What is Albumin's role in medicine? Insights from a vascular surgeon

Author: Lianshuo, Resident Physician in the Vascular Surgery Department at Shanghai First People's Hospital. Reviewer: Ding Qingwei, Associate Chief Physician of the Vascular Surgery Department at Shanghai First People's Hospital. Note: The cover image is from a copyrighted stock photo library, and reusing it may lead to copyright disputes.

In my clinical work, I am often asked this question by patients or their families: What is albumin's role in medicine? These questions seem reasonable, but they conceal a long-misunderstood fact—human serum albumin is not something used for "nourishing the body." What role does albumin play in the body? Albumin is the most abundant protein in plasma, and its primary role is not to "provide nutrition," but to serve regulatory and transport functions. In simple terms, it mainly does three things. 1. Maintain the osmotic pressure in the blood to prevent excessive fluid from leaking into the tissues, which could cause edema. 2. As a "porter," it carries substances such as medications and fatty acids flowing in the blood. 3. Under specific pathological conditions, it is involved in maintaining circulatory stability. Human serum albumin used in clinical settings is a strictly processed blood product that is classified as a therapeutic drug requiring evaluation by a physician before use. Many people consider albumin as a "supplement" for several reasons. Albumin is a protein that plays a crucial role in maintaining oncotic pressure and transporting various substances in the blood. Some individuals believe that consuming albumin can help in muscle building, recovery after workouts, or improving overall health. Additionally, it is often associated with sports nutrition and is thought to enhance physical performance. However, the perception of albumin as a supplement may stem from a misunderstanding of its functions and benefits in the body.

This type of misunderstanding is actually not uncommon and mainly stems from certain reasons. First of all, the term "albumin" easily evokes associations, as everyone knows that protein is an important nutritional component. This leads to the subconscious belief that albumin = high-quality protein = quick way to replenish the body. However, in terms of nutrition, the protein content in albumin preparations is not high, and they do not possess a complete and balanced amino acid profile, making them unable to replace the intake of high-quality proteins in a regular diet. Secondly, the perception of "injections and intravenous drips" leads many to mistakenly believe they are more effective. In the minds of many people, "anything that can be administered through an IV must be stronger than oral medication." However, in medicine, the route of administration is never the standard for assessing efficacy; rather, whether the treatment is appropriate for the condition is what truly matters.

When is albumin really "usable"? In clinical practice, doctors consider using albumin typically because the patient has a specific medical issue, such as: 1. The serum albumin level is significantly decreased, and it has affected circulatory stability. 2. Severe illness leads to significant protein loss or consumption. 3. Specific liver or kidney diseases accompanied by significant edema or ascites. 4. Volume support in the case of severe burns, shock, and other conditions. In other words, the role of albumin is to "correct abnormal states" rather than to "enhance healthy states." From the perspective of vascular surgery, which diseases are likely to lead to low albumin levels?

In vascular surgery, we indeed encounter many patients with low albumin levels. However, it is important to emphasize that the decline in albumin is often a result of the disease process rather than the starting point of the issue. 1. Severe limb ischemia combined with infection or necrosis. In patients with severe lower limb arterial occlusive disease, especially those with diabetic foot, ulcers, or gangrene, long-term ischemia, recurrent infections, and tissue necrosis can lead the body to remain in a state of persistent high energy consumption. In such patients, levels of albumin decrease, reflecting a heavy burden of inflammation, metabolic disorders, and insufficient nutritional intake. If vascular blockage is not addressed and infection is not controlled, simply infusing albumin often only provides a "temporary improvement," which quickly declines again.

2. Perioperative management of abdominal aortic aneurysm and complex vascular surgeries. It is not uncommon for patients undergoing abdominal aortic aneurysm repair or complex vascular surgery to experience a decrease in albumin levels in the short term after surgery. This is more related to surgical trauma, stress responses, and increased vascular permeability, and is not equivalent to true malnutrition. The decision to use albumin must be made based on a comprehensive assessment of the circulatory status, the presence of edema, and the overall condition of the patient, rather than solely focusing on a single value on the laboratory report. 3. Aortic dissection, acute ischemia, and other critical phases.

In critical conditions such as aortic dissection or acute limb ischemia, the body may exhibit a strong stress response, leading to a significant decrease in albumin levels within a short period. At this stage, the focus of treatment is always on stabilizing vital signs, controlling the primary disease, and ensuring organ perfusion. The decrease in albumin often appears as a concomitant phenomenon rather than a priority target for intervention. 4. Patients with chronic ulcers and vascular diseases who have undergone repeated surgeries. Some patients may gradually enter a state of chronic consumption due to chronic wounds that do not heal, repeated debridement, or multiple surgeries, resulting in persistently low albumin levels.

This type of situation requires systematic nutritional assessment and continuous nutritional support, rather than relying on short-term infusions of albumin to "boost the numbers." Why are vascular surgeons more cautious about administering "albumin"? The reason is actually very simple: 1. Having more albumin is not necessarily better; the human body has its own regulatory mechanisms. 2. Any infusion of blood products does carry some risks. 3. Low albumin is often a result rather than a cause. 4. If vascular issues, infections, and nutritional support are not addressed, albumin levels will only rise temporarily and will soon decrease again.

Several practical suggestions for patients: 1. Don't consider albumin as a way to nourish or enhance your constitution. 2. Do not request or purchase albumin infusions on your own. 3. Whether or not to use it should be determined by the doctor based on the patient's condition. 4. Improving nutritional status is more important than diet and standardized nutritional support.

In conclusion, human albumin is indeed an important medication in the field of medicine, but its value comes from precise use rather than misuse. In vascular surgery, our primary concern has never been about whether "albumin was administered," but rather whether the vessels are patent, whether the infection is under control, and whether there is systematic nutritional support. Once these issues are resolved, albumin will truly return to its appropriate level.