Comparison of stress-induced hemolysis in neonatal intravenous catheters: Theoretical and experimental analysis of shear stress, exposure time, and index of hemolysis.

BackgroundSeveral studies report hemolysis when packed red blood cells (PRBCs) are transfused through small-inner-diameter (ID) catheters using presence of biomarkers but do not address cause and amount of hemolysis. This study aims to determine the cause and index of hemolysis percent (IH%) when PRBCs are infused through small-ID catheters.MethodsThe IH% was calculated using Giersiepen's empirical power law, which describes a relationship between hemolysis and magnitude of shear stress and exposure time. Six- and 27-day-old PRBCs were infused through five catheters with IDs of 0.20 mm to 0.70 mm at infusion rates of 3 mL and 10 mL/hour. Shear stress and exposure time were calculated. Data were analyzed as a function of catheter ID, infusion rates, and blood age.ResultsThe study demonstrated that shear stress was supraphysiologic during laminar flow in catheters with IDs of 0.20 mm and 0.28 mm. These catheters' IH% were ∼117 times higher at 3 mL/hour and ∼75 times higher at 10 mL/hour than catheters with larger IDs of 0.48 mm, 0.51 mm, and 0.70 mm. For blood age, in catheters with IDs of 0.20 mm and 0.28 mm, IH% was ∼155 times higher at 6 days and ∼76 times higher at 27 days than in catheters with IDs of 0.48 mm, 0.51 mm, and 0.70 mm.ConclusionsThis study demonstrated that when RBCs are subjected to supraphysiologic shear stress in catheters with IDs of ≤0.28 mm, index of hemolysis is greater than in catheters with IDs ≥0.48 mm.