2.5 Renal/Urinary Flashcards
Major Functions of Kidneys
Regulatory functions
Regulatory functions:
Fluid & electrolyte balance
acid-base balance (through Bicarbonate reabsorption)
Done through urine elimination, glomerular filtration, tubular reabsorption and tubular secretion.
**Healthy renal system depends on health of other body systems especially circulatory, endocrine, & nervous systems.
Major Functions of Kidneys
Hormonal functions
Hormonal functions:
Renin production: assists in B/P control
Prostaglandin production: assists in regulation of glomerular filtration, renin production, increases H20 & Na excretion.
Erythropoietin: triggers RBC production in response to decreased O2 in kidneys blood.
Vit D activation: kidneys convert Vit. D to its active form which helps regulate calcium balance.
**Healthy renal system depends on health of other body systems especially circulatory, endocrine, & nervous systems.
Fluid & electrolyte balance via urine elimination & glomerular filtration
Acid-base balance
Waste excretion
Blood pressure regulation (Renin)
Red blood cell production (Erythropoietin)
Regulation of Ca/Phos metabolism
(activates vitamin D, enhances Calcium absorption)
Age related changes to renal system
Physiologic Changes:
GFR, NI, Rational
Decreased GFR NI: Monitor hydration status Ensure adequate fluid intake Use caution when administering nephrotoxic agents.
Rationales:
Kidneys ability to regulate water balance decreases with age, less able to conserve water when needed, dehydration reduces kidney blood flow and increases nephrotoxic potential of meds.
Age related changes to renal system
Physiologic Changes:
Nocturia, NI, Rational
Nocturia NI: Ensure nighttime lightening Availability of commode/ urinal Discourage excessive fluid intake 2-4hr before bed Evaluate drugs and timing
Rational:
Falls common while going to BR
Excessive fluid intake can increase nocturia.
Some drugs increase urine output.
Age related changes to renal system
Physiologic Changes:
Bladder, NI, Rational
Decreased bladder capacity
NI:
Encourage void q 2 hr.
Respond to pts. Need to void.
Rational:
Emptying bladder regularly avoids overflow incontinence.
Quick response alleviates stress incontinence.
Age related changes to renal system
Physiologic Changes:
Sphincter/urethra, NI, rational
Weakened urinary sphincters & shortened urethra in women
NI:
Provide through perineal care after each voiding.
Rational:
Shortened urethra increases risk for bladder infections.
Good hygiene may prevent skin irritations and UTI’s.
Age related changes to renal system
Physiologic Changes:
Urine retention, NI, rational
Tendency to retain urine
NI:
Observe for urinary retention.
Provide privacy & voiding stimulants (warm water)
Eval for drugs cause retention
Rational:
Urinary stasis may result in UTI leading to urosepsis or septic shock.
Anticholinergic drugs promote urinary retention.
Renal Assessment- Recognizing Cues
Demographic info (age, gender etc.) identifies nonmodifiable risk factors of kidney disease.
Previous kidney or urologic problems
- Tumors, infections, stones
- HTN or DM (causes damage to kidney blood vessels).
Use of heroin, cocaine, methamphetamine, ecstasy etc. assoc. with kidney disease.
Chemical exposures- gasoline, oil, mercury lead.
Educational levels- affects level of understanding.
Home meds (nephrotoxic risk?)
Incontinence, nocturia, retention, cancer hx. etc.
Diet:
Amount & type of fluid intake. Caffeine??
Excessive protein calcium intake (can cause kidney stones)
Change in appetite/taste? Indicates buildup of nitrogenous waste products
What a kidney does?
Water?
Water:
ensures that there’s not too much or too little water in the body
What a kidney does?
Blood pressure?
Makes sure that presure isn’t too high or too low
What a kidney does?
Waste?
Gets rid of urea, uric acid, toxins, other wastes via urine
What a kidney does?
Bones?
Activates vit D which helps the body absorb calcium
What a kidney does?
Acid-base balance?
Makes sure that the body isn’t too acidic or too alkaline
What a kidney does?
Heart?
Maintains a balance of electrolytes, like potassium, sodium, calcium, which is critical for heart rhythm
What a kidney does?
Blood?
Releases erythropoietin which tells bone marrow to make red blood cells
Renin, what is it?
hormone secreted by kidneys helps regulate b/p
Renin, also called angiotensinogenase, is an enzyme involved in the renin–angiotensin aldosterone system (RAAS), which regulates the body’s water balance and blood pressure level. The system regulates the extracellular volume in the blood plasma, lymph and interstitial fluid, as well as controlling constriction of the arteries and blood vessels.
Renin is stimulated by three factors?
When a fall in arterial blood pressure is detected by pressure sensitive receptors (baroreceptors) in the arterial vessels.
When a decrease in sodium chloride (salt) is detected in the kidney by the macula densa in the juxtaglomerular apparatus.
When sympathetic nervous system activity is detected through beta1 adrenergic receptors.
