Critical care medicine
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Critical care medicine · Feb 1991
Tissue oxygenation in hemorrhagic shock measured as transcutaneous oxygen tension, subcutaneous oxygen tension, and gastrointestinal intramucosal pH in pigs.
Tissue oxygenation, measured in peripheral tissue as transcutaneous PO2 (PtCO2) and subcutaneous PO2, was compared with the oxygenation in GI mucosa, which was measured as intramucosal wall pH (pHi), during experimental hemorrhagic shock and resuscitation in pigs. The pigs were hemorrhaged stepwise to a BP of 80 and 45 mm Hg, followed by retransfusion. PtCO2 was measured in the groin and subcutaneous PO2 was measured in the hip region. Intraluminal PCO2 was measured in the stomach, in the small intestine, and the sigmoid colon using silicone catheters. A simultaneous determination of arterial blood HCO3 concentration allowed pHi to be calculated using Henderson-Hasselbalch equation. Cardiac output was determined by thermodilution, and oxygen delivery (DO2) was calculated. ⋯ PtCO2 and pHi in the small intestine and sigmoid colon were the variables that most rapidly indicated blood volume loss. Subcutaneous PO2 and PtCO2, and small intestine and sigmoid colon pHi were correlated to total body oxygen transport. Peripheral tissue perfusion followed intestinal perfusion to some extent.
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Critical care medicine · Feb 1991
Use of the Pediatric Risk of Mortality score to predict nosocomial infection in a pediatric intensive care unit.
To define infection rates in patients with Pediatric Risk of Mortality (PRISM) scores greater than and less than 10 on admission to the pediatric ICU (PICU). ⋯ A PRISM score greater than 10 on PICU admission characterizes a population within the PICU at increased risk of infection. However, 93% of patients did not develop infection and thus, a negative predictive value of 97% yields little additional information.
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Critical care medicine · Feb 1991
Prolonged hemorrhagic shock does not impair regeneration of plasma coagulant masses in the rabbit.
Twelve adult male albino rabbits were assigned alternately to normotensive and hypotensive groups to assess the effect of hypovolemic shock on spontaneous correction of dilutional coagulopathy. All animals underwent dilutional exchange transfusion with 200 mL of rabbit RBCs and 5% human albumin. Half the animals were then acutely hemorrhaged and subsequent aliquots of blood removed as needed to maintain the mean arterial pressure at 40 mm Hg. ⋯ Dilutional coagulopathy corrects spontaneously within hours. Normovolemic shock prolongs dilutional coagulopathy not by impairment of factor regeneration but because of further (internal) dilution due to plasma expansion. Rapid correction of dilutional coagulopathy is likely to necessitate cryoprecipitate administration.
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Critical care medicine · Feb 1991
Oxygen debt and metabolic acidemia as quantitative predictors of mortality and the severity of the ischemic insult in hemorrhagic shock.
An experimental canine model of hemorrhagic, hypovolemic shock is described that uses oxygen debt and its metabolic consequences of lactic acidemia and metabolic base deficit as independent variables for the prediction of probability of death. ⋯ Of the single-variable predictors, BE shows the highest explained variability. However, a combined prediction from both lactate and BE appears superior to the use of either alone. Using this regression to compute the oxygen debt, it is possible to estimate accurately the actual level of oxygen debt from the BE and lactate values obtained during hemorrhagic hypovolemia. From serial determinations over time of the increase in these biochemical variables above the oxygen debt baseline, it is possible to estimate the rate of oxygen debt accumulation and the time remaining until the LD50 will be reached as indicators of the severity of the total body ischemia resulting from hemorrhagic shock.