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1.
BACKGROUND/AIMS: The portal pressure response to propranolol varies significantly in individual patients with cirrhosis. At present, propranolol responders can be identified only by measuring the hepatic venous pressure gradient. The aims of this study were: 1) to investigate whether the noninvasive monitoring of portal blood flow by pulsed Doppler ultrasound and forearm blood flow by strain-gauge plethysmography can predict the hepatic venous pressure gradient response to propranolol in patients with cirrhosis, and 2) to analyze the factors that may influence this response. METHODS: Hemodynamic measurements were undertaken in 80 patients with cirrhosis before and after receiving propranolol (0.15 mg/kg i.v., n = 60) or placebo (n = 20). RESULTS: No changes were observed in the placebo group. Propranolol lowered (p < 0.01) hepatic venous pressure gradient from 17.6 +/- 3.8 to 14.7 +/- 3.8 mmHg, portal blood flow from 1122 +/- 363 to 897 +/- 332 ml/min and forearm blood flow from 7.52 +/- 3.1 to 6.12 +/- 2.3 ml/min%. Changes in hepatic venous pressure gradient were correlated (p < 0.01) with those of portal blood flow (r = 0.82) and forearm blood flow (r = 0.54). The reduction in hepatic venous pressure gradient was > 20% in 23 patients ("responders"). The accuracy of portal Doppler flowmetry in identifying responders was higher than that of forearm plethysmography (88.3 vs. 68.3%, p < 0.05). Multivariate analysis proved that previous variceal bleeding was the only factor independently associated with a lack of response to propranolol (relative risk 3.42, 95% CI 1.5-7.4, p < 0.01). Hepatic venous pressure gradient reduction by propranolol was higher in non-bleeders than in bleeders (-19.9 +/- 9.4 vs. -11.3 +/- 8.6%, p < 0.01). CONCLUSIONS: Portal Doppler ultrasound can be used as a reliable surrogate indicator of the hepatic venous pressure gradient response to acute propranolol administration. In addition, our study indicates that this response is mainly influenced by previous variceal hemorrhage.  相似文献   

2.
AIMS: The aim of this study was to develop a technique to measure collateral blood flow in portal hypertensive rats. METHODS: Morphological techniques included inspection, casts and angiographies of portosystemic shunts. The main hemodynamic measurements were splenorenal shunt blood flow (transit time ultrasound method), percentage of portosystemic shunts and regional blood flows (microsphere method). In study 1, a model of esophageal varices was developed by ligating the splenorenal shunt. In study 2, morphological studies of the splenorenal shunt were performed in rats with portal vein ligation. In study 3, the relationship between splenorenal shunt blood flow with percentage of portosystemic shunts was evaluated in dimethylnitrosamine cirrhosis. In study 4, secondary biliary, CCl4 and dimethylnitrosamine cirrhosis were compared. In study 5, rats with portal vein ligation received acute administration of octreotide. In study 6, rats with dimethylnitrosamine cirrhosis received acute administration of vapreotide. RESULTS: Blood flow of para-esophageal varices could not be measured. SRS blood flow was correlated with the mesenteric percentage of portosystemic shunts (r = 0.74, P < 0.05), splenic percentage of portosystemic shunts (r = 0.54, P < 0.05) and estimated portosystemic blood flow (r = 0.91, P < 0.01). Splenorenal shunt blood flow was 6 to 12 times higher in portal hypertensive rats, e.g., in portal vein ligated rats: 2.8 +/- 2.7 vs 0.3 +/- 0.1 mL.min-1 in sham rats (P < 0.01), and was similar in the different cirrhosis models but was higher in portal vein ligated rats than in cirrhotic rats (1.2 +/- 0.7 vs 0.6 +/- 0.6 mL.min-1.100 g-1, P = 0.05). Octreotide significantly decreased splenorenal shunt blood flow: -23 +/- 20% (P < 0.01) vs -6 +/- 8% (not significant) in placebo rats. The variation of splenorenal shunt blood flow after vapreotide was significant but not that of the splenic percentage of portosystemic shunts compared to placebo. CONCLUSIONS: The splenorenal shunt is the main portosystemic shunt in rats. The measurement of splenorenal shunt blood flow is easy, accurate and reproducible and should replace the traditional measurement of the percentage of portosystemic shunts in pharmacological studies.  相似文献   

