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Filter by:Out-of-hospital cardiac arrest (OHCA) is one of the leading cause of death in the world. In Slovenia approximately 25% of resuscitated patients survives to discharge from hospitals, usually with poorer functional status. One of key pathophysiological process responsible for poorer functional status is global hypoxic-ischemic injury, which is two-stage. Primary stage occurs immediately after cardiac arrest due to cessation of blood flow. With return of spontaneous circulation a secondary injury occurs, of which the leading process is an imbalance between oxygen delivery and consumption. Reperfusion exposes ischemic tissue to oxygen, resulting in the formation of large amounts of highly reactive oxygen species (ROS) within minutes. ROS lead to oxidative stress, which causes extensive damage to cell structures and leads to cell death. Consequently, necrosis and apoptosis are responsible for organ dysfunction and functional outcome of these patients. Such injury of neural tissue causes brain damage, which is ultimately responsible for poor neurological and thus functional outcome of OHCA survivors. The extent of brain damage can be determined in several ways: clinically by assessing quantitative and qualitative consciousness and the presence of involuntary movements in an unconscious patient, by assessing activity on electroencephalographic record, by imaging of the brain with computed tomography and magnetic resonance imaging, as well as by assessing levels of biological markers of brain injury. Of the latter, the S-100b protein and neuron-specific enolase have been shown to be suitable for such assessment. Oxidative stress is counteracted by the body with endogenous antioxidants that balance excess free radicals and stabilize cellular function. Vitamin C (ascorbic acid) is the body's main antioxidant and is primarily consumed during oxidative stress. Large amounts of ROS rapidly depletes the body's vitamin C stores. Humans cannot synthesise vitamin C and enteral uptake of vitamin C is limited by transporter saturation. On the other hand, parenteral (venous) dosing of vitamin C can achieve concentrations of vitamin C above physiological and thus produce a stronger antioxidant effect. The beneficial effect of parenteral dosing of vitamin C has been establish in several preclinical and clinical studies in patients with ischemic stroke and cardiac arrest. The investigators hypothesize that there is a similarly beneficial effect of vitamin C in survivors of OHCA.
The French intensive care societies (SRLF and SFAR), in agreement with the European and American societies for enteral and parenteral nutrition, recommend to quickly administer an artificial nutrition to patients admitted to ICU and for which it is expected that they will not be able to eat normally in the three days of admission. Enteral nutrition should be used in priority if the gut is functioning. However, intolerance to enteral nutrition, such as vomiting, regurgitation, increased residual gastric volume, or diarrhea, occurs in 40% of patients hospitalized in ICU receiving enteral nutrition. Intolerance to enteral nutrition leads to the risk of not receiving enough nutrition. Feeding intolerance also exposes to the risk of acute mesenteric ischemia, especially in the most severe patients under catecholamine for shock. Currently, it is not possible to predict intolerance to enteral nutrition in ICU patients. Thus, the diagnosis of intolerance is made a posteriori while enteral nutrition is in progress. Citrullinemia (normal concentration of 20 to 60 μmol / L), could be a good biomarker of the function of enterocytes involved in the absorption of food. The aim of this study is to evaluate the interest of citrullinemia to predict tolerance to enteral nutrition in ICU patients.
Sepsis is an acute pathology defined as an inappropriate response of the host to infection, resulting in the onset of organ failure (Quick SOFA ≥2, or SOFA ≥2). Septic shock is a sepsis associated with an elevation of lactate ≥ 2 mmol / l and an arterial hypotension requiring vasoactive drugs. Several studies highlighted that sepsis is associated with a plasma L-arginine deficiency. This deficiency induces a lower availability of L-arginine for multiple metabolic pathways including those involved in the synthesis of nitric oxide (NO) in the vascular endothelium via NO synthase. NO is the main endogenous vasodilator mediator, a lower synthesis induces a vascular and endothelial dysfunction that can promote the occurrence of an organic dysfunction during sepsis. Decrease in available NO was confirmed in patients with sepsis and appears correlated with severity. L-arginine deficiency can have multiple origins: - L-arginine deficiency resulting from a decrease in endogenous production from citrulline synthesized by the enterocytes. Such enterocyte dysfunction has been confirmed in patients with sepsis and is characterized biologically by elevated plasma levels of I-FABP (intestinal fatty acid binding protein - enterocyte-specific protein, cytolysis marker) and lower than that of citrulline (hypocitrullinemia, marker of lower activity). - L-arginine deficiency may also result from a catabolism increase via arginase activity increased. This ubiquitous enzyme, having 2 isoforms (Arg1 and Arg2), allows the synthesis of urea and ornithine from L-arginine. An increase in arginase activity would decrease the available reserves of L-arginine for NO synthesis. The objectives of this work is to evaluate, in patients with severe sepsis or septic shock, the prognostic value of the plasma arginase activity and the plasma expression of 2 isoforms Arg1 and Arg2, their kinetics, and the link between activity / expression of arginase and enterocyte dysfunction.
Heparin induced thrombocytopenia (HIT) is a kind of catastrophic thrombotic complications after the application of heparin. If HIT without treatment, death rate is as high as 30% to 50%. Early diagnosis of HIT and prevention of thrombosis is very important. This study is planned to assess the use of thrombotic biomarkers in patients with HIT, including thrombin-antithrombin complex, d-dimer, fibrin degradation products and Thrombelastograghy monitoring . These biomarkers are monitored in 5-14 days post-operation to assess the risk of thrombosis in HIT patients. All patients were followed up for 30 days, and clinical outcomes, including new thrombus and death, were recorded during follow-up.