CLS 426 Urine & Body Fluid Analysis Renal Disease – Part II Tubular Disease Ricki Otten MT(ASCP)SC

2 Tubular Disease Altered tubular function Necrosis of tubular epithelium

3 Altered Tubular Function Caused by –Reabsorption-secretion capability lost –Concentrating-diluting capability lost Results in –Build up of waste products in bloodstream –Loss of essential substances into urine

4 Altered Tubular Function Renal glycosuria –Glucose in urine, renal threshold not exceeded Cystinuria Cystinosis Renal tubular acidosis –Tubules unable to secrete adequate H + despite systemic acidosis Inherited disorders Cystine crystals in urine

5 Urinalysis Findings Renal glycosuria: + glucose Cystinuria, cystinosis: cystine crystals Renal tubular acidosis: pH not as acid as is needed to compensate for systemic acidosis

6 Necrosis of Tubular Epithelium Destruction of tubular epithelial cells –Toxin –Ischemic event Most common cause of renal failure

7 Necrosis of Tubular Epithelium Clinical presentation: 3 phases –Onset –Renal failure Azotemia Hyperkalemia Metabolic acidosis Oliguria –Recovery

8 Acute Tubular Necrosis Toxic ATN –Drugs: Aminoglycosides Anesthetics Radiographic dyes Chemotherapy Anti-rejection drugs –Toxins: Mercury Lead Cadmium Ethylene glycol Pesticides Mushrooms

9 Acute Tubular Necrosis Ischemic ATN: decreased perfusion of kidneys as a result of hypotensive events –Sepsis: bacterial infection of bloodstream –Shock –Trauma

10 Acute Tubular Necrosis Urinalysis –Physical: Yellow, hazy –Chemical: Proteinuria (mild), +blood, low specific gravity –Microscopic: RBC, WBC, RTE Casts: RTE, granular, waxy, broad