Result of storage of packed RBCs
## Core Concept
The storage of packed red blood cells (RBCs) leads to various changes in their biochemical and physiological properties. These changes are critical to understand for ensuring the quality and safety of blood transfusions. The primary concerns include alterations in pH, levels of certain electrolytes, and the integrity of the RBCs themselves.
## Why the Correct Answer is Right
The correct answer, **2,3-Bisphosphoglycerate (2,3-BPG) decrease**, is a well-documented consequence of storing packed RBCs. 2,3-BPG is an organophosphate created in the RBCs during glycolysis. It plays a crucial role in regulating the oxygen affinity of hemoglobin; lower levels of 2,3-BPG increase hemoglobin's affinity for oxygen, making it less likely to release oxygen to tissues. During storage, the levels of 2,3-BPG decrease due to ongoing glycolysis without adequate replacement or regeneration of this molecule, which can impair the oxygen-carrying capacity of stored RBCs.
## Why Each Wrong Option is Incorrect
- **Option A: Increase in pH** - Incorrect because the storage of packed RBCs typically leads to a decrease in pH (acidosis) due to the accumulation of lactic acid and other metabolic byproducts.
- **Option B: Decrease in potassium** - Incorrect because during storage, there is actually a leakage of potassium ions from the RBCs into the plasma, leading to an increase in extracellular potassium levels.
- **Option C: Increase in 2,3-BPG** - Incorrect because, as mentioned, the levels of 2,3-BPG decrease during the storage of packed RBCs.
## Clinical Pearl / High-Yield Fact
A critical clinical consideration is that stored blood should ideally be used within a certain timeframe to maximize its efficacy. The decrease in 2,3-BPG and other changes highlight the importance of using blood products judiciously and considering the clinical status of the recipient. For example, in cases of massive transfusion, strategies to mitigate the effects of stored blood, such as adding 2,3-BPG or using fresher blood products when possible, might be considered.
## Correct Answer: D. 2,3-Bisphosphoglycerate decrease