RESUMO
Endogenous release of catecholamines is an important mechanism that can prevent alveolar flooding after brief but severe hemorrhagic shock. The objective of this study was to determine whether this catecholamine-dependent mechanism upregulates alveolar liquid clearance after prolonged hemorrhagic shock. Rats were hemorrhaged to a mean arterial pressure of 30-35 mmHg for 60 min and then resuscitated with a 4% albumin solution. Alveolar liquid clearance was measured 5 h later as the concentration of protein in the distal air spaces over 1 h after instillation of a 5% albumin solution into one lung. There was no upregulation of alveolar liquid clearance after prolonged hemorrhagic shock and fluid resuscitation despite a significant increase in plasma epinephrine levels. The intravenous or intra-alveolar administration of exogenous catecholamines did not upregulate alveolar liquid clearance. In contrast, catecholamine-mediated upregulation of alveolar liquid clearance was restored either by depletion of neutrophils with vinblastine, by the normalization of the concentration of reduced glutathione in the alveolar epithelial lining fluid by N-acetylcysteine, or by the inhibition of the conversion from xanthine dehydrogenase to xanthine oxidase. These experiments provide the first in vivo evidence that a neutrophil-dependent oxidant injury to the alveolar epithelium prevents the upregulation of alveolar fluid clearance by catecholamines in the absence of a major alteration in paracellular permeability to protein after prolonged hemorrhagic shock.
Assuntos
Alvéolos Pulmonares/fisiopatologia , Receptores Adrenérgicos beta/fisiologia , Choque Hemorrágico/fisiopatologia , Acetilcisteína/farmacologia , Antagonistas Adrenérgicos beta/farmacologia , Animais , Líquidos Corporais/fisiologia , Epinefrina/administração & dosagem , Epinefrina/sangue , Epitélio/fisiopatologia , Hidratação , Sequestradores de Radicais Livres , Glutationa/metabolismo , Masculino , Neutrófilos/efeitos dos fármacos , Neutrófilos/fisiologia , Oxirredução , Ratos , Ratos Sprague-Dawley , Receptores Adrenérgicos beta/efeitos dos fármacos , Choque Hemorrágico/terapia , Xantina Desidrogenase/metabolismo , Xantina Oxidase/antagonistas & inibidores , Xantina Oxidase/metabolismoAssuntos
Neoplasias Encefálicas/prevenção & controle , Carcinoma de Células Pequenas/prevenção & controle , Carcinoma de Células Pequenas/secundário , Irradiação Craniana , Neoplasias Pulmonares/terapia , Neoplasias Encefálicas/secundário , Humanos , Estudos Multicêntricos como Assunto , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Primary treatment for pancreatic pseudocyst is evolving from surgical intervention to needle aspiration with catheter drainage. The latter treatment results in a similar rate of resolution but has less patient morbidity. This study evaluated the adjuvant role of Sandostatin, which inhibits basal and stimulated pancreatic secretion, in the management of three patients with pancreatic pseudocysts who had prolonged catheter drainage subsequent to percutaneous drainage. Inhibition of secretion occurred in all three patients, as evidenced by decrease in catheter output, which allowed the catheter to be removed. All three patients have remained asymptomatic for 9, 10, and 15 months, respectively. In summary, Sandostatin decreased persistent catheter drainage from chronic pancreatic pseudocysts.
