Finn is a 50 year-old man, who was scheduled for a colon resectioning. The preop orders included a CBC and a crossmatch for 2 units. The CBC report showed his WBC count to be 14.5 x109/L. His hemoglobin was 14.0 g/dL, hematocrit: 43%, and a platelet count, 19,000/uL. The blood bank typed him as O positive and crossmatch 2 unites of O positive packed cells.
The platelet count of the patient is 19000/uL, which is low. (Normal range = 1.5 to 4 lakh / uL).
In addition to packed red blood cells, thr patient requires platelet transfusion, since the platelet count is low.
Indications for platelet transfusion in Adults :
a. Platelet count < 10,000 - 20,000/µL
b. Platelet count < 50,000/µL in the presence of bleeding
c. Platelet count < 50,000/µL & immediately prior to any invasive procedure.
d. Platelet count < 100,000/µL in the presence of CNS or retinal bleeding .
e. Platelet count < 100,000/µL & immediately prior to invasive CNS or retinal procedures.
1. Adult dose : one unit of Platelets Pheresis or one unit of pooled Platelets.
2. Pediatric dose : 10mL/kg body weight up to 10-15 kg body weight; > 15 kg = adult dose.
3. Neonate dose : 10mL/kg body weight + 7mL for tubing.
|Component||Volume||Content||Storage||Expected Increment in platelet count|
|Platelets Pheresis||250mL||≥ 3x1011 platelets||20-24o C (room temperature) with continuous agitation||30,000-60,000/µL|
|Whole blood derived Platelets||50mL||≥ 0.55x1011 platelets||20-24o C (room temperature) with continuous agitation||10,000/µL|
|Pooled Platelets||200mL||≥ 3x1011 platelets||20-24o C (room temperature) with continuous agitation||30,000-60,000/µL|
Guidelines recommend a platelet count threshold of 50 x 109/L prior to major surgery (and 100 x 109/L prior to surgery involving the brain or eyes).
Hence, one unit of pooled platelets/ pheresis is recommended in this patient, to raise the platelet count by 30000-60000/µL.
Corrected count increment (CCI) and percent platelet recovery (PPR) are measures of response to platelet transfusion that "correct" the count increment for blood volume and number of platelets transfused.
Platelet count increment is the 15-60 minute post-transfusion minus pre-transfusion platelet counts.
A] Corrected Count Increment (CCI) for platelets:
CCI = (platelet increment per ul) x (body surface area in m2)/ number of platelets transfused (x 1011)
B] Posttransfusion [Percent] Platelets Recovery (PPR):
a. Platelet count increment is the 15-60 minute post-transfusion minus pre-transfusion platelet counts .
b. Blood Volume (BV) is in liters (L).
c. Number (No.) of platelets transfused is presumed to be 3x1011 or the exact count if known .
d. Refractoriness suspected when PPR <50% of expected increment.
PPR = [(platelet increment per ul) x BV] / No of platelets transfused.
In this case, CCI = [(40000 - 19000) 2 ] / 3 = 14000.
( Note :In this case, the exact BSA cannot be calculated, since the heoght is not given. An average adult has a BSA of approximately 2.0 m2 .
1 unit of pooled platelet = 3x1011 platelets).
The CCI value is more than 7500.This indicates that there in no platelet refractoriness.
Platelet refractoriness is suspected when the CCI for 15-60 min post transfusion platelet count is:
i. < 5.0-7.5 x 109 m 2 /L (< 5,000-7,500 m2 /μL) after two consecutive platelet transfusions.
ii. On rare occasion, a 24 hour post-transfusion platelet count is used for the increment and then CCI < 4.5 x 109 m 2 /L (4,500 m 2 /μL) suggests refractoriness.
|Blood product type||Storage condition||Shelf life|
Platelets Pheresis : 0-24o C (room temperature) with continuous agitation
Pooled Platelets : 0-24o C (room temperature) with continuous agitation
|Fresh frozen plasma||Frozen (< - 18 o C ) within 24 hours of being donated.||1 year|
|RBC||1-6o C||Up to 42 days ( depending upon the anticoagulant used).|
|Cryoprecipitate||Frozen ( < - 18 o C)||1 year|
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