Critical care medicine
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To evaluate the effects of "ego bias" on physicians' prognostic judgments. Ego bias is defined as systematic overestimation of the prognosis of one's own patients compared with the expected outcome of a population of similar patients. ⋯ The critical care attending physicians exhibited reverse ego bias that was mainly a function of their optimism about the overall survival rate for critically ill patients. The house officers exhibited ego bias that was mainly a function of their pessimism about the overall survival rate for critically ill patients.
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Critical care medicine · Dec 1991
Effects of acute hypothermia and beta-adrenergic receptor blockade on serum potassium concentration in rats.
We hypothesized that beta-adrenergic receptor blockade would result in an increase in serum potassium concentration in hypothermic rats given a potassium load compared to non-beta-blocked, hypothermic, potassium-loaded rats. To test this hypothesis, we investigated the interaction between body temperature and beta-adrenergic receptor blockade on serum potassium concentrations in ureter-ligated rats with and without potassium loading. To achieve this goal, we performed three experiments. In the first experiment, serum potassium concentrations were determined in 16 rats as they were continuously cooled from 37 degrees C to 22 degrees C. In the second experiment, 12 ureter-ligated rats were cooled to 31 degrees C, after which they were rewarmed to 37 degrees C. Serum potassium concentrations were determined before and after cooling and on rewarming. Twelve other ureter-ligated rats were cooled to 31 degrees C, then given a potassium load until their serum potassium concentrations returned to their baseline values, after which they were rewarmed to 37 degrees C. Serum potassium concentrations were determined before and after cooling, during the potassium infusion, and on rewarming. In the third experiment, 14 rats were pretreated with propranolol and 14 rats served as controls. Half of the rats in each of these two groups were kept at 37 degrees C and half were cooled to 25 degrees C. All rats were then given a 690-mumol potassium chloride infusion. Serum potassium concentrations were determined before and after the potassium infusion. ⋯ These results suggest that acute hypothermia causes a decrease in serum potassium, probably secondary to redistribution, which is reversible on rewarming. Supplementation of potassium during hypothermia can cause a significant increase in serum potassium concentration on rewarming. Blocking beta-adrenergic receptors with propranolol did not effect hypothermia-induced hypokalemia, suggesting that the beta-adrenergic mechanism may not be functional in hypothermia.
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Critical care medicine · Nov 1991
Comparative StudyComparison of oxygen consumption measurements: indirect calorimetry versus the reversed Fick method.
To compare measurement of oxygen consumption (VO2) by spirometry and the reversed Fick method. ⋯ The repeatability of the spirometric method was four times better than the reversed Fick method. The latter gave a significantly lower value that probably, in part, reflects the VO2 of the lung, which is included in the spirometric method but not in the reversed Fick measurement.
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Critical care medicine · Nov 1991
Randomized Controlled Trial Clinical TrialEffects of bicarbonate therapy on hemodynamics and tissue oxygenation in patients with lactic acidosis: a prospective, controlled clinical study.
To determine whether correction of acidemia using bicarbonate improves hemodynamic variables and tissue oxygenation in patients with lactic acidosis. ⋯ Administration of sodium bicarbonate did not improve hemodynamic variables in patients with lactic acidosis, but did not worsen tissue oxygenation.