High blood flow rates with adjustment of needle diameter do not increase hemolysis during hemodialysis treatment.

BACKGROUND: Higher blood flow in dialysis therapy is often avoided due to concerns about shear-induced blood damage despite the lack of reliable data. OBJECTIVE: This study investigated the influence of higher blood flow rates on plasma free hemoglobin (Hb) concentration after hemodialysis (HD) treatment. METHODS: Thirty-two chronic HD patients were treated once with a blood flow rate of 250 mL/min using a 17G needle, and once with a blood flow rate of 500 mL/min using a 14G needle. Arterial and venous pressure and blood pressure (BP) were recorded before and after treatment. Blood samples were taken before and after treatment for analysis of plasma free Hb, pH, HCO3, base excess, hematocrit value, urea, sodium, potassium and calcium. RESULTS: HD treatment at blood flow rates of 500 mL/min did not increase plasma free Hb compared to treatments at blood flow rates of 250 mL/min. Frequency of intradialytic BP drops was not different either. By adaptation of the needle size, negative arterial pressure could be kept at a similar level. Urea reduction rates were significantly higher during treatments with higher blood flow rates. CONCLUSION: Higher blood flow rates can be applied without an increased hemolysis risk provided that needle sizes are adapted accordingly.