3.
Desmopressin (DDAVP), a synthetic analogue of vasopressin, has been shown to improve the bleeding time in patients with cirrhosis. The duration of this effect and the hemodynamic changes associated with DDAVP have not been studied so far. To evaluate these issues, 14 cirrhotics with portal hypertension were studied in basal conditions and after DDAVP (0.3 uk/kg). In 8 patients, hemostatic tests were done at basal conditions and 1, 3, 6 and 24 hs after drug administration. In the remaining 6 patients, mean arterial pressure, cardiac output, portal and femoral blood flows were evaluated. Hemodynamic parameters were measured by Doppler ultrasound. DDVP caused a marked decrease in bleeding time at 1, 3, 6 and 24 hs (14 +/- 9 vs 8 +/- 3, 7 +/- 4, 6 +/- 4 and 8 +/- 4 min, respectively); the decrease was maximal and statistically significant at 6 hs (55 +/- 15%, p < 0.02) after DDAVP infusion. Bleeding time reduction was observed in every patient studied. In the hemodynamic study, DDAVP caused a mild but significant decrease in mean arterial pressure (12 +/- 8%, p < 0.05); no significant changes were observed in the rest of hemodynamic parameters studied. These findings show that DDAVP can be used to shorten the bleeding time for a period of at least 24 hs in patients with cirrhosis, without deleterious hemodynamic effects. This beneficial effect may be of potential relevance in the medical management of patients with chronic liver diseases.  相似文献   

4.
BACKGROUND/AIMS: Cirrhosis with portal hypertension is associated with changes in the splanchnic and systemic haemodynamics, and subsequent complications, such as bleeding from oesophageal varices, have led to the introduction of long-acting somatostatin analogues in the treatment of portal hypertension. However, reports on the splanchnic and systemic effects of octreotide are contradictory and therefore the aim of the present study was to assess the effects of continuous infusion of octreotide on central and systemic haemodynamics, portal pressures, and hepatic blood flow. METHODS: Thirteen patients with cirrhosis underwent liver vein catheterisation. Portal and arterial blood pressures were determined at baseline and 10, 30, and 50 min after a bolus injection of octreotide 100 micrograms, followed by continuous infusion of octreotide 100 micrograms/ h for 1 h. Hepatic blood flow, cardiac output, central and arterial blood volume, and central circulation time were determined at baseline and 50 min after the start of the octreotide infusion. RESULTS: The mean arterial blood pressure increased during the first 10 min (p < 0.0005), but returned to baseline after 50 min. The central and arterial blood volume (-16%, p < 0.005) and the central circulation time (-8%, p < 0.05) were significantly decreased after 50 min, whereas the cardiac output did not change significantly. The hepatic venous pressure gradient and the hepatic blood flow did not change significantly at any time after infusion of octreotide. CONCLUSIONS: Octreotide does not affect the portal pressure or hepatic blood flow, whereas it may further contract the central blood volume and thereby exert a potentially harmful effect on central hypovolaemia in patients with cirrhosis. However, these early effects do not exclude the possibility that administration of longacting somatostatin analogues over a longer period may have a beneficial effect.  相似文献   

5.
To determine the relationship between quantitative Doppler parameters of portal, hepatic, and splanchnic circulation and hepatic venous pressure gradient (HVPG), variceal size, and Child-Pugh class in patients with alcoholic cirrhosis, we studied forty patients with proved alcoholic cirrhosis who underwent Doppler ultrasonography, hepatic vein catheterization, and esophagoscopy. The following Doppler parameters were recorded: time-averaged mean blood velocity, volume flow of the main portal vein flow, and resistance index (RI) of the hepatic and of the superior mesenteric artery. Doppler findings were compared with HVPG, presence and size of esophageal varices, and Child-Pugh class. There was a significant inverse correlation between portal velocity and HVPG (r = -.69), as well as between portal vein flow and HVPG (r = -.58). No correlation was found between RI in the hepatic artery or superior mesenteric artery and HVPG. No correlation was found between portal vein measurements and presence and size of varices. Severe liver failure was associated with lower portal velocity and flow. In patients with alcoholic cirrhosis, only portal vein blood velocity and flow, but neither hepatic nor mesenteric artery RI, are correlated to the severity of portal hypertension and to the severity of liver failure.  相似文献   

