What is the relationship between albumin and fluid retention, specifically in the context of hypoalbuminemia (low albumin) and edema (fluid retention)?

From the Guidelines

Albumin administration is crucial in preventing fluid retention, particularly in patients with cirrhosis and spontaneous bacterial peritonitis (SBP), as it helps maintain oncotic pressure and reduces the risk of acute kidney injury (AKI) and mortality, as evidenced by a recent multi-center RCT 1.

Relationship between Albumin and Fluid Retention

The relationship between albumin and fluid retention is complex, and albumin plays a vital role in maintaining oncotic pressure in the bloodstream. When albumin levels are low, the oncotic pressure decreases, allowing fluid to leak from blood vessels into surrounding tissues, resulting in edema or fluid retention. This is particularly important in conditions like liver disease, where albumin levels may be compromised.

Albumin Administration in SBP

In patients with SBP, albumin administration has been shown to reduce the risk of AKI and mortality. A recent multi-center RCT including 105 patients with SBP found that those who received antibiotics accompanied by IV albumin had a significantly lower rate of AKI (10% vs 33%) and death (10% vs 29%) compared with those who received antibiotics only 1. The recommended dose of albumin in this setting is 1.5 g/kg at day 1 and 1 g/kg at day 3.

Alternatives to Albumin

Regarding alternatives to albumin, an RCT comparing hydroxyethyl starch with albumin in 20 patients with SBP found albumin to be superior in improving systemic circulatory hemodynamics 1. Therefore, albumin is the preferred choice in patients with SBP.

Contraindications for Albumin Use

However, albumin is not advised in infections other than SBP, unless associated with AKI, as it has been shown to increase the risk of pulmonary edema in these patients 1. Additionally, albumin should not be used in patients with cirrhosis and uncomplicated ascites, as the standard therapy for cirrhotic ascites is sodium restriction plus diuretics (spironolactone with or without furosemide) 1.

Key Points

• Albumin administration is crucial in preventing fluid retention in patients with cirrhosis and SBP.
• The recommended dose of albumin in SBP is 1.5 g/kg at day 1 and 1 g/kg at day 3.
• Albumin is superior to hydroxyethyl starch in improving systemic circulatory hemodynamics in SBP.
• Albumin is not advised in infections other than SBP, unless associated with AKI.
• Albumin should not be used in patients with cirrhosis and uncomplicated ascites.

From the Research

Relationship between Albumin and Fluid Retention

• Albumin plays a crucial role in maintaining oncotic pressure, which helps to retain fluid in the vascular compartment 2.
• Hypoalbuminemia, or low albumin levels, can lead to fluid retention in the interstitial space, resulting in edema 3, 4.
• In patients with liver cirrhosis, hypoalbuminemia can contribute to the development of ascites, a condition characterized by fluid accumulation in the peritoneal cavity 5, 6.
• The administration of albumin can help to increase intravascular oncotic pressure, promoting the transfer of extravascular fluid into the intravascular compartment, which can be beneficial in patients with volume overload and reduced effective arterial volume 4.
• However, the use of albumin supplementation should be limited to well-defined clinical scenarios, and its effectiveness in reducing fluid retention and improving outcomes is still a topic of debate 5, 3.

Pathophysiological Mechanisms

• Inflammation can increase capillary permeability, leading to the escape of serum albumin and the expansion of interstitial space, resulting in hypoalbuminemia 3.
• Liver dysfunction, malnutrition, and nephrotic syndrome are also significant causes of hypoalbuminemia, which can contribute to fluid retention 2, 4.
• The management of hypoalbuminemia should focus on correcting the underlying causes of inflammation and fluid retention, rather than relying solely on albumin infusion 3, 4.

Clinical Implications

• Diuretics play a significant role in the management of fluid overload in conditions such as heart failure, cirrhosis, and nephrotic syndrome 6.
• The use of diuretics, in combination with other therapeutic strategies, can help to reduce fluid retention and improve outcomes in patients with hypoalbuminemia and fluid overload 6.