Navegando por Palavras-chave "shock"

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    Absolute and relative adrenal insufficiency in children with septic shock
    (Lippincott Williams & Wilkins, 2005-04-01) Pizarro, C. F.; Troster, E. J.; Damiani, D.; Carcillo, J. A.; Universidade Federal de São Paulo (UNIFESP)
    Objective: Corticosteroid replacement improves outcome in adults with relative adrenal insufficiency and catecholamine-resistant septic shock. We evaluated the relationship of absolute and relative adrenal insufficiency to catecholamine-resistant septic shock in children.Design. Prospective cohort study.Setting. University hospital pediatric intensive care unit in Brazil.Patients. Fifty-seven children with septic shock. Children with HIV infection, those with a history of adrenal insufficiency, and those submitted to any steroid therapy or etomidate within the week before diagnosis of septic shock were excluded.Interventions: None.Measurements and Main Results., A short corticotropin test (250 mu g) was performed, and cortisol levels were measured at baseline and 30 and 60 mins posttest. Adrenal insufficiency was defined by a response <= 9 mu g/dL. Absolute adrenal insufficiency was further defined by a baseline cortisol < 20 mu g/dL and relative adrenal insufficiency by a baseline cortisol > 20 mu g/dL. Absolute adrenal insufficiency was observed in 18% of children, all of whom had catecholamine-resistant shock. Relative adrenal insufficiency was observed in 26% of children, of whom 80% had catecholamine-resistant and 20% had dopamine/dobutamine-responsive shock. All children with fluid-responsive shock had a cortisol response > 9 mu g/dL. Children with adrenal insufficiency had an increased risk of catecholamine-resistant shock (relative risk, 1.88; 95% confidence interval, 1.26-2.79). However, mortality was independently predicted by chronic illness or multiple organ failure (p <.05), not adrenal insufficiency.Conclusions: Absolute and relative adrenal insufficiency is common in children with catecholamine-resistant shock and absent in children with fluid-responsive shock. Studies are warranted to determine whether corticosterold therapy has a survival benefit in children with relative adrenal insufficiency and catecholamine-resistant septic shock.
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    Role of the bradykinin B-2 receptor for the local and systemic inflammatory response that follows severe reperfusion injury
    (Nature Publishing Group, 2003-05-01) Souza, Daniele G.; Pinho, Vanessa; Pesquero, Jorge L.; Lomez, Eliane S.; Poole, Steve; Juliano, Luiz [UNIFESP]; Correa Junior, Ary; Castro, M Salete D; Teixeira, Mauro M.; Universidade Federal de Minas Gerais (UFMG); Universidade Federal de São Paulo (UNIFESP); Natl Inst Biol Stand & Controls
    1 Bradykinin (BK) appears to play an important role in the development and maintenance of inflammation. Here, we assessed the role of the BK B-2 receptor for the injuries that occur after ischemia and reperfusion (I/R) of the territory irrigated by the superior mesenteric artery.2 Tissue (lung and duodenum) kallikrein activity increased after ischemia with greater enhancement after reperfusion. A selective inhibitor of tissue kallikrein, Phenylacetyl-Phe-Ser-Arg-N-(2,3-dinitrophenyl)-ethylenediamine (TKI, 0.001 - 10 mg ml(-1)), inhibited kallikrein activity in a concentration-dependent manner in vitro. in vivo, pretreatment with TKI (30 mg kg(-1)) prevented the extravasation of plasma and the recruitment of neutrophils.3 Similarly, the bradykinin B-2 receptor antagonists, HOE 140 (0.01-1.0 mg kg(-1)) or FR173657 (10.0 mg kg(-1)), inhibited reperfusion-induced increases in vascular permeability and the recruitment of neutrophils in the intestine and lungs.4 in a model of more severe I/R injury, HOE 140 (1.0mg kg(-1)) inhibited the increase in vascular permeability, neutrophil recruitment, haemorrhage and tissue pathology. Furthermore, HOE 140 significantly inhibited the elevations of TNF-alpha in tissue and serum and partially prevented lethality. This was associated with an increase in the concentrations of IL-10 in tissue and serum.5 Thus, our results demonstrate that, following intestinal I/R injury, there is an increase in tissue kallikrein activity and activation of BK B-2 receptors. B-2 receptor activation is essential for the development of inflammatory tissue injury and lethality. These results contrast with those of others showing that BK mostly exerts a protective role during I/R injury.
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    Vasoactive properties of synthetic blood substitutes
    (Medicina (buenos Aires), 1998-01-01) Figueiredo, Luis Francisco Poli de [UNIFESP]; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)
    There is a great need for the development of a safe and efficient blood substitute, to overcome the important limitations of homologous blood transfusion. Currently available cell-free hemoglobin-based oxygen-carrying solutions present oxygen transport and exchange properties similar to blood and potential benefits over conventional transfusion, including large supply, absence of transfusion reactions, no need for cross-matching, no risk for transmission of disease and long shelf life. Several experimental studies have suggested that cell-free hemoglobin is a vasoactive agent. In animal models of hemorrhagic shock, small doses of cell-free modified hemoglobin restore arterial pressure, promote adequate tissue oxygenation, and improve survival, when compared with fluids with no oxygen-carrying capacity. On the other hand, it has been demonstrated that hemoglobin-induced vasoconstriction may result in decreased cardiac output, reduced blood flow to vital organs and severe pulmonary hypertension. Cell-free hemoglobin solutions cause their presser effects by binding and scavenging nitric oxide. Although hemoglobin within the red blood cells is the natural scavenger of NO, when the hemoglobin is free in solution, NO is inactivated to a greater extend. Cell-free hemoglobins are on advanced clinical trials, despite the fact that several concerns raised by experimental studies have not been adequately addressed in early clinical trials. The development of a safe and efficient blood substitute depends on the availability of these products for critical evaluation by the scientific community before the widespread clinical use of these blood substitutes.