Facteurs de variation du poids vif et de l’état corporel du zébu Arabe en zone soudanienne du Tchad

L’objectif de cette étude a été de déterminer les effets saisonniers sur l’évolution du poids et de la note d’état corporel (NEC) des zébus arabes du Tchad. Durant les cinq saisons liées au calendrier fourrager, des mensurations et des notations d’état corporel ont été effectuées sur des bovins mâles et femelles. Les mesures barymétriques ont concerné le périmètre thoracique. La NEC a été déterminée par palpation de la région lombaire de l’animal. L’alternance saisonnière a provoqué de grandes variations de poids et de l’état corporel des animaux qui ont été notées selon le sexe et l’âge. La variabilité des performances pondérales (2,2 ± 16 kg à 64 ±24 kg) et d’état corporel des animaux, obtenue à partir des facteurs individuels (sexe ou âge) et saisonniers (disponibilité fourragère), a montré que ce sont les animaux d’âge supérieur à 6 ans qui ont perdu plus de poids en saison sèche. Les femelles de 3-6 ans (64 ± 44,8 kg) et les mâles de 2-3 ans (54 ± 43 kg) ont montré les fluctuations pondérales les plus significatives en saison des pluies. Afin de minimiser les risques et maximiser la production en élevage extensif, des améliorations dans la conduite des animaux ont été proposées.Mots clés : Variations fourragères - Poids - Etat corporel - Zébu arabe - Tcha

Early fluid resuscitation with hyperoncotic hydroxyethyl starch 200/0.5 (10%) in severe burn injury

INTRODUCTION: Despite large experience in the management of severe burn injury, there are still controversies regarding the best type of fluid resuscitation, especially during the first 24 hours after the trauma. Therefore, our study addressed the question whether hyperoncotic hydroxyethyl starch (HES) 200/0.5 (10%) administered in combination with crystalloids within the first 24 hours after injury is as effective as 'crystalloids only' in severe burn injury patients. METHODS: 30 consecutive patients were enrolled to this prospective interventional open label study and assigned either to a traditional 'crystalloids only' or to a 'HES 200/0.5 (10%)' volume resuscitation protocol. Total amount of fluid administration, complications such as pulmonary failure, abdominal compartment syndrome, sepsis, renal failure and overall mortality were assessed. Cox proportional hazard regression analysis was performed for binary outcomes and adjustment for potential confounders was done in the multivariate regression models. For continuous outcome parameters multiple linear regression analysis was used. RESULTS: Group differences between patients receiving crystalloids only or HES 200/0.5 (10%) were not statistically significant. However, a large effect towards increased overall mortality (adjusted hazard ratio 7.12; P = 0.16) in the HES 200/0.5 (10%) group as compared to the crystalloids only group (43.8% versus 14.3%) was present. Similarly, the incidence of renal failure was 25.0% in the HES 200/0.5 (10%) group versus 7.1% in the crystalloid only group (adjusted hazard ratio 6.16; P = 0.42). CONCLUSIONS: This small study indicates that the application of hyperoncotic HES 200/0.5 (10%) within the first 24 hours after severe burn injury may be associated with fatal outcome and should therefore be used with caution

Characterization of in-situ Doped Polycrystalline Silicon Using Schottky Diodes and Admittance Spectroscopy

In this work, Schottky Au-Polycrystalline silicon diodes are successfully realised. The barrier height is around ФB = 0.74 eV as determined from Capacitance – Bias (C-V) characteristics. The depth profile of the apparent doping is deduced from these measurements. Its behaviour leads to the experimental profile. Moreover, the diode admittance measurements versus the frequency and the temperature at different biases show the possibility to use this device to characterise the electrical quality of the polycrystalline silicon

Model of end stage liver disease (MELD) score greater than 23 predicts length of stay in the ICU but not mortality in liver transplant recipients

INTRODUCTION: The impact of model of end stage liver disease (MELD) score on postoperative morbidity and mortality is still elusive, especially for high MELD. There are reports of poorer patient outcome in transplant candidates with high MELD score, others though report no influence of MELD score on outcome and survival. METHODS: We retrospectively analyzed data of 144 consecutive liver transplant recipients over a 72-month period in our transplant unit, from January 2003 until December 2008 and performed uni- and multivariate analysis for morbidity and mortality, in particular to define the influence of MELD to these parameters. RESULTS: This study identified MELD score greater than 23 as an independent risk factor of morbidity represented by intensive care unit (ICU) stay longer than 10 days (odds ratio 7.0) but in contrast had no negative impact on mortality. Furthermore, we identified transfusion of more than 7 units of red blood cells as independent risk factor for mortality (hazard ratio 7.6) and for prolonged ICU stay (odds ratio [OR] 7.8) together with transfusion of more than 10 units of fresh frozen plasma (OR 11.6). Postoperative renal failure is a strong predictor of morbidity (OR 7.9) and postoperative renal replacement therapy was highly associated with increased mortality (hazard ratio 6.8), as was hepato renal syndrome prior to transplantation (hazard ratio 13.2). CONCLUSIONS: This study identified MELD score greater than 23 as an independent risk factor of morbidity represented by ICU stay longer than 10 days but in contrast had no negative impact on mortality. This finding supports the transplantation of patients with high MELD score but only with knowledge of increased morbidity

