Noninvasive pH measurement to monitor changes during suboptimal storage of platelet concentrates

BACKGROUND: Noninvasive pH measurement of platelet concentrates (PCs) was evaluated as a tool for the quality control of PC storage by simulating worstcase conditions. STUDY DESIGN AND METHODS: PCs from pooling four buffy coats in 70% PAS-3M were both stored in bags wrapped to impair gas permeability and agitated or not until Day 9 of storage. pH values measured both in samples (electrode, blood gas analyzer) and noninvasively by fluorimetry (BCSI pH1000, Blood Cell Storage, Inc.) were compared groupwise and to changes in platelet (PLT) size and biochemical variables. RESULTS: The noninvasive pH measurements agreed well with the results from each of the two reference methods (R 2 > 0.9) in a wide range of pH values