Exam 3: Urinary system assessment Flashcards
Key anatomical components of renal system
Kidneys Ureters Bladder Sphincters Urethra
Primary function of renal system is to
maintain homeostasis by controlling the composition and volume of extracellular fluid
___% of cardiac output circulates through the kidneys
25%q
Formation of urine requires 3 steps:
Glomerular filtration
tubular reabsorption
tubular secretion
Filtration
Pressure forces liquids and dissolved substances through anatomical filtration –> filtrate created
Glomerular filtration rate (GFR):
Amount of filtrate formed/minute
GFR is directly relates to
Renal perfusion
Low bp/low volume =
low perfusion
High bp/high volume =
Increased perfusion
Impaired circulation =
low perfusion
~125 mL/min
Urine output at least
30 mL/hr
Urine output calculation
0.5-1.5ml/kg/hr
Bladder smooth muscle is supplied by
many parasympathetic fibers
The internal urethral sphincter is also
Smooth muscle
Internal urethral sphincter is under ____ control
Parasympathetic control
The external urethral sphincter is
composed of skeletal muscle
External urethral sphincter is under ____ control
Voluntary
External urethral sphincter can be tightened to
prevent urination even when the bladder is contracting and the internal sphincter is open
When relaxed and filled, both sphincters are
Closed to keep urine from dribbling out
Motor neuron inhibits external sphincter:
Relaxes and opens
Under voluntary control, impulses from cerebral cortex override
the reflex input from stretch receptors
Adults bladder capacity
600 mL
Adult urge to urinate is at
250 mL
Why are women more at risk for UTIs
because women have a 2 inch urethra while men have an 8 in
Children bladder capacity
50-60 ml
Pregnant women experienced increased frequency of urination due to
- Increased GFR secondary to increased blood volume
- Pressure of gravid (pregnant) uterus on bladder
Older male adults experience
Prostate enlargement which causes urination frequency and retention
How does menopause impact urination
frequency, nocturne, loss bladder tone, retention, residual urine–> increase UTI
By age 80, ____ of glomeruli are not function
40% of glomeruli
Th darker the urine, the more
concentrated
I & O
Intake/output
UA
urinalysis
What is in urinalysis
Albumin creatinine ratio
urine specific gravity
Urine specific gravity range
1.010 - 1.025 WNL
Urine specific gravity measures
Concentration/density
High number of urine specific gravity =
concentration urine = heavier weight/ml.
-indiacator of hydration
Blood tests of renal function and urinary status
BUN (blood urea nitrogen)
Serum Creatinine
Serum blood urea nitrogen
BUN
Serum blood urea nitrogen (BUN) normal
10-20 mg/dl
Urea:
End-product of protein metabolism
Urea is formed in the
Liver
Urea is eliminated by
Kidneys
Serum blood urea nitrogen (BUN) reflects
Liver’s ability to make urea AND kidney’s GFR
is serum blood urea nitrogen (BUN) as reliable as creatinine lab?
NO! not as reliable
Serum blood urea nitrogen (BUN) is usually measured in conjunction with
creatinine
Key factors that influence Serum blood urea nitrogen (BUN)
Impaired LIVER function
Hydration status
Nephrotoxic drugs
Why is BUN not the best measure of kidney function?
Because of the impact of the liver
Normal ranged of serum creatinine
0.5 - 1 mg/dL
Creatinine is a product of
Metabolism
Creatinine is produced and released into plasma at a
Constant rate and freely filtered glomerulus
Serum creatinine is a ___ estimate of ___ than BUN
Better estimate of renal function and GFR THAN BUN
Blood creatinine and GFR relationship
Inversely related
Low GFR means less creatinine filtered out to urine =
Blood creatinine levels are HIGH
Higher GFR means more creatinine filtered out =
Blood creatinine levels are low
Factors that influence creatinine levels
Impaired renal function Muscle mass/wasting Nephrotoxic drugs Exercise (break down muscle) Any state that decreases GFR will increase serum creatinine
BUN to creatinine ratio is usually
10 : 1
Creatinine clearance estimates
GFR; amount of blood the kidneys make creatinine-free / minute
Measuring creatinine present in a
24- hour sample of urine
the time for sampling urine starts immediately
AFTER emptying the bladder!
How to calculate creatinine clearance
Use a normal serum creatinine level & plug it into a formula
Urinary Albumin to creatinine ratio is a newer method for
detecting protein excretion
Is albumin creatinine ratio impacted by hydration?
