مقاربة البول أحمر اللون .. Red urine work up

Red urine with no blood on a dipstick implies that the child has ingested foods, medications, or chemicals that led to the color change. In infants, urate crystals, which are orangered, can be seen on diapers. Red urine, blood on dipstick, but no blood on microscopy (when the urine is promptly examined) suggests the presence of free hemoglobin or myoglobin. Hemoglobinuria may result from acute intravascular hemolysis, disseminated intravascular coagulation, or any other cause of hemolysis (see Chapter 150). Myoglobin reacts with the "blood-determining" portion of the dipstick and causes a positive result. Myoglobinuria results from rhabdomyolysis secondary to crush injury, burns, myositis, or asphyxia (see Chapter 182). Red urine, blood on dipstick and microscopy, but no RBC casts suggests urinary tract bleeding from a site beyond the renal tubules. Examining the morphology of the urinary RBCs is another mechanism for localizing hematuria. Altered RBC morphology is seen in glomerular hematuria (most renal parenchymal disease). The absence of casts or normal RBC morphology does not exclude a glomerular etiology, however. Red urine, blood on dipstick and microscopy, with RBC casts suggests one of a variety of glomerular diseases. Glomerular injury may be the result of immunologic injury (poststreptococcal acute glomerulonephritis, [PSAGN], inherited disease (Alport syndrome), or vascular injury (acute tubular or cortical necrosis). Children who have hematuria, with casts and proteinuria less than 1 g/m2/day, are considered to have nephritis.