(P-TA-7) Incompatible Plasma in Therapeutic Plasma Exchange Following Massive Transfusion

Background/Case Studies: The use of type A donor plasma (DP) for trauma resuscitation under massive transfusion protocol (MTP) is acceptable when the patient’s ABO type is unknown. In therapeutic plasma exchange (TPE), if DP is indicated as replacement fluid (RF), ABO-compatible DP should be used. Here we present a unique case of an adult male gunshot wound victim with an unknown blood type (BT) who received multiple rounds of MTP and subsequently underwent emergent TPE requiring DP as RF.

Study

Design/Methods: On arrival, two emergency release whole blood units were transfused, activating the MTP. Each MTP round includes type O red blood cells (RBCs), type A DP, and platelets of various ABO types based on inventory. Cryoprecipitate is provided on request. Total blood products transfused are shown in Table 1. A delay in collecting a type and screen specimen led to an inconclusive BT after the large volume of transfused blood products. Forward typing showed type O RBCs; reverse typing showed weak anti-B reactivity. On hospital day (HD) 2, emergent TPE requiring DP as RF was requested for acute liver failure and was performed daily on HD2, HD3 and HD4. When TPE was requested, the patient’s BT remained inconclusive. Type A DP was selected for RF because the patient was showing O RBCs on forward typing and the supply of universal type AB DP was limited.

Results/Findings: On HD4, after TPE#3, the patient’s native BT B started to show. Forward typing showed mixed field microscopic agglutination with a heterogeneous population of type O and type B RBCs; reverse typing showed weak anti-A1 reactivity. This revealed a minor incompatibility between the patient’s type B RBCs and the type A DP used during the MTP and TPE sessions. A hemolytic workup was immediately performed and a poly-specific direct antiglobulin test (DAT) was negative. Other hemolytic labs (haptoglobin, lactate dehydrogenase and urinalysis) could not be reliably interpreted due to liver failure, increased inflammatory response and bladder injury from trauma. With persistent mixed field on forward typing, universally compatible type O RBCs were given through HD12. The patient was then transitioned to type specific (type B) RBCs. No additional units of DP, platelets, or cryoprecipitate were needed after HD4.

Conclusions: This case was unusual because we needed to perform TPE with DP as RF without knowing the patient’s native ABO type. Although type A DP was used and later found to be incompatible, no overt catastrophic intravascular hemolysis was noted. These findings may be due to the recent resuscitation with all type O RBCs and possible neutralization of donor anti-B immunoglobulins by the B-antigens expressed elsewhere in the patient’s body. The use of MTP protocol and subsequent emergent TPE showed success with initial stabilization and marginal improvement in this patient’s liver function. However, on HD21 the patient expired from other trauma related complications.