Translocation bactérienne : mythe ou réalité ?

Bacterial translocation is defined as the passage of viable enteric bacteria across the intestinal mucosal barrier to the mesenteric lymph nodes and distant organs. Three mechanisms have been suggested to explain the phenomenon: altered intestinal barrier function, bacterial overgrowth, and impaired host defense. In experimental approach, reduced blood flow in the gut, trauma, chronic inflammation or immunosuppression are conditions that enhance bacterial translocation. In humans, bacterial translocation from the intestinal lumen has been demonstrated and some related infections have been identified. However, no data have confirmed the ˈintestinal hypothesisˈ which implicates the bacterial translocation in the systemic inflammatory response syndrome or in the multivisceral organ failure syndrome. Some nutritional variations may experimentally modify the incidence of bacterial translocations and are therefore proposed to clinicians.     

Défaillance multiviscérale précoce associée à la pancréatite aiguë : stratégie thérapeutique chirurgicale ou conservatrice ?

The mortality of severe acute pancreatitis still ranges between 10% and 20%. Nowadays, infected pancreatic necrosis is the leading cause of death. Despite advances in intensive care therapy, however, early and worsening multi-system organ failure remains a source of substantial morbidity and still accounts for 20–50% of the deaths.News and hotspots.– The three interrelated pathophysiological mechanisms underlying glandular necrosis include the premature intra-acinar activation of pancreatic pro-enzymes, an early pancreatic microcirculatory impairment, and the excessive stimulation of immune effector cells. In recent years, the systemic inflammatory response syndrome and the relevant cascades of inflammatory mediators have been implicated as the key factor in the emergence of remote tissue damage. Early multi-system organ failure that supervenes in the first week is typically associated with a sterile necrotizing process. The correlation between pathomorphological and clinical severity and the similarity between their respective pathophysiological mechanisms are not straightforward, however. There are no pathophysiological, clinical or economical data to support the practice of debridement of sterile necrosis to prevent or to control early multi-system organ failure. This issue has never been addressed in a controlled study. Besides intensive care support, non-surgical therapeutic modalities including urgent endoscopic sphincterotomy for impacted stones, antibiotic prophylaxis for the prevention of pancreatic infection and early jejunal nutrition have been specifically developed hopefully to attenuate multiple organ failure, to obviate the need of surgical drainage and to improve survival. Fine needle aspiration of necrotic areas must be incorporated in any conservative therapeutic strategy in order not to jeopardize those with infected necrosis that remains an absolute indication for drainage.Perspectives.– There is ample experimental and pathophysiological evidence in favour of immunomodulatory therapy in severe acute pancreatitis. The administration of one or several antagonists of inflammatory mediators possibly combined with a protease inhibitor may at last provide the opportunity to interfere with the two major determinants of prognosis: the severity of multiple organ failure and the extent of necrotic areas that creates the culture medium for bacterial superinfection. These benefits remain to be substantiated in a controlled study, however.     

Réserve de précharge ventriculaire gauche dans le choc septique : mythe ou réalité ?

An accepted concept in septic shock is that preload adaptation by acute left ventricular dilatation, when occurring spontaneously or with the help of volume loading, allows the maintenance of an adequate cardiac output, leading to final recovery. From a physiological point of view, this concept appears debatable because a normal pericardium exerts a restraining action on a normal heart. Echocardiographic studies did not observe any left ventricular dilatation in patients with septic shock. Recent studies with transesophageal echocardiography have demonstrated that the quality of left ventricular systolic function was the major determinant of cardiac output after reversal of hypovolemia. In conclusion, echocardiographic studies were unable to confirm the reality of the concept of early preload adaptation by left ventricular dilatation in septic shock.     

Méningites à pneumocoque : actualités,perspectives

Streptococcus pneumoniae is the most frequent cause of severe meningitis in adults. Effective antibiotic treatment must be given early, before lumbar puncture, even if a CT scan is needed. In France, 40% of pneumococci have a decreased susceptibility to penicillin. As a consequence, the recommended probabilistic treatment is the association of a third-generation cephalosporin and vancomycin. Neurological complications are the consequence of cytotoxic and vasogenic cerebral edema. Until now corticosteroids have failed to improve the prognosis of patients with pneumococcal meningitis. Other treatments, such as anti-TNF antibodies or antioxidants, seem to be able to decrease the risk of cerebral damages in some experimental models.     