Less impacted because it is not a concentration/mL
Microalbuminuria
ACR 30-300 mg/g
Microalbuminuria refers to
Albumin excretion above normal range but below the level of detection by tests for total protein
Macroaluminuria
ACR >300
Macroaluminuria refers to
higher elevation of albumin associated with progressive decline in glomerular filtration rate
What is reported with renal infection
Flank pain during costovertebral angle assessment
Tenderness/sharp pain during costovertebral angle assessment may indicate
pyelonephritis (kidney infection) renal calculi (renal stones) hydronephrosis (distention of the kidney with urine as a result of obstruction of the outflow of urine)
Noninvasive diagnostic TEST! (not lab)
Abdominal Roentgenogram: x-ray
Computerized Axial tomography (CT): imagery via cross-sectional imaging
Intravenous pyelogram (IVP): Image via x-ray using contrast dye
Ultrasound: sound waves
Invasive diagnostic TEST (not labs)
Endoscopy-cystoscopy: scope through urethra to visualize, obtain specimen, instill treatment
Common Urinary diagnosis
Urinary Retention UTI Incontinence Diversions (not discussed here) Renal Failure (not discussed here) BPH Pelvic Organ Prolapse (POP) (less common, but worth mentioning)
Urinary retention
Partial or complete inability to empty bladder
Urinary retention can lead to
UTI/Sepsis
Overflow incontinence
Urinary retention can often happen after
Catheter removed
Monitor for urinary retention by using
Post Void Residual machine (PVR)
Straight catheterization
Benefits for women of pelvic floor exercises
Strengthen pelvic floor muscles and restore vaginal tone Prevent/treat stress incontinence Prevent/treat fecal incontinence Recover from childbirth Improve sexual sensation/function
Benefits of pelvic floor exercises for men
Strengthens pelvic floor muscles especially after prostatectomy Prevent/treat stress incontinence Prevent/treat fecal incontinence Helps with erectile dysfunction Improves sexual sensation/function
Pelvic organ prolapse
- Muscles and ligaments supporting a woman’s pelvic organs weaken
- Pelvic organs can drop lower in the pelvis, creating a bulge in the vagina (prolapse).
- Women most commonly develop pelvic organ prolapse years after childbirth, after a hysterectomy, or after menopause.
Intermittent urinary catheterization
Bladder decompression, sterile specimen, assessing residual, spinal cord injury
urinary catheterization indwelling; short term
inter-operative/immediate post-op; critical care, BPH, bladder irrigation
urinary catheterization indwelling; long term
severe urinary retention, avoidance of urine contact with skin, terminal illness
Risks of urinary catheterization
Trauma to urethra: urethritis
Infection
___ % of UTIs are related to an indwelling catheter
80% of UTI
Infection risk of infections increases ________ catheter is in place
increases 3 - 10 % each day
Safety guidelines to follow for urinary catheterization
Catheter - associated urinary tract infections (CAUTI) guidelines
UTI is an infection in
ANY part of the urinary system
In older adults, UTIs clinical manifestations
Asymptomatic OR
Change in LOC/confusion
UTI in elder w/indweliing catheter is usually
Poly-microbial
Microbes ascend urethra and infect
Bladder (Cystitis)
Kidneys (Pyelonephritis)
UTI may progress into
Septic shock
treatment for UTI
Antibiotics, hydration
Efficacy of cranberry products for UTI is
heavily debated
Benign prostatic hyperplasia (sometimes called hypertrophy) occurs when
prostate cell proliferation exceeds programmed cell death (apoptosis) as a result of stimulated cell growth, inhibition of apoptosis, or both
Most common benign tumor in men
Bengin prostatic hyperplasia
As prostatic enlargement occurs, mechanical obstruction results
Can progress to complete obstruction
Benign prostatic hyperplasia and prostate cancer are
Genetically distinct, one is NOT at risk for the other
Medications for BPH
Alpha adrenergic antagonists
DRE =
Digital rectal examination for swelling
DRE =
Digital rectal examination for swelling
PSA
Prostate specific antigen in blood
BPH
Benign prostatic hyperplasia
TUIP
Transurethral incision of the prostate
TURP
Transurethral resection of the prostate
Urine can change color due to different
Drugs or conditions
Etiology of functional incontinence
person’s physical ability to get to the toilet is underlying cause
- NOT related to urinary function
Causes/examples of functional incontinence
Sensory impairment Cognitive impairment Mobility issues Dexterity issues Environmental barriers Neglect
Population most affected by functional incontinence
Frail elderly
Nursing home residents
Persons with dementia
Neglect at any age
Etiology of overflow incontinence
Over-distended bladder r/t functional/mechanical obstruction of outflow
– may be secondary to poor muscle tone
Causes/examples of overflow incontinence
Enlarged prostatic, fecal impaction, DM neuropathy
ex) dribbling or constant loss
Population most affected for overflow incontinence
Men w/ large prostate
Those on C+ channel blockers, anticholinergics, adrenergic
Diabetics in advanced stages OR easier with HX poor BG control
Stress incontinence etiology
Weak EXTERNAL sphincter/pelvic floor overwhelmed by intra-abdominal pressure
Causes/examples of stress incontinence
Cough
sneeze
laugh
exercise
Stress incontinence: population most affected
women: During/post pregnancy
Obese persons
Men AFTER prostatectomy
Urgent/urgency incontinence etiology
Detrusor instability and weak INTERNAL sphincter
-Neurological issues, bladder inflammation (UTI)
Urge/urgency causes/examples
Strong NEED/URGE with involuntary contractions w/ passage of urine. Overactive Bladder (OAB)
Population most affected: urge/urgency incontinence
Often idiopathic.
UTI
Older persons (men somewhat more affected)