6.
Splanchnic and systemic hemodynamics and plasma levels of aldosterone, glucagon and plasma renin were investigated in 12 patients with advanced cirrhosis before and 2 wk (14.6 +/- 2.8 days) and 2 mo (60.8 +/- 10.5 days) after orthotopic liver transplantation. Liver transplant was followed by significant (p < 0.01) changes in systemic hemodynamics at 2 wk, with a marked reduction in cardiac index (4.9 +/- 0.8 vs. 3.7 +/- 0.7 L/min.m2) and increases in mean arterial pressure (79 +/- 8 vs. 101 +/- 11 mm Hg) and peripheral vascular resistance (721 +/- 149 vs. 1,274 +/- 253 dyn.sec.cm-5). Two months after liver transplant, we saw further significant increases in peripheral vascular resistance (1,700 +/- 341 dyn.sec.cm-5; p < 0.05) without changes in cardiac index. Hepatic venous pressure gradient, very high before transplantation, was normal 2 wk after liver transplant (18.7 +/- 3.0 vs. 2.1 +/- 0.8 mm Hg; p < 0.01). Hepatic blood flow rose markedly from 1.03 +/- 0.46 to 2.25 +/- 0.79 L/min (p < 0.01) and was still elevated at 2 mo (1.84 +/- 0.74 L/min). Azygos blood flow had not changed after 2 wk with respect to pretransplant values (0.65 +/- 0.26 vs. 0.69 +/- 0.39 L/min) but had decreased significantly at 2 mo (0.39 +/- 0.16 L/min; p < 0.05). The elevated aldosterone, plasma renin and glucagon levels found in our cirrhotic patients before transplantation decreased to near-normal values 2 wk after the procedure. These results suggest that most of the hemodynamic and humoral abnormalities characteristic of advanced cirrhosis are reversed after liver transplant.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

7.
OBJECTIVES: Patients with cirrhosis and ascites have high plasma levels of atrial natriuretic peptide (ANP). Pharmacological doses of this hormone usually worsen systemic hemodynamics of cirrhotic patients. We assessed whether ANP influences cardiovascular homeostasis and renal function in patients with compensated cirrhosis at plasma levels comparable to those observed in patients with cirrhosis and ascites. METHODS: Radionuclide angiocardiography was performed in eight compensated cirrhotic patients during placebo (three periods of 15 min each) and ANP infusion (2, 4, and 6 pmol/kg.min for 15 min each), together with appropriate blood and urine sampling, to evaluate left ventricular diastolic, systolic, and stroke volume, heart rate, cardiac output, arterial pressure, peripheral vascular resistance, creatinine clearance, urinary sodium excretion, plasma renin activity, plasma aldosterone, norepinephrine and hematocrit. RESULTS: The infusion increased plasma ANP up to levels (52.03 +/- 2.29 pmol/L) comparable with those observed in 35 patients with ascites (46.42 +/- 1.57 pmol/ L). This increment was associated with significant reductions in left ventricular end diastolic volume, stroke volume, cardiac index (from 3.7 +/- 0.7 to 3.1 +/- 0.5 L/min.m2, p < 0.05) and mean arterial pressure (from 96.7 +/- 6.5 to 88.5 +/- 9.5 mmHg, p < 0.05), while heart rate and hematocrit significantly increased. Peripheral vascular resistance did not change. These hemodynamic effects occurred despite significant increases in plasma renin activity and norepinephrine. ANP also induced increases in creatinine clearance, urinary sodium excretion, and fractional sodium excretion. CONCLUSIONS: Low-dose ANP affected cardiovascular homeostasis and renal sodium handling in compensated cirrhosis, suggesting that this hormone may be involved in the pathophysiology of systemic hemodynamic and renal functional abnormalities of cirrhosis.  相似文献   

