Albumin Administration in Pleural Effusion
Albumin is generally NOT indicated for pleural effusion management, as hypoalbuminemia alone rarely causes pleural effusions, and routine albumin administration does not improve outcomes in critically ill patients with hypoalbuminemia. 1, 2
Key Evidence Against Routine Albumin Use
Hypoalbuminemia is an uncommon primary cause of pleural effusion. A prospective study of 172 patients found that among 68 patients with serum albumin ≤3.5 g/dL, none had an unexplained pleural effusion attributable solely to hypoalbuminemia—all had identifiable alternative causes upon careful evaluation. 2 The presence of pleural effusion in hypoalbuminemic patients should prompt investigation for other etiologies rather than reflexive albumin replacement.
Current guidelines recommend against albumin for first-line volume replacement or to increase serum albumin levels in critically ill patients. The 2024 International Collaboration for Transfusion Medicine Guidelines explicitly state that intravenous albumin should not be used routinely in critically ill adults (excluding thermal injuries and ARDS) for volume replacement or albumin correction, based on moderate certainty evidence showing no mortality benefit (RR 0.98; 95% CI 0.92-1.06). 1, 3
Pathophysiologic Considerations
The relationship between low albumin and pleural fluid accumulation is more complex than simple oncotic pressure reduction. While theoretically, hypoalbuminemia reduces plasma oncotic pressure and could favor fluid extravasation, clinical evidence demonstrates this mechanism alone is insufficient to cause pleural effusions in the absence of other pathology. 2 Patients with profound hypoalbuminemia (serum albumin <2.0 g/dL) showed no increased frequency of unexplained pleural effusions compared to those with normal albumin levels. 2
When Albumin May Be Considered (Specific Contexts)
Albumin has established benefit only in specific cirrhosis-related scenarios, not general pleural effusion:
- Large-volume paracentesis (>5L): 8g albumin per liter of ascites removed to prevent paracentesis-induced circulatory dysfunction 4, 3
- Spontaneous bacterial peritonitis: 1.5 g/kg within 6 hours of diagnosis, then 1.0 g/kg on day 3, which reduces kidney impairment (OR 0.21; 95% CI 0.11-0.42) and mortality (OR 0.34; 95% CI 0.19-0.60) 1, 4
- Sepsis-induced hypotension in cirrhotic patients: 5% albumin is superior to crystalloids for reversing hypotension and improving short-term survival 4, 3
Important Safety Concerns
Albumin administration carries significant risks that may worsen respiratory status:
- Fluid overload and pulmonary edema are dose-dependent adverse effects, particularly problematic in patients with compromised cardiac or pulmonary function 3
- Paradoxical hypotension can occur despite albumin being used to treat hypovolemia 3
- Hemodilution may necessitate RBC transfusion 3
- High cost (~$130 per 25g) without demonstrated benefit in this context 3, 5
Clinical Algorithm for Pleural Effusion Management
When encountering pleural effusion with hypoalbuminemia:
Perform diagnostic thoracentesis to determine if effusion is transudative or exudative using Light's criteria or serum-effusion albumin gradient (gradient >1.2 g/dL suggests transudate) 6
Identify the underlying cause: Investigate for heart failure, cirrhosis with hepatic hydrothorax, nephrotic syndrome, malignancy, infection, or pulmonary embolism—hypoalbuminemia is a marker of severity, not the primary cause 2
Treat the underlying condition rather than administering albumin empirically 2
Reserve albumin strictly for evidence-based indications where it improves patient-important outcomes (cirrhosis-specific scenarios listed above) 3
Common Pitfalls to Avoid
Do not assume hypoalbuminemia is causing the pleural effusion. This leads to unnecessary, expensive, and potentially harmful albumin administration while delaying diagnosis of the true underlying cause. 2
Do not use albumin to "correct" low serum albumin levels. Albumin infusions markedly increase albumin degradation (58% of infused albumin is degraded), and increasing albumin concentration actually decreases endogenous albumin synthesis. 1 Balanced crystalloids (lactated Ringer's, Plasma-Lyte) are preferred for volume resuscitation when needed. 4, 3