Critical care medicine
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Critical care medicine · Jun 1992
Comparative StudyEffect of a human immunoglobulin preparation for intravenous use in a rabbit model of meningococcal endotoxin-induced shock.
Endotoxin shock is mediated by various cytokines, including tumor necrosis factor. Treatment of patients with i.v. immunoglobulin has been shown to reduce the concentration of circulating cytokines. The purpose of this study was to determine the protective effects of immunoglobulin for i.v. use on meningococcal endotoxin-induced shock in a rabbit model. Experimental animals were challenged with i.v. meningococcal endotoxin (lipo-oligosaccharide) 10 micrograms/kg, and treated with either a 2-hr i.v. immunoglobulin infusion (400 mg/kg) or a similar saline infusion that was initiated 30 mins before endotoxin challenge. Control animals were challenged with saline alone. ⋯ In this model of circulatory shock in rabbits, i.v. immunoglobulin: a) does not significantly alter the physiologic responses to endotoxin challenge; b) significantly reduces endotoxin concentrations; c) reduces tumor necrosis factor concentrations, but not significantly; and d) does not improve survival rate.
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Critical care medicine · Jun 1992
Femoral arteriovenous extracorporeal carbon dioxide elimination using low blood flow.
Conventional extracorporeal CO2 removal systems require blood flow rates of 1 to 2.5 L/min in the extracorporeal circuit. We hypothesized that standard hemofiltration equipment can be combined with a high-performance extracorporeal lung to achieve high rates of CO2 removal at lower blood flow rates. To test this hypothesis, we performed experiments on nine sheep to examine the extent to which CO2 elimination can be achieved at blood flow rates less than 600 mL/min using a 5-m2 hollow fiber membrane lung with countercurrent gas flow, combined with a hemofiltration blood pump, and connected to femoral arterial and venous hemodialysis catheters. ⋯ Standard hemofiltration equipment may be combined with a hollow fiber membrane lung to remove the equivalent of a high proportion of the basal metabolic CO2 production of an adult human at low blood flow rates. Use of this technology would bring extracorporeal CO2 removal within the budget and capability of more ICUs.