Does Hemoperfusion Affect Platelet Count?
Yes, hemoperfusion significantly decreases platelet count, with the most dramatic decline occurring within the first 30 minutes of treatment, followed by continued gradual reduction throughout the procedure.
Magnitude and Timeline of Platelet Decline
Platelet counts drop rapidly during the initial phase of hemoperfusion, decreasing from baseline values of approximately 242 × 10³/μL to 185 × 10³/μL within the first 30 minutes, then continuing to decline to approximately 145 × 10³/μL over the course of treatment 1.
Thrombocytopenia occurs in approximately 31% of patients undergoing hemoperfusion, making it one of the most common complications of this extracorporeal therapy 2.
The severity of platelet loss is directly proportional to the surface area of the perfusion circuit, with larger circuits (0.9 m²) causing platelet counts to decrease to 20% of baseline within 2 minutes, while smaller circuits (0.1 m²) result in more modest decreases to 85% of baseline 3.
Mechanism of Platelet Loss
The platelet decline during hemoperfusion occurs through multiple mechanisms:
Direct platelet adhesion to the adsorbent material (modified charcoal or resin surfaces) removes platelets from circulation, as demonstrated by scanning electron microscopy showing activated platelets adhered to charcoal surfaces 1.
Incomplete platelet activation with impaired aggregation occurs during hemoperfusion, characterized by increased platelet distribution width (from 42% to 48%) indicating platelet activation, but with paradoxical dysfunction 1.
Altered glycoprotein expression on platelet surfaces develops during exposure to modified charcoal, with CD61 (fibrinogen receptor) expression decreasing from 95% to 74%, while CD49b (collagen receptor) expression increases from 25% to 52% 1.
Clinical Significance and Bleeding Risk
Systemic bleeding complications occur in approximately 3% of hemoperfusion cases, and when present, represent a significant mortality risk factor (OR 2.78,95% CI 1.07-7.23) 2.
The increased bleeding risk is multifactorial, resulting not only from thrombocytopenia but also from platelet dysfunction, reduced thrombin generation, and increased fibrinolysis (elevated fibrin degradation products and D-dimers) 1.
Despite these hemostatic impairments, continuous arteriovenous hemoperfusion can be performed safely when properly monitored, with studies reporting no significant complications when platelet counts and coagulation parameters are tracked 4.
Prevention Strategies
Calcium chelating agents effectively prevent platelet loss during hemoperfusion:
Citrate infusion during hemoperfusion can maintain platelet counts at near-baseline levels (95-96% of preperfusion values) across different adsorbent types including charcoal, resins, and albumin-agarose gel 5.
When citrate infusion is discontinued, platelet counts drop precipitously to 7-13% of baseline within minutes, confirming the protective effect of calcium chelation 5.
Prostaglandin E1 at high doses (5 μg/mL) also markedly reduces platelet losses, though lower doses are less consistently effective 5.
Monitoring Recommendations
Platelet counts should be monitored before, during (every 30 minutes initially), and after hemoperfusion to detect thrombocytopenia early 1, 2.
Additional coagulation monitoring should include activated clotting time, markers of platelet activation, and assessment for clinical bleeding 4.
If platelet counts fall below 50 × 10⁹/L in the presence of bleeding, platelet transfusion should be considered based on standard transfusion thresholds for bleeding patients 6.