Albumin 20% in surgical and critically ill patients; a comprehensive review

Hyper-oncotic (20%) albumin has long been used during surgery and intensive care, but its pharmacology and relevant clinical use have not been adequately summarized. Hyper-oncotic albumin expands the plasma volume by twice the infused volume due to colloid pressure-induced recuitment of interstitial fluid, which primarily occurs via the lymphatic route. The interstitium and also the whole body is dehydrated, which helps maintaining the intravascular space well filled also at low arterial pressures. Albumin reduces the capillary permeability by volume exclusion and by transporting sphingosine-1-phosphate to the endothelial surface. The plasma volume expansion has a half-life of 6–10 h. During surgery, albumin 20% provides long-term plasma volume expansion, counteracts edema, and is effective in compensating hemorrhage. Its most apparent use is for de-escalation in intensive care, which involves positive effects on microcirculation and lung function. The mortality might be reduced in septic shock, which needs final validation. Our group has identified six situations in which albumin 20% can be expected, or has shown to be, of clinical value. These are: (1) Intraoperatively where large amounts of crystalloid threaten to cause adverse effects. (2) For plasma volume expansion in patients with peripheral edema, in particular if the urine output is low. (3) Gastrointestinal surgery with major hemorrhage where intestinal suturing is needed. (4) De-escalation in the ICU. (5) Septic shock. (6) Lung injury including pleural effusions and respiratory distress. Hyper-oncotic albumin effectively increases the plasma volume, dehydrates the interstitium, and improves the microcirculation. These characteristics can be beneficial to patients in selected clinical situations.