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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Black transplant recipients have decreased graft survival and increased rejection rates compared with whites. Because increased rejection rates may lead to more immunosuppression in black recipients, ethnic differences may exist for outcomes of posttransplant infectious complications. All episodes of infection between December 1996 and October 1998 on the transplant services at the University of Virginia Health Sciences Center were prospectively evaluated. ⋯ White liver transplant recipients had an increased incidence of viral infections (15% vs. 0%, P = 0.03). All other infecting organisms were similar. The unexpected finding of a significantly decreased rate of mortality associated with posttransplant infections in black recipients remains largely unexplained but may be related to subtle differences in immune response between racial or ethnic groups.
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Ventilation with 100% oxygen (Fio(2) 1.0; hyperoxic ventilation; HV) as an alternative to red blood cell transfusion enables survival in otherwise lethal normovolemic anemia. The aim of the present study was to investigate whether HV as a supplement to fluid infusion therapy could also restore adequate tissue oxygenation and prevent death in otherwise lethal hemorrhagic shock. In 14 anesthetized pigs ventilated on room air (Fio(2) 0.21), hemorrhagic shock was induced by controlled withdrawal of blood (target mean arterial pressure 35-40 mmHg) and maintained for 1 h. ⋯ Death was preceded by a continuous increase of the serum concentrations of arterial lactate and persistent tissue hypoxia. In contrast to that, all animals of G 1.0 survived the 6-h observation period without lactic acidosis and with improved tissue oxygenation (i.e., 6-h mortality 0%; G 0.21 versus G 1.0 P < 0.05). In anesthetized pigs submitted to lethal hemorrhagic shock, the supplementation of partial fluid resuscitation with HV improved tissue oxygenation and enabled survival for 6 h.
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In both animal models of hemorrhagic shock and clinical settings, shock-induced gut ischemia has been implicated in the development of the systemic inflammatory response syndrome and distant organ injury, yet the factors transducing these events remain to be fully determined. Because hypoxia-inducible factor (HIF-1), a transcription factor composed of oxygen-labile HIF-1alpha and constitutive HIF-1beta subunits, regulates the physiologic/pathophysiologic response to hypoxia and ischemia, we examined the HIF-1 response in two rat models of gut ischemia-reperfusion. We found that ileal nuclear HIF-1alpha protein levels were induced in rats subjected to trauma (laparotomy) plus hemorrhagic shock for 90 min relative to their trauma sham-shock and naïve counterparts and that this trauma hemorrhagic shock-induced mucosal HIF-1alpha protein response persisted after 1 h and 3 h of reperfusion. ⋯ Furthermore, the addition of P. aeruginosa during either the hypoxic or reoxygenation phase prevented the degradation of HIF-1alpha protein levels. Moreover, the observation that lipopolysaccharide induced HIF-1alpha expression in a time-dependent manner in IEC-6 cells indicated that the induction of HIF-1 by exposure to P. aeruginosa is not dependent on bacterial viability. In conclusion, these results suggest that HIF-1alpha activation is an early reperfusion-independent event in models of gut ischemia-reperfusion and that this HIF-1alpha response is potentiated by the presence of P. aeruginosa or lipopolysaccharide.
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Hypotensive resuscitation has been advocated as a better means to perform field resuscitation of penetrating trauma. Our hypothesis is that hypotensive resuscitation using either crystalloid or colloid provides equivalent or improved metabolic function while reducing the overall fluid requirement for resuscitation of hemorrhage. We compared hypotensive and normotensive resuscitation of hemorrhage using lactated Ringer's (LR) with hypotensive resuscitation using Hextend (Hex), 6% hetastarch in isotonic buffered saline. ⋯ Mean minimum base excess (BE) values were +1.9 +/- 1.4, -5.8 +/- 4.3, and -5.9 +/- 4.0 mEq/L in the LR-90, LR-65, and Hex-65 treatments, respectively. Hypotensive resuscitation with LR greatly reduced volume requirements as compared with normotensive resuscitation, and Hex achieved additional volume sparing. However, trends toward lower BE values and the occurrence of deaths only in the hypotensive treatment protocols suggest that resuscitation to a target MAP of 65 mmHg may be too low for optimal outcomes.
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The postresuscitation phase after out-of-hospital circulatory arrest shares similarities with severe sepsis. Corticosteroid replacement is beneficial in patients with septic shock and adrenal dysfunction. The goal of this study was to assess baseline cortisol and adrenal reserve of out-of-hospital circulatory arrest patients after recovery of spontaneous circulation. ⋯ Corticotropin response status was not associated with standard severity markers and seemed uninfluenced by therapeutic hypothermia. In conclusion, patients who die of early refractory shock after cardiopulmonary resuscitation may have an inadequate adrenal response to the stress associated with this condition. Thresholds for cortisol levels at baseline and after corticotropin need to be determined in this clinical setting.