Week 8: Renal and Genitourinary Disorders Flashcards
The Kidney Primary Function
-Remove waste products from blood
-Maintain water and electrolyte balance
-Maintain acid-base balance
The Kidney Primary Function
-Remove waste products from blood
-Maintain water and electrolyte balance
-Maintain acid-base balance
Inside the Kidney
Medulla
-Medullary pyramids
-Papillae
Minor Calyces
-Small collection tubules
Major Calyces
-Large collection tubules
Renal Pelvis
-Drains into ureter
Kidney- Blood & Nerve Supply
Aorta -> renal artery
-Delivers blood to nephron units at the capillary level (glomerulus)
Renal vein -> inferior vena cava
Renal nerves travel with the renal blood vessels to the kidney
Primary sympathetic nerves
-Control blood flow
-Regulates release of BP enzyme
The Nephron
-Functional unit of the kidney
-Each kidney = 1 million nephrons
-Filters blood and forms urine
-Each nephron has 2 parts
1.) tubular structure - renal tubules
2.) vascular structure - blood vessels
Nephron Unit- Tubular Structure
Four Tubules
1.)Bowman’s capsule
2.)Proximal convoluted tubule
3.)Distal convoluted tubule
*many nephrons connect to collecting duct
Nephron Unit- Vascular Structure
-Afferent arterioles from the aorta branch into a cluster of capillaries (glomerulus)
-Efferent arterioles leave the glomerulus to form a secondary capillary network
-Capillaries then form into venules leading to the renal vein and inferior vena cava
Urine Formation
-The basic function of nephrons is to cleanse or clear blood plasma of unnecessary substances
-After the glomerulus has filtered the blood, the tubules separate the portions of tubular fluid that are useful to the body from those that are
not
-The necessary portions are returned to the blood, and the unnecessary portions pass into urine as waste
Urine Formation 1.) Glomerular Filtration
Glomerulus: selective filtration of water & solutes from the blood
-Contains ~ 50 capillaries
-Hydrostatic pressure
-Blood (water & solutes) is filtered across the membrane into Bowman’s capsule
-Semi permeable membrane
-Large molecules are not filtered (RBCs, platelets, large plasma proteins)
-Unfiltered blood goes on to the peritubular capillaries
-Glomerular filtration rate (GFR) = 125ml/min
-Results in ~1 ml urine/min
Urine Formation- 2.) Tubular Reabsorption
Returns filtrate from the tubules to the blood of
peritubular capillaries
Proximal Tubule
~80% of the electrolytes are reabsorbed
Loop of Henle
-Important in conserving water
-Concentrates the filtrate
Distal Convoluted Tubule
-Final regulation of water balance
-Acid-base balance
Collecting Tubule
-Reabsorption of water if necessary
Urine Formation- 2.) Tubular Secretion
Secretes very small amounts of select substances from the peritubular capillaries into the tubules
Potassium
Hydrogen
Ammonia
Urine Formation
What is reabsorbed from the urine & returned to the blood?
-Water (most)
-Glucose & other nutrients
-Sodium & other salts
What is secreted from the blood into the urine & voided from the body?
-Hydrogen & potassium ions
-Some drugs
Aldosterone
-Acts on the distal tubule
“salt-retaining” hormone
Stimulates
-reabsorption of Na+ & H2O
-Expands blood volume & BP
-K+ excretion
-Deficiency: drop blood volume, drop BP, shock
Antidiuretic Hormone (ADH)
-Released by posterior pituitary in response to low blood volume or high Na+ concentration in blood
-H2O moves out of collecting duct into tissue spaces and then into peritubular capillaries
The Kidney- Secondary Functions
Blood Pressure
-Renin regulates BP and is released from the nephron
-In response to drop arterial BP, renal ischemia, ECF depletion, increased norepinephrine,
increased urinary Na+ concentration
Bone Density
-Vitamin D is activated in the kidneys
Erythropoiesis
- Erythropoietin stimulates the production of RBCs in the bone marrow in response to hypoxia & decreased renal blood flow
Ureters
-0-12” long
-Smooth muscle
-Peristalsis – one-way flow
-Renal pelvis to bladder
Bladder
-Sac-like hollow organ
-Reservoir for urine (300-400ml)
-Voluntary contraction of external sphincter can prevent urination until bladder filled to capacity
Urethra
-Tube allowing passage of urine from bladder neck to outside of the body (voiding, micturition, peeing)
-Shorter in women (UTIs)
Characteristics of Urine
Volume
-Average 1500 mL/24h
-Oliguria < 400 ml/24h
-Polyuria > 1500 ml/25h
Colour
-Amber or straw-colored
-Deep yellow in dehydration
-Pale yellow with overhydration
Age Related Considerations
-drop in size and weight of kidney from 30 to 90 years of age
-decreased blood flow to and within the kidneys
-Physiological changes to kidney, bladder, and urethra
-Decreased elasticity, weakening of GU system
-Decreased bladder capacity
-Increased incidence of UTI
-Prostatic enlargement
-Decreased estrogen = decreased elasticity of the female urethra & bladder
Assessment- Subjective Data
-Painful urination
