Dr. Ola Samir Ziara Modified by Dr. Amal Al Maqadma Urine analysis Dr. Ola Samir Ziara Modified by Dr. Amal Al Maqadma

Importance of urine analysis It can detect diseases which pass unnoticed. For example, D.M, chronic UTI. Diagnosis of many renal diseases. As nephrotic, nephritic syndrome, acute renal failure, multiple myeloma

Urine composition Urine, a very complex fluid, is composed of 95% water and 5% solids .It is the end product of the metabolism carried out by billions of cells and results in an average urinary out put of 1-1.5 L per day. Almost all substances found in urine are also find in the blood although in different concentration. Urine may also contain formed elements such as cells, casts, crystals, mucus and bacteria.

Anatomy of urinary system

FORMATION OF URINE

FILTRATION It is the first process. 20% of C.O.P pass to the kidney (filtration fraction). As the blood passes through the glomeruli, much fluids with useful substances ( water, Na, glucose) and waste products (urea) will pass in the tubules. The GFR is 125 ml/min 180 L/day. If 200 liters of filtrate enter the nephrons each day, but only 1-2 liters of urine result, then obviously most of the filtrate (99+ %) is reabsorbed.

REABSORBTION It is the passage of fluids from the renal tubules to the peritubular capillaries. The useful particles reabsorbed from the proximal convoluted tubule till the loop of Henle. Water, 99% of the water filtrate is reabsorbed by passive reabsorbtion. Glucose, actively reabsorbed in the proximal tubules according to the renal threshold. Na, actively reabsorbed according to the diet.

Secretion It is the reverse of reabsorbtion. It is either by active process or by diffusion. H +,K+, ammonia. Are the principle particles that is execreted by the kidney. H+ ions play an important role in acid base balance.

Control Of Urine Excretion Antidiuretic Hormone (ADH) Aldosterone

ROLE OF ADH HORMONE

Specimen collection -The specimen must be collected in a clean dry, disposable container. - The container must be properly labeled with the patient name, date, and time of collection. The labels should be applied to the container and not to the lid. - The specimen must be delivered to the laboratory on time and tested within 1hr, OR it should be Refrigerated or have an appropriate chemical preservative added. eg. Toluene, thymol, formalin or boric acid).

CHANGES OCCUR IN NON PRESERVED SPECIMEN Transformation of urea to ammonia which increase pH. urease Urea ─────── 2NH3 + Co2. (Bacteria) Decrease glucose due to glycolysis and bacterial utilization. Decrease ketones because of volatilization. Decrease bilirubin from exposure to light. Increase bacterial number. Increase turbidity caused by bacteria & amorphous. Disintegration of RBCs casts. Increase nitrite due to bacterial reduction of nitrate. Changes in color due to oxidation or reduction of metabolic.

TYPES OF SPECIMEN Random specimen (at any time). First morning specimen 24 hr’s collection Post. Prandial sample Clean catch sample (midstream urine) Catheterized urine Supra - pubic

Female clean catch

Supra pubic sample

urinanalysis Macroscopic Chemical microscopic