Critical care medicine
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Critical care medicine · Nov 1997
Comparative Study Clinical TrialEffect of antihypertensive agents on the arterial partial pressure of oxygen and venous admixture after cardiac surgery.
To determine whether stopping nitroglycerin and sodium nitroprusside (both vasodilators) infusions in hypertensive, postcardiac surgical patients requiring a high FIO2 improves PaO2 and venous admixture. ⋯ Substituting labetalol for nitroglycerin and sodium nitroprusside improves arterial oxygenation and venous admixture in hypertensive postcardiac surgical patients who require a high FIO2. This change in therapy may allow patients to be weaned from mechanical ventilation sooner.
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Critical care medicine · Nov 1997
Randomized Controlled Trial Clinical TrialEffect of intravenous lactated Ringer's solution infusion on the circulating lactate concentration: Part 3. Results of a prospective, randomized, double-blind, placebo-controlled trial.
We previously discovered that small amounts of lactated Ringer's solution, which are inadequately cleared from an intravenous catheter, falsely increase the circulating lactate concentration in blood samples collected from that catheter. That finding prompted us to test the hypothesis that intravenous lactated Ringer's solution, infused at a rate used in resuscitation, would increase the circulating lactate concentration. ⋯ The short-term infusion of lactated Ringer's solution in normal adults (hemodynamically stable) does not falsely increase circulating lactate concentrations when 1 L is given over 1 hr. Therefore, clinicians should not disregard increased lactate concentrations in patients receiving a rapid infusion of lactated Ringer's solution.
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Critical care medicine · Nov 1997
Comparative Study Clinical Trial Controlled Clinical TrialUse of different anticoagulants in test tubes for analysis of blood lactate concentrations: Part 2. Implications for the proper handling of blood specimens obtained from critically ill patients.
a) To test the hypothesis that the measurement of the circulating lactate concentration is influenced by the anticoagulant in the test tube that contains the blood sample; b) to test the hypothesis that the measurement of the circulating lactate concentration is influenced by the tissue used for analysis. ⋯ a) Sodium citrate, as an anticoagulant, caused lower lactate concentrations to be measured as compared with heparin or EDTA; b) the measurement of lactate concentrations in plasma or serum samples yields a higher value than the concentration found in the original whole blood specimen.
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Critical care medicine · Nov 1997
Comparative Study Clinical TrialComparison of simultaneously obtained arterial and capillary blood gases in pediatric intensive care unit patients.
To determine whether capillary blood gas measurements provide a clinically acceptable estimate of arterial pH, PCO2, and PO2. ⋯ Capillary blood gases accurately reflect arterial pH and PCO2 in most pediatric intensive care unit patients. Capillary samples did not significantly underestimate arterial hypercarbia or acidosis. This conservative reflection of metabolic status may be particularly useful in hemodynamically stable patients with mild-to-moderate lung disease.
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Critical care medicine · Nov 1997
Comparative StudyEffects of crystalloid solutions on circulating lactate concentrations: Part 1. Implications for the proper handling of blood specimens obtained from critically ill patients.
a) To test the hypothesis that circulating lactate concentrations are the same in simultaneously collected arterial and central venous blood specimens; b) to test the hypothesis that even small amounts of crystalloid solutions, which are inadequately "cleared" from these indwelling arterial and venous catheters, can lead to clinically important and misleading changes in the measured lactate values. ⋯ a) Arterial and central venous lactate concentrations are similar in hemodynamically stable critically ill patients, b) Even small amounts of RL-containing solutions in catheters used for blood sampling may cause false increases in the circulating lactate concentration. c) Even small amounts of non-RL crystalloid solutions in catheters used for blood sampling may falsely decrease circulating lactate values. d) When blood specimens are drawn from indwelling catheters, all crystalloid solutions must be cleared from the line.