What type of albumin is used to improve hypotension and intravascular fluid shift in critically ill patients?

Albumin Types for Improving Blood Pressure and Intravascular Fluid Shift in Critically Ill Patients

Both 4-5% (iso-oncotic) and 20% (hyperoncotic) albumin solutions can be used as second-line therapy to improve blood pressure and intravascular fluid shift in critically ill patients, with 20% albumin showing greater benefits for cardiovascular function and requiring lower infusion volumes. 1

Evidence for Different Albumin Concentrations

• The two main concentrations of albumin used in clinical practice are 4-5% (iso-oncotic) and 20% (hyperoncotic) albumin solutions 1
• In the SAFE study, 4% albumin was associated with lower volume requirements compared to crystalloids (3011 ± 1924 vs. 3522 ± 2507 mL, p < 0.001) 1
• In the ALBIOS study, 20% albumin administration resulted in significantly lower cardiovascular SOFA scores compared to crystalloids (1.20 vs. 1.42, p = 0.03) 1
• 20% albumin was also associated with shorter duration of vasopressor treatment (3 vs. 4 days, p = 0.007) and improved fluid balance on days 2-4 1

Clinical Benefits of Albumin for Hemodynamic Support

• Albumin solutions help preserve effective circulatory volume due to their significant effect on colloid oncotic pressure 2
• Administration of albumin has been shown to improve circulatory function and reduce the volume of vascular load needed 1
• In hemodialysis patients, 25% albumin improved hypotension, lowest intradialytic systolic BP, and ultrafiltration rate compared to saline 1
• Albumin administration can effectively raise colloid osmotic pressure in hypoalbuminemic patients 3

Limitations and Considerations

• Current guidelines do not recommend albumin as first-line treatment for fluid resuscitation in sepsis or septic shock (GRADE 2-) 1
• The 2021 Surviving Sepsis Campaign suggests using albumin in addition to crystalloids only in sepsis and septic shock patients requiring large volumes of saline 1
• Albumin is significantly more expensive than crystalloid alternatives ($130/25g USD) 4, 5
• There is no substantial evidence that albumin reduces mortality in critically ill patients compared to cheaper alternatives like saline 5, 6
• A potential deleterious effect of 20% albumin on renal function was suggested in the CRYCO observational study, though subsequent RCTs have not confirmed this risk 1

Specific Clinical Scenarios

• In patients with intradialytic hypotension, 25% albumin may be more effective than saline for maintaining blood pressure, though this is not a first-line recommendation 1, 4
• In patients with traumatic brain injury, albumin should be avoided as it has been associated with higher mortality 6
• In patients with hypoalbuminemia, focus should be on treating the underlying cause rather than the low albumin level itself 4, 7

Practical Algorithm for Albumin Use in Critically Ill Patients

1. Start with balanced crystalloids as first-line fluid therapy (GRADE 2+) 1
2. Consider albumin as second-line therapy only after adequate crystalloid resuscitation when:
   • Patient requires large volumes of fluid 1
   • Patient has persistent hypotension despite adequate crystalloid resuscitation 1
   • Patient has poor response to crystalloids with worsening fluid balance 1
3. When selecting albumin concentration:
   • Use 4-5% albumin when larger volume expansion is needed 1
   • Use 20% albumin when fluid restriction is desired or for improved cardiovascular function 1
4. Monitor response by assessing:
   • Hemodynamic parameters (blood pressure, heart rate) 1, 2
   • Fluid balance 1
   • Vasopressor requirements 1