Hemodynamic effects of glucagon in portal hypertension

It has been suggested that glucagon contributes to the pathogenesis of portal hypertension by increasing portal blood flow. This study examined this issue by assessing the hemodynamic effects of a pharmacological dose of glucagon (1 mg, intravenously) in patients with cirrhosis and portal hypertension (n = 10) and in subjects without significant liver disease (controls = n = 5). Patients with cirrhosis had much higher glucagon levels than control subjects (875 +/- 167 vs. 186 +/- 25 pg/ml, p less than 0.01) and showed blunted hemodynamic responses after glucagon administration. This occurred despite greater circulating glucagon levels, probably because of a significant prolongation of the plasma half-life of exogenously administered glucagon (4.9 +/- 0.4 vs. 2.7 +/- 0.1 min, p less than 0.1). Control subjects had marked increases in heart rate (+ 19% +/- 4%, p less than 0.01), cardiac index (+ 16% +/- 4%, p = 0.01) and arterial pressure (+ 10% +/- 3%, p less than 0.05), but corresponding changes in patients with cirrhosis (+ 7% +/- 1%, + 6% +/- 1%, and + 6% +/- 2%, respectively) were significantly less pronounced (p = 0.05), and there was a negative correlation between basal glucagon levels and the response of heart rate to glucagon injection (r = -0.804, p less than 0.001). Resistance to the systemic effects of glucagon in cirrhosis may thus be caused by a down-regulation of vascular glucagon receptors. In addition, glucagon administration caused a significant increase in portal pressure (from 18.1 +/- 1.1 to 19.0 +/- 1.2 mm Hg, p less than 0.01), as well as in azygos blood flow (from 0.54 +/- 0.03 to 0.64 +/- 0.04 L/min, + 19% +/- 4%, p less than 0.02), reflecting increased portocollateral blood flow. These findings are consistent with the hypothesis that glucagon is one of the factors contributing to the splanchnic vasodilatation and increased portal pressure of cirrhosis.     

Low dose of nitroglycerin failed to improve splanchnic hemodynamics in patients with cirrhosis: evidence for an impaired cardiopulmonary baroreflex function

High doses of nitroglycerin may decrease portal pressure in patients with cirrhosis with untoward effects such as arterial hypotension and a decrease in systemic O2 uptake. In the present study, low doses of nitroglycerin (7 to 15 micrograms per min, i.v.) were administered in 11 patients with cirrhosis in order to unload cardiopulmonary baroreceptor--one of the possible mechanisms by which nitroglycerin may improve splanchnic hemodynamics--and moreover to avoid deleterious systemic effects. Nitroglycerin significantly decreased right atrial pressure (-35%) and pulmonary wedged pressure (-27%) with significant increase in plasma norepinephrine concentration (+23%), which indicated that cardiopulmonary baroreceptor unloading was achieved. Changes in systemic hemodynamics were slight, although significant, with a decrease in arterial pressure (-8%) and an increase in heart rate (+8%); this indicates a minimal effect on high-pressure baroreflexes. In contrast, no significant change was observed in hepatic venous pressure gradient, hepatic blood flow and azygos blood flow. However, the fraction of cardiac output reaching the azygos system significantly increased by 18%. Plasma renin activity did not change significantly. Moreover, O2 transport and uptake were significantly decreased. These findings show that low doses of nitroglycerin failed to improve splanchnic hemodynamics in patients with cirrhosis. These results suggest an impaired cardiopulmonary baroreflex function which is probably located on the efferent arch.     

Hemodynamic effects of a clonidine-induced decrease in sympathetic tone in patients with cirrhosis

A decrease in plasma noradrenaline--a reflection of sympathetic nervous system activity--by clonidine, a centrally acting alpha 2-agonist, could reduce the hyperdynamic circulation observed in cirrhosis and may thereby decrease portal hypertension. Plasma noradrenaline concentration and plasma renin activity as well as systemic and splanchnic hemodynamics were measured in 12 patients with cirrhosis and ascites before and after administration of either 150 micrograms of clonidine or placebo. Plasma noradrenaline concentration significantly decreased in all patients after clonidine administration, whereas plasma renin activity did not change significantly. There were statistically significant reductions of cardiac output (-17.4%), mean arterial pressure (-12.2%), hepatic venous pressure gradient (-19.7%) and azygos blood flow (-26.6%) after administration of clonidine. No significant correlation was found between the reduction of plasma noradrenaline concentration and changes in systemic or splanchnic hemodynamics. Hepatic blood flow was not changed by clonidine. Placebo administration had no effect on any laboratory or hemodynamic measurement. We conclude that the reduction in sympathetic nervous system activity by clonidine and the subsequent decrease in the hyperdynamic circulation suggests that sympathetic overactivity contributes to the circulatory derangements in patients with cirrhosis.     

