An important determinant of platelet viability following storage is?

Platelet viability during storage is significantly influenced by plasma pH levels. Platelets are sensitive to changes in pH, as a drop in pH can lead to a decrease in their functional capacity. An optimal storage environment typically maintains a pH range of around 6.0 to 7.4. If the pH falls below this range, it can interfere with the metabolic processes of platelets, potentially reducing their ability to aggregate and function properly when transfused into patients.

In contrast, while plasma potassium concentration and coagulation tests such as prothrombin time or activated partial thromboplastin time are important in the context of hemostasis and overall coagulation function, they do not directly impact the viability of platelets during storage. Plasma potassium levels can indicate cellular activity but are not as critical a determinant of platelet functionality under storage conditions as pH is. Coagulation times assess the blood's ability to clot but do not relate to how well platelets may perform post-storage. Therefore, the stability of the pH within the storage environment is the key factor affecting platelet viability.