Exam 1: Chapter 53: Assessment of Kidney Functions Flashcards
Functions of Kidney
Urine Formation Excertion of Waste Products Regulation of Electrolytes Regulation of Acid-Base Control of Water Balance Control of Blood Pressure Renal Clearance Regulation of RBC Prod Synthesis of Vitamin D to Active Form Secretion of Prostaglandins
Urine Formation: Formed in
Nephrons through glomerular filtration -> tubular reabsorption and tubular secretion
Urine Formation: What is usually excreted in urine?
Sodium, Chloride, Bicarbonate, Potassium, Glucose, Urea, Creatine, and Uric Acid
Antidiuretic Hormone: Also known as
Vasopressin
Antidiuretic Hormone: What is this?
Secreted by posterior portion of pituitary gland is response to changes in osmolality in blood .
Antidiuretic Hormone: With decreased water intake, what happens to blodo osmolaity?/
Increased. This stimulates ADH reelase
Antidiuretic Hormone: Acts on what organ ____ and does ___
kidney, increase reabsorption fo water and returning osmolality of blodo to normal
Antidiuretic Hormone: Excess water intake leads to
secretion of ADH, and leads to diuresis (increased urine volumme)
Antidiuretic Hormone: A dilute urine with SpG of 1.010 and osmolality of 300 mOsm/L indicates
inability to concentrate and dilute urine
Osmolarity: This refers to
the ratio of solute to water
1 lb of fluid equal to ? mL
500 mL
Regulation of Electrolyte Excretion: With increased aldosterone in the blood.
less sodium is excreted in the urine
Regulation of Electrolyte Excretion: Release of Aldosterone form adrenal cortex largely under control of
Angiotensin II
Regulation of Electrolyte Excretion: RAAS activated when
pressure in the renal arterioles falls below nromal levels . Occurs with shock, dehydration, or decreased sodium chloride delivery
Regulation of Acid-Base: Normal serum pH is
7.35 - 7.45
Regulation of Acid-Base: One of kidneys function to keep this balanced is to
reabsorb and reutrn ot the body circulation any bicarbonate from the urinary filtrate
Autoregulation of Blood Pressure: Specialized vessels of the kidney called vasa recta monitor
blodo pressure as blood begins passage into the kidney
Autoregulation of Blood Pressure: When vasa recta detect decrease in blood pressure,
afferent artiole, distal tibule and juxtaglomerular cells secrete renin
Autoregulation of Blood Pressure: Renin convets
Angiotensinogen into Angiotensin I, which is then converted in Angiotensin II. This causes blood pressure to increase
Autoregulation of Blood Pressure: Adrenal cortex secretes aldosterone in response to
stimulation by pituitary gland , which occurs asresponse to poor perfusion or increasing serum osmolality. results in increase of bp
Autoregulation of Blood Pressure: Failure to stop Renin is one of the primary causes of
hypertension
Renal Clearance: This refers to
the ability of the kidney to clear solutes from the plasma
Renal Clearance: Primary test?
24 hour collection of urine used to evaluate how well the kidney performs
Renal Clearance: Renal clearance depends on what several factors?
How quickly substance is filtered across the glomerulus
how much the substance is reabsorbed along the tubules
how much the substance is secreted into tubules
Renal Clearance: One measure that is partically useful is?
Creatinine clearance
Renal Clearance: Creatinine is
an endogenous waste product that is filtered at the glomerulus. Hence why its a good measure of GFR, the amount of plasma filtered through the glomeruli per unit of time
Renal Clearance: Adult GFR can vary from
125-200 mL/min
Renal Clearance: AS renal function decline, what happens to creatinine and renal clearance?
decrease
Regulation of RBC Production: When kidneys detect decrease in oxygen tension in renal blood flow because of anemia, arterial hpoxia, or inadequate blood flow, they reelase
erythropoietin
Regulation of RBC Production: What is Erythropoietin?
