Renal effects in cirrhotic patients with avid sodium retention of atrial natriuretic factor injection during norepinephrine infusion

Effects and safety of natriuretic peptides as treatment of cirrhotic ascites: A systematic review and meta-analysis

BACKGROUND

Natriuretic peptides are involved in the cascade of pathophysiological events occurring in liver cirrhosis, counterbalancing vasoconstriction and anti-natriuretic factors. The effects of natriuretic peptides as treatment of cirrhotic ascites have been investigated only in small studies, and definitive results are lacking.

AIM

To examine the effects and safety of natriuretic peptides in cirrhosis patients with ascites.

METHODS

We searched MEDLINE, Web of Science, Scopus, Cochrane Library and Embase for all available studies applying intravenous administration of any natriuretic peptide to patients suffering from cirrhotic ascites. Inclusion was not limited by treatment duration or dose, or by follow-up duration. Both randomised controlled trials and non-randomised studies were eligible for inclusion. The primary outcome was change in renal sodium excretion. Secondary outcomes included safety measures and changes in renal water excretion, plasma aldosterone concentration, and plasma renin activity.

RESULTS

Twenty-two studies were included. Atrial natriuretic peptide (ANP) was the only intensively studied treatment. Sodium excretion increased in response to continuous ANP infusion and was more pronounced when infusion rates of > 30 ng/kg/min were administered compared with ≤ 30 ng/kg/min (P < 0.01). Moreover, natriuresis was significantly higher in study subgroups with mild/moderate ascites compared with moderate/severe and refractory ascites (P < 0.01). ANP infusions increased renal water excretion, although without reaching a statistically significant dose-response gradient. Plasma aldosterone concentration and plasma renin activity were significantly lower at baseline in study subgroups achieving a negative sodium balance in response to an ANP administration compared with treatment non-responders (P < 0.01). Blood pressure decreases occurred less frequently when ANP doses ≤ 30 ng/kg/min were applied. The quality of evidence for a natriuretic response to ANP was low, mainly due to small sample sizes and considerable between-study heterogeneity. Data were sparse for the other natriuretic peptides; B-type natriuretic peptide and urodilatin.

CONCLUSION

Intravenous ANP infusions increase sodium excretion in patients with cirrhotic ascites. Continuous infusion rates > 30 ng/kg/min are the most effective. However, safety increases with infusion rates ≤ 30 ng/kg/min.

Effects of a 7-day treatment with midodrine in non-azotemic cirrhotic patients with and without ascites

BACKGROUND/AIMS

Splanchnic arterial vasodilatation has been causally related with hyperdynamic circulation and impaired natriuresis in advanced cirrhosis and has also been suggested to be responsible for the subtle sodium retention in pre-ascitic cirrhosis. This study evaluated the effects of a 7-day treatment with the alpha1-adrenergic agonist midodrine in non-azotemic cirrhotic patients with and without ascites.

METHODS

Thirty-nine cirrhotic patients were studied at baseline and 7 days after administration of oral midodrine 10mg, t.i.d. (11 without and 12 with ascites) or placebo (8 without and 8 with ascites).

RESULTS

A significant increase in urine sodium excretion was noted after midodrine administration in patients without and with ascites, in line with significant increases in mean arterial pressure and systemic vascular resistance, and significant decreases in cardiac output and heart rate. Significant increases in glomerular filtration rate, filtration fraction, and urine volume and significant decreases in plasma renin activity and aldosterone were observed in patients with ascites. Placebo had no effect in any study group.

CONCLUSIONS

The administration of midodrine for 7 days improves systemic haemodynamics and sodium excretion in non-azotemic cirrhotic patients without or with ascites. In patients with ascites, but not in those without ascites, these effects are associated with a suppression of the activity of the renin-angiotensin-aldosterone system, suggesting that the increase in natriuresis is related to the improvement in the effective arterial blood volume.

Prevention of Renal Impairment by Continuous Infusion of Human Atrial Natriuretic Peptide after Liver Transplantation

BACKGROUND

Acute renal failure occurring immediately after liver transplantation and requiring hemodialysis is a major problem resulting in a poor prognosis. We investigated the efficacy of human atrial natriuretic peptide, which has potent natriuretic effects and unique protective effects for glomeruli in preventing acute renal failure after liver transplantation.

