B.10. Given the thromboelastometry findings and high clinical suspicion for occult postsurgical bleeding, what hemostatic products would you arrange to have in the operating room?
Answer:
Clinical coagulopathy usually occurs when coagulation factor levels are below 30% of normal levels, fibrinogen levels are below ~70 mg/dL, and platelet count is 100,000/mL or below. By thromboelastometry, there is evidence of coagulation factor, fibrinogen, and possibly platelet deficiency. Therefore, sufficient plasma, cryoprecipitate, and platelets to normalize coagulation function should be arranged before the start of surgery.
Plasma, whether fresh frozen (ie, fresh frozen plasma, frozen within 8 hours of phlebotomy) or frozen within 24 hours of phlebotomy (FP24), differ slightly in their levels of the labile factors, factors VIII and V, but are dosed the same. A 15 mL/kg infusion of plasma will increase most coagulation factors by 25%. Therefore, it is reasonable to have 15 mL/kg of plasma available. In this patient, using her ideal or adjusted body weight of 60 to 70 kg, this corresponds to 4 units.
Cryoprecipitate is a concentrated blood component made from frozen plasma thawed to 1 °C to 6 °C. At this temperature, residues that constitute cryoprecipitate appear in plasma and are separated from the supernatant. One unit of cryoprecipitate is prepared from 1 unit of plasma and contains approximately 10 to 15 mL plasma, 150 to 250 mg fibrinogen (ie, 300-3,000 mg/dL, 32% of original plasma content), and factors VIII and XIII. This is often pooled into a single bag containing 5 to 10 units from multiple donors. One unit of cryoprecipitate increases plasma fibrinogen by 10 mg/dL; therefore, the equivalent of 5 to 10 units should be available.
Platelets may be separated by apheresis directly from the donor, or separated from whole blood. The volume of one apheresed unit of platelets is 200 to 400 mL, whereas 4 to 6 units of platelets spun from whole blood will need to be pooled to produce the equivalent volume. A dose of 10 mL/kg will increase platelet count by 30,000 to 50,000/mL. For an ideal or adjusted body weight of 60 to 70 kg, 1 to 2 units of apheresed or pooled platelets should be available.
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