Glycoproetin from the kidney that stimulates the bone marrow to produce red blood cells
Vitamin D Synthesis: Kidneys response for final conversionof
inactive vitamin d to its active form 1,25-dihydroxycholecalciferol
Vitamin D Synthesis: Vitamin D is necessary for maintaining
normal calcium balance in the body
SEcretion of Prostaglandins and other substances: What do this do?
Help afferent and efferent arterioles maintain renal blood flow by causing selective vasodilation or vasoconstriction
Excretion of Waste Products: Major waste product of body?
Urea. 25-30 g excreted daily.
Urine Storage: Filling and emptying of the bladder are mediated by coordinated
sympathetic and parasympathetic nervous system control of mechanisms involving the detrouser muscles and the bladder outlet
Urine Storage: At night, the reelase of vasopressin causes
decrease in the production of urine and makes it more concentrated. Thats why we dont pee at night
Common Symptoms - Pain: Genitourinary pain usually caused b
distention of some portion of urinary tract bc of obstructed urine flow or inflammation and swelling
Urinalysis: What does this provide?
Clinical information about kdiney function and helps diagnose other diseases such as diabetes
Urine Culture: Determines whether
bacteria are present in urine, as well as their strains and concentration
Urinalysis and Urine Culture: Hematuria common causes include
acute infection (cystitis, urethritis, or prostatitis), renal calculi or neoplasm
Urinalysis and Urine Culture: What test should be done to test for protein?
Dipstick examination, because urine concentration, pH, hematuria, and radiocontrast materials all affect the results
Urinalysis and Urine Culture: Causes of persistent proteinuria include
glomerular diseases, malignancies, collagen dsieases, diabetes, preeclampsia, hypothyroidism, heart failure, exposure to heavy metals and use of medications
Specific Gravity: SpG of water?/
1.000
Specific Gravity: When fluid intake decreaes, SpG..
increases
Specific Gravity: With high fluid intake, SpG…
decreaes
Specific Gravity: Methods for Testing?
Multiple Test Dipstick (Most Common)
Urinometer (Least)
Refractometer
Specific Gravity: Patients with kidney disease and fluid intake
it does not vary and patients urine is said to have fixed specific gravity
Specific Gravity: Disorders that cause decreased SpG include
diabetes, glomerulonephritis, and severe renal damage
Specific Gravity: Increased SpG caused by
diabetes, nephritis, and fluid defific
Osmolaity: Most accurte measurement of
kidneys ability to dilute and concentrate urine . Measures number of solute molecules in a kilogram of water
Osmolaity: Serum osmolality is usually
280-300
Osmolaity: Urine osmolality is usually
200-800
Osmolaity: 24 Hour urine sample osmolality is usully
300-900
Renal Function TEsts: Used to evaluate
severity of kidney disease and to assess the status of the patients kidney function. Provide information about effectiveness of kidney in carrying out its excretory function
Renal Function TEsts: Specific Gravity normal value
1.010 - 1.025
Renal Function TEsts: Normal Creatinine Level
0.6-1.2
Renal Function TEsts: Normal BUN Level?
7-18 > 60 years
8-20 normally
Renal Function TEsts: BUN-to-Creatinine Ratio Level
10:1
What falls under Diagnostic Imaging?
Kidney, Ureter, and Bladder Studies General Ultrasonography Bladder Ultrasonography CT and MRI Nuclear Scans Intravenous Urography Retrograde Pyelography Cytography Voiding Cystourethrography Renal Angiography MAG3 Renogram
Kidney, Ureter, and Bladder Studies: What is this?
X-Ray study of abdomen or KUB to delineate size, shape and position of kidney and reveal urinary abnormalities
General Ultrasonography: What is this?
