Is the use of albumin of value in the treatment of ascites in cirrhosis? The case in favour

In patients with cirrhosis, ascites accumulates because of sodium retention, triggered by a reduction of the effective arterial blood volume, and imbalanced Starling forces in the splanchnic area due to portal hypertension and hypoalbuminemia. Albumin is the ideal plasma expander in this setting, since it ameliorates systemic and reneal haemodynamics, so reducing sodium retention, and increases oncotic pressure in the splanchnic compartment. In particular, albumin proved useful in patients treated with diuretics, as demonstrated by a randomised study performed at our Instituition in which 126 ascitic inpatients were treated according to a stepped-care diuretic regimen. In fact, patients receiving diuretics plus albumin (n = 63) had a higher cummulative rate of response (p < 0.05) and a shorter hospital stay (20 +/- 1 versus 24 +/- 2 days, p < 0.05) than those given diuretics alone. Treatment with albumin on an outpatient basis (25 g/week) resulted in a lower probability of developing ascites (p < 0.02 vs. patients not given albumin) and a lower probability of readmission (p < 0.02). Patients given albumin also had a better quality of life. As discussed in another article, evidence also supports the use of albumin in patients treated for paracentesis, as well as in patients with spontaneous peritonitis or hepatorenal syndrome.

Update on ascites and hepatorenal syndrome

Ascites is the most common complication occurring during liver cirrhosis. Even if a significant decrease in renal clearance may be observed in the first step of chronic active liver disease, renal impairment, at times complicated by the typical signs of hepatorenal syndrome, occurs only in patients with ascites, especially when tense and refractory. Experimental and clinical data seem to suggest a primary sodium and water retention in the pathogenesis of ascites, in the presence of an intrahepatic increase of hydrostatic pressure, which, by itself, physiologically occurs during digestion. Abnormal sodium and water handling leads to plasma volume expansion, followed by decreased peripheral vascular resistance and increased cardiac output. This second step is in agreement with the peripheral arterial vasodilation hypothesis, depicted by an increase in total blood volume, but with a decreased effective arterial blood volume. This discrepancy leads to the activation of the sympathetic nervous and renin-angiotensin-aldosterone systems associated with the progressive activation of the renal autacoid systems, especially, that of the arachidonic acid. During advanced cirrhosis, renal impairment becomes more sustained and renal autacoid vasodilating substances are less available, possibly due to a progressive exhaustion of these systems. At the same time ascites becomes refractory inasmuch as it is no longer responsive to diuretic treatment. Various pathogenetic mechanisms leading to refractory ascites are mentioned. Finally, several treatment approaches to overcome the reduced effectiveness of diuretic therapy are cited. Paracentesis, together with simultaneous administration of human albumin or other plasma expanders is the main common approach to treat refractory ascites and to avoid a further decrease in renal failure. Other effective tools are: administration of terlipressin together with albumin, implantation of the Le Veen shunt, surgical porto-systemic shunting or transjugular intrahepatic portosystemic stent-shunt, or orthotopic liver transplantation, according to the conditions of the individual patient.

Albumin improves the response to diuretics in patients with cirrhosis and ascites: results of a randomized, controlled trial

BACKGROUND/AIMS

Diuretic treatment of ascites could result in intravascular volume depletion, electrolyte imbalance and renal impairment. We investigated whether intravascular volume expansion with albumin exert beneficial effects in cirrhosis with ascites.

METHODS

In protocol 1, 126 cirrhotic inpatients in whom ascites was not relieved following bed rest and a low-sodium diet, were randomly assigned to receive diuretics (group A) or diuretics plus albumin, 12.5 g/day (group B). In protocol 2, group A patients continued to receive diuretics and group B diuretics plus albumin (25 g/week) as outpatients and were followed up for 3 years. End points were: disappearance of ascites, duration of hospital stay (protocol 1), recurrence of ascites, hospital readmission and survival (protocol 2).

RESULTS

The cumulative rate of response to diuretic treatment of ascites was higher (p < 0.05) and hospital stay was shorter (20 +/- 1 versus 24 +/- 2 days, p < 0.05) in group B than in group A patients. After discharge, group B patients had a lower cumulative probability of developing ascites (19%, 56%, 69% versus 30%, 79% and 82% at 12, 24 and 36 months, p < 0.02) and a lower probability of readmission to the hospital (15%, 56%, 69% versus 27%, 74% and 79%, respectively, p < 0.02). Survival was similar in the two groups.

CONCLUSIONS

Albumin is effective in improving the rate of response and preventing recurrence of ascites in cirrhotic patients with ascites receiving diuretics. However, the cost/benefit ratio was favorable to albumin in protocol 1 but not in protocol 2.

Effects of KW-3902, an adenosine A1-receptor antagonist, on ascites volume in puromycin aminonucleoside (PAN)-induced nephrotic rats

We investigated the effects of KW-3902 (8-(noradamantan-3-yl)-1,3-dipropylxanthine), a potent adenosine A1-receptor antagonist, on the nephrotic edema induced by puromycin aminonucleoside (PAN; 100 mg/kg, i.v.) in rats. The treatment with PAN decreased urine volume and urinary excretions of sodium and potassium, resulting in the ascites formation in 7 days. In rats with the nephrosis, KW-3902 (0.01-1 mg/kg/day for 3 days, p.o.) showed diuretic effects and reduced the volume of ascites, as was the case with furosemide (30 mg/kg/day) and trichlormethiazide (1 mg/kg/day). These results suggest that even in the nephrotic state, the adenosine A1-receptor antagonist can be an effective diuretic to ameliorate edema.

