Shock : molecular, cellular, and systemic pathobiological aspects and therapeutic approaches : the official journal the Shock Society, the European Shock Society, the Brazilian Shock Society, the International Federation of Shock Societies
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The defect in energy production in an organism during shock states may be related to the impairment of mitochondrial respiration early in shock. The aim of this study was to investigate the timing and degree of cellular energetic changes during hemorrhagic shock in real time. Instrumented, splenectomized swine were randomized to undergo hemorrhagic shock, induced by a 35% blood volume bleed, for 90 min with (n = 10) or without (n = 9) subsequent resuscitation. ⋯ StO2 in skeletal muscle, stomach, and liver correlated with whole organism oxygen delivery (r2 = 0.356, 0.368, and 0.432, respectively). We conclude that hemorrhagic shock induces early elevation of phosphomonoesters in skeletal muscle, which correlates with the severity of shock. This implies an early transition to anaerobic glycolysis during hemorrhagic shock, which may be indicative of early mitochondrial dysfunction.
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It has been suggested that hyperdynamic (HD) resuscitation improves outcomes. We hypothesized that initial HD resuscitation of burn injury using fluid and inotropes would improve metabolic function as indicated by base excess. We used an anesthetized ovine model of 60% TBSA full-thickness flame burn with delayed resuscitation started at 90 min after burn and continued for 8 h. ⋯ The mean postburn urinary outputs were similar in both Parkland and HD-Drug groups, e.g., Parkland (0.9 +/- 0.08 mL/kg/h), HD-Drug (1.0 +/- 0.2 mL/kg/h) and increased in HD-Fluid (3.7 +/- 1.0 mL/kg/h; P = 0.0005). Base excess remained positive in both HD-Drug (+2.5 +/- 1 mmol/L) and Parkland (+1.5 +/- 1.7 mmol/L), and declined to -4.0 +/- 3.6 mmol/L in HD-Fluid group (P = 0.036). We conclude that there may be no benefit to using hyperdynamic regimens for the initial resuscitation of burn injury.
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Sepsis is among the leading causes of death in the critically ill, yet the pathophysiology of sepsis is incompletely understood. Genetically engineered mice offer a unique opportunity to explore the cellular and molecular pathogenesis of sepsis. However, the hemodynamic responses of mice during sepsis are not completely understood because of the difficulty in performing cardiovascular measurements in mice. ⋯ The slope of end systolic pressure volume relationship also decreased over time, as did the time varying maximum elastance and preload-recruitable stroke work of the left ventricle. In conclusion, septic mice exhibit hemodynamic alterations during sepsis that are similar to those observed in humans. The miniaturized conductance catheter allows for effective measurements of hemodynamic function in septic mice and provides measurements that cannot be obtained using other cardiovascular monitoring techniques.
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The effects of different volumes of fluid resuscitation on traumatic hemorrhagic shock in unacclimated rats to high altitude were investigated. Seventy-eight Wistar rats were transported to LaSa, Tibet, 3760 meters above sea level, and traumatic hemorrhagic shock was induced by right-femur fracture plus bleeding to 45 mmHg of mean arterial pressure (MAP) for 1 h under the anesthesia of sodium pentobarbital (40 mg/kg, i.p.). Experiments were conducted in two series. ⋯ Meanwhile 2 and 3 vol of LR resuscitation decreased the survival time. These results suggest that 1 and 1.5 vol of LR resuscitation can effectively resuscitate traumatic hemorrhagic shock at high altitude. More than two volumes of LR resuscitation would deteriorate the resuscitation outcome.
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In biomedical research using animal models, the phrase "humane endpoints" refers to predetermined criteria used to judge when the research animals should be humanely euthanized. The intended goal of humane endpoints is to minimize the distress or suffering of research animals; however, if applied incorrectly, this well-intended concept could lead to premature decisions and inaccurate data, resulting in a waste of animal life. A concensus on specific endpoints for shock and inflammation research is not available but several biochemical, physical and behavioral parameters have been suggested for other research models. ⋯ Consequently, humane endpoints should be assigned cautiously and preferably after preliminary studies to prevent aberrant research results. In order to accomplish this, investigators must become aware of certain concepts including: when to implement endpoints, what endpoints to consider, and how to establish the endpoints for their studies. Equipped with the basic principles of humane endpoints, investigators can make informed decisions that meet current standards of animal care while still achieving the scientific goals of their research studies.