Corrected Count Increment (CCI) for Platelet Transfusion

Why Use

CCI is a more accurate measure of refractoriness, as it adjusts for the number of platelets transfused and the patient’s blood volume. Can guide the decision to pursue platelets with improved compatibility (i.e., HLA-matched platelets).

When to Use

Use in patients undergoing platelet transfusion.

Formula

Pearls / Pitfalls

Corrected count increment (CCI) is a measure of the expected increase in platelets following a platelet transfusion. The “count increment” refers to the increase in platelets following a transfusion. The “correction” is based on the patient’s size and the number of platelets transfused. Refractory = failure to achieve acceptable increase in platelet count following platelet transfusion on at least two occasions and no alternate cause for refractoriness such as fever, sepsis, DIC, bleeding, splenomegaly, or drug interaction (e.g. amphotericin B). Response to platelet transfusion is typically measured within one hour. However, a sample collected 10 minutes after transfusion yields similar information and may be easier to obtain routinely. A post-transfusion platelet count can alternatively be taken at 20 hours.

Advice

When no compatible platelets can be found to transfuse to a patient with platelet refractoriness, alternative measures can be tried to stem or forestall hemorrhage, but these are of unpredictable benefit. Administration of antifibrinolytic agents, such as ε-aminocaproic acid (Amicar), either intravenously or, in the case of gingival bleeding, as a mouthwash, may allow the clot that is formed to be sustained. Consider baseline patient factors, including age, gender, height/weight, history of pregnancy, and previous transfusion. Possible patient characteristics to be evaluated for each transfusion: Administration of amphotericin, heparin, or γ-globulin. HLA and/or PLT antibody status of the closest sample prior to the transfusion. Presence of bleeding, fever, infection, transfusion reaction, splenomegaly.

More Information

Interpretation: CCI at 1 hour CCI at 20 hours Interpretation >7,500 >4,800 Successful transfusion ≤7,500 ≤4,800 Repeat transfusion. Two CCIs below the cutoff indicate refractoriness.