What laboratory parameter is a predictor of hospitalization and mortality in a patient on hemodialysis (maintenance dialysis) with hypoalbuminemia (low albumin), anemia (low hemoglobin), impaired renal function (elevated serum creatinine), and electrolyte imbalance?

Albumin is the Laboratory Parameter that Predicts Hospitalization and Mortality in Maintenance Hemodialysis Patients

In patients on maintenance hemodialysis, serum albumin should be used as the primary predictor of hospitalization and mortality, with lower levels strongly associated with higher risk of both outcomes. 1

Evidence Supporting Albumin as the Key Predictor

The 2020 KDOQI Clinical Practice Guideline for Nutrition in CKD provides the strongest and most recent evidence, stating that in adults with CKD 5D on maintenance hemodialysis, serum albumin may be used as a predictor of hospitalization and mortality, with lower levels associated with higher risk (1A recommendation). 1 This represents the highest level of evidence available for any of the laboratory parameters listed.

Quantifiable Impact of Albumin on Outcomes

The relationship between albumin and outcomes is remarkably strong and dose-dependent:

• Each 0.1 g/dL decrease in serum albumin is associated with a 5% increase in risk of technique failure, 5% increase in days hospitalized, and 6% increase in risk of death 1
• In the CANUSA study, this relationship was consistent and reproducible across different patient populations 1
• A 1.0 g/dL decrease in serum albumin increases mortality odds by 137% 2

Why Not the Other Parameters?

Serum creatinine (Option B) is not a predictor of mortality in dialysis patients; rather, it reflects residual muscle mass and nutritional status but lacks the prognostic power of albumin 1

Phosphorus (Option C) is important for mineral bone disease management but is not established as an independent predictor of hospitalization and mortality in the same way albumin is 1

Potassium (Option D) requires monitoring for safety but is not used as a prognostic marker for long-term outcomes 1

Clinical Context of This Patient

This patient's albumin of 2.4 g/dL is severely low (normal ≥3.5 g/dL), placing them at substantially elevated risk:

• Hypoalbuminemia <3.5 g/dL is independently associated with increased cardiac morbidity, cardiac mortality, and overall mortality 3
• Patients with albumin <3.5 g/dL have a 30-day mortality of 16.3% compared to 4.3% in those with normal albumin 4
• The relative risk for mortality with low albumin is 1.95 in acute settings and even higher in chronic dialysis patients 4

Monitoring Recommendations

Serum albumin should be measured at least every 4 months in all dialysis patients 1 because:

• It serves as both a nutritional marker and an outcome predictor 1
• Trending albumin over time provides additional prognostic information beyond single measurements 1
• A declining albumin (even if still in normal range) may indicate higher risk than a stable low albumin 1

Important Caveats About Albumin Interpretation

While albumin is the strongest predictor, it is influenced by multiple non-nutritional factors 1:

• Inflammation is a powerful driver of low albumin through downregulation of hepatic synthesis 1, 5
• Comorbid conditions (cardiovascular disease, diabetes) independently affect albumin levels 1
• Fluid overload can dilute albumin concentration 1, 2
• External protein losses (dialysate, urine) contribute to hypoalbuminemia 1

Therefore, low albumin should not be interpreted solely as malnutrition 1, but rather as a marker of overall illness burden that encompasses inflammation, comorbidity, and nutritional status—all of which contribute to increased mortality risk.

Clinical Action Based on Low Albumin

When albumin is low (as in this patient with 2.4 g/dL):

• Ensure adequate protein intake of 1.2-1.3 g/kg body weight/day 2, 6
• Evaluate for and treat underlying inflammation 1, 2
• Assess dialysis adequacy (Kt/V targets) 6
• Do NOT routinely administer albumin infusions, as they are not recommended for treating hypoalbuminemia in dialysis patients 6
• Monitor albumin trends closely as part of comprehensive nutritional assessment 1

The answer is A. Albumin.