8.
BACKGROUND: Hyaluronan is an endogenous polysaccharide whose clearance from the plasma is predominantly by liver sinusoidal cells and is sinusoidal flow dependent. This study was designed to determine if a change in serum hyaluronan might reliably reflect short-term drug-induced changes in sinusoidal perfusion. METHODS: Hemodynamic changes following an oral dose of ketanserin were compared with changes in serum hyaluronan levels in 12 patients with alcoholic liver disease and portal hypertension. Indices determined comprised heart rate, mean arterial pressure (MAP), cardiac output (CO), systemic vascular resistance, hepatic venous pressure gradient (HVPG), indocyanine green (ICG) clearance and extraction, and total hepatic blood flow. Measurements were made in a basal state 1 hour after ketanserin ingestion and expressed as a ratio of values post- to pre-ketanserin administration. RESULTS: Ketanserin had variable effects comprising both increases and decreases in all indices. On univariate and multivariate analysis, changes in serum hyaluronan concentration (1.05 +/- 0.13, mean +/- SD) significantly correlated with only one index: changes in ICG clearance (0.93 +/- 0.17, r = -0.65, P = 0.02). CONCLUSIONS: Changes in serum hyaluronan levels reflect short-term drug-induced changes in sinusoidal perfusion in patients with alcoholic liver disease and portal hypertension. Serial measurement of serum hyaluronan levels may offer a simple method of screening vasoactive drugs for their short-term effects on sinusoidal perfusion.  相似文献   

9.
BACKGROUND AND METHODS: To find an intra-abdominal pressure (IAP) range for laparoscopic procedures that elicits only moderate splanchnic and pulmonary hemodynamic and metabolic changes, including hepatic and intestinal tissue pH and superficial hepatic blood flow, we installed an IAP of 7 and 14 mm Hg each for 30 minutes in 10 healthy pigs (30 +/- 4 kg). RESULTS: In parallel with the increase of IAP, the mean transmural pulmonary artery pressure increased (from 25 +/- 3 to 27 +/- 4 at 7 mm Hg IAP and 30 +/- 6 mm Hg at 14 mm Hg IAP, p < 0.05); the pulmonary artery-to-pulmonary capillary wedge pressure gradient also increased (from 17 +/- 2.7 to 21 +/- 3 mm Hg at 7 mm Hg IAP and 24 +/- 4.2 mm Hg at 14 mm Hg IAP, p < 0.01), and the arterial oxygenation decreased (p < 0.005). Relevant changes at an IAP of 14 mm Hg were observed in right atrial pressure during inspiration (from 7 +/- 2 to 12 +/- 3 mm Hg, p < 0. 0001) and in abdominal aortic flow (from 1.43 +/- 0.4 to 1.19 +/- 0. 3 L/min, p < 0.01). However, transmural right atrial pressure and cardiac output remained essentially unchanged. Portal and hepatic venous pressure increased in parallel with the IAP (portal: from 12 +/- 3 to 17 +/- 3 at 7 mm Hg IAP and 22 +/- 3 mm Hg at 14 mm Hg IAP, p < 0.01; hepatic venous: from 8 +/- 3 to 14 +/- 6 at 7 mm Hg IAP and 19 +/- 6 mm Hg at 14 mm Hg IAP, p < 0.005), but the transmural portal and hepatic venous pressures decreased (p < 0.01), indicating decreased venous filling. Portal flow was maintained at 7 mm Hg but decreased at 14 mm Hg from 474 +/- 199 to 395 +/- 175 mL/min (p < 0. 01), whereas hepatic arterial flow remained stable. Hepatic superficial blood flow decreased during insufflation and increased after desufflation. Tissue pH fell together with portal and hepatic venous pH (intestinal: from 7.323 +/- 0.05 to 7.217 +/- 0.04; hepatic: from 7.259 +/- 0.04 to 7.125 +/- 0.06, both p < 0.01) at 14 mm Hg. CONCLUSION: The hemodynamic and metabolic derangement in the pulmonary and splanchnic compartments are dependent on the extent of carbon dioxide pneumoperitoneum. The effect of low IAP (7 mm Hg) on splanchnic perfusion is minimal. However, higher IAPs (14 mm Hg) decrease portal and superficial hepatic blood flow and hepatic and intestinal tissue pH.  相似文献   