Diagnostic Tests
Intravenous pyelogram retrograde pyelogram (IVP) MRI Bladder Scan Renal arteriogram or angiogram Renal biopsy Renal scan Renal Ultrasound UA Post-void residual Blood urea nitrogen (BUN) Creatinine (serum) Creatinine clearance Cystatin C CT scan Cystometrogram (CMG) Cystoscopy Glomerular filtration rate (GFR)
Kidneys, Ureter & Bladder (KUB) X-RAY
Identifies any gross anatomic features & obvious stones.
X-ray visualizes kidneys, ureters and bladder.
No specific prep needed.
More diagnostic tests needed to diagnose functional or structural problems.
Intravenous Pyelogram (renal pelvis) (IVP)
Radiologic exam that visualizes the entire urinary tract by using contrast dye to improve visualization.
Diagnoses kidney disorders ,detects renal calculi, tumors, or cysts.
Intravenous Pyelogram (renal pelvis) (IVP) NI?
Nursing Interventions Assess for iodine or seafood allergy NPO 8-12 prior clear liquids ok No oral hypoglycemic- contraindicated with dye Creatinine/ BUN levels IV access for dye injection
Oral hypoglycemic meds like metformin can cause lactic acidosis.
Metformin may interact with the dye used for an X-ray or CT scan. Your doctor should advise you to stop taking it before you have any medical exams or diagnostic tests that might cause less urine output than usual. You may be advised to start taking the medicine again 48 hours after the exams or tests if your kidney function is tested and found to be normal.
MRI of Kidneys
what is it?
NI?
Provides improved imaging between normal & abnormal tissue.
Nursing Interventions:
Assess for metal implants (pacemaker, joint replacements, aneurysm clips, cosmetic or medical devices).
Remove transdermal patches
Claustrophobia
Renal Arteriogram or Angiogram
Visualizes renal arteries using radiopaque dye.
Dye injected via femoral or brachial artery.
Seldom used as stand-alone diagnostic procedure.
Usually done at time of renal angioplasty or other intervention.
Renal Arteriogram or Angiogram
NI
Nursing Interventions
Assess dye allergy & anticoagulant use
NPO 8-12 h prior
Oral hypoglycemic’s contraindicated with contrast medium
Renal Arteriogram or Angiogram
Post procedure?
Post procedure: Monitor bleeding @femoral artery Restrict activity x 1 day Monitor output (dye is hard on kidneys) Monitor peripheral pulses
Renal Arteriogram or Angiogram
Metformin, how it interaction occurs?
How the interaction occurs:
If you are taking metformin when you have your imaging test procedure, your kidneys may not be able to properly remove metformin from your blood.
Renal Arteriogram or Angiogram
Metformin, what might happen?
What might happen:
The effects of metformin may increase and cause a serious condition called lactic acidosis, especially if you have kidney problems. Symptoms of lactic acidosis are: feeling very weak, tired, or uncomfortable, unusual muscle pain, trouble breathing, unusual or unexpected stomach discomfort, feeling cold, dizziness or lightheadedness, suddenly developing a slow or irregular heartbeat.
Renal Scan
Examines:
Perfusion, function & structure of the kidneys.
Uses IV radioisotope- contains no iodine, less kidney injury risk.
Renal Scan
NI
Nursing Interventions
Insert IV for isotope administration
Enc. Fluid intake to aide in isotope elimination.
Isotope generally eliminated within 6-24 hrs.
Renal Scan
Pre-procedure?
Pre-Procedure: Drink several glasses of water Obtain weight and have patient void Post-Procedure: Increase fluid intake
Kidney Biopsy
Helps determine cause of unexplained kidney problems guides care.
Performed percutaneously (through skin) with a biopsy needle using ultrasound/CT guidance.
Bleeding is a MAJOR risk.
Kidney Biopsy
NI
Nursing care:
Informed consent
NPO 4-6 hrs. before.
PT, PTT drawn prior r/t major risk of bleeding complication.
Manage B/P (HTN increases bleeding risk).
Strict bedrest 24 hrs. post biopsy. Limited bathroom privileges after 24 hr. if no evidence of bleeding.
Discomfort expected at biopsy site. If pain radiates to flank, back and abdomen suspect bleeding.
Monitor:
Urine output, hematuria, vital signs.
Bruising/flank pain (indicates internal bleed)
Cystometrography (CMG) AKA: voiding cystogram
Provides info about bladder capacity, pressure and voiding reflexes.
Cystometrography (CMG) AKA: voiding cystogram
procedure?
Procedure:
Pt. voids normally. Record amount and time of void.
Insert catheter to measure residual urine volume.
Cystometer attached to catheter and fluid is instilled (about 500 ml) into the bladder.
Pt. reports when 1st feeling urge to void is felt & the point when strong urge to void is felt.
Bladder capacity & pressure readings are recorded.
Bladder capacity?
Urge?
Fullness?
Bladder capacity is about 300-600 ml’s.