Hyperkinetic circulatory syndrome in patients with presinusoidal portal hypertension : Effect of propranolol

This study evaluates systemic and splanchnic haemodynamics and the effect of propranolol in 15 patients with presinusoidal portal hypertension (portal vein obstruction, n = 11; schistosomiasis, n = 4). These patients exhibited a hyperkinetic circulatory syndrome characterized by high cardiac index (4.4 +/- 1.61.min-1.m-2, mean +/- S.D.) and by low systemic vascular resistance despite normal liver function and sinusoidal pressure. Hepatic blood flow was decreased in half of the patients with portal vein obstruction. Azygos blood flow, an estimate of superior portal-systemic collateral circulation, was markedly increased in all patients (0.46 +/- 0.19 l/min, upper limit of normal: 0.19 l/min). Therefore, in these patients with normal hepatic venous pressure gradient, azygos blood flow measurement provides an index of splanchnic haemodynamic changes. Propranolol administration (15 mg, i.v.) reduced the hyperkinetic circulatory syndrome, with a significant decrease in heart rate (-17 +/- 6%), cardiac index (-25 +/- 12%) and azygos blood flow (-40 +/- 26%) and a significant increase in systemic vascular resistance (+40 +/- 40%). These results suggest that the hyperkinetic circulatory syndrome observed in these patients, could be related to an increase in beta-adrenergic activity. The decrease in azygos blood flow, after propranolol administration, was significantly correlated (r = 0.94) with the increase in right atrial pressure. This finding suggests that propranolol may act through an increase in portal-systemic collateral venous tone. These haemodynamic results justify, in patients with presinusoidal portal hypertension, clinical trials investigating the beneficial effect of beta-blockers on gastrointestinal bleeding caused by portal hypertension.     

Use of color Doppler EUS in assessing azygos blood flow for patients with portal hypertension.

BACKGROUND: Azygos blood flow is an index of blood flow through gastroesophageal collateral vessels and varices in portal hypertension. Conventional measurement of azygos blood flow involves catheterization of the azygos vein. We studied the feasibility of assessing azygos blood flow with color Doppler endosonography and of monitoring the effects of vasoactive agents on azygos blood flow. METHODS: Patients with portal hypertension were examined by means of linear array color Doppler endoscopic ultrasonography (EUS). Patients who had taken propranolol or nitrates in the 4 weeks before the day of measurement of azygos blood flow were excluded. After identification of the azygos vein and recording of baseline readings of mean arterial blood pressure, pulse rate, and azygos blood flow, patients were selected in a random manner to receive a bolus injection of 2 mg terlipressin, 250 microg somatostatin, or saline solution (control). Azygos blood flow was measured 1, 5, and 10 minutes after injection (AzBF-1, AzBF-5, AzBF-10). RESULTS: Six patients were recruited in each treatment group. Basal azygos blood flow showed a positive association with the Child-Pugh grade of cirrhosis (p < 0.005). After bolus injection of terlipressin and somatostatin, there was a marked decrease in AzBF-1 (24% and 37%), AzBF-5 (42% and 19%), and AzBF-10 (40% both) compared with baseline. The control group showed no significant change in azygos blood flow. CONCLUSIONS: Color Doppler EUS is useful in assessing azygos blood flow in portal hypertension and in monitoring the effects of vasoactive agents.     

