and heart rate variability.Various regulatory systems in the cardiovascular system play crucial roles in controlling and assuring adequate perfusion of the peripheral tissues. Among them the baroreceptor reflex is the most important regulatory mechanism in the short-term control of the heart rate and blood pressure, and operates through the autonomic nervous system. The gain of the cardiac baroreflex further referred to, as baroreflex sensitivity is an interesting way to study this system. Unfortunately, with our current knowledge, it is not possible to predict the instantaneous output of the baroreceptor in response to instantaneous changes in input within a frequency range of physiological importance. The fast Fourier transform can describe variables as the sum of elementary oscillatory components and it has been established as practical clinical methods for detecting abnormalities in cardiovascular control. A time-frequency distribution provides an indication of how the spectral energy distribution varies with time and it is an interesting tool in non-stationary data. One of the major motivations behind spectral analysis is the hope that the combination of time-domain and frequency-domain analyses will provide dynamical informations about the relation between blood pressure and heart rate.

A 62-year-old patient was scheduled for coronary artery bypass surgery because of tritroncular coronary artery disease. The early postoperative period was uncomplicated until the 10th postoperative day when purulent fluid appeared from the sternal wound. Cultures of blood, wound and mediastinal tissues yielded Streptococcus pneumoniae with decreased susceptibility to penicillin G. Despite prompt surgical debridement and appropriate antibiotics, a septic shock with multiorgan failure occurred and the patient died on the 19th postoperative day. Although Streptococcus pneumoniae is uncommonly implicated in postoperative mediatinitis, it frequently leads to multiple organ failure and death.

Introduction Pendant une intervention chirurgicale, les anesthesistes doivent souvent faire face a des evenements hemorragiques avec des variations rapides de la concentration d’hemoglobine. Une methode de mesure continue et non invasive de l’hemoglobine par spectrophotometrie, la Pulse CO-oxymetrie (SpHb), est disponible [1] . Nous avons compare la concordance et la tendance des mesures de l’hemoglobine par la SpHb et par un analyseur de gaz sanguins (AGS) avec une mesure de reference par l’analyseur d’hematologie (HbXE). Materiel et methodes Apres approbation par le comite d’ethique local, et recueil du consentement eclaire, les patients adultes beneficiant d’une chirurgie potentiellement hemorragique, ont ete inscrits. Tous les patients ont ete suivis avec le Radical-7® Pulse CO - oxymetres (Revision K, Masimo SET 7.8.0.1, R7.7.4.8 Portable, D-Gare (DC) R5.1.4.0 Masimo Corp, Irvine, CA). Des echantillons de sang arteriel ont ete preleves 15 minutes apres l’incision, a la suite de chaque evenement hemorragique (perte d’au moins 400 mL de sang en 40 minutes), et la fin de la chirurgie. Ils ont etes analyses avec un analyseur d’hematologie (XE-2100®, Sysmex Corporation, Kobe Japon) comme methode de reference et un analyseur de gaz sanguins (COBAS-B221®, Roche Diagnostics, Indianapolis, Etats-Unis). De meme, les lectures SpHb au moment des prelevements arteriels ont ete notees. Le biais, la precision et les limites de concordances de l’hemoglobine mesuree par la SpHb et par l’AGS par rapport a l’HbXE ont ete calcules. Le pourcentage de valeurs aberrantes (difference ≥ 1 g.dL-1) a ete calcule. L’analyse du test de Wilcoxon a ete effectuee pour determiner les differences significatives entre les methodes. Afin d’evaluer la precision de la tendance, (changements entre les mesures des echantillons analyses avec l’HbXE comparees a ceux avec laSpHb et avec l’AGS), la sensibilite de chaque methode a detecter l’evolution de la tendance a ete calculee. Resultats Cent dix-huit echantillons de sang (59 pour HbXE et 59 pour l’AGS) ont ete preleves et les 59 valeurs SpHb simultanees ont ete recueillies a partir de 29 patients. Les mesures de l’hemoglobine avec l’HbXE ont varie de 6,9 a 13,4 g/dL. L’analyse de la performance des 2 methodes est indiquee sur la figure ci-dessous. Il n’y a pas de difference statistique entre la SpHb et l’AGS (p = 0,08) concernant la precision et sa tendance (p = 0,6) ( Fig. 1 ). Discussion Notre etude montre pour la SpHb un biais plus petit mais un plus grand intervalle de confiance par rapport a l’AGS en comparaison avec l’HbXE. Les mesures avec la SpHb ont moins de valeurs aberrantes qu’avec l’AGS. Par contre, ces deux methodes ont la meme sensibilite a detecter l’evolution de la tendance entre les echantillons telle que celle determinee par l’HbXE. D’autres etudes avec un plus grand nombre de patients seront necessaires pour confirmer ces resultats.

Lateral wall pressure may cause tracheal injury by affecting tracheal capillary blood flow. Damage to the trachea is less severe when lateral wall pressure exerted by the endotracheal tube cuff does not exceed the mean capillary perfusion pressure of the mucosa. The purpose of this study was to determine the effects of hypothermic and normothermic cardiopulmonary bypass (CPB) on tracheal tube cuff pressure dynamics.Twenty-two patients were studied during normothermic CPB (pulmonary artery blood temperature in the CPB period between 36 and 35 degrees C), and 22 patients during hypothermic CPB (pulmonary artery temperature in the CPB period between 32 and 28 degrees C). A Mallinckrodt Medical Lo-Contour Murphy tracheal tube, with high-volume, low-pressure cuff was used without lubricant. Intracuff pressure (ITCP) was recorded at end-expiration before, during and after cardiopulmonary bypass.ITCP measurements were different between groups during CPB at aortic cross-clamping (13.9 +/- 0.8 mmHg in the normothermic group versus 11.3 +/- 0.4 mmHg in the hypothermic group, P0.05), and respectively during CPB after aortic declamping (15.3 +/- 0.8 mmHg and 12.6 +/- 0.8 mmHg, P0.05) and after CPB at the end of surgery (16.8 +/- 0.7 mmHg and 18.6 +/- 0.3 mmHg, P0.05).We conclude that the ITCP is higher in normothermic CPB than in hypothermic CPB; however, the clinical significance of this observation needs further investigation.

The arm is particularly vulnerable to neurological injury, due to the intimate anatomical relationship between the brachial plexus and the traction zones. Severe injuries of the brachial plexus can be caused by compression, traction or laceration. Fortunately, many deficits are superficial and permanent neurovascular deficits are rare. Nevertheless, it is important to identify the probable cause of the injury since the prognosis for recovery directly depends on the underlying nature of the neurological deficit. Two anaesthetised children who suffered brachial plexus injury during cardiac catheterisation are reported. The first, with Ebstein's anomaly and significant pulmonary valve stenosis, presented, after the procedure, with a right arm motor deficit with proximal predominance. The second patient, with tetralogy of Fallot and pulmonary atresia, presented difficulty in left arm abduction and external rotation on awakening. The risk factors for brachial plexus lesions during anaesthesia are discussed. These include improper positioning, anaesthetic agents, extreme variations of body mass index and anatomical anomalies. Prevention, evolution and treatment of the brachial plexus injury are also considered. With proper care by the cardio-radiologist and anaesthesiologist the frequency of this injury can be reduced.