HEMATURIA is a common presentation of the disorder of the urinary tract in children. For the family, macroscopic hematuria is an alarming occurrence which usually leads the parents to seek medical help fast irrespective of whether the child has other symptoms.
This presentation will be most common for doctors, though with the increasing sensitivity and use of dipstix tests as a routine tests, an increasing number of children are coincidentally found to have microscopic hematuria whilst being examined for another reason.
These two different clinical presentations will be considered separately though there is clearly an overlap in the causes since their only difference is the degree of hematuria.
Moreover, some vigilant relatives will notice a very small degree of urine discoloration which for another family would only come to light as a result performed on the urine.
It is termed gross or macroscopic when a sufficient amount of blood is present in the urine to discolor it red or brown or "Coca cola color or tea color" as seen by the naked eye.
If the urine is of normal yellowish color and the blood in it can be detected only by a chemical test or by visualization of RBCs following microscopic examination, it is termed micro or microscopic. It should be pointed out that only a small amount of blood is needed to discolor the urine and thus to fulfill the definition of gross hematuria.
For example, the addition of only 1 ml of whole blood to 1000 Ml. (normal daily volume of urine for most children) of a normal saline solution will produce a red color.
Despite the difference in the quantity of blood present in the urine, the types of diagnoses that can cause the problem are the same, and the workup or evaluation that is needed is identical.
Hematuria detected in each every urine in a patient is termed persistent; if interspersed between normal urines, it is termed intermittent or recurrent. It is termed asymptomatic when it is painless and symptomatic when accompanied by symptoms such as pain. These terms are useful because certain renal disorders are more likely than to follow particular patterns and because these terms are often used in medical papers.
Since blood in the urine must have come from one of the organs involved in making or transporting the urine, the evaluation of hematuria requires that we consider the entire urinary tract.
This organ system includes the kidneys, ureter (the tube that carries the urine from the kidney to the bladder), bladder, prostate, or urethra (tube leading out of the bladder). It must be emphasized that even a single episode of hematuria requires evaluation, even if it resolves spontaneously.
Hematuria maybe defined as the excretion in urine of abnormal amounts of red blood cells (RBCs) or their hemoglobin. It is important to stress that RBCs can be present in normal urine.
The presence of six or more RBCs per 0.9 mm3 counted in a counting chamber in fresh uncentrifuged midstream urine was considered abnormal in a large study of children.
In another study in children, the presence of five or more RBCs per high power field in the centrifuged urine sediment was defined as hematuria.
In general, three RBCs per high power field are commonly accepted as the upper limit of normal. These definitions are not applicable to females who are menstruating or to catheterized urine samples.
In both these situations, excessive excretion of RBCs would be expected. Red blood cells and their hemoglobin are included in the definition because the cells may be lysed during excretion (hypotonic urine) or storage of urine (alkaline pH). This situation is differentiated from hemoglobinuria, where free hemoglobin is filtered at the glomerulus and then excreted in the urine.
If the child has hematuria at the time of the consultation, assessment is fairly straight forward.
However, when it is merely a story of red urine with no adequate chemical or microscopic test of the urine previously done, and the urine test at the time of the consultation is normal, assessment is more problematic.
Assuming that the child seems normal and is healthy on examination then it may be best to instruct the parent how to use a dipstix test and to send them away with the test plus instructions to either check the urine regularly or at the time that it is next discolored in order to verify hematuria. (To be continued next week)