Propranolol decreases portal pressure without changing portocollateral resistance in cirrhotic rats

Propranolol decreases portal pressure by reducing portal blood inflow. Studies in rats with prehepatic portal hypertension due to portal vein stenosis (a model with extensive portosystemic shunting) have shown that propranolol increases the portocollateral resistance, which hinders the fall in portal pressure. The present study examined the effects of propranolol on splanchnic and systemic hemodynamics in rats with portal hypertension due to cirrhosis of the liver, a model which is characterized by mild portosystemic shunting. Two groups of rats with CCl4-induced cirrhosis were studied: the propranolol group (n = 8), which received a propranolol infusion of 2 mg per 15 min, and controls (n = 9), which received a placebo (saline) infusion. Hemodynamic measurements were done using radiolabeled microspheres. Propranolol-treated rats had significantly lower cardiac output (-31%) and heart rate (-26%) than controls (p less than 0.001). Hepatic artery flow was not modified by propranolol. Propranolol caused splanchnic vasoconstriction, manifested by increased splanchnic resistance (+57%) and by a significant fall in portal blood inflow (4.8 +/- 0.4 vs. 6.3 +/- 0.5 ml per min.100 gm in controls, p less than 0.05). In contrast with rats with prehepatic portal hypertension, propranolol did not increase portal resistance in cirrhotic rats [2.0 +/- 0.2 vs. 2.0 +/- 0.1 mmHg per ml per min.100 gm body weight (not significant)]. Hence, the fall in portal pressure (-19%) was expected from the decrease in portal inflow (-24%). These results suggest that increased portal resistance in rats with prehepatic portal hypertension may represent an intrinsic effect of propranolol on the portocollateral vessels, since beta-blockade does not modify portal vascular resistance in cirrhosis.     

Systemic, splanchnic and renal hemodynamic effects of a dopaminergic dose of dopamine in patients with cirrhosis

The effects of dopamine on kidney function have not been elucidated in patients with cirrhosis. Moreover, although increased portal pressure has been observed with supradopaminergic doses of dopamine in these patients, the splanchnic hemodynamic effects of low doses of dopamine have not been previously studied. Thus we studied the acute systemic, splanchnic and renal hemodynamic effects of a dopaminergic dose of dopamine (1.5 micrograms/kg body wt min) in nine cirrhotic patients. Plasma dopamine levels increased markedly from 35 +/- 20 pg/ml to 31,400 +/- 4,900 pg/ml during dopamine administration. A significant diastolic pressure decrease of 10% was associated with a 15% increase in heart rate. Cardiac output was not altered. Although dopamine significantly increased azygos blood flow by 16%, wedged and free hepatic venous pressures were not altered. Dopamine significantly increased renal blood flow by 31%, but did not change the glomerular filtration rate. We conclude that a dopaminergic dose of dopamine increases azygos blood flow but not the hepatic venous pressure gradient. Finally, although it increases renal blood flow, dopamine does not seem to have any beneficial effects on glomerular filtration rate in cirrhotic patients.     

Regional sympathetic activity, severity of liver disease and hemodynamics in patients with cirrhosis.

One hundred and eight patients with cirrhosis (23 grade A, 46 grade B and 39 grade C, according to Pugh's classification) underwent hemodynamic studies and plasma catecholamine concentration measurements. Blood samples were withdrawn from the pulmonary artery (n = 108), the hepatic vein (n = 108), the azygos vein (n = 59), the right renal vein (n = 66), the right jugular vein (n = 34) and the femoral vein (n = 33). Plasma noradrenaline concentrations in the pulmonary artery and the hepatic vein were more elevated in grade B (607 +/- 52 and 402 +/- 42 pg/ml, respectively) and C patients (630 +/- 59 and 475 +/- 53 pg/ml, respectively) than in grade A patients (411 +/- 51 and 243 +/- 40 pg/ml, respectively). Plasma noradrenaline concentrations from these two vessels were negatively correlated with indocyanine green clearance. These results indicate that both overall and splanchnic sympathetic activities are dependent on altered hepatic function. Significant correlations were found between the wedged hepatic venous pressure and plasma noradrenaline concentrations from either the pulmonary artery, the hepatic vein or the azygos vein. These correlations indicate that both overall and splanchnic sympathetic activities are dependent on the degree of portal hypertension. Moreover, significant correlations were found between hepatic venous plasma noradrenaline concentrations and systemic hemodynamic values, suggesting that splanchnic sympathetic nervous activity could either play a role in the systemic hyperkinetic syndrome or be a consequence of this hyperkinetic syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)     