Torasemide in the treatment of patients with cirrhosis and ascites

The effects of torasemide (20 mg/day) and furosemide (50 mg/day), each given over 4 days, were compared in a randomized and crossover study carried out in seven patients with cirrhosis and tense ascites. Patients also received a low-sodium (40 mmol/day) diet and the aldosterone antagonist, potassium canrenoate (100 mg b.i.d.). Torasemide induced a remarkably higher natriuretic (120 +/- 15 vs. 33 +/- 6 mmol/day, p < 0.02) and diuretic (1450 +/- 63 vs. 900 +/- 58 ml, p < 0.005) effect than furosemide. Body weight loss was also significantly higher (2.5 +/- 1.6 vs. 0.2 +/- 1.3 kg, p < 0.01) during the torasemide period. Kaliuresis was similar during the two treatment periods, despite the striking differences observed in natriuresis. Neither torasemide nor furosemide induced any significant change in serum electrolyte or creatinine concentrations, or in ammonia levels. The results of this study indicate that torasemide is suitable for the treatment of sodium retention in patients with cirrhosis and ascites.

Pathophysiology and treatment of ascites and the hepatorenal syndrome

Ascites indicates the accumulation of fluid in the peritoneal cavity, due to a wide range of causes. These causes can be classified according to the presence of portal hypertension, severe blood dyscrasia and peritoneal disease. Cirrhosis is the most frequent cause of ascites. The occurrence of ascites in cirrhosis is due to portal hypertension, which is responsible for the increase in hydrostatic pressure at the sinusoidal level and the alterations of splanchnic and systemic haemodynamics. These latter include increased splanchnic inflow, reduced systemic resistance and increased plasma volume and cardiac output. Portal hypertension also plays a major role in determining sodium retention, which occurs in the setting of increased RAA system and SNS activity. The mechanisms by which portal hypertension leads to the activation of antinatriuretic factors and sodium retention are not completely understood; three main hypotheses have been proposed to explain this relationship, namely the underfilling, the overflow and the peripheral arterial vasodilatation theories. In patients with cirrhosis and ascites, there is an overall activation of the renal prostaglandin system, which probably acts to maintain renal haemodynamics and GFR by counteracting the vasoconstricting effects of AII and noradrenaline on renal circulation. In advanced stages, ascites may become refractory to medical treatment and renal function shows a progressive impairment and eventually acute renal failure, the so-called HRS, due to a marked vasoconstriction of the renal arteries and the opening of the intrarenal-arteriovenous (A-V) shunts. In this condition, the reduced renal synthesis of vasodilating prostaglandins is probably of pathogenic importance. Treatment of ascites is usually based on bed rest, low-sodium diet and administration of aldosterone antagonists and loop diuretics. A sequential treatment of ascites based on the progressive addition of more potent drugs is the best way to relieve ascites while avoiding potentially dangerous side-effects. Patients who fail to respond to the above manoeuvres are said to have refractory ascites. Current treatment of this latter condition is mainly based on therapeutic paracentesis and the application of the LeVeen shunt, but long-term results are unsatisfactory.

Effects of OKY 046, a thromboxane-synthase inhibitor, on renal function in nonazotemic cirrhotic patients with ascites

To assess the possible role of increased renal thromboxane A2 (TXA2) synthesis in nonazotemic patients with cirrhosis and ascites and to establish the potential beneficial effect of inhibitors of renal TXA2 production in this clinical setting, we administered OKY 046, a selective TXA2 synthase inhibitor, 200 mg t.i.d. for 5 days, to 9 nonazotemic cirrhotic patients with ascites and avid sodium retention. OKY 046 inhibited platelet TXA2 production, as expressed by serum thromboxane B2 (TXB2) concentration, by approximately 85% (p less than 0.001 vs. baseline values) and reduced urinary TXB2 excretion by 72% (p less than 0.01). A significant increase of approximately 19% in inulin clearance was observed during the treatment (from 61.0 +/- 8.42 to 72.7 +/- 7.45 ml/min, p less than 0.05), whereas renal blood flow was unchanged (from 408.50 +/- 19.97 to 424.50 +/- 30.84 ml/min). Drug administration did not affect positive sodium balance [sodium excretion was 4.67 +/- 1.22 mEq/day before drug administration and 6.26 +/- 1.05 mEq/day during drug administration (on day 7)], plasma renin activity, plasma aldosterone concentration, or the urinary excretion of prostaglandin E2, 6-keto prostaglandin F1 alpha, or prostaglandin F2 alpha. These results suggest that renal TXA2 synthesis contributes to the regulation of renal hemodynamics in nonazotemic cirrhotic patients with ascites and avid sodium retention, but it does not seem to affect sodium balance.