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Publications (3)10.27 Total impact

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    ABSTRACT: To investigate the physiologic effects of exogenous vasopressin as a potential alternative to traditional high-dose catecholamine therapy for septic patients with vascular hyporeactivity to catecholamines. Prospective, case-controlled study. Intensive care unit of a university hospital. Vasopressin was infused in 16 critically ill septic patients who remained persistently hypotensive despite infusions of pharmacologic doses of catecholamines. Continuous intravenous infusion of vasopressin at 0.04 units/min for 16 hrs, in place of escalating the amount of catecholamines being infused. After administration of vasopressin, systemic vascular resistance and mean arterial pressure were immediately and significantly increased in comparison with the values obtained just before vasopressin. When the vasopressin infusions were discontinued, mean arterial pressure decreased immediately and dramatically. We did not detect any obvious adverse cardiac effects during the vasopressin infusions. Vasopressin had no effect on other hemodynamic parameters or any of the metabolic parameters studied, including measures of oxygenation, plasma glucose, or electrolytes. Urine output increased significantly during the administration of vasopressin, although this effect may be nonspecific. Lactate concentrations decreased, particularly in the survival group, but the decreases were not significant. Overall survival was 56%. Low-dose vasopressin infusions increased mean arterial pressure, systemic vascular resistance, and urine output in patients with vasodilatory septic shock and hyporesponsiveness to catecholamines. The data indicate that low-dose vasopressin infusions may be useful in treating hypotension in these patients.
    Critical Care Medicine 04/2001; 29(3):487-93. · 6.12 Impact Factor
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    ABSTRACT: The effects of ligustrazine on hepatic oxygenation in the isolated rat liver were investigated during prolonged perfusion and following the injection of norepinephrine. After injection of erythrocytes into the perfusate, the hemoglobin spectra in the liver were measured by Erlangen microlightguide spectroscopy, and the hemoglobin oxygenation (HbO2) in the liver was calculated on the basis of the Kubelka-Munk theory. During artificial perfusion, the HbO2 value was decreased from 59.3 +/- 6.4% (after one hour's perfusion) to 25.5 +/- 19.5% (n = 441; after six hours' perfusion). However, when ligustrazine was injected into the perfusate after six hours' perfusion, the HbO2 values recovered to 56.4 +/- 9.7% (n = 441). After injection of norepinephrine, HbO2 in the liver decreased from 48.8 +/- 10.4% to 25.2 +/- 18.4% (n = 961), while subsequent administration of ligustrazine caused a recovery to 62.9 +/- 6.0% (n = 961). Our results suggested that ligustrazine is a powerful hepatic vasodilator for improving hepatic oxygenation.
    In vivo (Athens, Greece) 01/1999; 13(1):29-34. · 1.22 Impact Factor
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    ABSTRACT: To evaluate microvascular regulation in human skin, changes in intracapillary hemoglobin oxygen saturation (HbO2) were studied in human finger skin following an abrupt change in local ambient temperature. In the first series of experiments, we assessed the heterogeneity of HbO2 in the skin by using a 2-D scanning system and a rapid micro-lightguide spectrophotometer at each of two near-normal skin temperatures. The data showed that heterogeneous oxygenation exists in human skin even at near-normal temperatures (although the pattern is different at different skin temperatures). In a second series of experiments, the performance of the microcirculation of the skin was continuously examined in a selected area with initially different oxygenation levels during an abrupt change in local ambient temperature (5, 15, 25, 35, and 45 degrees C). At very low (5 degrees C) or very high (45 degrees C) temperatures, oxygenation in tissues within the low HbO2 area increased greatly, but there was no such change within the high HbO2 area. Our data indicate that different types of capillary supply units exist in human skin (indicated by the initially different oxygenation levels). These different capillary supply units may operate to produce a local redistribution of flow between the various capillary supply units. This effect may be initiated by heat sensors and oxygen sensors when temperature of the skin is varied.
    Microvascular Research 10/1998; 56(2):104-12. · 2.93 Impact Factor