RESUMO
To assess whether an intact mechanism of sodium transport in the distal nephron is a prerequisite for the development of a kaliuresis in response to an acute potassium load (0.4 M KCl, 1 ml/min), the effects of a simultaneous infusion of KCl and amiloride (1 mg/kg/h) were evaluated in anesthetized dogs. A major reduction in potassium excretion mainly due to a sharp decrease in urine K+ concentration to one tenth of control levels was found after amiloride. The simultaneous infusion of KCl and amiloride resulted in a rapid and major increase in kaliuresis that was accounted for mostly by the rise in urine K+ concentration. The increased kaliuresis after the acute potassium infusion was of similar magnitude when expressed as percent value of control to that previously reported in dogs not receiving amiloride; the absolute rates of K+ excretion, however, were only 2.7 and 7.3% (before and after KCl infusion, respectively) of the values in dogs not receiving amiloride. Our observations suggest that potassium infusion in the intact dog increases kaliuresis primarily as a result of a more favorable chemical gradient of this cation between blood and/or distal tubular cells and urine. Yet, when a chemical gradient is the only driving force of potassium secretion, as was the case in our amiloride-treated dogs, the absolute rate of kaliuresis is very modest. The presence of an unimpaired electrical profile and sodium transport mechanisms in the distal nephron, although not critical for the development of kaliuresis in response to a K+ load, accounts for a severalfold rise in renal potassium excretion above basal levels.
Assuntos
Amilorida/farmacologia , Rim/metabolismo , Potássio/urina , Absorção , Animais , Pressão Sanguínea/efeitos dos fármacos , Desoxicorticosterona/farmacologia , Cães , Córtex Renal/ultraestrutura , Túbulos Renais Coletores/ultraestrutura , Túbulos Renais Distais/citologia , Membranas/metabolismo , Néfrons/metabolismo , Potássio/administração & dosagem , Potássio/farmacocinética , Pré-Medicação , Sódio/farmacocinética , Canais de Sódio/efeitos dos fármacosRESUMO
Se trataron con cefoperazone sodico 20 pacientes (promedio 45.7 anos) portadores de una infeccion grave del tracto respiratorio inferior (8 bronquitis, 5 bronconeumonias, 3 abscesos de pulmon, 2 neumonias lobares, 1 empiema y 1 bronquiolitis). De los 20 pacientes, 18 presentaban una enfermedad predisponente a la infeccion y 12 de ellos requirieron intubacion endotraqueal y/o traqueostomia con asistencia respiratoria mecanica. El germen mas frecuentemente aislado (90% de las veces por puncion transtraqueal) fue la Pseudomonas aeruginosa, siendo en todos los casos sensible a la prueba por difusion de disco.El cefoperazone se administro por vias endovenosa o intramuscular a una dosis de dos a tres gramos cada 12 horas y el tratamiento duro, en promedio, 12.1 dias (rango entre 6 y 19 dias). La respuesta global fue entre excelente y buena en 85% de los pacientes,con una cura bacteriologica de 70%. No hubo efectos colaterales ni alteraciones de laboratorio atribuibles a la droga en ninguno de los 20 pacientes. El cefoperazone sodico resulto ser un antibiotico eficaz y seguro para el tratamiento de las infecciones graves del tracto respiratorio inferior
Assuntos
Adolescente , Humanos , Masculino , Feminino , Cefalosporinas , Infecções RespiratóriasAssuntos
Broncopneumonia , Vírus da Influenza A/isolamento & purificação , Pneumonia Viral , Doença Aguda , Adulto , Biópsia , Gasometria , Broncopneumonia/diagnóstico , Broncopneumonia/patologia , Broncopneumonia/fisiopatologia , Feminino , Humanos , Pulmão/patologia , Masculino , Pneumonia Viral/patologia , Pneumonia Viral/fisiopatologia , Insuficiência Respiratória/etiologiaRESUMO
1 - Five patients with severe metabolic acidosis secondary to methanol poisoning were studied before and after receiving 6.7 to 10 mEq NaHCO3/kg body weight. 2 - Two thirds of the infused HCO3- left the extracellular space and, since its apparent volume of distribution was much larger than under normal conditions, it largely overestimated HCO3- needs. On the contrary, the volume of distribution of the buffer base excess was found to be more stable and little affected by the acid-base status. 3 - Based on these observations, a simple method for estimating HCO3- needs in severe metabolic acidosis is proposed, requiring only the initial excess buffer base space which is calculated from body weight and blood buffer base excess values obtained before and after a first dose of bicarbonate.
Assuntos
Acidose/tratamento farmacológico , Bicarbonatos/uso terapêutico , Acidose/induzido quimicamente , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Concentração de Íons de Hidrogênio , Lactente , Masculino , Matemática , Metanol/intoxicação , Pessoa de Meia-Idade , Intoxicação/tratamento farmacológicoRESUMO
1 - Five patients with severe metabolic acidosis secondary to methanol poisoning were studied before and after receiving 6.7 to 10 mEq NaHCO3/kg body weight. 2 - Two thirds of the infused HCO3- left the extracellular space and, since its apparent volume of distribution was much larger than under normal conditions, it largely overestimated HCO3- needs. On the contrary, the volume of distribution of the buffer base excess was found to be more stable and little affected by the acid-base status. 3 - Based on these observations, a simple method for estimating HCO3- needs in severe metabolic acidosis is proposed, requiring only the initial excess buffer base space which is calculated from body weight and blood buffer base excess values obtained before and after a first dose of bicarbonate.
RESUMO
1 - Five patients with severe metabolic acidosis secondary to methanol poisoning were studied before and after receiving 6.7 to 10 mEq NaHCO3/kg body weight. 2 - Two thirds of the infused HCO3- left the extracellular space and, since its apparent volume of distribution was much larger than under normal conditions, it largely overestimated HCO3- needs. On the contrary, the volume of distribution of the buffer base excess was found to be more stable and little affected by the acid-base status. 3 - Based on these observations, a simple method for estimating HCO3- needs in severe metabolic acidosis is proposed, requiring only the initial excess buffer base space which is calculated from body weight and blood buffer base excess values obtained before and after a first dose of bicarbonate.