Unit 6 Flashcards
– Bean shaped organs
– located retroperitoneally
– Adrenal gland on top of each
– Cushioned by fat and connective tissue
– Covered by a fibrous membrane
– Hilus on medial side - arteries and nerves enter/ veins and ureters exit
Macrostructure of kidneys
– Nephron is the functional unit
– Glomerulus
– Bowmans capsule
– Tubular system
Micro structure of the kidneys
Renal artery arises from the aorta, and divides into smaller branches, each of those divides into and afferent arterial, and those further divided into a capillary network called the glomerulus
Renal blood supply
Blood is filtered by hydrostatic pressure, it passes through Bowmans capsule, glomerular filtrate passes down the tubule
Glomerular function of urine formation
125 mL/ minute
Normal glomerular filtration right (GFR)
- The proximal convoluted tubule reabsorbs 80% of electrolytes
- loop of henle reabsorbs water
- descending loop reabsorbs water, some Na, urea and other solutes
Tubular function of urine formation - reabsorption
– Re-absorption
– Secretion
Tubular function of urine formation
– RBC production stimulated by erythropoietin production
– BP regulation by RAAS
– Vitamin D activation
– Acid-base balance
Other functions of the kidney
- Join the renal pelvis at the ureteropelvic junction (JVP)
- Join the Bladder at the ureterovesicle junction
(UVJ)
Ureters
- Serves as a reservoir for urine – capacity 600 to 1000 mL
- Trigone
- Bladder muscle (detruser)
- urination, micurtation, voiding
Bladder
– Extends from bladder neck to external meatus
– Conduit for urine during voiding
– Length is 1 to 2 inches in females, and 8 to 10 inches and males
Urethra
– Formed by bladder, urethra, and pelvic floor muscles
– Voluntary control of this unit is defined as continence
Urethrovesical unit
– Size and weight of kidneys decrease
– 30 to 50% of glomerular function lost by seventh decade
– Atherosclerosis accelerates the decrease of renal size with age
Effects of aging on urinary system
– Decreased renal bloodflow decreases GFR
– Altered hormone levels result in decreased ability to concentrate urine, and altered excretion of water, sodium, potassium, and acid
– Loss of elasticity and muscle support
– Prostate enlargement
Physiologic changes on the urinary system due to aging
Gather past health history, current medications, surgical or other treatment history
Subjective data - Important health information
Health perception – health management pattern, nutritional pattern, elimination pattern, activity – exercise pattern, sleep – rest pattern, cognitive – perceptual pattern, self perception – self-concept pattern, roll – relationship pattern, sexuality – reproductive pattern
Subjective data - functional health patterns
- Inspection of the mouth, skin, face, extremities and abdomen
- weight and general state of health
Physical exam – inspection
– Kidneys and bladder should not be palpable
Physical exam – palpation
– Kidney punch, and bladder
Physical exam – percussion
- bell at costovertebral angle (CVA)
- diaphragm for bowel sounds
Physical exam – auscultation
– No costovertebral angle tenderness
– Nonpalpable kidney and bladder
– No palpable masses
Normal physical assessment of the urinary system
– First morning void, examine the urine within one hour
Urinalysis
- Urinalysis
- creatinine clearance
Urine diagnostic studies
– Collect 24 hour urine specimen, this closely reflects GFR
– Most accurate indicator of renal function
– Reflects amounts of creatinine completely cleared by the kidneys in one minute
Creatinine clearance
– Visualizes renal blood vessels
– Can assist in diagnosing renal artery stenosis, renal cyst/ tumor differentiation
Renal angiogram
Prepare patient the prior evening by giving Catharitic or enema, assess for iodine sensitivity, explain the transient warm feeling felt when the media is injected
Preparing a patient for renal angiogram
Place a pressure dressing over the for moral artery injection site, observe for bleeding. Maintain bed rest. Take peripheral pulses Q 30 to 60 minutes. Observe for complications including thrombus, embolus, inflammation, and hematoma.
Taking care of a patient after a renal angiogram
Used to insert catheters, remove calculi, obtain biopsies, and treat bleeding lesions. Lithotomy position is used
Cystoscopy
Force fluids or give IV fluids if Anesthesia is to be used. And sure consent is signed, and give preop medication.