Combination of ketanserin and verapamil or propranolol in patients with alcoholic cirrhosis: search for an additive effect

Drugs reported to reduce portal pressure through different mechanisms were combined in the hope of either additive portal hypotensive effects in "responders," or inducing a portal hypotensive effect in "nonresponders" to the initial drug. Seven patients with alcoholic cirrhosis received verapamil, 10 mg i.v., and, 60 min later, ketanserin, 5 mg i.v. Verapamil decreased heart rate and increased free hepatic venous pressure but had no effect on hepatic venous pressure gradient or azygos blood flow. When combined with verapamil, ketanserin significantly diminished wedged hepatic venous pressure and hepatic venous pressure gradient. Ten other patients with alcoholic cirrhosis received propranolol, 15 mg i.v., and 45 min later, ketanserin, 5 mg i.v. In all patients, heart rate, cardiac index and azygos blood flow significantly decreased after propranolol. After propranolol alone, however, wedged hepatic venous pressure decreased in only five patients, responders. In five other patients, defined as nonresponders, propranolol did not decrease this pressure. The addition of ketanserin to propranolol induced further significant reduction in wedged hepatic venous pressure, hepatic venous pressure gradient and azygos blood flow. Among the five nonresponders, three had a reduced wedged hepatic venous pressure after ketanserin was combined. We conclude that verapamil does not reduce portal pressure or collateral blood flow in patients with alcoholic cirrhosis. The splanchnic hemodynamic effects of propranolol and ketanserin appear to be independent and additive, without significant systemic alteration.     

Blood flow and blood oxygen partial pressure of the azygos vein in portal hypertension evaluated by the catheter method

To evaluate the clinical significance of blood flow in the azygos vein and the oxygen partial pressure in azygos venous blood in portal hypertension, we examined 25 patients with liver cirrhosis, 4 with chronic hepatitis, 4 with idiopathic portal hypertension (IPH) and 16 controls by the continuous thermodilution method and azygos venous blood sampling. The azygos venous flow was significantly higher in the patients with chronic liver diseases than in the controls. There was a significant correlation between azygos venous flow and hepatic venous pressure gradient. In the patients with liver cirrhosis, about one half of the azygos venous flow was assumed to represent upward collateral flow, as the azygos venous flow was 3.4% of cardiac output in the controls, 6.3% in the liver cirrhosis patients, and 5.1% in the IPH patients. Oxygen partial pressure in azygos venous blood was higher in patients with portal hypertension, especially in the IPH patients, which indicates that part of splenic flow drains into the azygos vein.     

The extent of the collateral circulation influences the postprandial increase in portal pressure in patients with cirrhosis

BACKGROUND: In cirrhosis, repeated flares of portal pressure and collateral blood flow provoked by postprandial hyperaemia may contribute to variceal dilation and rupture. AIM: To examine the effect of the extent of the collateral circulation on the postprandial increase in portal pressure observed in cirrhosis. PATIENTS AND METHODS: The hepatic venous pressure gradient (HVPG), hepatic blood flow and azygos blood flow were measured in 64 patients with cirrhosis before and after a standard liquid meal. RESULTS: Peak increases in HVPG (median+14.9%), hepatic blood flow (median+25.4%), and azygos blood flow (median+32.2%) occurred at 30 min after the meal. Compared with patients with marked postprandial increase in HVPG (above the median, n = 32), those showing mild (<15%, n = 32) increase in HVPG had a higher baseline azygos flow (p<0.01) and underwent a greater postprandial increase in azygos flow (p<0.02). Hepatic blood flow increased similarly in both groups. Postprandial increases in HVPG were inversely correlated (p<0.001) with both baseline azygos flow (r = -0.69) and its postprandial increase (r = -0.72). Food intake increased nitric oxide products in the azygos (p<0.01), but not in the hepatic vein. Large varices (p<0.01) and previous variceal bleeding (p<0.001) were more frequent in patients with mild increase in HVPG. CONCLUSIONS: Postprandial hyperaemia simultaneously increases HVPG and collateral flow. The extent of the collateral circulation determines the HVPG response to food intake. Patients with extensive collateralisation show less pronounced postprandial increases in HVPG, but associated with marked flares in collateral flow. Collateral vessels preserve their ability to dilate in response to increased blood flow.     

