IV albumin is a protein solution infused into your bloodstream to pull fluid from surrounding tissues into your blood vessels, expanding your blood volume. It’s one of the most commonly used products in hospitals for patients with liver disease, severe infections, and other conditions where the body can’t maintain enough fluid in circulation on its own. The effects begin within minutes of infusion, though the albumin itself only lasts about 12 to 16 hours in the bloodstream before breaking down.
How IV Albumin Works in Your Body
Albumin is the most abundant protein in your blood. Its main job is maintaining what’s called oncotic pressure, which is essentially the force that keeps fluid inside your blood vessels rather than leaking out into surrounding tissues. When albumin levels drop too low, fluid seeps out of the bloodstream and accumulates in places it shouldn’t, like the abdomen or the tissue under your skin.
When albumin is infused through an IV, it raises the protein concentration inside your blood vessels. This creates an osmotic pull that draws fluid from the spaces between your cells back into your circulatory system, effectively increasing the volume of blood your heart can pump. Beyond this volume-expanding role, albumin also acts as a transport molecule, carrying fatty acids, hormones, metals, and certain medications through the bloodstream to where they’re needed.
Two Concentrations for Different Goals
IV albumin comes in two main concentrations, and they behave quite differently in the body.
The lower concentration (4% to 5%) is closer to the natural protein level in your blood. It expands plasma volume by roughly 66% of the amount infused, meaning if you receive 500 mL, your blood volume increases by about 330 mL. Because about a third of the fluid leaks back out of the bloodstream relatively quickly, larger volumes are typically needed.
The higher concentration (20% to 25%) is a much more powerful fluid magnet. It expands plasma volume by about 200% of the infused amount, pulling significantly more water out of surrounding tissues and into the bloodstream. If a clinician infuses 100 mL of 25% albumin, your blood volume increases by roughly 200 mL. This concentration is particularly useful when the goal is to reduce swelling or fluid buildup in tissues without adding a large amount of extra fluid. It’s also preferred when a diuretic effect is desired, since it draws excess fluid back into circulation where the kidneys can then filter and remove it.
Liver Disease and Fluid Drainage
The most well-established use of IV albumin is in advanced liver disease. When the liver fails, it can no longer produce enough albumin on its own, and fluid accumulates in the abdomen, a condition called ascites. Patients with severe ascites often need a procedure called large-volume paracentesis, where a needle drains liters of fluid from the abdominal cavity. Without albumin replacement, removing that much fluid can cause a dangerous drop in blood pressure because the circulatory system suddenly loses effective volume.
Guidelines recommend giving 6 to 8 grams of albumin for every liter of fluid removed beyond the first 5 liters. In practice, this means a patient who has 7 to 10 liters drained receives about 50 grams of 25% albumin (two vials), while someone who has more than 10 liters removed gets about 75 grams. This replacement keeps blood pressure stable and protects kidney function during and after the procedure.
IV albumin also plays a key role in hepatorenal syndrome, a serious complication where liver failure triggers kidney failure. In this situation, albumin is given alongside medications that constrict blood vessels, helping restore blood flow to the kidneys. Studies show albumin is the most effective volume expander for this purpose, and using it alongside other treatments significantly improves their effectiveness. For a milder form of this syndrome, the combination can improve kidney function, though there’s roughly a 50% chance of recurrence once treatment stops.
Sepsis and Critical Illness
In intensive care settings, IV albumin is sometimes used for patients with severe infections, particularly septic shock, where blood pressure drops dangerously low because blood vessels dilate and leak fluid. The idea is that albumin stays in the bloodstream longer than simple salt-water solutions (crystalloids), providing more sustained volume support.
Some evidence suggests albumin may offer advantages over crystalloids in septic shock specifically, but the benefits haven’t been consistently confirmed across studies. Current guidelines offer only a weak recommendation for albumin in this context, and it’s generally considered an option rather than a first-line treatment.
How Long the Effects Last
The fluid shift from IV albumin begins within minutes. However, the albumin itself has a surprisingly short lifespan once infused. While albumin your body produces naturally circulates for about three weeks, infused albumin breaks down in just 12 to 16 hours. In patients with conditions that make blood vessels leakier than normal (common in sepsis, burns, and severe inflammation), it breaks down even faster. This is why repeated infusions are often necessary rather than a single dose.
It’s also worth noting that albumin does very little for dehydrated patients. Because the fluid shift depends on pulling water from surrounding tissues, there needs to be adequate fluid in those tissues for it to work. If someone is dehydrated, the fluid movement into the bloodstream is limited or absent until the dehydration is corrected with other fluids first.
Side Effects and Risks
The most common reactions during an albumin infusion include chills, nausea, low blood pressure, rapid heart rate, fever, vomiting, and skin rash. These are generally mild and resolve when the infusion rate is slowed.
The more serious risk is fluid overload. Because albumin pulls extra fluid into the bloodstream, it can overwhelm the heart and lungs if given too quickly or in too large a dose, particularly in patients with heart or kidney problems. Warning signs of fluid overload include headache, shortness of breath, visible swelling of the neck veins, and rising blood pressure. For patients on kidney dialysis, initial doses are kept small and monitoring is especially close.
True allergic reactions, including anaphylaxis, are rare but possible. These require the infusion to be stopped immediately. Before and during any albumin infusion, your care team will monitor your vital signs and adjust the rate based on how your cardiovascular system is responding.