METHODS

Thirty-seven patients who underwent live donor liver transplantation with model for end-stage liver disease scores greater than 15 were the subjects of the study. Subjects were prospectively randomized into two groups: patients that received synthetic human atrial natriuretic peptide infusion (Group H: n=19) and those that received conventional diuretics, furosemide and potassium canrenoate (Group C: n=18). The peri- and postoperative changes in hemodynamic status and renal function were compared between the two groups.

RESULTS

There were no statistical differences in the changes in hemodynamic status between groups. Hemodialysis was required after liver transplantation in nine patients, two in Group H and seven in Group C (P=0.04). Postoperative creatinine clearance was higher in Group H (P=0.03). Aldosterone level was suppressed in group H (P=0.006).

CONCLUSIONS

Continuous infusion of synthetic human atrial natriuretic peptide might be effective for preventing acute renal failure requiring hemodialysis after liver transplantation.

Acute effects of the oral administration of midodrine, an alpha-adrenergic agonist, on renal hemodynamics and renal function in cirrhotic patients with ascites

The effects of the acute administration of arterial vasoconstrictors on renal plasma flow (RPF) and urinary sodium excretion (UNaV) in cirrhotic patients with ascites with or without hepatorenal syndrome (HRS) are still controversial. As a consequence, vasoconstrictors are not actually used in the treatment of renal sodium retention or HRS in these patients, regardless of the several lines of evidence suggesting that these renal functional abnormalities are related to a marked arterial vasodilation. The lack of an orally available effective arterial vasoconstrictor probably represents a further reason for this omission. Consequently, the present study was made to evaluate the acute effects of the oral administration of midodrine, an orally available -mimetic drug, on systemic and renal hemodynamics and on UNaV in cirrhotic patients with ascites. Mean arterial pressure (MAP), heart rate (HR), cardiac index (CI), systemic vascular resistance (SVR), left forearm blood flow (LFBF), left leg blood flow (LLBF), RPF, glomerular filtration rate (GFR), UNaV, plasma renin activity (PRA), plasma concentration of antidiuretic hormone (ADH), and the serum levels of nitrite and nitrate (NOx) were evaluated in 25 cirrhotic patients with ascites (17 without HRS and 8 with type 2 HRS) before and during the 6 hours following the oral administration of 15 mg of midodrine. During the first 3 hours after the drug administration, a significant increase in MAP (89.6 +/- 1.7 vs. 81.80 +/- 1.3 mm Hg; P < .0001) and SVR (1, 313.9 +/- 44.4 vs. 1,121.2 +/- 60.1 dyn . sec . cm-5; P < .0001) accompanied by a decrease in HR (69 +/- 2 vs. 77 +/- 3 bpm; P < .005) and CI (2,932.7 +/- 131.4 vs. 3,152.5 +/- 131.4 mL . min-1 . m2 BSA; P < .0025) was observed in patients without HRS. No change was observed in LFBF and LLBF. The improvement in systemic hemodynamics, which was also maintained during the the 3- to 6-hour period after midodrine administration, was accompanied by a significant increase in RPF (541.5 +/- 43.1 vs. 385.7 +/- 39.9 mL . min-1; P < .005), GFR (93.1 +/- 6.5 vs. 77.0 +/- 6.7 mL . min-1; P < .025), and UNaV (92.7 +/- 16.4 vs. 72.2 +/- 10.7 microEq . min-1; P < .025). In addition, a decrease in PRA (5.33 +/- 1.47 vs. 7.74 +/- 2.17 ng . mL-1 . h; P < .05), ADH (1.4 +/- 0.2 vs. 1.7 +/- 0.2 pg . mL-1; P < .05), and NOx (33.4 +/- 5.0 vs. 49.3 +/- 7.3 micromol-1; P < .05) was found. In patients with HRS, the effects of the drug on the systemic hemodynamics was smaller and shorter. Accordingly, regardless of a significant decrease in PRA (15.87 +/- 3.70 vs. 20.70 +/- 4.82 ng . mL-1 . h; P < .0025) in patients with HRS, no significant improvement was observed in RPF, GFR, or UNaV. In conclusion, the acute oral administration of midodrine is associated with a significant improvement in systemic hemodynamics in nonazotemic cirrhotic patients with ascites. As a result, renal perfusion and UNaV also improve in these patients. By contrast, midodrine only slightly improves systemic hemodynamics in patients with type 2 HRS, with no effect on renal hemodynamics and renal function.

