In our last discussion about platelet transfusion for patients with cancer it is recommended that prophylactic platelet transfusion be administered to patients with thrombocytopenia resulting from impaired bone marrow function to reduce the risk of hemorrhage when the platelet count falls below a predefined threshold level. This threshold level for transfusion varies according to the patient’s diagnosis, clinical condition, and treatment modality.
Today we will talk about the specific cases to implement the rule above. There are total 5 specific cases which consist of acute leukemia, hematopoietic cell transplantation, chronic stable severe thrombocytopenia, solid tumors, and surgical or invasive procedures.
We recommend a threshold of 10 × 109/L for prophylactic platelet transfusion in adult patients receiving therapy for acute leukemia, on the basis of the results of multiple randomized trials that demonstrate that this approach is equivalent to the use of 20 × 109/L threshold. Transfusion at higher levels may be necessary in newborns or in patients with signs of hemorrhage, high fever, hyperleukocytosis, rapid fall of platelet count, or coagulation abnormalities and in those undergoing invasive procedures or in circumstances in which platelet transfusions may not be readily available in case of emergencies.
For children and older infants it is reasonable to use similar recommendation.
Hematopoietic Cell Transplantation
Fewer studies have been performed in recipients of high-dose therapy with stem-cell support. Although such patients may experience more mucosal injury than patients receiving conventional antileukemic chemotherapy, clinical experience and the available data suggest that guidelines for prophylactic tranfusion similar to those for patients with acute leukemia can be used in transplant recipients, with similar caveats about transfusion at higher counts in patients with complicating clinical conditions.
Chronic, Stable, Severe Thrombocytopenia
No randomized studies have been performed in patients with sustained, severe thrombocytopenia such as can be seen in individuals with myelodysplasia and aplastic anemia. Many such patients have minimal or no significant bleeding for long periods of time despite low platelet counts. On the basis of clinical experience and limited retrospective studies, we suggest that many of these patients can be observed without prophylactic transfusion, reserving platelet transfusion for episodes of hemmorrhage or during times of active treatment.
The risk of bleeding in patients with solid tumors during chemotherapy-induced thrombocytopenia is related to the depth of the platelet nadir, although other factors contribute as well. Evidence obtained from observational studies supports the clinical benefit of prophylactic transfusion at a threshold of 10 × 109/L platelets or less. However, for bladder tumors as well as those with demonstrated necrotic tumors, based on the experts’ option guideline suggest that prophylactic transfusion threshold should be 20 × 109/L , if patients are receiving aggressive therapy.
Surgical or Invasive Procedures in Thrombocytopenia
Thrombocytopenic patients frequently require invasive diagnostic or therapeutic procedures. Common procedures include placement of permanent or temporary central venous catheters, transbronchial and esophageal endoscopic biopsies, paranasal sinus aspirations, bone marrow biopsies, and occasionally even major surgery. We suggest, on the basis of accumulated clinical experience, that a platelet count of 40 × 109/L to 50 × 109/L is sufficient to perform major invasive procedures with safety, but in the absence of associated coagulation abnormalities. If platelet transfusions are administered before a procedure, it is critical that a posttransfusion platelet count be obtained to prove that the desired platelet count level has been reached. Platelet transfusions should also be available on short notice, in case intraoperative or postoperative bleeding occurs. For alloimmunized patients, histocompatible platelets must be available in these circumstances.