Urge to void sensed @ >150ml
Fullness sensed @ 300 ml
Urodynamic studies: examine the processes of voiding and includes
Tests of bladder capacity, pressure and tone
Studies of urethral pressure and urine flow
Tests perineal voluntary muscle function.
Includes CMG (Cystometrogram), urethral pressure profile (UPP) urine stream testing (evaluates pelvic muscle strength). EMG (Electromyography) of perineal muscles to test strength of muscles used in voiding
Cystoscopy
Evaluates bladder, urethra and lower portions of ureters.
Endoscope inserted through urethra into the bladder.
Requires pre-op checklist and informed consent.
Performed for diagnosis or treatment of:
Bladder trauma
Identify causes of urinary tract obstructions.
Remove bladder tumors or implant radium seeds into a tumor.
Stop areas of bleeding
Resect an enlarged prostate gland.
Cystoscopy
Post op care
Post-op care:
Monitor airway patency & breathing.
Urine may be pink tinged. Gross bleeding not expected.
Monitor urine output. Enc. Fluids to decrease burning sensation.
Urinary frequency expected initially due to irritation from procedure.
Monitor for s/s bladder puncture- severe pain (including abdominal pain) nausea and vomiting.
**Cystoscopy can be done under general or local anesthetic with conscious sedation. Done in surgery, outpatient clinics and doctors offices.
Cystatin C
Measures glomerular filtration rate.
Is a protein produced in the body at a constant rate & can be used as indicator of GFR.
When GFR is reduced cystatin-c increases
Increased levels can be considered a predictor of chronic renal disease.
Not influenced by factors that influence BUN and creatinine. Maybe be better indicator of GFR.
Increased blood concentration = indicate decrease GFR & kidney dysfunction.
Nursing Interventions:
No specific preparation is required.
Blood Urea Nitrogen (BUN)
Measures effectiveness of kidneys excretion of urea nitrogen.
Urea nitrogen is by-product of protein breakdown in the liver.
Kidneys filter urea nitrogen from the blood and excrete in the urine.
Elevated BUN does not always mean kidney disease is present.
Normal range 10-20 mg/dl. Slightly higher in older adults.
Blood Urea Nitrogen (BUN)
factors that increase BUN?
Contributing factors to increased BUN levels:
Rapid cell destruction from infection, cancer Tx., or steroid therapy.
Blood (protein) from injured tissues.
Dehydration
Urea is an end product of what?
Urea is an end product of protein metabolism. An elevated BUN level could be indication of dehydration, prerenal failure, or renal failure or GI bleeding. Dehydration from vomiting diarrhea or inadequate fluid intake is common cause of elevated BUN. If dehydration after hydrated the BUN should return to normal if not prerenal or renal failure should be suspected. Digested blood from GI bleeding is a source of protein and can cause the BUN to elevate. A low BUN usually indicates over hydration (hypervolemia).
Serum Creatinine-
Blood test that evaluates kidney function.
Creatinine is produced when muscles & other proteins are broken down & excreted by the kidneys.
Higher in men vs women r/t larger muscle mass.
Normal value: 0.5-1.2 mg/dl
Kidney disease is the only condition that raises serum creatinine.
When serum creatinine levels doubled, it indicates a 50% reduction in GFR.
Kidney function properly?
Kidney not function?
Regarding serum creatinine
If kidneys are functioning properly you’d expect to see higher levels of creatinine in urine and less in blood. When kidneys do not function well less creatinine is seen in urine and more in the blood.
Serum Creatinine clearance/Glomerular Filtration Rate (GFR)
Best test to measure level of kidney function
Determines stage of kidney disease.
Calculated by blood creatinine, age, body size, and gender.
Low numbers mean kidney is not working well.
24 hr. Urine Creatinine Clearance
Urine sample that is collected for 24 h period of time.
Evaluates GFR & renal function.
Done along with serum creatinine
Normal 85-135
Expect low levels if kidney function impaired.
Thought: “kidneys clear creatinine from blood”
So higher levels would be seen in urine of normal kidneys
24 hr. Urine Creatinine Clearance
NI
Nursing Interventions:
First urine is discarded
Keep urine on ice or in refrigerator during 24h period (unless preservative in the container)
Instruct pt. and family to save all urine during 24h
Assess meds: thiazides steroids may decrease creatinine while Methyldopa, vit c, cimetidine may increase levels.
How is creatinine removed from kidney?
Creatinine is removed, or cleared, from the body entirely by the kidneys. If kidney function is abnormal, creatinine level increases in the blood because less creatinine is released through the urine.
Urinalysis (UA)
UA part of a physical exam. Provides useful info for pts. with suspected kidney disorders.
Ideally collected 1st morning urine. Other specimens may be too dilute.
Specimens become more alkaline when left unrefrigerated for more than 1 hr. or when bacteria are present. Promptly cover and deliver to the lab.
Significant Components of a UA
Color?
Normal?
Abnormal?
Yellow
Dark amber= concentrated urine
Very pale yellow= dilute urine
Dark red or brown= indicates blood or increased bilirubin