Thrombophlébites cérébrales : aspects cliniques,diagnostic et traitement

Cerebral venous thrombosis (CVT) may present with a wide spectrum of symptoms and signs, and a high index of suspicion is necessary to make an early diagnosis. CVT should be suspected when a patient develops any combination of symptoms or signs of raised intracranial pressure, focal neurological deficits, and seizures. Clinical features depend on the localization of CVT and, sometimes, CVT may present with unusual symptoms and signs. With the advent of sensitive and noninvasive neuroimaging techniques of CVT, early diagnosis of CVT is now possible. MRI has become the imaging modality of choice for the immediate evaluation of CVT; angiography is performed only when suspicion persists after MRI. Treatment should be devoted to the thrombotic process, the consequences of CVT and the underlying cause. A meta-analysis of both trials concerning anticoagulants shows that it is justified to anticoagulate all patients with definite CVT, even with hemorrhagic infarct, provided there are no contraindications. There is, at present, no proof that thrombolytics are more effective than heparin treatment. Thrombolytic treatment should be considered in the subgroup of patients who deteriorate despite adequate anticoagulation, with rapidly progressing thrombosis.     

Évaluation des propriétés hémostatiques et hypocholestérolémiantes des feuilles de <Emphasis Type="Italic">Spondias mombin L</Emphasis> (Anacardiaceae)

Postpartum hemorrhage remains health problem observed in maternity. In Sub-Saharan Africa, traditional phytotherapy propose plants reputed to manage postpartum bleeding. Spondias mombin is one of Togolese plant used by rural folk to stop hemorrhage at the time of complicated deliverances. The aim of this present work is to evaluate the effects this plant on some haemostatic parameters and on cholesterolemia in order to justify its traditional use to struggle post-partum hemorrhage. Tests are performed on Sprague-Dawley female rats and show an increase of hematocrit, of formed elements of blood and of hemoglobin level at rats fed with extract compared to their control. The extract exhibits an anti-fibrinolytic property. Cholesterolemia was decreased at immature rats which were fed with extract in relation to their respective control.     

Coagulation intravasculaire disséminée en réanimation : utilisation des inhibiteurs de la voie du facteur tissulaire

In most disseminated intravascular coagulation (DIC) syndromes, the culprit is an inappropriate exposition of tissue factor (TF) to the circulation. This contact results from major tissue lesions, abnormal TF expression by circulating cells (monocytes) in Gram⁺ or Gram^– sepsis, or TF expression by malignant cells. TF exposition to plasma leads to the activation of the coagulation cascade, and to a subsequent thrombin generation. Moreover, the binding of TF to its natural ligand, factor VII, leads to intracellular signalisation which induces the synthesis of proinflamatory cytokines, with subsequent leukocyte activation and majoration of the pathophysiological process. The TF pathway can be specifically inhibited by two means: 1. Infusion of recombinant TFPI, which is the natural inhibitor of the TF-factor VIIa complex, or 2. Infusion of an inactive recombinant substitute for FVIIa, FFR-VIIa. These two molecules are currently tested in humans, the first one in sepsis-related DIC, and the second one in acute respiratory distress syndrome, another condition associated with TF pathway activation.     

12<Superscript>e</Superscript> Symposium International D’Aromathérapie et des Plantes Meédicinales

Agenda

12^e Symposium International D’Aromathérapie et des Plantes Meédicinales 26–28 mars 2010 Palais des Congrès, Grasse     

Substituts à l'hémoglobine, érythropoïétine et fer : quel avenir en réanimation ?

To reduce the blood transfusion exposure in intensive care, three treatments are now on evaluating process: hemoglobin solution, perfluorocarbon emulsion, and recombinant erythropoietin. The half-life of fluorocarbon emulsions is too short to make these agents suitable in the treatment of hemorrhagic shock. Clinical trials have been conducted only in the peroperative period of well-known hemorrhagic surgery in association with acute normovolemic hemodilution. Modern hemoglobin solutions have a normal P50 and a plasma half-life long enough to be useful in intensive care medicine. Theirs main pharmacologic properties are: an increase in blood pressure due to the increase in vascular resistances, an increase in diffusion capacity of oxygen, a decrease in cardiac output, and lack of nephrotoxicity. Two studies have demonstrated a sparing effect on postoperative and posttrauma blood transfusion. However, one poor designed study has shown an increase in the mortality rate in polytraumatized patients treated with hemoglobin solutions. These negative results have induced a prematurely stop of all trials in the US and in Europe as well. In intensive care patient, physiologic erythropoiesis is impeded mainly because erythropoietin secretion is blunted in response to anemia. In this clinical setting, the effects of recombinant erythropoietin (rh EPO) have been tested. Four over five studies have demonstrated that rh EPO has induced an increase in reticulocyte count showing a stimulation of erythropoiesis. Two of these studies, coming from the same team, have showed a significant reduction of blood transfusion requirements in patients receiving rh EPO. Currently, based on the evidence available from the literature published at that time, hemoglobin solution and rh EPO as well cannot be now recommended to reduce the need to blood transfusions in anemic, critically ill patients.     

6<Superscript>e</Superscript> Symposium International d’Aromathérapie et Plantes Médicinales (1<Superscript>re</Superscript> partie)

Compte rendu

6^e Symposium International dAromathérapie et Plantes Médicinales (1^re partie)