The effect of obstruction of bag surface on platelet concentrate pH

Platelet concentrates stored in bags (made of a plastic film incorporating a new plasticizer) on flat-bed agitators for up to 5 days were found to have accelerated pH decline when the surface of the bag was obstructed with added labels and an invoice on the non-labeled side. Without the over-labeling and invoice, only one of 20 concentrates had a pH below 6.0, even at very high concentrations of platelets. Blood banks experiencing problems with pH decline in the platelet concentrates being stored up to 5 days should consider eliminating surface obstruction on the bag.