Albumin is the most abundant protein in blood and accounts for about 50% of all plasma proteins. It is synthesized by the liver and secreted immediately without storing. The physiological regulators of albumin are the colloid osmotic pressure and the nutritional status. The metabolism of albumin depends on the synthesis, distribution over interstitium and intravascular compartment, and excretion. Normal blood plasma concentration is between 3.5 to 5 g/dL, and 60% of the total albumin is in the interstitial space. Mean half-life is about 28 to 36 days .
Main medical uses are pharmacological therapy, serum marker to monitor diseases, biomaterials, and vaccines.
Spontaneous bacterial peritonitis (SBP) is a significant cause of mortality in cirrhotic patients. Administration of albumin 1.5 g/kg within 6 hours and 1 g/kg on day 3 along with antibiotics have a better effect in preventing renal impairment and reducing mortality from 29% to 10% in cirrhotic patients with SBP compared to those receiving antibiotics only. Another clinical trial confirmed the benefit of this therapy with laboratory, cardiac and Doppler parameters. Improvement in portal vein flow volume (p = 0.01) and reduction of inflammatory marker TNFa in ascites (p = 0.04) were reported.
The regular price of intravenous albumin solution is around $0.5 to $6 per milliliter. Compared to saline solutions $0.01 to $0.1 per milliliter, albumin solutions are 60-times more expensive. Price takes place when saline solutions and albumin infusions have the same efficacy in the treatment of a disease.
Albumin has 2 important physiologic functions:
The principal mechanism of action of albumin infusion is to increase the colloid osmotic pressure. It drives the interstitial fluid into the intravascular compartment and increases the effective volume of the circulatory system.
The only mode of administration of albumin is by intravenous (IV) infusion. There are 2 formulations available that differ on the albumin concentration; albumin 5% and 25%. In general terms, albumin 25% is used when sodium or fluid are restricted or in cases of oncotic deficiencies. Albumin 5% is more used in situations of volume loss as dehydration. However, concentration, the rate of infusion and dosage depend on the clinical situation as stated above.
Since albumin solution is a human-derived blood product, adverse effects are rare. In less than 0.1%, anaphylactoid reactions, flushing, urticaria, fever, chills, nausea, vomiting, tachycardia, and hypotension can occur. These reactions normally disappear when the infusion rate is slowed or stopped. Edema and fluid overload are common adverse effects, which depend on the volume, speed of the infusion and the clinical scenario. In very rare cases, anaphylactic shock may occur. (Pharmaceutical prescribing information).
Hypersensitivity to any component in albumin preparations or excipients.
Contraindications include clinical situations that present with volume overload, for example, severe anemia, congestive heart failure, or renal insufficiency, are at high risk of hemodynamic instability when treated with albumin solutions.
Do not dilute any albumin solution with sterile water because may cause hemolysis and acute kidney injury (AKI) in the recipient. (Pregnancy Category C).
It is recommended to assess fluid overload, hemodilution, and electrolyte disturbances. This could be prevented by monitoring: blood pressure, heart rate, central venous pressure, pulmonary artery occlusion pressure, electrolytes, hemoglobin and hematocrit. (Pharmaceutical prescribing information)
Albumin solution is a derived product from a large pool of human plasma. It goes through a sterilization process, pasteurization, and heating, but it is not completely sterile. However, the risk of infectious disease transmission, virus, or prions, is remote. It contains no preservative. Once opened it has to be used immediately and the unused portion discarded. (Pharmaceutical prescribing information).
Healthcare workers, including nurses, who work in the emergency department or the ICU need to know about the indications and contraindications for albumin. While the colloid is safe, in the rare patient it may induce an anaphylactoid reaction. Thus, it is important to know how to manage this adverse reaction. After massive use, albumin infusions can cause fluid overload and electrolyte disturbances.