Introduction

Altough electronic crossmatch (E-XM) is cost effective and reduce laboratory workload, practical difficulties of determining 2 consecutive ABO/Rh in patients, requirement for the verification of the donor ABO group, concerns for errors in patient identification/specimen labeling and lack of reimbursement for performing ABO confirmation testing on a second separately collected specimen could avoid its widespread implementation in some countries.

Method

Using gel santrifuge method, ABO/Rh grouping and immuno-hematologic tests are done by a fully automatic system and recorded in blood bank information system. For patients and donors who do not have a previous blood group and antibody screen in the system, study steps are: 1. ABO/Rh group is performed with the 1st specimen and recorded 2. Donor blood group and antibody screen are done in the same gel card. 3. A second specimen is required at the time of transfusion request for regular antiglobulin crossmatch and antibody screen. ABO confirmation of patient and donor is done concomitantly in the same card with XM. 4. When 2 or more units are requested, first unit is selected by serologic XM, subsequent units are selected by E-XM from the available donor pool. Donor pool for electronic selection is fed by serologically compatible but undelivered units. Computer system is capable of questioning availability for E-XM eventhough serologic XM is not performed and could show the missing parameters needed for E-XM.

Results

After 6 months of validation process, between 1.01.2012- 31.07.2013, 36.7% of erythrocytes were reserved by E-XM using this method (table 1). Evaluation of the efficacy of the XM process revealed that 37.5% of the serologically confirmed units were undelivered and those supported the pool for E-XM (table 2).

Table 1

Crossmatch methods and results

Method of crossmatch and result Number of crossmatched units Ratio % 
Serologic compatible 43461 61 % 
Electronic compatible 25882 36,33 % 
Serologic and electronic compatible 308 0,43 % 
Serologic incompatible 1596 2,24 % 
TOTAL 71247  
Method of crossmatch and result Number of crossmatched units Ratio % 
Serologic compatible 43461 61 % 
Electronic compatible 25882 36,33 % 
Serologic and electronic compatible 308 0,43 % 
Serologic incompatible 1596 2,24 % 
TOTAL 71247  
Table 2

Efficacy of crossmatch tests in blood center

Crossmatch type Fate of crossmatch compatible erythrocytes Number (69651 total) 
TOTAL Undelivered units 25697 
Transfused units 43954 
C/T ratio 1.58 
ELECTRONIC Undelivered units 9406 
Transfused units 16784 
C/T ratio 1.56 
SEROLOGIC Undelivered units 16398 
Transfused units 27371 
C/T ratio 1.59 
Crossmatch type Fate of crossmatch compatible erythrocytes Number (69651 total) 
TOTAL Undelivered units 25697 
Transfused units 43954 
C/T ratio 1.58 
ELECTRONIC Undelivered units 9406 
Transfused units 16784 
C/T ratio 1.56 
SEROLOGIC Undelivered units 16398 
Transfused units 27371 
C/T ratio 1.59 

C/T ratio : crossmatch/ transfusion ratio

Conclusions

1. This method implements a double specimen system for ABO/Rh verification to ensure the transfusion security and guarantees the selection of at least 1 unit serologically. 2. Reduces work load and cost effective even in centers who are currently using serologic XM.

Disclosures:

No relevant conflicts of interest to declare.

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