Transfusions via hand-held syringes and small-gauge needles as risk factors for hyperkalemia

Pediatric emergency RBC transfusions are often infused rapidly through 22-gauge (ga) or smaller needles or catheters using hand-held syringes. Data relating needle size, unit age, and infusion rate are needed to assess the risk of hemolysis and hyperkalemia in this setting.

Multiple simulated transfusions were performed during storage of RBC units. Aliquots from five units were rapidly passed through needles (18, 20, 22-25 ga) using a hand-held syringe. Resulting plasma Hb and K+ concentrations were measured. Free Hb levels were used as a measure of needle-associated hemolysis (NAH).

Passage through 18-ga and 20-ga needles caused no hemolysis, but rapid passage through 23-ga, 24-ga, and 25-ga did. RBCs stored less than 7 days showed significant K+ release with 23- to 25-ga needles. The greatest needle-associated K+ release was 10 mEq per L, on Day 5. Due to high K+ concentrations resulting from spontaneous efflux, K+ release from NAH was not detectable after 2 or more weeks of storage.

Rapidly transfusing RBCs using hand-held syringes through 23-ga or smaller needles can cause hemolysis. In RBCs stored 2 weeks or more, NAH does not measurably increase K+ concentrations above that present from storage-related efflux. During rapid transfusions, RBC storage time is the primary risk factor for transfusion-associated hyperkalemia.