The main methods of functional diagnostics of kidney system

Anatomy Hilum (hilus) Renal artery and vein Cortex Medulla Renal pyramids and renal papillae Major and minor calyces Renal Pelvis Ureters

Urine Specimens The nurse is responsible for collecting urine specimens for a number of tests: Clean voided specimens for routine urinalysis, clean – catch or midstream urine specimens for urine culture, timed urine specimen, indwelling catheter specimen.

Clean voided Urine Specimen Usually done on the first voided specimen in the morning At least 10 ml of urine sufficient for routine analysis Client who is disabled, seriously ill or disoriented may need to use a bedpan or urinal in bed, these need special instructions: The specimen must be free of fecal contamination Don’t discard the toilet tissue in bedpan Put the lid tightly on the container to prevent spillage of the urine. If the outside of container is contaminated, clean it with a disinfectant.

The nurse must:- Make sure that the specimen label with laboratory requisition carry the correct information and attach them securely to the specimen.  

Clean-Catch or Midstream Urine Specimen It is collected when a urine culture is ordered to identify microorganisms causing urinary tract infection. Care is taken to ensure that the specimen is as free as possible from contamination around the urinary meatus. Clean – catch specimens are collected into a sterile specimen container with a lid. Clean the urinary meatus with antiseptic solution Instruct the client to start voiding Collect 30-60 ml of urine in the container. Label the specimen and transport it to the laboratory.

Timed Urine Specimen It requires collection of all urine produced and voided over a specific period of time, ranging from 1-2 hours to -24 hours. Each voiding of urine is collected in a small, clean container and then emptied immediately into the large refrigerated bottle or carton.

It is done for the following purposes: To assess the ability of the kidney to concentrate and dilute urine. To determine disorders of glucose metabolism such as DM. To determine levels of specific constitutes such as albumin, creatinine.

To collect the time urine specimen: Obtain the specimen with preservative from the laboratory. Label the container with identifying information for the client, the test to be performed, time started, and time of completion. Provide a clean receptacle to collect urine (bedpan). Post signs in the client’s chart, room, alerting the person to save all urine during the specified time. At the start of the collection period, discard the first voiding Save all urine produced during the time collection period in the container. At the end of collection, ask the pt to void the last time and add them in the container. Record collection of the specimen, timed started and completed.  

Urine Testing  Several simple urine tests are often done by nurses on the nursing units. These include tests for specific gravity, PH, and the presence of abnormal constituent such as glucose, ketones, protein. Specific gravity – is indicator of urine concentration, or the amount of solutes present in the urine Normally ranges from 1.010 to 1.025 PH is measured to determine the relative acidity or alkalinity of urine (7 is neutral, less than 7 is acidic, greater than 7 is alkaline).

Glucose – urine is tested for glucose to screen clients for diabetes mellitus and to assess clients for abnormal glucose to tolerance during pregnancy. Ketones – ketones bodies a product of the breakdown of fatty acids normally are not present in the urine. Protein Occult blood Osmolality – is measure of the solute concentration of urine. Normal values are 500 to 800 mOsm/kg.

Clients with Urinary Alterations  Visualization procedures also may be used to evaluate urinary function. An X – ray of the KUB: Kidneys, Ureters, Bladder IVP (Intravenous pyelography) – contrast medium is injected intravenously. Retrograde pyelography – contrast medium is instilled directly into the kidney pelvis via the urethra, bladder, and ureters following injection or instillation of the contrast medium, x- ray are taken to evaluate urinary tract structures. Ultrasonography: noninvasive test that uses reflected sound waves to visualize the kidney. Cystoscopy: a lighted instrument inserted through the urethra to visualize the bladder, urethral orifices and urethra.

Magnetic Resonance Imaging (MRI) Is a noninvasive diagnostic scanning technique in which the client is placed in a magnatic field. MRI provides a better contrast between normal and abnormal tissue than the CT scan. For visualization of the brain, spine, limbs, and joints, heart, blood vessels, abdomen and pelvis. The procedure lasts between 60 and 90 minutes.  

Radiological examination : 1.ultrasonography: <>it is cheap, easy , non invasive and non hazardous. It can demonstrate clearly the renal size ,contour, echotextures ,stone , back pressure, renal mass or cyst, and perirenal collection, also show the upper and lower parts of the ureter. <>pelvic ultrasonogrophy may show mass and calculate the residual urine <>it is useful for guiding needle for renal biopsy or aspiration of perirenal collection. Doppler flow imaging of the renal vessels will assess both anatomy (structure) and physiology (flow) of the blood supply of the kidney. So it may help in diagnosis of renal artery occlusion or stenosis , renal vein thrombosis and kidney transplant rejection.

2.plain abdominal x-ray (KUB):(kidney ,ureter, bladder)may show a.stones b.calcification of the kidney ,urinary bladder, seminal vesicles. c.renal contour and soft tissue shadow 3.Intravenous urography (IVU): shows the anatimy of the kidney and urinary system ,any mass ,stones ,back pressure changes and also demonstrates kidney function and obstruction. It should be done in the light of renal function . 4.Cystography and voiding cystourethrography to show vesicoureteric reflux (VUR) and residual urine. 5.Urodynamic studies: these will give anatomic and physiologic assessment of the lower urinary tract. 6.angiography: this includes a.renal arteriography (either conventional or digital subtraction). It is mainly indicated for diagnosis of renovascular hypertension or persistent haematuria following trauma. b. renal venography. This is indicated for diagnosis of renal vein thrombosis.

7. Computerized tomography (CT):it is strongly indicated in patients with obstructive uropathy with non-evident cause. 8.Radionuclides imaging (renogram): a.static renal imaging to diagnose renal scaring ,renal tumours anatomic abnormalities. b.dynamic renal imaging which is helpful in examining renal perfusion and dynamic parenchymal images and excretion into bladder (vascular phase)and so diagnosing renal vascular occulsion ,narrowing as well as ureteric obstruction and measurement of the total or individual kidney GFR. 9.Magnetic resonance imaging (MRI) MRI provides excellent anatomical information which are helpful in studying malignancies of the urinary tract and assessment of renal vessels by MRI angiography.

Kidney biopsy It shows the pathology of the underlying renal disease. The biopsy should be examined by light microscope (LM) ,electronic microscope (EM) and immunofluorescent microscope (IF) Very helpful in diagnosing, prognosis and therapeutic guidance.

cystoscopy, ureteroscopy. Diagnosis : of bladder disease , (tumour)by direct vision or biopsy. Therapeutic: ureteric catheter: also , ascending pyelography , differential renal function.