10.
OBJECTIVE: This study was designed to clarify how thrombopoietin (TPO) functions in and, to some extent, causes thrombocytopenia complicating liver cirrhosis and portal hypertension. METHODS: Our study population consisted of 19 cirrhotic and six noncirrhotic patients who underwent percutaneous transhepatic portography (PTP) and hepatic venography. RESULTS: The platelet counts of the cirrhotic patients were significantly lower than those of the noncirrhotic patients (8.7 +/- 4.1 vs 17.4 +/- 7 x 10(4)/microl; p < 0.01). The flow direction in the splenic vein was confirmed by PTP. Ten hepatofugal and nine hepatopetal flow directions in the splenic vein were noted among the cirrhotics. The hepatofugal group showed lower portal venous pressure (20 +/- 10 vs 32 +/- 4 cm H2O; p < 0.01) than the hepatopetal group and had a higher incidence of hepatic encephalopathy (six of 10 vs zero of nine; p < 0.01). The hepatic vein-portal difference in TPO did not differ substantially between the cirrhotics and noncirrhotics (0.12 +/- 0.04 vs 0.24 +/- 0.07 fmol/ml). Comparisons of this value among the three groups showed the TPO difference to be lowest in the hepatofugal group (hepatofugal: 0.04 +/- 0.03, hepatopetal: 0.21 +/- 0.07, noncirrhotic: 0.24 +/- 0.07; p < 0.05). CONCLUSIONS: Our findings suggest that TPO production in the cirrhotic liver is regulated by the portal blood supply to the liver. Thus, portal hemodynamics may play a critical role in the development of thrombocytopenia.  相似文献   

11.
OBJECTIVE: This study was undertaken to determine the effects of transjugular intrahepatic portasystemic shunt (TIPS) and small-diameter prosthetic H-graft portacaval shunt (HGPCS) on portal and effective hepatic blood flow. SUMMARY BACKGROUND DATA: Mortality after TIPS is higher than after HGPCS for bleeding varices. This higher mortality is because of hepatic failure, possibly a result of excessive diminution of hepatic blood flow. METHODS: Forty patients randomized prospectively to undergo TIPS or HGPCS had effective hepatic blood flow determined 1 day preshunt and 5 days postshunt using low-dose galactose clearance. Portal blood flow was determined using color-flow Doppler ultrasound. RESULTS: Treatment groups were similar in age, gender, and Child's class. Each procedure significantly reduced portal pressures and portasystemic pressure gradients. Portal flow after TIPS increased (21 mL/second +/- 11.9 to 31 mL/second +/- 16.9, p < 0.05), whereas it remained unchanged after HGPCS (26 mL/second +/- 27.7 to 14 mL/second +/- 41.1, p = n.s.). Effective hepatic blood flow was diminished significantly after TIPS (1684 mL/minute +/- 2161 to 676 mL/minute +/- 451, p < 0.05) and was unaffected by HGPCS (1901 mL/ minute +/- 1818 to 1662 mL/minute +/- 1035, p = n.s.). CONCLUSIONS: Both TIPS and HGPCS achieved significant reductions in portal vein pressure gradients. Portal flow increased after TIPS, although most portal flow was diverted through the shunt. Effective hepatic flow is reduced significantly after TIPS but well preserved after HGPCS. Hepatic decompensation and mortality after TIPS may be because, at least in part, of reductions in nutrient hepatic flow.  相似文献   

12.
OBJECTIVE: In this study the effect of the hemorheological agent pentoxifylline on the pressure of esophageal varices was investigated in portal hypertensive cirrhotic patients. METHODS: Intravariceal pressure was measured endoscopically using the direct puncture technique in 20 patients. Measurements were obtained under baseline conditions and 30 min after double-blind administration of pentoxifylline (1.4 mg/kg BW, n = 10 patients) or an identical volume of NaCl 0.9% solution (n = 10 patients). RESULTS: Under baseline conditions, intravariceal pressure was similar in pentoxifylline and placebo groups (17.3+/-5.5 mm Hg vs 18.8+/-4.6 mm Hg, respectively; p = N.S.). Placebo administration had no significant effect on intravariceal pressure (18.8+/-4.6 mm Hg vs 18.3+/-4.1 mm Hg; p = N.S.). In contrast, pentoxifylline caused a highly significant reduction of intravariceal pressure, (from 17.3+/-5.5 mm Hg to 11.4+/-5.9 mm Hg; p = 0.0001), the overall mean reduction being 36.1+/-14.1% mm Hg. CONCLUSIONS: We concluded that pentoxifylline, by reducing blood flow viscosity, caused a significant decrease in variceal pressure in patients suffering from portal hypertension.  相似文献   

