Transfusion-Associated Hyperkalemia

Highlights
- the [K+] (in mmol/L) increases linearly and is approximately equal to the number of days of RBC unit storage (View Highlight)
- irradiation causes a rapid increase in [K+] (View Highlight)
- there is potentially sufficient potassium in the supernatant of current RBC preparations to lead to hyperkalemia with large transfusion volumes (View Highlight)
- any rise in patient potassium after transfusion is usually transient due to the redistribution of the potassium load (View Highlight)
- One of the consistent changes during RBC storage is increasing potassium concentration [K+] of the RBC supernatant. Although the volume of the supernatant in current RBC preparations is small (less than 40% of the total volume), the [K+] can be substantially higher than that of normal human plasma [K+]. (View Highlight)
- The [K+] of the supernatant bathing the RBCs increases with storage time. RBCs rely on membrane sodium-potassium pumps to maintain intracellular electrolyte concentrations. These pumps are energy-dependent, using adenosine triphosphate, and highly temperature-sensitive. With refrigeration, there is a gradual leak of sodium into, and potassium out of, the RBCs (View Highlight)
- From the first day until the 35th day of RBC storage, the [K+] of CPDA-1 whole blood increases from 5.1 to 78.5 mmol/L (View Highlight)
- Citrate-phosphate-dextrose SAGM RBCs have also been studied during storage from 0 to 42 days.11 The [K+] initially is 2.1 mEq/L and increases to 45.3 ± 3.7 mEq/L on the 42nd day of storage. The increase in [K+] appears to be roughly linear with time, suggesting that the [K+] of CPD-SAGM RBCs might be estimated as approximately equaling the number of days of storage (View Highlight)
- The plasma [K+] of both types of blood was approximately 4 mmol/L initially. [K+] rose to about 46 mmol/L by day 21 for packed RBCs and to about 20 mmol/L for whole blood. The whole blood units studied were of a 500-mL volume, and the packed RBC units consisted of approximately 300 mL. The total plasma load of potassium was therefore slightly higher for the whole blood despite the lower concentration because of the larger volume of supernatant. (View Highlight)