American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Apr 1998
Effect of dexfenfluramine treatment in rats exposed to acute and chronic hypoxia.
The anorexiant dexfenfluramine, which inhibits 5-hydroxytryptamine (5-HT) uptake, has been associated with an increase in the relative risk of developing primary pulmonary hypertension. The aim of this study was to investigate in rats whether dexfenfluramine (1) alters the pulmonary vasomotor effects of 5-HT and (2) aggravates the development of pulmonary hypertension during exposure to various levels of chronic hypoxia. In isolated lungs from normoxic rats, dexfenfluramine up to 10(-4) M did not elicit any vasoactive effects, and neither did pretreatment with dexfenfluramine (10[-5] M in the perfusate) modify the vasoactive effects of 5-HT. ⋯ In contrast, a continuous 5-HT infusion providing a sustained increase in plasma 5-HT levels was associated with increased muscularization of distal pulmonary arteries in response to 10% O2. Simultaneous administration of dexfenfluramine prevented the effect of exogenous 5-HT on vascular remodeling. Our findings show that dexfenfluramine does not potentiate the development of pulmonary hypertension in rats exposed to chronic hypoxia, despite its effect on plasma 5-HT concentrations.
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Am. J. Respir. Crit. Care Med. · Apr 1998
Biography Historical ArticleBlood gas analysis and critical care medicine.
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Am. J. Respir. Crit. Care Med. · Apr 1998
Mild hyperlactatemia in stable septic patients is due to impaired lactate clearance rather than overproduction.
A prospective study was conducted on 34 stable septic patients to determine whether mild hyperlactatemia is a marker of lactate overproduction or an indicator of lactate underutilization during sepsis. Plasma lactate clearance and lactate production were evaluated by modeling the lactate kinetic induced by an infusion of 1 mmol/kg L-lactate over 15 min. ⋯ A second analysis including all the patients confirmed that the blood lactate concentration was closely linked to the reciprocal of lactate clearance (r2 = 0.73, p < 0.001) but not to lactate production (r2 = 0.03, p = 0.29). We conclude that a mild hyperlactatemia occurring in a stable septic patient is mainly due to a defect in lactate utilization.
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Am. J. Respir. Crit. Care Med. · Apr 1998
ReviewThe American-European Consensus Conference on ARDS, part 2: Ventilatory, pharmacologic, supportive therapy, study design strategies, and issues related to recovery and remodeling. Acute respiratory distress syndrome.
The acute respiratory distress syndrome (ARDS) continues as a contributor to the morbidity and mortality of patients in intensive care units throughout the world, imparting tremendous human and financial costs. During the last 10 years there has been a decline in ARDS mortality without a clear explanation. The American-European Consensus Committee on ARDS was formed to re-evaluate the standards for the ICU care of patients with acute lung injury (ALI), with regard to ventilatory strategies, the more promising pharmacologic agents, and the definition and quantification of pathologic features of ALI that require resolution. It was felt that the definition of strategies for the clinical design and coordination of studies between centers and continents was becoming increasingly important to facilitate the study of various new therapies for ARDS.