Noninvasive procedure that uses sound waves pases into body through a transducer to detect abnormalities of internal tissues and organs
General Ultrasonography: Abnormalities in body may include
fluid accululation, masses, congenital malformations, changes in organ size, and obstructions
General Ultrasonography: During test, lower …
abdomen and genitalia may need to be exposed
General Ultrasonography: This requires a full
bladder, therefore fluid intake encouraged before procedure
Bladder Ultrasonography: What is this?
Noninvasive method of measuring urine volume in the bladder
Bladder Ultrasonography: May be indicated for
urinary frequency, inability to void after removal of catheter, measurement of postvoiding residual volume, inability to void postoperative, or assessment of need for catheterization
Bladder Ultrasonography: How is this test performed?
Scan head placed on patietns abdomen and directed toward bladder. DEvice automatically calculates and displayes urine volume
CT and MRI: What is this?
Noninvasive techniques that provide excellend cross-sectional views of the anatomy of the kidney and urinary tract
CT and MRI: Used to evaluate
genitourinary masses, nephrolithiasis, chronic renal infection, renal or urinary trauma, and soft tissue abnormalities
CT and MRI: Occassionally, what is used to enhance visualization?
Oral or IV Radiopaque
CT and MRI: Preparation includes educating patient about
RElaxaiton Techniques
And how they’ll be able to communicate with stuff
Why are contrast agents problematic?
Some patients are nephrotoxic and allergenic to contrast agents
Contrast Agents: What allergies should be watched out for?
Iodine, Shellfish, and other seafood because many agents contain iodine
CT and MRI: Before patient enters rom, all what must be removed?
Metal objects and credit cards because magnetic field can erase them
Patches with metal backings as well bc they can cause burns
CT and MRI: Prior to MRI of Urinary Ssytem, patients is informed to avoid
Caffeine, Smoking, Alcohol for two hours.
Food for at least one hour
Iron supplements interfere with imaging
Nuclear Scans: These require
injection of a radioisotope (technetium 99m - labeled compound or Iodine 123 Hippurate) into the circulatory system
Nuclear Scans: Isotope is monitored as it moves through
blood vessels of the kidney
Nuclear Scans: What is placed behind the kidney with the patient in a supine, prone, or seated position?
Scintillation Camer
Nuclear Scans: Technetium scan provides
information about kidney perfusion
Nuclear Scans: I-Hippurate renal scan provides information about
kidney function such as GFR
Nuclear Scans: Used to evaluate
acute and chronic kidney injury, renal masses and blood flow before and after kidney transplant.
Nuclear Scans: After procedure, patient is encouraged to
drink fluids to promote excretion of the radioisotope y the kidney
Intravneous Urography: Includes various tests such as
excretory urography, (IVP) and infusion drip pyelography
Intravneous Urography: IVP shows
the KUB via x ray imaging as the dye moves through the upper and then lower urinary system
Intravneous Urography: A nephrotomogram may be carried out as
part of the study to visualize different layers of the kidney and diffuse structures within each layer
Intravneous Urography: IV Urography may be used as the initial asessment of many
urologic ocnditions, especially lesions in the kidneys and ureters . Also provides aproximate estimate of renal function
Intravneous Urography: After IV is given, multiple
x-rays are obtained to visualize drainage of structures in upper and lower urinary systems
Intravneous Urography: Infusion drip pyelography requires
IV infusion of a large volume to dilute contract agent to opacify the renal parenchyme and fills teh urinary tract
Intravneous Urography: Any restrictions?
fludis not restricted
Retrogrgade Pyelography: What is this?
Catheters advanced through ureters into renal pelvis by means of cytoscopy. Contrast agent then injected
Retrogrgade Pyelography: This usually performed if
IV urography provides inadequate visualization of collecting system
Retrogrgade Pyelography: may also be used before
before extracorporeal shock wave lithotripsy and patients with urologic cancer who need follow up and are allergic to IV contrast agents
Retrogrgade Pyelography: Complications?
Infection, Hematuria and performation of the ureter
Retrogrgade Pyelography: Is this used a lot??
