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Serum Albumin

Low serum albumin is associated with postoperative complications and mortality. It is useful for risk assessment, but does not diagnose malnutrition, measure muscle mass or show that nutrition support is adequate.[1]

Thresholds and Their Limits​

  • Albumin <3.5 g/dL is a common definition of hypoalbuminemia. The reporting laboratory's reference interval applies.
  • Albumin <3.0 g/dL, without hepatic or renal dysfunction, is one ESPEN 2025 criterion for high metabolic risk before surgery. It is not a stand-alone malnutrition diagnosis.[2]
  • Albumin ≤3.3 g/dL was a data-derived risk split in a retrospective plastic-surgery cohort.[3]

What Changes the Concentration​

Albumin has an approximately 20-day half-life under usual conditions. Inflammation changes synthesis, capillary permeability, distribution and turnover. Fluid administration, liver disease and renal or gastrointestinal protein loss also affect the concentration.[1][4][5]

Albumin may remain normal despite profound nutritional deprivation. Conversely, acute illness can produce a low concentration in someone whose intake was previously adequate. Malnutrition and inflammation often coexist, and neither a normal albumin nor a normal CRP excludes malnutrition.[1] Albumin is not one of the phenotypic or etiologic criteria in the GLIM framework for diagnosing malnutrition.[10]

In a prospective cohort of 2,465 emergency-department patients, CRP >20 mg/L and nutritional risk were independently associated with hypoalbuminemia (adjusted ORs 10.51 and 2.87, respectively). Combining albumin, CRP and NRS-2002 predicted 30-day mortality with AUC 0.82. The finding is an acute-care prognostic association.[6]

What the Reconstructive Evidence Shows​

StudyFindingInterpretation
Alfertshofer 2026. 200,015 plastic and reconstructive surgery patients in NSQIPAmong patients with measured albumin, the 30-day composite of death, reoperation, readmission, or surgical/medical complication occurred in 36.5% with albumin ≤3.3 g/dL versus 10.4% with albumin >3.3 g/dL; albumin was the strongest predictor among the studied preoperative laboratory variables[3]Retrospective association across diverse plastic surgery procedures; these are not GU wound or graft-failure rates, and raising albumin alone has not been shown to prevent complications
Herzog 2024. 3,038 head-and-neck free-flap patients in NSQIP; hypoalbuminemia defined as <3.5 g/dLFlap failure 6.3% with versus 2.1% without hypoalbuminemia; adjusted OR 3.37 (95% CI 1.38–8.21)[7]Increased odds in head-and-neck free-flap patients; the estimate has not been shown for GU reconstruction
Panayi 2024. 34,571 free-tissue-flap records in NSQIPFrailty (mFI-5) and hypoalbuminemia (<3.5 g/dL, present in 8.2% of the 16,250 records with albumin) each independently predicted complications[8]Free-flap cohort; albumin was missing in 53% of records
Manivasagam 2026. 6,748 radical cystectomy patients in NSQIPAlbumin <3.5 g/dL was associated with adjusted 30-day mortality (OR 1.74), reoperation (OR 1.39), and remaining hospitalized after postoperative day 30 (OR 1.28)[11]—

Sources: Alfertshofer,[3] Herzog,[7] Panayi,[8] and Manivasagam.[11] Observational changes in albumin during hospitalization also track disease severity and outcomes.[9]

Clinical Approach​

  1. Investigate a low result. Review inflammation or infection, fluid balance, hepatic synthesis and protein losses alongside the nutrition history.
  2. Assess nutrition independently. A validated risk screen leads to dietetic assessment, SGA or a GLIM-based diagnosis. Screening and diagnosis are separate steps.[1][10]
  3. Treat identified problems. Provide appropriate nutrition and manage the underlying disease. A rise in albumin may reflect resolving inflammation.[1]
  4. Plan the operation in context. ESPEN 2025 recommends preoperative nutrition therapy for severe malnutrition and/or high metabolic risk even if surgery is postponed (grade A, strong consensus); consider 10–14 days (grade B). Urgent source control or other disease-related urgency may change the balance. Normalization of albumin is not a treatment endpoint.[2]