Hemodynamic, metabolic and hormonal responses to oral glibenclamide in patients with cirrhosis receiving glucose

BACKGROUND: In patients with cirrhosis, glucose may induce splanchnic and renal vasodilation. Since the antidiabetic sulfonylurea glibenclamide is known to induce splanchnic and renal vasoconstriction in portal hypertensive animals, this drug may inhibit glucose-induced hemodynamic responses in patients with cirrhosis. The aim of the present study was to investigate, in patients with cirrhosis, the short-term effects of glibenclamide on hemodynamic and humoral responses to glucose. METHODS: Patients were randomly assigned to receive either glibenclamide (5-mg tablet) or a placebo. All patients received an infusion of 10% glucose (62.5 ml/h for 12 h) that was started at the same time as glibenclamide or placebo administration. Studies were performed prior to and 90 min after glibenclamide or placebo. RESULTS: Glibenclamide (i.e. glibenclamide plus glucose) significantly increased plasma insulin concentrations and glycemia while placebo (i.e. glucose alone) significantly increased glycemia but did not change plasma insulin levels. Glibenclamide did not significantly change the hepatic venous pressure gradient while this value was significantly increased following glucose alone. Glibenclamide did not significantly change renal blood flow and glomerular filtration rate while glucose alone significantly increased renal blood flow without affecting the glomerular filtration rate. Glibenclamide significantly decreased cardiac index while glucose alone did not change this value. CONCLUSIONS: In patients with cirrhosis receiving glucose, glibenclamide blunted glucose-induced splanchnic and renal vasodilation. In addition, glibenclamide per se induced a decrease in cardiac index. These findings should be taken into account when glibenclamide is administered to patients with cirrhosis and type 2 diabetes.     

Effects of metoclopramide and domperidone on azygos venous blood flow in patients with cirrhosis and portal hypertension

The effects of pharmacological manipulation of the lower esophageal sphincter pressure on the esophageal circulation in patients with cirrhosis and portal hypertension were investigated in 33 patients by measuring the azygos venous blood flow, which is an index of blood flow through esophageal varices and periesophageal collaterals draining into the azygos venous system. Measurements were performed in baseline conditions and after the blind administration of metoclopramide (20 mg i.v.) (12 patients), domperidone (10 mg i.v.) (12 patients) and placebo (9 patients). Both metoclopramide and domperidone caused a significant reduction of azygos blood flow, that decreased by 11.5% (p less than 0.01) and 15.6% (p less than 0.02) respectively, while no change was observed in patients receiving placebo (+1.4%, not statistically significant). Reduction of azygos blood flow represents a selective effect of metoclopramide and domperidone on the esophageal circulation, since portal pressure, hepatic blood flow, cardiac output, heart rate and arterial blood pressure were unchanged by the administration of metoclopramide, domperidone or placebo. These results indicate that the administration of drugs that increase the lower esophageal sphincter pressure may reduce the inflow of blood into the esophageal varices in cirrhotic patients with portal hypertension.     

Hemodynamic,Metabolic and Hormonal Responses to Oral Glibenclamide in Patients with Cirrhosis Receiving Glucose

Background: In patients with cirrhosis, glucose may induce splanchnic and renal vasodilation. Since the antidiabetic sulfonylurea glibenclamide is known to induce splanchnic and renal vasoconstriction in portal hypertensive animals, this drug may inhibit glucose-induced hemodynamic responses in patients with cirrhosis. The aim of the present study was to investigate, in patients with cirrhosis, the short-term effects of glibenclamide on hemodynamic and humoral responses to glucose. Methods: Patients were randomly assigned to receive either glibenclamide (5-mg tablet) or a placebo. All patients received an infusion of 10% glucose (62.5 ml/h for 12 h) that was started at the same time as glibenclamide or placebo administration. Studies were performed prior to and 90 min after glibenclamide or placebo. Results: Glibenclamide (i.e. glibenclamide plus glucose) significantly increased plasma insulin concentrations and glycemia while placebo (i.e. glucose alone) significantly increased glycemia but did not change plasma insulin levels. Glibenclamide did not significantly change the hepatic venous pressure gradient while this value was significantly increased following glucose alone. Glibenclamide did not significantly change renal blood flow and glomerular filtration rate while glucose alone significantly increased renal blood flow without affecting the glomerular filtration rate. Glibenclamide significantly decreased cardiac index while glucose alone did not change this value. Conclusions: In patients with cirrhosis receiving glucose, glibenclamide blunted glucose-induced splanchnic and renal vasodilation. In addition, glibenclamide per se induced a decrease in cardiac index. These findings should be taken into account when glibenclamide is administered to patients with cirrhosis and type 2 diabetes.     