-Changes in urine, colour (blood, cloudy)
-Changes in urination (diminished, excessive)
-Past health history- illness, hospitalization
-Cigarette smoking
-Medications: OTC/prescribed
-Surgery or other treatments
-Family history
Assessment- Objective Data
Inspect
Skin: pallor, yellow-grey cast, excoriations, changes in turgor, bruises, texture
Mouth: stomatitis, ammonia breath
Extremities: edema
Abdomen: distension, masses
General State of health: fatigue, lethargy, and diminished alertness
Palpate
Kidneys: not usually palpable
Abdomen: for bladders distension, masses, tenderness
Auscultate:
-over both CVAs and in the upper abdominal quadrants
-renal arteries for bruits (an abnormal murmur), which indicates impaired blood flow to the kidneys
Assessment- Signs & Symptoms
-Anorexia
-Blurred vision
-Chills
-Change in body weight
-Change in mentation
-Excess thirst
-Fatigue
-Headaches
-Hypertension
-Itching: advanced kidney disease
-N & V
Diagnostics
Urine- urinalysis, culture & sensitivity (C&S)
-Voided midstream clean-catch urine sample
Blood tests- blood urea nitrogen, creatinine
Radiological Procedures
-CT scan, MRI
-Ultrasound- bladder scan
-Cystography – voiding cystourethrogram
-Intravenous pyelography (IVP)
-Renal angiography
Renal biopsy
-Cystoscopy
Bladder Scan
-Noninvasive, portable ultrasound device that provides:
~a virtual 3D image of the bladder
~the volume of urine retained within the bladder
-Safe, painless, reliable
**Contraindicated if the patient has wounds in suprapubic area or is pregnant
Urinary Tract Infection (UTI)
-Inflammation of the urinary tract may be attributable to a variety of disorders, but bacterial infection is by far the most common, particularly among females
-The urinary tract above the urethra is normally sterile
-The organisms that usually cause UTIs are introduced via the ascending route
from the urethra
(E. coli is the most common pathogen leading to a UTI)
-An important source of UTIs is health care–acquired infection
-Urological instrumentation, particularly with an in-dwelling urinary catheter, is the most common predisposing factor
-CAUTI: catheter-associated UTI
UTI Signs and Symptoms
-Dysuria
-Frequency of urination (>q2h)
-Urgency
-Suprapubic discomfort or pressure
-Hematuria
-May contain sediment- cloudy appearance
-Flank pain
-Chills
-Fever: indicating pyelonephritis
UTI Diagnostics
Dipstick Urinalysis
-Provides chemical analysis of urine, along with a microscopic interpretation
Urine Culture & Sensitivity (C&S)
-To confirm suspected urinary tract infection & identify causative organisms
IVP
-The presence, position, size, and shape of the kidneys, the ureters, and the bladder can be evaluated
Abdominal CT
UTI Classification
Urethritis (lower tract)
Cystitis (lower tract)
Pyelonephritis (upper tract)
UTI Collaborative Care & Drugs
Antibiotics
-trimethoprim–sulfamethoxazole (TMP-SMX) (Bactrim)
-nitrofurantoin (Macrodantin)
-Increase fluid intake
-Avoidance of unnecessary catheterization
-Early removal of indwelling catheters
Urethritis- Presentation
Inflammation of the urethra, most commonly from a sexually transmitted bacterial or viral infection
-Dysuria & frequency
-Feeling the frequent or urgent need to urinate
-Difficulty starting urination
-Discharge from urethral opening
Tx: identify & treat the cause & provide symptomatic relief
Trichomonas & monilial infection: esp females
Chlamydia
Gonorrhea: esp males
Interstitial Cystitis (IC)
Interstitial cystitis (IC) is a chronic, painful inflammatory disease of the bladder
-The bladder wall becomes inflamed or irritated
-Can cause scarring, stiffening, and bleeding
IC should not be confused with common cystitis, a bacterial infection of the bladder
-IC is not caused by bacteria, nor does it respond to antibiotics
S & S: pain, frequency, urgency
Care: to alleviate symptoms
-Dietary and lifestyle changes (low acid diet)
-Some meds
Pyelonephritis
-Inflammation of the renal parenchyma & collecting system (incl. renal pelvis)
-Most common cause is bacterial infection that begins in the lower urinary tract
-Commonly starts in the renal medulla & spreads to cortex
-Usually a pre-existing factor resulting in
backward flow of urine from lower to upper
tract
Pyelonephritis Signs and Symptoms
-Mild fatigue, malaise
-Sudden onset of chills
-Fever
-Vomiting
-Flank pain
-Frequency
-Urgency
Pyelonephritis Care
-Antibiotics 14-21 days
-F/U urine culture
-Increase fluid intake (8 glasses/d)
Glomerulonephritis (Nephritis)
-Immune- related inflammation of the glomeruli characterized by:
* proteinuria, hematuria (smoky), oliguria & edema
-Fluid retention occurs as a result of decreased glomerular filtration
-Periorbital edema initially, then spreads
-Hypertension related to increased ECF volume
Adjust protein intake
Sodium & fluid restriction
Rest
Drugs
Diuretics
Antihypertensives
Polycystic Kidney Disease (PKD)
