Volume adaptation in chronic liver disease: on the static and dynamic location of water, salt, protein and red cells in cirrhosis

Hepatic blood volume is decreased in patients with cirrhosis and does not decrease further after a meal like in healthy persons

BACKGROUND & AIMS

The aim was to measure fractional hepatic blood volume (HBV) and hepatic blood flow (HBF) before and after a meal in patients with cirrhosis (n = 7) and healthy persons (n = 6).

METHODS

Catheters were placed in a radial artery and a hepatic vein for blood sampling and a peripheral vein for indocyanine green (ICG) infusion. A 6-min positron emission tomography (PET) liver scan was performed after inhalation of 1000 MBq ¹⁵O-CO and repeated after ingestion of a standard meal. HBV was calculated as the ¹⁵O-CO concentration in liver tissue (PET) divided by that in arterial blood. HBF was calculated from ICG infusion rate and arterial and hepatic venous blood concentrations according to Fick's principle.

RESULTS

Mean fasting HBV was 14 mL blood/100 mL liver tissue in patients with cirrhosis and 21 mL blood/100 mL liver tissue in healthy subjects (p < .01). Mean HBV did not change postprandially in patients with cirrhosis (13 mL blood/100 mL liver tissue) but decreased in healthy subjects (17 mL blood/100 mL liver tissue; p = .02). Mean fasting HBF was 1.5 L blood/min in patients with cirrhosis and 1.1 L blood/min in healthy subjects and increased in both groups of subjects to 1.8 L blood/min.

CONCLUSIONS

Fasting HBV was lower in patients with cirrhosis and did not decrease postprandially as it did in the healthy controls although the HBF increased equally. Patients with cirrhosis thus have a disturbed hemodynamic response to normo-physiological changes such as a meal.

Hemodynamic Instability During Liver Transplantation in Patients With End-stage Liver Disease: A Consensus Document from ILTS, LICAGE, and SATA

Hemodynamic instability (HDI) during liver transplantation (LT) can be difficult to manage and increases postoperative morbidity and mortality. In addition to surgical causes of HDI, patient- and graft-related factors are also important. Nitric oxide-mediated vasodilatation is a common denominator associated with end-stage liver disease related to HDI. Despite intense investigation, optimal management strategies remain elusive. In this consensus article, experts from the International Liver Transplantation Society, the Liver Intensive Care Group of Europe, and the Society for the Advancement of Transplant Anesthesia performed a rigorous review of the most current literature regarding the epidemiology, causes, and management of HDI during LT. Special attention has been paid to unique LT-associated conditions including the causes and management of vasoplegic syndrome, cardiomyopathies, LT-related arrhythmias, right and left ventricular dysfunction, and the specifics of medical and fluid management in end-stage liver disease as well as problems specifically related to portal circulation. When possible, management recommendations are made.

Splanchnic and systemic circulation cross talks: Implications for hemodynamic management of liver transplant recipients

The interaction between splanchnic and systemic circulation has many hemodynamic and renal consequences during liver transplant. In a patient with liver cirrhosis, splanchnic vasodilatation causes arterial steal from the systemic circulation into the splanchnic bed, which decreases the effective blood volume. Moreover, rapid volume loading in these patients has less impact on the cardiac output because a higher proportion of infused fluid is shifted to the splanchnic area. Thus, in dissection phase, the traditional approach of volume loading to maintain intraoperative hemodynamic stability not only seems ineffective, but it may also aggravate surgical bleeding. Two approaches of volume therapy have been mentioned to maintain hemodynamic stability during liver transplantation: splanchnic volume reduction by volume restriction with or without phlebotomy to maintain low central venous pressure (CVP), and splanchnic decongestion using splanchnic vasoconstrictors. After reperfusion, an increase in the central blood volume was thought to have a deleterious effect on the new graft function; however, the precise central venous pressure value that causes hepatic congestion after reperfusion is unknown.

Modulation of splanchnic circulation: Role in perioperative management of liver transplant patients

