Albumin is a highly soluble, globular protein (MW 66,500), accounting for 70 - 80% of the colloid osmotic pressure of plasma. Therefore, it is important in regulating the osmotic pressure of plasma1,2. Human albumin grifols 20% supplies the oncotic equivalent of approximately 4 times its volume of human plasma. It will increase the circulating plasma volume by an amount approximately 2.5 times the volume infused within 15 minutes, if the recipient is adequately hydrated3. This extra fluid reduces hemoconcentration and decreases blood viscosity. The degree and duration of volume expansion depend upon the initial blood volume.
When treating patients with diminished blood volume, the effect of infused albumin may persist for many hours. The hemodilution lasts for a shorter time when albumin is administered to individuals with normal blood volume.
Albumin is also a transport protein and binds naturally occurring, therapeutic, and toxic materials in the circulation2.
Albumin is distributed throughout the extracellular water and more than 60% of the body albumin pool is located in the extravascular fluid compartment. The total body albumin in a 70 kg man is approximately 320 g; it has a circulating life span of 15 - 20 days, with a turnover of approximately 15 g per day1. Indications and Usage
Albumin (Human), Human albumin grifols 20% is indicated:
- For the prevention and treatment of hypovolemic shock2,4, and
- in conjunction with exchange transfusion in the treatment of neonatal hyperbilirubinemia2.
- Concentrated Albumin (Human) solutions (e.g., 20%) have also been used successfully to induce diuresis in some patients with acute nephrosis1 who were refractory to other forms of treatment. However, Albumin (Human) has no role in the management of chronic nephrosis.
- More dilute Albumin (Human) solutions (e.g., 5%) have been used as pump priming fluids during cardiopulmonary bypass. However, an adequate blood volume can also be maintained during bypass with crystalloid as the only priming fluid without a significant difference in the clinical outcome achieved1,2.
Conditions in which Albumin (Human) use is usually not justified:
- Postoperative hypoproteinemia. Major surgery or other injury of capillary walls may lead to substantial losses of circulating albumin over and above those due to bleeding1,2,4,5. However, this redistribution of albumin in the body rarely causes clinically significant hypovolemia, hence treatment with Albumin (Human) is usually not indicated.
- Renal dialysis. Patients undergoing long-term hemodialysis may occasionally require Albumin (Human) for the treatment of an acute volume or oncotic deficit1. Such patients who receive Albumin (Human) should be carefully monitored for signs of circulatory overload, to which they are particularly sensitive.
- Paracentesis or Acute liver failure. Removal of even large volumes of ascites fluid is usually well tolerated. However, if significant hypovolemia and/or cardiovascular function changes ensue, Albumin (Human) can provide short-term benefit. Similarly, in patients with acute liver failure, Albumin may have a stabilizing effect, but the therapy must be guided by individual circumstances1. Albumin (Human) is of no value in the management of chronic cirrhosis.
Unless the pathologic condition responsible for hypoalbuminemia can be corrected, administration of Albumin (Human) can afford only symptomatic relief. There is NO valid reason for the use of Albumin (Human) as an intravenous nutrient.