Pretransplant dyslipidaemia influences primary graft dysfunction after lung transplantation

OBJECTIVES: Primary graft dysfunction (PGD) is a major cause of mortality within the first year following lung transplantation. Pulmonary hypertension, elevated body mass index (BMI), prolonged ischaemic time of the graft, intraoperative blood transfusions >1000 ml and the use of cardiopulmonary bypass or extracorporeal membrane oxygenation increase the risk for PGD. We aimed to evaluate whether dyslipidaemia is an additional risk factor for the development of PGD. METHODS: We retrospectively analysed demographic and clinical data of 264 patients who received their first bilateral lung transplantation between March 2000 and October 2013 at our institution. The endpoint was PGD grade 3 at any time, defined according to the International Society for Heart and Lung Transplantation (ISHLT) criteria. Fasting lipid profiles at listing time or just before transplantation (baseline) were documented and dyslipidaemia was defined as any of the parameters being out of range. Comparisons of continuous variables between patients with PGD grade 3 and patients without were performed with the Mann-Whitney U-test, whereas proportions were compared with the χ(2) test. Continuous variables were presented as arithmetic means with standard deviation for ease of comparison, but levels of statistical significance were computed using the appropriate non-parametric statistical test. To identify PGD risk factors, a forward stepwise logistic regression model was used. RESULTS: PGD occurred in 63 recipients (24%). Pretransplant dyslipidaemia was documented in 153 recipients (58%) and was significantly more prevalent among recipients developing PGD (45 vs 108, P < 0.013). Despite various underlying pulmonary pathologies, higher triglyceride (TG) levels (1.41 ± 0.78 vs 1.16 ± 0.78, P < 0.012), lower high-density lipoprotein-cholesterol (HDL-C) concentrations (1.24 ± 0.55 vs 1.57 ± 0.71, P < 0.0005) and higher cholesterol/HDL-C values (3.80 ± 2.02 vs 3.00 ± 0.92, P < 0.0005) were associated with a lower incidence of PGD. Patients with PGD had significantly longer ischaemic time (350 ± 89 vs 322 ± 91, P = 0.017) and higher BMI (23 ± 5 vs 21 ± 4.4, P < 0.007). CONCLUSION: Dyslipidaemia seems to be an independent risk factor for PGD after lung transplantation: low circulating levels of HDL-C and hypertriglyceridaemia increase the incidence of PGD. Even if HDL-C levels are difficult to alter today, triglyceride and cholesterol levels can be addressed therapeutically and may have a positive influence on the development of PGD

Two different hematocrit detection methods: Different methods, different results?

BACKGROUND: Less is known about the influence of hematocrit detection methodology on transfusion triggers. Therefore, the aim of the present study was to compare two different hematocrit-assessing methods. In a total of 50 critically ill patients hematocrit was analyzed using (1) blood gas analyzer (ABLflex 800) and (2) the central laboratory method (ADVIA(R) 2120) and compared. FINDINGS: Bland-Altman analysis for repeated measurements showed a good correlation with a bias of +1.39% and 2 SD of +/- 3.12%. The 24%-hematocrit-group showed a correlation of r2 = 0.87. With a kappa of 0.56, 22.7% of the cases would have been transfused differently. In the-28%-hematocrit group with a similar correlation (r2 = 0.8) and a kappa of 0.58, 21% of the cases would have been transfused differently. CONCLUSIONS: Despite a good agreement between the two methods used to determine hematocrit in clinical routine, the calculated difference of 1.4% might substantially influence transfusion triggers depending on the employed method

Thromboelastography to Monitor Clotting/Bleeding Complications in Patients Treated with the Molecular Adsorbent Recirculating System

Background. The Molecular Adsorbent Recirculating System (MARS) has been shown to clear albumin-bound toxins from patients with liver failure but might cause bleeding complications potentially obscuring survival benefits. We hypothesized that monitoring clotting parameters and bed-side thromboelastography allows to reduce bleeding complications. Methods. Retrospective analysis of 25 MARS sessions during which clotting parameters were monitored by a standardized protocol. Results. During MARS therapy median INR increased significantly from 1.7 to 1.9 platelet count and fibrinogen content decreased significantly from 57 fL−1 to 42 fL−1 and 2.1 g/L to 1.5 g/L. Nine relevant complications occurred: the MARS system clotted 6 times 3 times we observed hemorrhages. Absent thrombocytopenia and elevated plasma fibrinogen predicted clotting of the MARS system (ROC 0.94 and 0.82). Fibrinolysis, detected by thromboelastography, uniquely predicted bleeding events. Conclusion. Bed-side thromboelastography and close monitoring of coagulation parameters can predict and, therefore, help prevent bleeding complications during MARS therapy

