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

Abstract

BACKGROUND: 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. STUDY DESIGN AND METHODS: 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). RESULTS: 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. CONCLUSIONS: 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.