Nicardipine Infusion Improved Hepatic Function But Failed to Reduce Hepatic Venous Pressure Gradient in Patients with Cirrhosis

We investigated the effects of nicardipine on systemic and splanchnic hemodynamics and on liver function in 16 patients with cirrhosis and portal hypertension. Patients received a continuous infusion of 0.3 mg/min of nicardipine (n = 10) and a control infusion (n = 6). No significant changes were observed after a control infusion. In contrast, systemic vasodilatation, evidenced by a significant fall in mean arterial pressure (-14%, p less than 0.01) and systemic vascular resistance (-30%, p less than 0.01), increased heart rate (+8%, p less than 0.01) and cardiac output (+21%, p less than 0.01), and increased hepatic blood flow (+43%, p less than 0.01) were observed at 60 min after a continuous infusion of nicardipine. Although nicardipine improved hepatic function (intrinsic clearance from 0.29 +/- 0.13 to 0.33 +/- 0.15 L/min, p less than 0.05), portal pressure evaluated by hepatic venous pressure gradient was not reduced significantly (from 16.3 +/- 4.9 to 15.1 +/- 5.7 mm Hg; NS). We conclude that a continuous infusion of nicardipine improves liver function but has no beneficial effect on portal pressure in patients with cirrhosis.     

Effect of terlipressin on blood volume distribution in patients with cirrhosis

BACKGROUND: Patients with cirrhosis and portal hypertension have an altered blood volume distribution and a hyperdynamic systemic circulation. Terlipressin is known to reduce portal pressure by decreasing splanchnic inflow, but its effect on the blood volume distribution is unknown. The aim of the study was to investigate changes in regional blood volume distribution and systemic haemodynamics after administration of terlipressin to patients with cirrhosis. METHODS: Blood volume distribution was determined in 13 patients with cirrhosis and portal hypertension by a dual-head gamma-camera technique and systemic haemodynamics was measured before and after intravenous administration of terlipressin (2 mg). RESULTS: Terlipressin increased the blood volume in the thorax region (+6.0%, P < 0.002) and the liver region (+12.2%, P < 0.002), whereas blood volume in the splanchnic region remained unchanged. Systemic vascular resistance (SVR) and mean arterial blood pressure increased after terlipressin (+34 and +21%, P < 0.001). The increase in liver blood volume correlated directly with the increase in SVR (r = 0.88. P < 0.001). CONCLUSIONS: Terlipressin ameliorates the hyperdynamic circulation, increases thorax and liver blood volumes, but produces no effect on the splanchnic blood volume. Besides decreasing the splanchnic inflow, terlipressin may affect portal pressure by causing vasodilatation of intrahepatic vessels.     

Mechanisms of a clonidine-induced decrease in portal pressure in normal and cirrhotic conscious rats

The effects of clonidine on portal pressure and splanchnic blood flow were studied in conscious rats with sinusoidal portal hypertension due to cirrhosis induced by bile duct ligation. In cirrhotic and sham-operated rats, clonidine (20 micrograms per kg body weight, intravenously) significantly reduced portal, pressure from 19.0 +/- 0.6 to 14.5 +/- 1.0 mmHg and from 9.8 +/- 0.9 to 7.3 +/- 0.5 mmHg, respectively. No significant change in systemic hemodynamics was observed. In cirrhotic rats, clonidine reduced portal pressure, probably by producing a significant increase in portal tributary vascular resistance leading to a 25% decrease in portal tributary blood flow (radioactive microsphere method). In sham-operated rats, clonidine reduced portal pressure presumably by decreasing hepatic portal vascular resistance, since no significant change in portal tributary blood flow was observed. In both groups, clonidine administration significantly decreased plasma noradrenaline concentration. Placebo administration produced neither significant hemodynamic nor significant plasma noradrenaline concentration change. These findings indicate that the sympathetic regulation of the splanchnic circulation is impaired in cirrhotic rats.     