-One of the most common genetic diseases in Canada
-The cortex and the medulla are filled with thin-walled cysts
-The cysts enlarge and destroy surrounding tissue by compression
-Filled with fluid and may contain blood or pus
Polycystic Kidney Disease (PKD)
-Symptoms appear when the cysts begin to enlarge
-Common early symptom is abdominal or flank pain: steady or abrupt in onset as well as episodic and colicky
-This pain is often caused by bleeding into the cysts
-On physical examination, palpable bilateral enlarged kidneys are often found
-Other clinical manifestations include hematuria (from rupture of cysts), UTI, and hypertension
-Usually progress to end- stage renal failure
Tx: nothing specific
Goal: prevent or treat infections of the urinary tract
Urinary Incontinence
Uncontrolled loss of urine that is of sufficient magnitude to be a problem
-The prevalence is higher among older women and older men, but it is not a natural consequence of aging
Urinary Retention
Inability to empty the bladder despite micturition or the accumulation of urine in the bladder because of the inability to urinate
-obstruction leads to urinary retention when the blockage (i.e. enlarged prostate) prevents bladder evacuation
MEDICAL EMERGENCY
Urinary Catheters
-Tube inserted into bladder to drain urine
-Promoting comfort when unable to use other means (weakness, disabilities, dying)
-Specimen collection
-Measuring exact urine output
-Before, during, and after surgery
-LAST resort for incontinence
Catheter & Drainage
Closed system for indwelling catheters
Sterile environment
Tubing + drainage bag
Subrapubic Catheter
-Surgically inserted through abdomen into bladder
Indicators for use:
-Gynecological surgeries
-Long-term catheterization
-Urethral injury or obstruction
Different Types of Catheters
Simple: “in & out”
Indwelling: foley
Indwelling: 3 way (for bladder irrigation)
Continuous Bladder Irrigation (CBI)
-Indicated to maintain catheter patency and prevent blockages in patients with significant hematuria
-Fluid (0.9% saline) is continuously administered into the bladder via 3-way catheter and allowed to drain
Urinary Diversion
Surgically created route to allow urine passage after cystectomy
INCONTINENT:
-diversion to the skin, requiring an appliance
CONTINENT:
-intra-abdominal urinary reservoir that is catheterizable or has an outlet controlled by the anal sphincter
Contributing Factors
-Cystectomy for cancer treatment
-Cystectomy following injury
Incontinent Urinary Diversion
Ureterostomy
-Ureter(s) brought directly to abdominal surface
-One stoma for each ureter
-Simplest
Ileal Conduit
-Section of intestine links ureters to abdominal surface
-Construction of an artificial bladder
Continent Urinary Diversion
-Internal pouch created from the ileum, ileocecal segment, or colon
-Pt must self-catheterize q4-6h
-No need for external appliance
-Does not leak involuntarily
Acute Kidney Injury (AKI)
Previously known as acute renal failure
-sudden onset after severely decreased blood flow to the kidneys
-usually affects people with other life-threatening conditions
Can Be Caused By:
-Severe bleeding
-Heart attack
-CHF
-Burns
-Infections
-Severe allergic reactions
Acute Renal Failure- Phases
Phase 1:
-oliguria (urine output <400ml in 24h)
-lasts few days to 2 weeks
Phase 2:
-diuresis (output 1000-5000 ml in 24h)
Recovery increase kidney function improves and returns to normal:
-Can take 1 month - 1 year
-Some don’t recover: chronic renal failure
Acute Renal Failure- Presentation
-Decreased urine output
-Edema: legs, ankles, feet
-shortness of breath
-Confusion
-Nausea
-Flank pain
-Fatigue, weakness
Acute Renal Failure- Treatment
Dialysis
Treatment of underlying issue
Medications
Two Possible Outcomes
-Kidney function returns to normal without permanent damage
-Chronic renal disease develops
Dialysis
Technique in which substances move from the blood through a semipermeable membrane (dialyzer) and into a dialysis solution (dialysate)
-to correct fluid and electrolyte imbalances
-to remove waste products in renal failure
PERITONEAL DIALYSIS
HEMODIALYSIS
Principles of Dialysis
Diffusion
-movement of solutes from an area of greater concentration to an area of lesser concentration
Osmosis
-movement of fluid from an area of lesser to an area of greater concentration of solutes
Ultrafiltration
-water & fluid removal results when there is an osmotic gradient or pressure gradient across the membrane
Peritoneal Dialysis
Thin tube into the peritoneal cavity
-Peritoneal catheter
-Space between abdominal wall and bowel
Fills peritoneal cavity with solution
-Absorbs waste and excess fluids
-Wastes move from high to low concentration
Solution + waste drains from the body
Daily (minimum): 30-40 mins each time
Hemodialysis
Blood removed from body
-Access port in the arm
Filtered by machine (artificial kidney)
Returned to body
3 times/week: 4 h each time