Natriuretic response to the combination of atrial natriuretic peptide and terlipressin in patients with cirrhosis and refractory ascites

BACKGROUND/AIMS

Refractory ascites, which occurs in certain patients with cirrhosis, is associated with a blunted natriuretic response to exogenous atrial natriuretic peptide (ANP). Since this blunting seems to be related to ANP-induced arterial hypotension, a vasoconstrictor, such as terlipressin (a vasopressin analogue), may restore natriuresis to exogenous ANP. Moreover, since cirrhosis-elicited vasodilation is thought to play a role in sodium retention, a vasoconstriction caused by terlipressin alone may lead to an increase in sodium excretion. This study aimed to evaluate the natriuretic response to either a combination of ANP with terlipressin or terlipressin alone in patients with cirrhosis and refractory ascites.

METHODS

Sixteen consecutive patients with cirrhosis and refractory ascites were randomly assigned to receive either a combination of terlipressin (1-2 mg, i.v. bolus) with ANP (35 ng/kg, i.v. bolus followed by 15 ng x kg(-1) x min(-1) for 60 min) (n=8) or terlipressin alone (1-2 mg, i.v. bolus) (n=8). Sodium excretion and urine output, systemic, splanchnic and renal hemodynamics and renal oxygen consumption were measured before and during treatments.

RESULTS

Combined therapy did not change arterial pressure but significantly increased urinary sodium excretion and urine output. These effects were associated with a significant increase in glomerular filtration rate and a decrease in renal oxygen consumption. Terlipressin alone significantly increased arterial pressure but did not change urinary sodium excretion or urine output. Moreover, terlipressin did not change either glomerular filtration rate or renal oxygen consumption.

CONCLUSIONS

The combination of exogenous ANP with terlipressin, but not terlipressin alone, increases sodium excretion in patients with cirrhosis and refractory ascites.

Renal and neurohormonal changes following simultaneous administration of systemic vasoconstrictors and dopamine or prostacyclin in cirrhotic patients with hepatorenal syndrome

BACKGROUND/AIMS

Intravenous ornipressin in cirrhotic patients with hepatorenal syndrome causes marked improvement of systemic hemodynamics and suppression of plasma renin and norepinephrine but only moderate improvement of renal function. This study was designed to investigate whether these beneficial effects could be enhanced by the simultaneous administration of dopamine. The renal effects of the i.v. infusion of norepinephrine plus prostacyclin in patients with hepatorenal syndrome were also assessed.

METHODS

Renal plasma flow, glomerular filtration rate, free water clearance, sodium excretion and the plasma levels of renin and norepinephrine were measured in baseline conditions and during the administration of ornipressin (6 i.u./h) and ornipressin (6 i.u./h) plus dopamine (2 micrograms/kg.min) in nine patients with hepatorenal syndrome. Five additional patients with hepatorenal syndrome were studied prior to and following the administration of norepinephrine (0.45 +/- 0.1 microgram/kg.min) and norepinephrine (0.85 +/- 0.2 microgram/kg.min) plus prostacyclin (5 ng/kg.min).

RESULTS

Despite a significant increase in arterial pressure and marked suppression of plasma renin activity during ornipressin and ornipressin plus dopamine administration, no significant improvement in renal function was observed. Norepinephrine and norepinephrine plus prostacyclin also failed to increase renal perfusion and glomerular filtration rate.

CONCLUSIONS

The combined administration of systemic vasoconstrictors (ornipressin or norepinephrine) and vasodilators (dopamine or prostacyclin), at the doses used in the current study and for a short period of time, does not improve renal function in cirrhotic patients with hepatorenal syndrome. The current study does not confirm a potential role for ornipressin in the treatment of hepatorenal syndrome.

Blunted natriuresis and abnormal systemic hemodynamic responses to C-type and brain natriuretic peptides in rats with cirrhosis

BACKGROUND/AIMS

The effects of C-type and brain natriuretic peptides (CNP and BNP, respectively) on renal excretion of sodium and hemodynamics have not yet been studied in cirrhosis.

METHODS

This study aimed to examine the effects of saline, CNP (300 ng.kg-1.min-1 i.v. for 30 min) and BNP (600 ng.kg-1.min-1 i.v. for 30 min) on natriuresis and diuresis in normal and rats with cirrhosis. Moreover, regional and systemic hemodynamics were measured prior to and following CNP and BNP administration in normal rats and rats with cirrhosis with ascites.