Effects of molsidomine, a long acting venous dilator, on portal hypertension. A hemodynamic study in patients with cirrhosis.

The present study investigated the effects of molsidomine, a predominant venous dilator which, contrary to organic nitrates, does not produce pharmacological tolerance on splanchnic and systemic hemodynamics in patients with cirrhosis. Twenty-seven cirrhotic portal hypertensive patients were studied prior to and up to 2 h after the oral administration of 2 mg of molsidomine (n = 11), 4 mg of molsidomine (n = 8) or placebo (n = 8). Molsidomine caused a significant reduction in the hepatic venous pressure gradient. The mean decrease at 60 min was -6.8 +/- 9% after 2 mg (p less than 0.05) and -15.4 +/- 12% after 4 mg (p less than 0.01). The decrease in the hepatic venous pressure gradient was maintained at 120 min: -11% after 2 mg (p less than 0.05) and -19% with 4 mg (p less than 0.01). This was associated with mild changes in azygos blood flow and with a significant decrease in hepatic blood flow (-17%, p less than 0.05). There was a moderate reduction in mean arterial pressure (-12.6% after 2 mg and -13.2% after 4 mg, p less than 0.01), which was due to a reduction in cardiac output, without any significant fall in systemic vascular resistance. Placebo administration did not change systemic or hepatic hemodynamics. This study shows that molsidomine causes a significant and sustained reduction in portal pressure in patients with cirrhosis, suggesting the potential role of this agent in the treatment of portal hypertension.     

Measurement of azygos venous blood flow in the evaluation of portal hypertension in patients with cirrhosis. Clinical and haemodynamic correlations in 100 patients

Blood flow in the azygos vein, an index of blood flow through gastro-oesophageal collaterals, was measured by continuous thermal dilution in 100 patients with cirrhosis. Azygos blood flow was directly related to portal pressure (r = 0.54, P less than 0.001). Patients with portal hypertension had very high azygos blood flow (692 +/- 32 ml/min) in comparison with controls (n = 11, 174 +/- 29 ml/min). Patients with previous oesophageal bleeding had similar azygos blood flow as those without, but azygos blood flow was significantly greater in patients with massive or recurrent bleeding than in those with less severe haemorrhage, suggesting that the magnitude of collateral flow may influence the course of variceal bleeding. Patients with grade III varices had higher azygos blood flow than those with grades II or I. In addition, both oesophageal tamponade and vasopressin infusion, procedures of known value in variceal bleeding, markedly reduced azygos blood flow (-40% and -25%, respectively). Measurement of azygos blood flow allows evaluation of haemodynamic changes in the oesophageal collaterals of patients with portal hypertension, and provides useful information on the effect of therapeutic procedures aimed at arresting or preventing variceal haemorrhage.     

Effects of glypressin on the splanchnic and systemic circulation in patients with cirrhosis

Although not demonstrated in patients with cirrhosis, it is generally claimed that administration of vasopressin in the form of triglycyl-lysine-vasopressin (glypressin) may prevent untoward systemic effects of this former hormone. The aim of this study was to assess the effects of intravenous administration of 2 mg of glypressin on splanchnic and systemic hemodynamics in 9 patients with cirrhosis under stable circulatory conditions. One hour after the injection, the following statistically significant changes were observed as compared to the baseline values (m +/- SEM): wedged hepatic venous pressure, -9 +/- 2 p. 100; hepatic venous pressure gradient, -16 +/- 3 p. 100; azygos blood flow, -24 +/- 6 p. 100; heart rate, -16 +/- 3 p. 100; cardiac index, -23 +/- 2 p. 100; systemic vascular resistances, +47 +/- 11 p. 100; wedged pulmonary arterial pressure, +44 +/- 15 p. 100. In conclusion, in patients with cirrhosis in a stable hemodynamic condition, intravenous administration of glypressin decreased portal venous pressure and blood flow into the superior portal systemic collateral circulation but did not prevent the untoward systemic hemodynamic effects of vasopressin.