13.
BACKGROUND/AIMS: The aim of this study was to investigate glucagon and insulin metabolism in order to clarify the mechanisms that lead to hyperglucagonemia and hyperinsulinemia in cirrhosis. METHODOLOGY: Splanchnic output and metabolic clearance rates were studied in 16 cirrhotic patients and 5 non-cirrhotic controls. Splanchnic glucagon and insulin output into the portal circulation were calculated by the difference between portal venous and systemic arterial concentration multiplied by portal plasma flow. The metabolic clearance rate was calculated as the ratio of output to systemic arterial concentration. Portal blood flow was measured by continuous local thermodilution. RESULTS: Arterial glucagon levels were higher in cirrhotics than in controls. Glucagon output was triple of that found in controls (52.4 +/- 7.0 vs 17.7 +/- 2.9 ng/min, p < 0.05). Both groups exhibited similar metabolic clearance rates of glucagon. Systemic arterial insulin values were higher in cirrhotics than in non-cirrhotics. Insulin output was not significantly different between the two groups. However, metabolic clearance of insulin in cirrhotics was reduced to one half of the rate found in controls (237.0 +/- 39.8 vs. 450.5 +/- 17.5 mL/min, p < 0.05). CONCLUSIONS: Hyperglucagonemia in cirrhotic patients results from increased pancreatic output, while hyperinsulinemia results from decreased insulin clearance.  相似文献   

14.
Enoximone, a phosphodiesterase inhibitor (PDEI), has both positive inotropic and vasodilatory properties. We examined the effect of a single oral dose of enoximone as compared with placebo on myocardial ischaemia and global left ventricular (LV) function using both exercise ECG and Doppler measurements of aortic blood flow, respectively. Twenty patients (16 men, 4 women) with a mean age of 59 years and stable angina were studied. Total exercise duration was significantly longer after enoximone as compared with placebo treatment, with a mean difference of 22.8 s (p = 0.003). Times (mean +/- SD) to onset of angina and development of significant ST-segment decrease were similar after placebo (454 +/- 101 and 352 +/- 155 s, respectively) or enoximone (500 +/- 155 and 413 +/- 192 s, respectively), although both showed trends in favour of enoximone. As compared with placebo, significantly higher heart rate (HR) was measured for enoximone both at rest (75 +/- 18 vs. 90 +/- 22 beats/min, p < 0.01) and on recovery from exercise (81 +/- 18 vs. 89 +/- 19 beats/min, p < 0.05). Enoximone had no significant effect on systolic or diastolic blood pressure (SBP, DBP) or rate-pressure product (RPP) generated at rest or during exercise. Changes in both acceleration and velocity of aortic blood flow during exercise were similar after administration of enoximone or placebo. We showed that a single oral dose of enoximone is well tolerated in patients with ischaemic heart disease, improving both exercise capacity and favourably influencing ST-segment changes with no increase in adverse events or significant haemodynamic disturbances.  相似文献   

15.
The aim of this study was to assess the effect of the early and chronic administration of octreotide in the prevention of hepatic fibrosis and portal hypertension (PHT). Two experimental models of liver fibrosis caused by bile duct ligation (BDL) or CCl4 were divided into 4 rat groups: sham, placebo, and octreotide (10 and 100 micrograms/kg twice daily, subcutaneously). Liver fibrosis was assessed by the area of fibrosis (image analysis), liver hydroxyproline and fibronectin mRNA contents, and serum hyaluronate. Systemic and splanchnic hemodynamic changes were also evaluated, including the splenorenal shunt blood flow by the transit-time ultrasound (TTU) technique. In both models, splenorenal shunt blood flow was significantly lower in the octreotide groups than in the placebo group (P <.05), while portal pressure was not significantly decreased. There was a significant decrease in fibrosis by octreotide in the CCl4 model only: area of fibrosis: 13.9% +/- 3.7% vs. 9.8% +/- 2.5% (P <.01), hydroxyproline: 1.8 +/- 0.6 vs. 1.3 +/- 0.4 mg/g wet liver (P <.05), respectively, placebo vs. octreotide 10 micrograms/kg. There was a significant correlation between the area of fibrosis and hydroxyproline liver content (r =.87 in the biliary model and r =.91 in the CCl4 model; P <.0001). The early and chronic administration of octreotide prevents the development of portocollateral blood flow without reducing portal pressure in two models of liver fibrosis and the development of liver fibrosis in the CCl4 model.  相似文献   

