Renal hemodynamics and the renin--angiotensin system in cirrhosis: relationship to sodium retention

Isolated Subclinical Right Ventricle Systolic Dysfunction in Patients after Liver Transplantation

Although hemodynamic alterations in end-stage liver disease (ESLD) and its association with porto-pulmonary hypertension have been well-established, the long-term effects of ESLD on RV systolic function in patients without porto-pulmonary hypertension remain disregarded. Here we aimed to assess the long-term effect of ESLD on RV function and its relationship with the use of NSBBs and clinical, laboratory and imaging parameters in end-stage liver disease. The use of NSBBs is still controversial due to concerns about reduced cardiac contractility and the possibility of increased mortality. Thirty-four liver transplant recipients were included. Demographic characteristics, laboratory and baseline echocardiography measures were obtained. Patients were recalled for transthoracic echocardiographic evaluation after transplantation. Right ventricle dysfunction was identified by having at least one value below the reference levels of RV S’, or TAPSE. Isolated subclinical RV dysfunction was observed at 20.6% of the sample population. The present study demonstrates hemodynamic circulation in cirrhosis and increased preload and afterload might have long-term effects on RV function, even the lack of porto-pulmonary hypertension. These findings underline the significance of cardiac function follow-up in cirrhotic patients after transplantation. In this study, patients treated with propranolol seemed to have better RV function and less gastrointestinal bleeding. We speculated that preoperative propranolol treatment might help preserve RV function by providing RAS suppression, improving endothelial function and hyperdynamic circulation seen in ESLD. This potential protective relationship between the use of propranolol and RV function might improve mortality or graft-failure during OLT and after liver transplantation in patients with cirrhosis.

The changing role of beta-blocker therapy in patients with cirrhosis

Cirrhosis is a leading cause of death in the United States and worldwide. Beta-blockers have been established in numerous studies as part of the cornerstone of the medical management of cirrhosis, particularly in the primary and secondary prevention of variceal hemorrhage. However, new evidence has cautioned the use of beta-blockers in patients with end-stage cirrhosis and refractory ascites. In this article, we review the beneficial effects of beta-blocker therapy, the potential harms of aggressive beta-blocker therapy, and provide suggestions regarding the appropriate use of this class of medications in patients with cirrhosis.

Endocrine and hemodynamic changes during liver surgery in patients with compensated liver cirrhosis

The purpose of this study was to determine hormonal levels in compensated liver cirrhotic patients under general anesthesia before and after liver surgery. We measured plasma norepinephrine, epinephrine, arginine vasopressin, and aldosterone levels and renin activity in non-cirrhotic and compensated cirrhotic patients undergoing liver resection after induction of anesthesia but before skin incision and after the end of operation but before discontinuation of nitrous oxide. We simultaneously measured hemodynamic variables. Plasma levels of norepinephrine (P < 0.001), epinephrine (P < 0.001), arginine vasopressin (P < 0.05), renin (P < 0.05) and aldosterone (P < 0.001) significantly increased after completion of surgery compared with those before incision in both groups. There was a significant positive correlation between plasma renin and aldosterone (r = 0.56, P < 0.01) levels in non-cirrhotics, but no correlation was observed in cirrhotics; and there was a significant positive correlation between plasma norepinephrine and arginine vasopressin (r = 0.45, P < 0.05) levels in non-cirrhotics, but no correlation in cirrhotics. Cardiac index and arterial pressure increased after the end of operation (P < 0.05). This increase after the operation was the same between cirrhotic and non-cirrhotic groups. There were no changes in heart rate, mean pulmonary arterial pressure, and pulmonary capillary wedge pressure after the end of operation. We conclude that hemodynamic and endocrinological changes were similar between compensated cirrhotic patients and non-cirrhotic patients during liver surgery. Endocrine changes might partly explain the hemodynamic changes during surgery.

