Critical care medicine
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Critical care medicine · Mar 1989
Hydrochloric acid infusion for treatment of metabolic alkalosis associated with respiratory acidosis.
Hypercapnia due to respiratory failure can be more severe when accompanied by coexistent metabolic alkalosis. We therefore tested the hypothesis that hydrochloric acid (HCl) infusion could improve PaCO2 in 15 critically ill patients admitted with mixed respiratory acidosis and metabolic alkalosis, and a pH of between 7.35 and 7.45. HCl was infused at a constant rate of 25 mmol/h until the bicarbonate concentration decreased less than 26 mmol/L, or until the pH decreased less than 7.35 (initial pH greater than 7.40) or 7.30 (initial pH less than 7.40). ⋯ The effects of HCl were still present 12 h after the end of the infusion. No complications related to the acid infusion were noted. These results indicate that, even in the absence of alkalemia, active correction of metabolic alkalosis by HCl infusion can improve CO2 and oxygen exchange in critically ill patients with mixed respiratory acidosis and metabolic alkalosis.
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Critical care medicine · Feb 1989
Weaning from mechanical ventilation: adjunctive use of inspiratory muscle resistive training.
We used inspiratory resistive training (IRT) in an effort to improve the respiratory muscle endurance of 27 patients with respiratory failure who had failed repeated weaning attempts using standard techniques. Seven patients had primary neuromuscular diseases; the other 20 had primary lung diseases. All patients had stable respiratory failure, without gross malnutrition or electrolyte disorders. ⋯ Under this regimen, maximal inspiratory pressure improved from -37 +/- 15 to -46 +/- 15 cm H2O (p less than .001) and vital capacity improved from 561 +/- 325 to 901 +/- 480 ml (p less than .001). Twelve of the 27 patients were successfully weaned after 10 to 46 days; five more were weaned to nocturnal ventilation, for a total of 63%. We conclude that IRT can improve respiratory muscle strength and endurance in patients with respiratory failure, and can allow many of them to be weaned from mechanical ventilation.
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Critical care medicine · Feb 1989
Randomized Controlled Trial Clinical TrialAnalysis of the effects of continuous on-line monitoring of mixed venous oxygen saturation on patient outcome and cost-effectiveness.
Continuous measurement of mixed venous oxygen saturation (Sv-O2) has recently been introduced as a monitoring and management technique in critical care patients. To determine the impact of Sv-O2 monitoring on patient management and cost-effectiveness, we conducted a prospective, randomized clinical trial of 99 consecutive patients receiving pulmonary artery (PA) catheters in the ICU. One group (n = 49) received an Edwards quadruple-lumen flow-directed PA catheter. ⋯ Statistical analysis by step-deletion multiple regression analysis and the unpaired Student's t-test demonstrated that use of the Opticath was not associated with a decrease in potentially adverse hemodynamic events, length of ICU stay, or mortality. In terms of cost-effectiveness, mixed venous oximetry is economically favorable in a charge-based reimbursement system, but economically unfavorable in a fixed-cost-based reimbursement system. Although continuous Sv-O2 monitoring has been shown to be accurate and reliable, it does not appear to be beneficial in all patients requiring PA catheterization.
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Critical care medicine · Feb 1989
Comparative StudyComparison of hydroxyethyl starch and lactated Ringer's solution on hemodynamics and oxygen transport of critically ill patients in prospective crossover studies.
The cardiopulmonary effects of lactated Ringer's solution (RL) were compared with those of 10% hydroxyethyl starch, hetastarch (HES), given in 44 therapeutic interventions in 15 critically ill patients by crossover design. Each agent was given to each patient at least once; seven patients received each agent twice. ⋯ HES 10% produced significantly increased cardiac index, left and right ventricular stroke work index, CVP, WP, oxygen delivery, oxygen consumption, and reduced pulmonary vascular resistance index (PVRI). RL increased CVP, WP, and PVRI, but did not significantly improve other hemodynamic or oxygen transport variables.