16.
BACKGROUND: Previous studies in rats have demonstrated that anemia induces a significant increment in gastric mucosal blood flow. In the present study, we investigated whether chronic anemia induces similar changes in gastric blood perfusion in humans, and if this effect is also present in cirrhotic patients in whom gastric blood flow is usually increased in basal conditions. METHODS: Gastric mucosal blood perfusion was assessed by means of laser-Doppler flowmetry and reflectance spectrophotometry applied through the endoscope. RESULTS: Anemia significantly increases laser-Doppler signal in cirrhotic (2.3 +/- 0.11 vs 2.9 +/- 0.22 volts, p < 0.05) and noncirrhotic patients (1.71 +/- 0.15 vs 2.24 +/- 0.17, p < 0.05). In anemic patients the index of hemoglobin concentration of the gastric mucosa, assessed by reflectance spectrophotometry, was significantly decreased in cirrhotic patients (107.6 +/- 4.7 vs 95.5 +/- 3.3, p < 0.05) and noncirrhotic patients (93.9 +/- 4.1 vs 76.1 +/- 4.2, p < 0.01), whereas the index of oxygen saturation was increased (36.7 +/- 0.7 vs 40.4 +/- 1.4, p = 0.05; and 36.4 +/- 1.1 vs 43.2 +/- 1.9, p < 0.01, respectively). CONCLUSIONS: In conclusion, chronic anemia is associated with an enhanced gastric blood perfusion reflected by an increased laser-doppler signal and gastric mucosal oxygen index despite a decrease in gastric hemoglobin concentration. In cirrhotic patients, anemia promotes a further increment in its basal gastric hyperemia.  相似文献   

17.
BACKGROUND/AIMS: Diminished postprandial portal hyperemia has been demonstrated by echo-Doppler flowmetry in patients with liver cirrhosis, but its diagnostic role is unclear. This prospective study was therefore undertaken in patients with varying severity of portal hypertension and degree of liver cirrhosis. METHODS: Portal flowmetry was performed in 66 patients with cirrhosis and 20 healthy volunteers during fasting and 30 min after ingestion of a standardized meal. Hemodynamic parameters were related to the degree of esophageal varices, variceal bleeding, portal hypertensive gastropathy and Child-Pugh score. RESULTS: The postprandial portal blood velocity increment was low in patients with esophageal varices of any degree (22-24%), compared to patients without varices (49%, p<0.01) and healthy controls (65%, p<0.001), but was not different in patients with or without variceal bleeding (22% vs. 20%). In contrast, the congestion index (CI; ratio of portal vein cross-sectional area and portal blood velocity) pre-/postprandial decreased in the bleeding group only (CI pre/ CI post 1.30+/-0.23 (no bleeding) vs. 0.86+/-0.29 (bleeding); p<0.01). Portal hypertensive gastropathy was not related to any of the portal flow parameters. The portal blood velocity increment was comparable in controls (65%) and patients with Child-Pugh class A cirrhosis (56%), but lower in patients with class B (32%) and class C cirrhosis (15%, p<0.05 vs. class A). Also, there was no postprandial decrease in congestion index in patients with the most severe cirrhosis (p<0.01 class C vs. class A and B). CONCLUSIONS: The postprandial rise in portal flow is inversely related to the severity of portal hypertension and liver cirrhosis, and may be a valuable parameter with respect to the risk of variceal bleeding.  相似文献   

18.
Gastric intramucosal bleeding in portal hypertensive gastropathy was investigated in terms of gastric mucosal microcirculation, coagulation-fibrinolysis factors, and local fibrinolysis in patients with liver cirrhosis. The gastric mucosa was examined by endoscopy, and the patients were classified into two groups with or without bleeding. Gastric mucosal blood flow was measured simultaneously with coagulation-fibrinolysis factors or local fibrinolysis in both groups. As gastric mucosal blood flow, the gastric mucosal blood volume (IHb) and the oxygenated hemoglobin concentration (ISO2) were determined by the organ reflection spectrum method. Coagulation-fibrinolysis factors were measured in the blood. For evaluation of local fibrinolysis, gastric biopsy specimens were placed on a standard fibrin plate, and the fibrinolysis area was measured. Compared with the non-bleeding group, the bleeding group showed increased IHb and decreased ISO2 (p < 0.05), suggesting marked congestion of blood flow. Gastric intramucosal bleeding was frequently observed in patients with marked congestion of blood flow and markedly abnormal values of coagulation-fibrinolysis factors. Gastric local fibrinolysis was also significantly enhanced in the bleeding group (p < 0.05). In addition, local fibrinolysis was correlated positively with the gastric mucosal blood volume (r = 0.68, p < 0.05) and negatively with the oxygenated hemoglobin concentration (r = -0.58, p < 0.05). These results suggest the following mechanism of gastric mucosal bleeding in liver cirrhosis and portal hypertension. Congestion of gastric mucosal blood flow is present in liver cirrhosis and portal hypertension. An increase in the microvascular pressure and hypoxia cause release of tissue plasminogen activators from gastric mucosal cells and vascular endothelial cells. As a result, gastric local fibrinolysis is enhanced, causing gastric mucosal bleeding.  相似文献   

