Laboratory and Diagnostic Tests

1. Laboratory and Diagnostic Tests PN 134

2. Urinalysis: most common study of urine Performed on either a clean-catch specimen or catheterized specimen Use of Reagent Strips (e.g.. MultiStix 10) Culture & Sensitivity prn evidence of infection – i.e. Blood, leucocytes, etc.

3. 24 hr. Urine – The kidneys excrete substances at various rates and amounts during a 24 hr. period. • Some substances that are measured are: urine protein, urine creatinine, uric acid levels, and catecholamines + 66 other items • Procedure: • Discard the first voiding of the day. • Start the “time” for the 24 hr. collection • Collect urine x 24 hrs.

4. Collection- remind patient not to place toilet paper in collection container. Have patient void before BM to avoid contamination. -if there is a preservative in the collection container, may need to refrigerate or put on ice. If no preservative, may need to refrigerate or put on ice. Check with the lab and for any institutional procedures.

5. Specific Gravity – measures the patients hydration status. Also gives information about the kidneys ability to concentrate urine • High Specific Gravity indicates dehydration • Low Specific Gravity indicates high fluid intake

6. BUN vscreatine http://www.youtube.com/watch?v=iYy7heyog0Q

7. Serum (blood) Tests -Blood Urea Nitrogen (BUN) Used to determine the kidney’s ability to rid the blood of non-protein nitrogen waste and urea which results from protein breakdown -Normal range- 10-20 mg/dL -If it becomes too high, may result in disorientation and seizures

8. Blood Creatinine measures the amount of creatinine in the blood. Used to diagnosis impaired kidney function. • Creatinine is the catabolic product of creatine. Creatine is used in skeletal muscle contraction. The daily production of creatinine [and therefore, creatinine] depends on muscle mass. • Creatinine is present in both blood and urine. • Creatinine is excreted by the kidneys. Only renal disorders will cause an elevation in creatinine.

9. Creatinine Clearance • Creatinine is generated during muscle contraction and excreted by glomerular filtration. • The levels are directly related to muscle mass and measured over a 24 hr period • Fasting blood sample is drawn at the start and conclusion of a 24 hr urine collection. • Normal range for serum (female)= 0.5 – 1.1 mg./dL; (male) = 0.6 – 1.2mg/dL • Normal range for urine = (female) 87-107 ml/min; (male) = 107-139ml/min

10. Prostate-Specific Antigen (PSA) • An organ-specific glycoprotein produced by normal prostatic tissue • Elevated levels result from prostate cancer, BPH, and prostatitis • Urine Osmolality • This measures the weight of the solute compared with its own weight. May be preferred over specific gravity • Plasma osmolality may be done at the same time when pituitary disorders are suspected • Results provide information of the concentration ability of the kidney

11. Radiograph Studies • Kidney-Ureter-Bladder (KUB) – evaluates the status of the abdomen and urinary tract structures. • No special prep. Explanation to patient of the test and reason for it. • Abnormal findings may indicate: tumors, calculi, cysts, glomerulonephritis, etc.

13. Intravenous Pyelogram (IVP) • Evaluates the structures of the urinary tract, filling of the renal pelvis with urine, and the transport of urine via the ureters to the bladder • A radiopaque dye is injected into a vein. • *Most important that the nurse ask the patient if he/she is allergic to iodine or iodine-containing foods. If the answer is “yes”, then an alternative method must be ordered

15. Preparation: NPO x 8 hrs. before the test; light meal the night before; non-gas forming laxative • During the Procedure: VS check -Radiographs will be taken at various intervals to monitor the movement of the dye • Abnormal finding: structural deviations, calculi within the urinary tract, tumors, hydronephrosis, etc.

