By: Dr. Rene V. Baltazar
THE AILING KIDNEY
Some very common chronic disorders, which we usually encounter in clinical practice may predispose to chronic renal failure. These chronic illnesses include diabetes mellitus, hypertension, glomerulonephritis and gout to name a few. A majority of these chronic renal failure patients progressed relentlessly to end stage renal failure (ESRD). A small percentage appears to lose their renal function at constant fracture rate hence a stable renal function for a sustained period of time. However, they seem to have a breakpoint in the disease course suggesting an acceleration of the rate of progression of their renal insufficiency. This breakpoint could either be spontaneous or secondary to such events as infection, dehydration, uncontrolled blood pressure, intrarenal precipitation of uric acid or calcium and drugs that can worsen intraglomerular hypertension and alter prostaglandin synthesis. Hence these secondary factors have to be corrected or modified in order to prevent these renal failure patients from going to end stage renal failure.
Progression to end stage renal failure necessitates dialysis and eventually renal transplantation. These have been a marked increase in the incidence of ESRD around the world, including the
With the rising cost of dialysis therapy and transplantation as well as economic and productivity loss, there is now increasing awareness among the general population and caregivers in what constitute a normal renal function. Several modalities to measure renal function include urinalysis, serum urea and creatinine, creatinine clearance, glomerular filtration rate (GFR) and imaging studies. Urinalysis is a major, non – invasive diagnostic tool available to the physician. Determination of severity however, could be achieved with correlation of serum urea, creatinine, GFR, creatinine clearance and imaging studies. Exact values of GFR are not always available and are not usually needed in clinical practice. Endogenous creatinine clearance determination maybe available in most centers but the main drawback is inadequate and improper urine collection. Imaging studies are quite expensive and results are sometimes affected by technical factors.
Serum urea and creatinine determinations are easy to perform and readily available. Serum creatinine is more specific and sensitive indicator of renal disease compared with urea but the use of simultaneous urea and creatinine determination provides more information. Creatinine is endogenous substances mainly produce in muscle cells. Concentration of serum creatinine depends on its excretion which mainly reflects the GFR. However, serum creatinine is not a good marker of GFR in renal failure since tubular secretion is enhanced when renal function is reduced. Most important is the fact that production of creatinine depends on muscle mass. Therefore patients with reduced muscle mass such as in women, infants, children, elderly and patients with malnutrition may have markedly reduced renal failure but with normal values of serum creatinine.
It is therefore very important to correlate everything in determining renal function. Laboratory procedures are useful in assessing the nature and severity of renal failure. Although not a single test is really diagnostic, more precise evaluation can be made based on integration of all laboratory data. Much more important is complete comprehension of some common systemic disorders which can predispose some individuals to renal insufficiency. It is by vigilance and complete understanding of the causes of nephropathies that we can prevent and lessen the impact of chronic renal failure.