Fasting plasma caffeine level in cirrhotic patients: relation to plasma levels of catecholamines and renin activity

Fasting plasma caffeine concentrations, plasma levels of catecholamines and plasma renin activity were measured in patients with cirrhosis and control patients without hepatic dysfunction. A careful dietary history showed no significant difference in caffeine consumption (mean +/- S.E.) among 46 cirrhotics (86 +/- 7 mg per day) vs. 34 control patients (91 +/- 8 mg per day). Fasting plasma caffeine concentrations, however, were significantly higher (7.68 +/- 1.42 micrograms per ml) in cirrhotics than in controls (1.01 +/- 0.20 micrograms per ml) (p less than 0.01). Fasting plasma caffeine concentrations in cirrhotics varied significantly with Child's criteria, namely Child's A patients (2.06 +/- 0.38 micrograms per ml); Child's B patients (6.92 +/- 1.86 micrograms per ml), and Child's C patients (17.70 +/- 3.65 micrograms per ml) (p less than 0.001). In 44 cirrhotics, fasting plasma caffeine concentrations were compared with plasma levels of catecholamines and plasma renin activity. Plasma epinephrine concentrations were normal; however, plasma norepinephrine concentrations were increased in six cirrhotics, and plasma renin activities were increased in 28 cirrhotics. After a 3-day caffeine abstinence, plasma caffeine concentration and renin activity were significantly decreased (p less than 0.01), and high plasma norepinephrine levels were also decreased in 12 cirrhotics. Plasma caffeine concentration, renin activity and norepinephrine level did not change in a control group of cirrhotics who continued to receive caffeine for 3 days (n = 6). After abstinence from caffeine, the decrease of fasting plasma caffeine concentration correlated well with the decrease of plasma renin activity (r = +0.746, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical applications of antimineralocorticoids

The renin-angiotensin-aldosterone system plays an important role in the development and maintenance of high blood pressure in several forms of hypertension. In hypertensive patients with primary aldosteronism, antimineralocorticoids are, as expected, very effective in reducing blood pressure and correcting metabolic disturbances. In patients with essential hypertension, an abnormal relationship between angiotensin II and aldosterone can occur. Aldosterone secretion in these patients is often too high relative to circulating levels of angiotensin II. Antimineralocorticoids effectively lower blood pressure in a large number of these patients. The reactive hyperreninemia caused by salt depletion is a factor limiting the antihypertensive effect of natriuretic agents including that of antimineralocorticoids. The enhanced aldosterone secretion resulting from treatment with a diuretic other than an antimineralocorticoid may diminish the natriuretic action of that diuretic. Therefore, antimineralocorticoids given in addition to a diuretic enhance natriuresis. The renin-angiotensin-aldosterone system is also involved as a compensatory mechanism in cardiovascular and body fluid homeostasis of patients with severe congestive heart failure or liver cirrhosis with ascites. Antimineralocorticoids are very effective in such conditions. In patients with congestive heart failure treated with digitalis, these natriuretic agents are particularly useful because of their potassium-sparing properties. The risk of developing hyperkalemia during antimineralocorticoid administration is negligible unless renal function is impaired. Antimineralocorticoids have the advantage of exerting no deleterious effect on carbohydrate and lipid metabolism. The use of these agents seems therefore rational in a variety of diseases concerned with blood pressure and body fluid volume regulation.

The pathogenesis of renal sodium retention and ascites formation in Laennec's cirrhosis

This chapter critically reviews our current understanding of the pathogenesis, clinical syndrome, and therapy of the disturbances of renal sodium handling, renal perfusion, and glomerular filtration rate that occur in patients with Laennec's cirrhosis. Avid renal sodium reabsorption, a characteristic feature of cirrhosis, occurs independent of moderate changes in renal function and precedes the onset of ascites. The initiation of sodium retention may be a direct consequence of the hepatic disease process and may also result from defective intravascular filling. In the presence of ascites the most important sodium retaining signal is a defective intravascular volume. The principal effectors of renal sodium retention and vasoconstriction are stimulation of the renin-angiotensin-aldosterone axis and augmentation of renal sympathetic nerve activity. Deficient production of natriuretic hormone(s) and endogenous renal vasodilators, such as prostaglandins and kinins, also contributes to the sodium retention and renal hypoperfusion seen in cirrhosis. The hepatorenal syndrome is an extreme imbalance in these renal vasoconstrictor and vasodilator forces. In the therapy of ascites in Laennec's cirrhosis, abstention from alcohol, sodium restriction, and cautious diuresis are the principal therapeutic measures. A grave prognosis accompanies the diagnosis of the hepatorenal syndrome although recoveries have been reported.