19.
OBJECTIVE: The purpose of this study was to answer two questions: (1) Does a mixed amino acid infusion enhance systemic and renal perfusion in the early postoperative period after heart operations? (2) Does the addition of insulin (glucose-insulin-potassium solution) provide additional effects to those of an amino acid infusion? METHODS: Thirty-three male patients undergoing coronary artery bypass grafting (mean age 65.9 +/- 1.2 years) were included in a prospective, controlled, randomized study. Eleven patients (AA group) received infusion of mixed amino acids (11.4 gm), 11 patients (AA + GIK group) received infusion of mixed amino acids (11.4 gm) and insulin solution (225 IU insulin, glucose with glucose clamp technique, and potassium), and 11 patients served as control subjects. RESULTS: Amino acid infusion alone had no effect on systemic vascular resistance or cardiac index but increased renal blood flow 51% +/- 11% (from 114 +/- 13 to 172 +/- 24 ml.min-1.m-2 in one kidney, p < 0.05 vs the control group). Insulin solution in addition to amino acid infusion reduced systemic vascular resistance 24% +/- 3% (from 1280 +/- 85 to 960 +/- 57 dyn.sec.cm-5, p < 0.05 vs the control and AA groups) and increased cardiac index 13% +/- 3% (from 2.3 +/- 0.2 to 2.6 +/- 0.2 L.min-1.m-2, p < 0.05 vs the control and AA groups). Insulin had no significant additive effect on renal blood flow. CONCLUSIONS: Our data imply that (1) infusion of mixed amino acids enhances renal blood flow after cardiac operations but has no effect on systemic perfusion and (2) the addition of insulin solution improves systemic perfusion. The combined treatment may potentially reduce the risk of renal hypoperfusion injury in the postoperative period after coronary artery bypass grafting.  相似文献   

20.
OBJECTIVE: The aims of the study were to establish the roles of angiotensin II and of the cardiopulmonary baroreceptor reflex in the regulation of peripheral vascular tone in patients with cirrhosis. METHODS: Forearm blood flow responses to subsystemic, locally active intrabrachial infusions were measured in patients with Child's Grade C cirrhosis and matched controls using bilateral venous occlusion plethysmography. Responses were determined to the angiotensin II type I receptor antagonist, losartan, noradrenaline, angiotensin II and the nitric oxide synthase inhibitor, L-NG-monomethyl arginine. RESULTS: Losartan at 30 and 90 micrograms/min caused no significant change in blood flow in controls, but caused 23 +/- 6% and 27 +/- 5% increases in patients respectively (p < 0.001). Lower body negative pressure caused a mean bilateral reduction in forearm blood flow of 20 +/- 4% in controls (p < 0.001) but only tended to reduce flow (9 +/- 5%; p = 0.06) in patients (p < 0.001; controls vs. patients). Noradrenaline, angiotensin II and L-NG-monomethyl arginine caused significant vasoconstriction (p < 0.001) in both patients and controls although angiotensin II caused significantly less vasoconstriction in patients (p = 0.01). CONCLUSIONS: We conclude that angiotensin II makes an important contribution to basal peripheral vascular tone in patients with cirrhosis in the face of reduced vascular responses to its local administration. In addition, the vasoconstrictor response to cardiopulmonary baroreceptor unloading is attenuated despite normal vascular responses to noradrenaline. These responses are consistent with chronic activation of the renin-angiotensin and sympathetic nervous systems in patients with advanced cirrhosis.  相似文献   

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