Albumin infusion given only to correct a low laboratory concentration is not nutritional rehabilitation. Management targets the cause of the low concentration, including inflammation, fluid excess, impaired hepatic synthesis or protein loss. In the single-center SuperAdd randomized trial, 600 high-risk noncardiac surgical patients whose perioperative albumin fell below 3.0 g/dL were assigned albumin infusion to maintain >3.0 g/dL or standard care; grade ≥2 complications by postoperative day 15 occurred in 254/300 (84.7%) versus 262/300 (87.3%; risk difference −2.7%, 95% CI −8.3% to 2.9%).[12] Albumin infusion requires a separate clinical indication.[4][5]

See Also​

References​

1. Evans DC, Corkins MR, Malone A, et al. "The Use of Visceral Proteins as Nutrition Markers: An ASPEN Position Paper." Nutrition in Clinical Practice. 2021;36(1):22–28. doi:10.1002/ncp.10588

2. Weimann A, Bezmarevic M, Braga M, et al. ESPEN guideline on clinical nutrition in surgery — Update 2025. Clin Nutr. 2025;53:222–261. doi:10.1016/j.clnu.2025.08.029. Full guideline.

3. Alfertshofer M, Knoedler S, Broer PN, et al. "From serum to surgery: the significance of albumin in preoperative risk stratification — an analysis of 200,015 plastic surgery patients." Aesthetic Plastic Surgery. 2026. doi:10.1007/s00266-026-05800-8

4. Soeters PB, Wolfe RR, Shenkin A. "Hypoalbuminemia: Pathogenesis and Clinical Significance." JPEN. Journal of Parenteral and Enteral Nutrition. 2019;43(2):181–193. doi:10.1002/jpen.1451

5. Allison SP, Lobo DN. "The Clinical Significance of Hypoalbuminaemia." Clinical Nutrition. 2024;43(4):909–914. doi:10.1016/j.clnu.2024.02.018

6. Eckart A, Struja T, Kutz A, et al. "Relationship of Nutritional Status, Inflammation, and Serum Albumin Levels During Acute Illness: A Prospective Study." The American Journal of Medicine. 2020;133(6):713–722.e7. doi:10.1016/j.amjmed.2019.10.031

7. Herzog I, Panchal D, Sikder S, et al. "Malnutrition in head and neck free flap reconstruction as a predictor of adverse outcomes." Annals of Plastic Surgery. 2024;92(4S Suppl 2):S251–S254. doi:10.1097/SAP.0000000000003868

8. Panayi AC, Knoedler L, Matar DY, et al. "The combined risk predictive power of frailty and hypoalbuminemia in free tissue flap reconstruction: a cohort study of 34,571 patients from the NSQIP database." Microsurgery. 2024;44(4):e31156. doi:10.1002/micr.31156

9. Li Y, Chen L, Yang X, et al. "Dynamic Association of Serum Albumin Changes With Inflammation, Nutritional Status and Clinical Outcomes: A Secondary Analysis of a Large Prospective Observational Cohort Study." European Journal of Medical Research. 2025;30(1):679. doi:10.1186/s40001-025-02925-5

10. Jensen GL, Cederholm T, Correia MITD, et al. GLIM consensus approach to diagnosis of malnutrition: A 5-year update. JPEN J Parenter Enteral Nutr. 2025. doi:10.1002/jpen.2756.

11. Manivasagam SS, Raman JD, Kaag MG. "Impact of Hypoalbuminemia on Morbidity and Mortality After Radical Cystectomy." Cancers (Basel). 2026;18(2):313. doi:10.3390/cancers18020313

12. Schaller SJ, Fuest K, Ulm B, et al. "Goal-directed Perioperative Albumin Substitution Versus Standard of Care to Reduce Postoperative Complications: A Randomized Clinical Trial (SuperAdd Trial)." Ann Surg. 2024;279(3):402–409. doi:10.1097/SLA.0000000000006030