What is the role of albumin in treating acidosis?

Role of Albumin in Acidosis

Albumin does not have a direct therapeutic role in treating acidosis, and current guidelines do not recommend its use for this purpose. 1

Physiological Relationship Between Albumin and Acid-Base Balance

Albumin's relationship with acid-base balance is complex:

• Albumin functions as a weak acid in the blood and contributes to the body's buffering capacity
• Hypoalbuminemia can lead to a mild metabolic alkalosis (not acidosis) due to decreased weak acid in circulation
• Metabolic acidosis can negatively impact albumin synthesis and metabolism:
  • Chronic metabolic acidosis decreases albumin synthesis rates 2
  • Correction of metabolic acidosis in hemodialysis patients increases serum albumin concentrations 3, 4

Evidence Against Using Albumin to Treat Acidosis

The International Collaboration for Transfusion Medicine Guidelines (ICTMG) and American College of Chest Physicians recommend:

• Against routine treatment of hypoalbuminemia alone 1, 5
• Against using albumin as nutritional support 5
• Against routine use of albumin in most ICU patients 5

In fact, albumin administration may potentially worsen acidosis:

• Hetastarch and other colloid solutions can cause dilutional acidosis 6
• Administration of large volumes of albumin may contribute to hyperchloremic acidosis in critically ill children 1

Appropriate Indications for Albumin

Current guidelines support albumin use in specific conditions:

• Liver disease complications:

  • Large-volume paracentesis (>5L): 6-8g albumin per liter of ascitic fluid removed 5, 7
  • Spontaneous bacterial peritonitis: 1.5g/kg on day 1, followed by 1g/kg on day 3 5
  • Hepatorenal syndrome (with vasoconstrictors) 7

• Other potential indications with weaker evidence:

  • Second-line fluid in septic shock (when large volumes of crystalloids required) 1, 7
  • Fluid replacement in plasmapheresis 7
  • Severe burns and toxic epidermal necrolysis 7

Addressing Acidosis Directly

For treating acidosis itself:

• Identify and treat the underlying cause (sepsis, renal failure, diabetic ketoacidosis, etc.)
• For metabolic acidosis:
  • Sodium bicarbonate supplementation is effective in correcting metabolic acidosis in hemodialysis patients 3, 4
  • Correction of acidosis reduces protein catabolism and may improve serum albumin levels in non-inflamed patients 4

Clinical Pitfalls to Avoid

• Do not administer albumin solely to correct hypoalbuminemia without specific clinical indications 5
• Do not use albumin as first-line fluid therapy for resuscitation in most conditions 1
• Be cautious about fluid overload, pulmonary edema, and other complications when administering albumin 5
• In critically ill children, albumin boluses may be associated with higher rates of respiratory and neurologic dysfunction and hyperchloremic acidosis 1

In summary, while albumin levels may be affected by acid-base disturbances, albumin administration is not an appropriate treatment for acidosis. Correcting the underlying cause of acidosis is the appropriate therapeutic approach.