Splanchnic circulation is the primary mechanism that regulates volumes of circulating blood and systemic blood pressure in patients with cirrhosis accompanied by portal hypertension. Recently, interest has been expressed in modulating splanchnic circulation in patients with liver cirrhosis, because this capability might produce beneficial effects in cirrhotic patients undergoing a liver transplant. Pharmacologic modulation of splanchnic circulation by use of vasoconstrictors might minimize venous congestion, replenish central blood flow, and thus optimize management of blood volume during a liver transplant operation. Moreover, splanchnic modulation minimizes any high portal blood flow that may occur following liver resection and the subsequent liver transplant. This effect is significant, because high portal flow impairs liver regeneration, and thus adversely affects the postoperative recovery of a transplant patient. An increase in portal blood flow can be minimized by either surgical methods (e.g., splenic artery ligation, splenectomy or portocaval shunting) or administration of splanchnic vasoconstrictor drugs such as Vasopressin or terlipressin. Finally, modulation of splanchnic circulation can help maintain perioperative renal function. Splanchnic vasoconstrictors such as terlipressin may help protect against acute kidney injury in patients undergoing liver transplantation by reducing portal pressure and the severity of a hyperdynamic state. These effects are especially important in patients who receive a too small for size graft. Terlipressin selectively stimulates V1 receptors, and thus causes arteriolar vasoconstriction in the splanchnic region, with a consequent shift of blood from splanchnic to systemic circulation. As a result, terlipressin enhances renal perfusion by increasing both effective blood volume and mean arterial pressure.

Hepatotoxicity and drug interactions in liver transplant candidates and recipients

In this article the medications that have been shown to increase rates of drug-induced liver injury in patients with cirrhosis and the important drug-drug interactions in recipients of liver transplantation are reviewed. In general, the risk of drug-induced liver injury in patients with cirrhosis does not seem to be higher when compared with the noncirrhotic population. There are, however, 2 classes of agents that have been implicated-medications used to treat tuberculosis and medications used to treat human immunodeficiency virus infection. However, with careful monitoring, even significant interactions can be effectively managed.

99mTc-albumin can replace 125I-albumin to determine plasma volume repeatedly

OBJECTIVE

Plasma volume assessment may be of importance in several disorders. The purpose of the present study was to compare the reliability of plasma volume measurements by technetium-labeled human serum albumin ((99m)Tc-HSA) with a simultaneously performed plasma volume determination with iodine-labeled human serum albumin ((125)I-HSA).

MATERIALS AND METHODS

In 15 healthy volunteers, simultaneous plasma volume measurements with (99m)Tc-HSA and (125)I-HSA were performed after ½ hour in the supine position. Blood samples were obtained 10, 15, 20, and 30 minutes after the injection for accurate retropolation from the plasma counts to time zero to correct for leakage of the isotopes from the circulation.

RESULTS

The mean difference (bias) between plasma volume measured with (125)I-albumin and (99m)Tc-albumin was 8 ml (0.1 ml/kg) with limits of agreement (bias ±1.96 SD) ranging from -181-196 ml (-2.3-2.5 ml/kg). The tracer disappearance rate was significantly higher with (99m)Tc-albumin (-23.1±7.1%/h) than with (125)I-albumin (-6.7±3.6%/h) (p <0.001).

CONCLUSION

This study demonstrates that (99m)Tc-HSA can replace (125)I-HSA for single measurements of plasma volume in healthy volunteers. It needs to be emphasized however, that repeated blood sampling for 1/2 hour after injection of the tracer is required to correct for the disappearance of (99m)Tc and (99m)Tc-HSA from the circulation.

Pathogenesis and management of hepatorenal syndrome in patients with cirrhosis

Hepatorenal syndrome is a severe complication of advanced liver cirrhosis, in patients with ascites and marked circulatory dysfunction. It is clearly established that it has a functional nature, and that it is related to intense renal vasoconstriction. Despite its functional origin, the prognosis is very poor. In the present review, the most recent advances in diagnosis, pathophysiology, and treatment are discussed. Recent developments in pathophysiology are the basis of the new therapeutic strategies, which are currently under evaluation in randomised clinical trials.

Review article: Management of ascites and associated complications in patients with cirrhosis

BACKGROUND

Ascites is the most common complication of cirrhosis, associated with an expected survival below 50% after 5 years. Prognosis is particularly poor for patients with refractory ascites and for those developing complications, including spontaneous bacterial peritonitis (SBP) and hepatorenal syndrome (HRS).

AIM

To provide an evidence-based overview of the pathophysiology, diagnosis and clinical management of ascites secondary to liver cirrhosis.

METHODS

Review based on relevant medical literature.

RESULTS

Portal hypertension, splanchnic vasodilatation and renal sodium retention are fundamental in the pathophysiology of ascites formation. The SAAG (serum-ascites albumin gradient) allows reliable assessment of the cause of ascites. The majority of cirrhotic patients with ascites can be managed with dietary sodium restriction in combination with diuretic agents. Large volume paracentesis with albumin suppletion and TIPS are therapeutic options in patients with refractory ascites. Prophylactic antibiotics for SBP should be given in certain patient populations.

CONCLUSIONS

Recent advances in the diagnosis and treatment of ascites and associated complications have improved the medical management and poor prognosis of patients with these manifestations of advanced liver disease. Early diagnosis, adequate treatment and focus on prevention of complications remain essential as well as timely referral for liver transplantation.