Preparing a patient for a cystoscopy
Explain that Burning on urination, pink tinged urine, and urinary frequency are expected. Observe for bright red bleeding, monitor for orthostatic hypotension. Offer sits baths, heat or analgesics
Caring for a patient after cystoscopy
Regulate volume and composition of extracellular fluid – reflects the kidneys ability to produce a concentrated or diluted urine
Primary function of the kidneys
Excreting fluid, waste products and toxins
Secondary function of the kidneys
- Influenced by protein intake, G.I. bleed, and hydration
- two thirds of renal function is lost before significant rise in this level occurs
BUN
Kidneys secrete or retain bicarbonate and hydrogen ions in response to the pH of the blood
Acid-base balance function of the kidney
Produces enzyme called erythropoietin factor which activates erythropoietin which stimulates bone marrow to produce red blood cells
Erythropoietin production - function of the kidneys
Alterations in drug excretion, nocturia, decreased ability to concentrate urine; less concentrated urine
Changes in urinary assessment findings due to aging
– More reliable than BUN
- reflects GFR
– Used to estimate functional capacity of the kidneys
Serum creatinine
– GFR and renal function fallen to half of its normal state
Creatinine level two times normal
– 75% loss of renal function
Creatinine value of three times normal
- Assume 90% of renal function lost
– A critical value
Creatinine level of 10 or more
- Normal ratio is 10 to 1
- ratio of 15 to one or more indicates a pre-renal condition
- ratio of less than 10 to 1 indicates liver disease or low-protein diet
BUN/creatinine ratio
Accumulation of waste products in blood
Azotemia
Sudden onset
Acute kidney injury
Gradual onset, over many years
Chronic kidney disease
Acute tubular necrosis
Most common cause of acute kidney injury
Diabetic neuropathy
Most common cause of chronic kidney disease
Acute reduction in urine output and or elevation of serum creatinine
Diagnostic criteria for acute kidney injury
GFR less than 60 mL per minute for longer than three months for kidney damage lasting longer than three months
Diagnostic criteria for chronic kidney disease
Potentially reversible
Reversibility of acute kidney injury
Progressive and irreversible
Reversibility a chronic kidney disease
Infection
Primary cause of death in acute kidney injury
Cardiovascular disease
Primary cause of death in chronic kidney disease
– Factors external to the kidneys that reduced renal bloodflow causing decreased GFR, and oliguria
– Examples being dehydration, heart failure, and decreased cardiac output
Prerenal causes of acute kidney injury
– Causes include conditions that directly damaged kidney tissue resulting from prolonged ischemia, nephrotoxins, hemoglobin release from hemolyzed RBCs, myoglobin release from the Necrotic muscle cells, and acute tubular necrosis (ATN)
Intrarenal causes of acute kidney injury
- Results from ischemia, nephrotoxins, or sepsis
- potentially reversible
Acute tubular necrosis (ATN)
– Caused by mechanical obstruction in the urinary tract, including BPH, prostate cancer, calculi, trauma, and extrarenal tumors
Post renal causes of acute kidney injury
Risk, injury, failure, lost, end-stage kidney disease
RIFLE classification
– Urine output less than 400 mL/day
– Occurs within 1 to 7 days after injury, and lasts 10 to 14 days
– Urinalysis may show cast, RBCs, and WBCs
Urinary changes during the oliguric phase of acute kidney injury
–fluid retention occurs which manifests as Standard black beans, abounding plus, Edema and HTN
- can lead to HF, pulmonary edema, pericardial/pleural effusions
Fluid volume changes in the oliguric phase of acute kidney injury
– Serum bicarbonate drops
– Severe acidosis develops, which can cause Kussmaul respirations
Metabolic changes in the oliguric phase of acute kidney injury
– Increased excretion of sodium can cause hyponatremia which can lead to cerebral edema
Sodium balance changes in the oliguric phase of acute kidney injury
– Usually asymptomatic, but can cause ECG changes
Potassium changes (excess) in the oliguric phase of acute kidney injury
Can cause leukocytosis
Hematologic changes during the oliguric phase of acute kidney injury
Causes elevated BUN and serum creatinine levels
Waste product accumulation during the oliguric phase of acute kidney injury
Can cause fatigue and difficulty concentrating, seizures, stupid or coma
Neurologic changes in the oliguric phase of acute kidney injury
– Daily urine output is 1 to 3 L, but can reach five or more
– Monitor for hyponatremia, hypokalemia, hypotension and dehydration
– Kidneys have recovered ability to excrete waste, but not concentrate in the urine
Diuretic phase of acute kidney injury
– May take up to 12 months for kidney function to stabilize
– Begins when GFR increases, and BUN and serum creatinine levels plateau and then decrease
Recovery phase of acute kidney injury
– Obtain a thorough history, serum creatinine levels, urinalysis, kidney ultrasound, renal scan, CT scan, and/or renal biopsy
Diagnostic studies for acute kidney injury