Noninvasive cardiac output and blood pressure monitoring cannot replace an invasive monitoring system in critically ill patients

Background: Monitoring of cardiac output and blood pressure are standard procedures in critical care medicine. Traditionally, invasive techniques like pulmonary artery catheter (PAC) and arterial catheters are widely used. Invasiveness bears many risks of deleterious complications. Therefore, a noninvasive reliable cardiac output (CO) and blood pressure monitoring system could improve the safety of cardiac monitoring. The aim of the present study was to compare a noninvasive versus a standard invasive cardiovascular monitoring system. Methods: Nexfin HD is a continuous noninvasive blood pressure and cardiac output monitor system and is based on the development of the pulsatile unloading of the finger arterial walls using an inflatable finger cuff. During continuous BP measurement CO is calculated. We included 10 patients with standard invasive cardiac monitoring system (pulmonary artery catheter and arterial catheter) comparing invasively obtained data to the data collected noninvasively using the Nexfin HD. Results: Correlation between mean arterial pressure measured with the standard arterial monitoring system and the Nexfin HD was r2 = 0.67 with a bias of -2 mmHg and two standard deviations of ± 16 mmHg. Correlation between CO derived from PAC and the Nexfin HD was r2 = 0.83 with a bias of 0.23 l/min and two standard deviations of ± 2.1 l/min; the percentage error was 29%. Conclusion: Although the noninvasive CO measurement appears promising, the noninvasive blood pressure assessment is clearly less reliable than the invasively measured blood pressure. Therefore, according to the present data application of the Nexfin HD monitoring system in the ICU cannot be recommended generally. Whether such a tool might be reliable in certain critically ill patients remains to be determined

Constitutive Overexpression of Muscarinic Receptors Leads to Vagal Hyperreactivity

BACKGROUND: Alterations in muscarinic receptor expression and acetylcholinesterase (AchE) activity have been observed in tissues from Sudden Infant Death Syndrome (SIDS). Vagal overactivity has been proposed as a possible cause of SIDS as well as of vasovagal syncopes. The aim of the present study was to seek whether muscarinic receptor overexpression may be the underlying mechanism of vagal hyperreactivity. Rabbits with marked vagal pauses following injection of phenylephrine were selected and crossed to obtain a vagal hyperreactive strain. The density of cardiac muscarinic receptors and acetylcholinesterase (AchE) gene expression were assessed. Blood markers of the observed cardiac abnormalities were also sought. METHODOLOGY/PRINCIPAL FINDINGS: Cardiac muscarinic M(2) and M(3) receptors were overexpressed in hyperreactive rabbits compared to control animals (2.3-fold and 2.5-fold, respectively) and the severity of the phenylephrine-induced bradycardia was correlated with their densities. A similar overexpression of M(2) receptors was observed in peripheral mononuclear white blood cells, suggesting that cardiac M(2) receptor expression can be inferred with high confidence from measurements in blood cells. Sequencing of the coding fragment of the M(2) receptor gene revealed a single nucleotide mutation in 83% of hyperreactive animals, possibly contributing for the transcript overexpression. Significant increases in AchE expression and activity were also assessed (AchE mRNA amplification ratio of 3.6 versus normal rabbits). This phenomenon might represent a compensatory consequence of muscarinic receptors overexpression. Alterations in M(2) receptor and AchE expression occurred between the 5th and the 7th week of age, a critical period also characterized by a higher mortality rate of hyperreactive rabbits (52% in H rabbits versus 13% in normal rabbits) and preceeded the appearance of functional disorders. CONCLUSIONS/SIGNIFICANCE: The results suggest that cardiac muscarinic receptor overexpression plays a critical role in the development of vagal hyperreactivity, whereas AchE hyperactivity appears as a compensatory consequence of it. Since similar vagal disorders were observed recently by us in SIDS, muscarinic receptor overexpression could become a marker of risk of vasovagal syncopes and SIDS

Effects of Anesthetic Agents on Brain Blood Oxygenation Level Revealed with Ultra-High Field MRI

During general anesthesia it is crucial to control systemic hemodynamics and oxygenation levels. However, anesthetic agents can affect cerebral hemodynamics and metabolism in a drug-dependent manner, while systemic hemodynamics is stable. Brain-wide monitoring of this effect remains highly challenging. Because T2*-weighted imaging at ultra-high magnetic field strengths benefits from a dramatic increase in contrast to noise ratio, we hypothesized that it could monitor anesthesia effects on brain blood oxygenation. We scanned rat brains at 7T and 17.2T under general anesthesia using different anesthetics (isoflurane, ketamine-xylazine, medetomidine). We showed that the brain/vessels contrast in T2*-weighted images at 17.2T varied directly according to the applied pharmacological anesthetic agent, a phenomenon that was visible, but to a much smaller extent at 7T. This variation is in agreement with the mechanism of action of these agents. These data demonstrate that preclinical ultra-high field MRI can monitor the effects of a given drug on brain blood oxygenation level in the absence of systemic blood oxygenation changes and of any neural stimulation