Zumberg, M.S., del Rosario, M.L., Nejame, C.F., Pollock, B.H., Garzarella, L., Kao, K.J., . . . Wingard, J.R. (2002). A prospective randomized trial of prophylactic platelet transfusion and bleeding incidence in hematopoietic stem cell transplant recipients: 10,000/L versus 20,000/microL trigger. Biology of Blood and Marrow Transplantation, 8(10), 569–576. 

To determine the prophylactic platelet transfusion threshold (10,000/L versus 20,000/microL) in bone marrow transplant (BMT) patients, comparing transfusion requirements, incidence of bleeding, and adverse events

Patients undergoing BMTs that matched study requirements were randomized into two groups. One group would receive a prophylactic platelet transfusion if their morning platelet count was below 20,000/micro/L, and the other group would receive a transfusion at less than 10,000/L. For the 10,000/L group whose morning count was between 10–15,000/L, platelet count was checked a second time 12 hours later, and patients received a transfusion if this count fell below 10,000/L. A postplatelet count was taken 30–90 minutes post transfusion, and another bag was given if the threshold was not met with the first transfusion. If patients had scheduled procedures, acute bleeding events, or other safety concerns, platelets were transfused as needed. The threshold level was resumed following the acute event. Red blood cells were transfused as needed for hematocrit levels below 20%. Leukocyte-reduced, irradiated platelets were used for the study; they were single-donor, ABO matched when available. A transfusion algorithm was developed for both groups so that it was clear for the care team when to transfuse, redraw labs, and/or perform calculations.

• N = 159
• AGE RANGE = 3–70 years
• MALES: 52%, FEMALES: 48%
• KEY DISEASE CHARACTERISTICS: BMT patients with leukemia, lymphoma, myeloma, and solid tumor/other
• OTHER KEY SAMPLE CHARACTERISTICS: The median age in the 10,000/L group was 44. The median age in the 20,000/microL group was 47. The majority of patients received an autologous transplant followed by allogeneic and had a matched, unrelated donor. 98% of transfusions were from single donor products.  

• SITE: Single-site  
• SETTING TYPE: Inpatient  
• LOCATION: Florida, United States

• PHASE OF CARE: Active antitumor treatment
• APPLICATIONS: Pediatrics, elder care

Randomized, controlled trial, unblinded for patient safety

Bleeding events were scored by a single-study nurse using a modified Gruppo Italiano Malattie Ematologiche Maligne dell'Adulto (GIMEMA) Bleeding Severity Grading Scale.

There was no significant difference in bleeding events between the two groups with similar causes of bleeding in both (mucocutaneous and genitourinary). None of the patient deaths in the study were attributed to bleeding, although CNS bleeds occurred in both groups. The mean number of bleeding days were similar for the two groups. Bleeding was more frequent for the allogeneic or matched unrelated donor groups, but the results were not statistically significant. The time to first transfusion was 3.7 days in the 10,000/L group versus 4.2 days in the 20,000/microL group (p = 0.91). The total number of transfusions was similar in both groups. Amphotericin B, GVHD, transplant type, and VOD were statistically significant predictors of bleeding, while the threshold transfusion level was not.

The findings of this study mirrored prior research of this kind that was done for other populations, finding that the lower, 10,000/L platelet count can be used safely as a threshold for transfusions for the BMT population as well. There were no significant differences among the two groups with respect to bleeding risks and/or safety to patients. Of note, amphotericin B use did lead to a significantly increased risk of bleeding to patients, and so those patients may need a higher platelet threshold although that level was not studied in this trial.

• Risk of bias (no control group)
• Risk of bias (no blinding)
• Risk of bias (no appropriate attentional control condition)  
• Risk of bias (sample characteristics)
• Measurement validity/reliability questionable

Nurses need to look at the policy and procedures for platelet transfusions at their own institutions and suggest changes in practice if patients are given platelets for values above 10,000/L unless otherwise contraindicated. This study implies that this threshold is as safe as a higher one, and it leads to fewer transfusions for patients, which can reduce risk of transfusion reactions and platelet refractoriness without increasing bleeding risk.