Hemoglobinuria

Hemoglobinuria is a condition in which the oxygen transport protein hemoglobin is found in abnormally high concentrations in the urine. The condition is caused by excessive intravascular hemolysis, in which large numbers of red blood cells (RBCs) are destroyed, thereby releasing free hemoglobin into the plasma. Excess hemoglobin is filtered by the kidneys, which excrete it into the urine, giving urine a purple color. Hemoglobinuria can lead to acute tubular necrosis which is an uncommon cause of a death of uni-traumatic patients recovering in the ICU.

Diagnosis
The diagnosis is often made based on the medical history, blood samples, and a urine sample. The absence of urine RBCs and RBC casts microscopically despite a positive dipstick test suggests hemoglobinuria or myoglobinuria. The medical term for RBCs in the urine is hematuria.