16. Retrograde Pyelography – involves an exam of the lower urinary tract with a cystoscope under aseptic conditions • Urologist injects radiopaque dye directly into the ureters to visualize the upper urinary tract. Urine samples can be obtained directly from renal pelvis Retrograde Cystography -Radiopaque dye is injected via a catheter to visualize the bladder to asses its structure or to determine the reason for recurrent infections. • RETROGRADE URETHROGRAPHY: A catheter is inserted and dye is injected to asses the state of the urethral structure

17. Retrograde Pyelography Retrograde Cystography

18. Voiding Cystourethrography: used with other tests to detect abnormalities of the bladder and urethra. • Preparation: Enema before test; insertion of catheter • The pt. will be asked to void while radiographs are being taken. • Defects that can be noted are: structural abnormalities, diverticulitis, reflux back up into the ureter, etc.

20. Endoscopic Procedures are visual exams of hollow organs using an instrument with a scope and a light source. • Performed by a urologist. Consent form needs to be signed • Cystoscopy – a visual exam to inspect, treat, or diagnose disorders of the bladder and proximal structures • Preparation: Explanation to pt. Patient is sedated, then a local anesthesia is given.

22. ALWAYS KEEP THE PT. SAFE. • Pt. placed in lithotomy position • Scope is passed. Continuous fluid irrigation is needed to facilitate visualization • Post Procedure: Hydration to dilute the urine and monitor the first post-procedure void – Urologist can obtain a brush biopsy [from the renal pelvis or calyces] with a ureteral catheter during this procedure.

23. Nephroscopy -A renal endoscopy is done using the percutaneous (skin puncture) route. This method provides direct visualization of the upper urinary structures. A biopsy, urine specimen, or calculi can be obtained

24. Renal Angiography shows the blood supply to the kidneys, masses, and detects complications after a kidney transplantation. • Preparation: NPO the night before; explanation to pt. • A small catheter is inserted into an artery (usually the femoral artery). Radiopaque dye is inserted and x-rays taken. • Post Care: Pt. must lie flat in bed x 6hrs with the involved leg straight • Puncture site assessed by nurse q 15 min. x 1 hr.; then q 2 hrs. x 24 hrs. • Pressure dressing must remain on x 6 hrs. or as ordered. • Pedal pulses included with VS

25. Renal Venogram gives information about the kidney’s venous drainage • Femoral vein is common access site for dye injection • Post Care: similar to arterial angiogram but not for as long.

26. Renal Angiography Renal Venogram

27. Computerized Tomography (CT) • a computer-controlled scanner is used to obtain the images • Can differentiate masses • A radiopaque dye may be used. NOTE: Before the dye is used, serum creatinine and urea levels are drawn. If these are abnormal, the dye is not used. • The pt. must lie very, very still. This is extremely IMPORTANT!

29. Magnetic Resonance Imaging (MRI) • Uses nuclear magnetic resonance as its source of energy. • No special prep. but the pt. cannot have any metal on his/her person or body.

30. Renal Scan – A radionuclide tracer (IV injection) will be taken up by the renal tubular cells or excreted by the glomerular filtrate. • Provides data re: function of kidney cells • Check the facility’s policy concerning the disposal of the pt.’s urine for the first 24 hrs. • No pregnant nurse should work with this pt.

31. Ultrasonography uses the reflection of sound waves to produce images of deep body structures. • a conducting jelly is placed on the skin over the area to be studied. • Size, shape, position, and any delineations of the kidney can be provided by this way • No special prep. except pt. explanation.

32. Transrectal Ultrasound • This is instrumentation of the prostate gland • Provides clear prostatic tumor images • A biopsy can also be done to provide tissue samples. • Renal Biopsy • 2 ways to perform this: • 1. Open procedure • 2. Percutaneous needle insertion

33. Transurethral Ultrasound Renal Biopsy

34. Urodynamic Studies are indicated when a neurological disease is suspected of being a reason for incontinence • Also known as a cystometrogram • Catheter is inserted then connected to a cystometer which measures bladder capacity and pressure • Cholinergic and Anticholinergic medication may be administered to determine their effects on bladder function: a cholinergic drug stimulates an atonic bladder, an anticholinergic drug brings and overactive bladder to a more normal level or function • Evaluated the detrusor reflex • Urethral pressures can also be measured.