No because of improved techniques in excretory urography
Cytography: What is this?
Aids in evaluating vesicoureteral reflux and in assessing for bladder injury
Cytography: How is this done?
catheter inserted into bladder, contrast agent instilled to outline bladder.
What is Voiding Cystourethrography: What is this?
Uses fluroscopy to visualize lower urinary tract and asses urine storage in bladder
What is Voiding Cystourethrography: Commonly used as diagnostic tool to identify
vesicoureteral reflux
What is Voiding Cystourethrography: How is this done?
Uretheral catheter is inserted and a contrast agent is instilled into the bladder. When badder is full and patient feels the urge to void, catheter is removed and patienet voids
REnal Angiography: What is this?
Provides image of the renal arteries.
REnal Angiography: How is this done?
Femoral artery pierced with a needle and catheter is threded through femoral and iliac arteries into aorta or renal artery. Contract agent is injected.
REnal Angiography: This is used to evaluate what?/
Renal blood flow in suspected renal trauma, to differentiate renal cysts from tumors adn to evaluate hypertension
REnal Angiography: Is it used preoperatively for
renal transplation
REnal Angiography: Before procedure, what may be prescribed?/
Laxative to evacuate colon so unobstructed x-rays can be obtained.
REnal Angiography: Possible complications include
hematoma formation, arterial thrombosis or dissection, false aneurysm formation and altered renal function
MAG3 Renogram: What is this used for?
Scan used to further evaluate kidney function in some center by permitting visualization of renal clearance
MAG3 Renogram: How is this done?
Patient given injection containing small amount of radioactive material, which will show how kidney function. Pt lies still for 35 minutes while special camera takes image
Endourology or Urologic Endoscopic procedures can be performed in what two ways?
Using a cytoscope inserted into the urethra
Percutaneously, thorugh a small incision
Urologic Endoscopic Procedure: Cytoscopic examination used to directly ivisualize
ureathra, and bladder
Urologic Endoscopic Procedure: Cytoscope inserted through what?
Urethra into the bladder
Urologic Endoscopic Procedure: What can be removed form urethra, bladder, and ureter using cytoscopy?
Calculi
Urologic Endoscopic Procedure: If lower tract cytoscopy performed, patient is usally
conscious.
Urologic Endoscopic Procedure: To minimize urethral discomort what is given
viscous lidocaine minutes before study
Urologic Endoscopic Procedure: If cytoscopy includes examiniation of upper tracts, what is given?
General anesthesia to ensure theyre no involuntary muscle spasms
Urologic Endoscopic Procedure: If an upper cytoscopy is to be performed, patient is restricted to
NPO serveral hours befrehand
Renal and Urethral Brush Biopsy: This techniques provides information when
abnormal x-ray finding of the ureter or renal pelvis raise questions of what it is.
Renal and Urethral Brush Biopsy: What is first done?
Cytoscopic examination is conducted
Renal and Urethral Brush Biopsy: Second step?
Urethral catheter is intrdocued followed by biopsy brush that is passed through catheter. Suspected lesion brushed back and forth
Kidney Biopsy: Biopsy used to help
diagnose and evaluate the extent of kdiney disease.
Kidney Biopsy: Indications for biopsy include
unexplained AKI, persistent proteinuria, transplant rejection
Kidney Biopsy: Small section of renal cortex obtained by
percutaneously (needle biopsy) or by open biopsy through small flank incision.
Kidney Biopsy: Before biopsy is carried out, what is done?
Coagulation studies are conducted to identify risk of post biopsy bleeding
Kidney Biopsy: Contradictions include
bleeding tendencies untroller hypertension sepsis UTI Obesity
Kidney Biopsy: Regimen before test?
Fasting regimen 6-8 hours before test. IV line established and urine specimen saved to compare
Kidney Biopsy: If needle biopsy is to be performed, patient is instructed to
breathe in and hold breath to prevent kidney from moving while needle is inserted