RESULTS

In rats with cirrhosis, the effects of CNP or BNP or natriuresis and diuresis did not significantly differ from the effects of saline. CNP significantly decreased portal pressure and systemic vascular resistance and significantly increased the cardiac index. BNP significantly decreased portal tributary blood flow, portal pressure and cardiac index. In normal rats, natriuresis and diuresis were significantly higher with CNP and BNP than with saline. Systemic hemodynamics were not changed by CNP. A decrease in arterial pressure was the sole BNP-induced hemodynamic change.

CONCLUSIONS

In conclusion, this study shows that the natriuretic response to pharmacological doses of CNP and BNP is blunted in rats with cirrhosis. This blunting may be related to an activation of the endogenous antinatriuretic systems secondary to systemic vasodilation (by CNP) or to a decreased cardiac index (by BNP). Finally, this study shows that CNP and BNP have a portal hypotensive action.

Hyperdynamic circulation of advanced cirrhosis: a re-appraisal based on posture-induced changes in hemodynamics

Little is known about the effect of posture on the circulatory abnormalities of advanced cirrhosis. We evaluated the systemic hemodynamics, measured by Doppler-echocardiography, atrial natriuretic factor, plasma renin activity and plasma norepinephrine, in 10 patients with cirrhosis and ascites and 10 healthy controls, after 2 h of standing and during lying down for a further 2 h. Standing hemodynamic patterns of controls and patients with cirrhosis did not differ significantly. The latter, however, showed higher plasma renin activity, norepinephrine and atrial natriuretic factor. The assumption of the supine position led to greater increases in cardiac index and atrial natriuretic factor, and reduction in systemic vascular resistance in patients with cirrhosis. Norepinephrine and plasma renin activity declined in both groups to a similar extent, while heart rate only slowed in controls. Thus, after 2 h in the supine position, patients with cirrhosis showed hyperdynamic circulation with increased cardiac index and heart rate and reduced systemic vascular resistance. Norepinephrine, plasma renin activity and atrial natriuretic factor were also elevated. The hyperdynamic circulation in advanced cirrhosis appears during or is enhanced by lying down. This finding suggests that this syndrome is, at least in part, attributable to excessive blood volume translocation towards the central area. However, the persistent activation of renin-angiotensin and sympathoadrenergic systems suggests that a concomitant reduced vascular sensitivity to vasoconstrictors concurs in its development.

Renal sodium handling in cirrhosis with ascites: mechanisms of impaired natriuretic response to reclining

We recently showed that patients with compensated cirrhosis can dispose of their fluid overload while reclining. In contrast, patients with ascites fail to develop supine-induced natriuresis. To assess the effect of reclining on renal sodium handling in patients with advanced cirrhosis and the mechanisms blunting natriuresis in this situation, renal function and plasma concentrations of atrial natriuretic factor, aldosterone and norepinephrine were evaluated in 10 nonazotemic patients with cirrhosis and ascites and 10 healthy controls standing for 2 h and reclining for 2 h. While standing, all patients showed marked sodium retention and significantly elevated plasma atrial natriuretic factor levels, aldosterone and norepinephrine. Glomerular filtration rate did not differ from healthy controls. The reclining increased renal sodium excretion in both groups, but this change was far less marked in patients; natriuresis only rose to the control range in two of them. An increase in atrial natriuretic factor and a depression of plasma aldosterone and norepinephrine was seen in both controls and patients. In the latter, despite the greater change in atrial natriuretic factor and aldosterone, the aldosterone to atrial natriuretic factor ratio, which was inversely correlated with natriuresis during both standing and reclining remained significantly elevated. In the two patients who achieved normal natriuresis during reclining, reclining was associated with both the normalization of the aldosterone/atrial natriuretic factor ratio, and with an increase in glomerular filtration rate. The supine-induced increase in atrial natriuretic factor was not only preserved but was even enhanced in cirrhosis with ascites.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of atrial natriuretic peptide (ANP) in chronic liver disease

The role of atrial natriuretic peptide (ANP) and potential defects of ANP in liver disease are reviewed. Patients with cirrhosis of the liver show no decrease of ANP plasma concentrations nor changes in the pattern of ANP immunoreactivity nor changes of splanchnic ANP clearance. The renal effects of exogenously administered as well as endogenously released ANP are blunted in cirrhosis, in particular in patients with ascites. This seems due to increased activity of sodium-retaining hormonal systems and changes of the renal ANP receptor status. Pharmacological inhibition of ANP-degradation or clearance may yield therapeutic potential.