Noninvasive pH monitoring of platelet concentrates: a large field test

Abstract

In this setting where the vast majority of PCs were of good quality and within acceptable pH limits, daily, noninvasive routine pH measurement has limited added value in identifying quality-compromised PCs.

Noninvasive pH monitoring for bacterial detection in platelet concentrates

“…More recently, a field trial was conducted at the Sanquin Blood Bank that monitored the pH of 13,693 PLT units utilizing the pH SAFE technology. It was shown that units with positive bacterial contamination had a more rapid decline in pH than noncontaminated units …”

“…Upon receiving the PCs in Ottawa, the sterility of the units was confirmed with the BacT/ALERT system as previously described . The pH was then measured using the pH SAFE reader as described by Gkoumassi and coworkers . Briefly, pH SAFE PC bags have a small sensor tube welded in the rim.…”

“…Currently, PC pH monitoring is not recommended by the AABB due to poor sensitivity and specificity (AABB Bulletin 10‐05). However, the pH SAFE system offers an alternative to PC pH measurement using reagent strips as this system allows for noninvasive, continuous pH monitoring during PLT storage . This system was used to detect pH changes in aliquots of 15 mL of buffy coat PCs stored in scaled bags inoculated with commercial bacterial strains at concentrations of 10 to 10 3 CFUs/mL .…”

Residual aggregates in platelet products: what do we know?

“…Products with macroaggregates or clumps may be discarded due to concerns linked to efficacy and safety of the product. Discard may occur at different occasions, for example, at the blood centre when staff notice irreversible clumps, in the hospital blood bank when clumps are missed by the blood centre or form on blood bank shelves, or on the hospital ward when clumps are missed by the blood bank staff or form during transport to the ward . Currently there is no consensus on a general discard strategy and procedures therefore vary from centre to centre.…”

Diagnostic Methods for Platelet Bacteria Screening: Current Status and Developments

“…This sensor comprises a pH-sensitive fluorescent membrane fixed to a clear window inside a small sensor tube, which is welded in the rim of the PC container. Fluorescence of the sensor membrane is measured through the window using a fiber optic probe and the BCSI pH SAFE reader calculates pH based on the ratio of yellow and red fluorescence measured [61,62]. Preliminary studies by Montag et al [63] demonstrated a decrease of pH (6.7 to 6.5) in bacterially contaminated units after reaching high bacterial counts.…”