In vitro platelet function of platelet concentrates prepared using  three different apheresis devices determined by impedance and  optical aggregometry.
BACKGROUND
Septic transfusion reactions to apheresis platelets (PLTs) continue to occur despite preventive measures. This study evaluated the effect of two operational changes designed to reduce bacterial risk: 1) introducing inlet-line sample diversion on two-arm procedures and 2) increasing the sample volume cultured from 4 to 8 mL from all donations.


METHODS
Aerobic culture results and septic transfusion reactions reported between December 1, 2006, and July 31, 2008 (Period 2), were compared to March 1, 2004, to May 31, 2006 (Period 1).


RESULTS
During Period 2, a total of 781,936 apheresis PLT collections were cultured, of which 130 donations (1:6015) were confirmed positive and 9 (1:86,882) had negative culture results but were associated with 11 septic reactions. Confirmed-positive cultures from two-arm procedures decreased (27.2 to 14.7 per 10⁵ collections; odds ratio [OR], 0.54; 95% confidence interval [CI], 0.41-0.70) in Period 2, owing to a lower rate of skin flora contamination. Detection of contamination of one-arm collections significantly increased by 54% in Period 2 (13.7 vs. 21.1 per 10⁵ collections; OR, 1.54; 95% CI, 1.05-2.27). Fewer septic transfusion reactions occurred in Period 2, but the difference did not reach significance (1.7 vs. 1.2 per 10⁵ donations; OR, 0.68; 95% CI, 0.30-1.53).


CONCLUSIONS
Inlet-line diversion decreased bacterial contamination during two-arm collections by more than 46%. Concurrently, doubling the sample volume was associated with a 54% relative increase in culture sensitivity. These interventions act cooperatively to decrease bacterial risk.
Jilma-Stohlawetz
Petra
P
Department of Blood Group Serology and Transfusion Medicine, Medical University of Vienna, Vienna, Austria. petra.jilma@meduniwien.ac.at
Eichelberger
Beate
B
Horvath
Michaela
M
Jilma
Bernd
B
Panzer
Simon
S
D000328:Adult; D001792:Blood Platelets / Q000166:cytology* / Q000378:metabolism*; D017097:Electric Impedance; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation; D010979:Platelet Function Tests / Q000379:methods; D010983:Plateletpheresis / Q000295:instrumentation* / Q000379:methods