The present disclosure relates to a hemodialysis membrane for the treatment of hemolytic events, especially acute episodes of hemolysis which lead to elevated levels of plasma free hemoglobin. The present disclosure further relates to methods of removing hemoglobin from the blood of patients undergoing a hemolytic event. The treatment and method encompasses using a hemodialysis membrane which is characterized in that it comprises at least one hydrophobic polymer and at least one hydrophilic polymer and in that it has a MWRO of between 15 and 20 kD and a MWCO of between 170-320 kD, or, in the alternative, has a MWRO of between 9 and 14 kD and a MWCO of between 55 kD and 130 kD.