Download AH Renal I

The Urinary System
Primary Functions
• In addition:
1. Regulates
– Control BP
volume &
– Erythropoietin
composition of
– Activates Vitamin D
extracellular
– Regulates acid-base
fluid (ECF)
balance
2. Excrete waste
Brief A&P Review
• Macro:
– Cortex
– Medulla
– Renal Pelvis
Brief A&P Review
• Micro
– Nephron (Cortex)
• Glomerulus
• Bowman’s Capsule
• Proximal & Distal
Tubule
– Nephron (Medulla)
• Loop of Henle
• Collecting Tubules
Blood Supply
• 2 Renal arteries off main aorta
• 1200ml/min flows through kidneys
~25% of cardiac output
Urine Formation
• Filtration
• Reabsorption
– Tubules to capillaries
• Secretion
– Capillaries to tubules
• Excretion
• Glomerular Function
– Selective Filtration
– Semipermeable
membrane
– Hydrostatic pressure of
the blood within the
glomerular capillaries
• GFR
– Normal 125ml/min.
– Only 1ml/min excreted
due to reabsorption
Ultrafiltrate
• What passes through the glomerulus:
– Is similar in composition to blood
– But it lacks cells, platelets, and large plasma
proteins
– Normally: capillary pores are too small to allow
the loss of these large blood components
– Many renal diseases: capillary permeability is
increased
• permitting plasma proteins and blood cells to pass into
the urine
Tubular Function
• Proximal tubule
– Reabsorbs 80% of
electrolytes & H2O
– Reabsorbs all the glucose
and amino acids, HCO3
– Secretion of H+ and Cr
• Collecting Duct
– Reabsorption of H2O
• ADH required
• Loop Of Henle
– Reabsorption of Na+ and
Cl- in ascending
– Reabsorption of H20 in
descending
• Distal tubule
– Secretion of K+, H+,
Ammonia,
– Reabsorption of H2O, (by
ADH), HCO3,
– Regulation of Ca++, PO4
(by PTH)
– Regulation of Na+, K+ (by
Aldosterone)
ADH (Antidiuretic Hormone)
• Makes distal tubules & collecting ducts
permeable to H2O (reabsorption)
• Without ADH (impermeable)
• Any H2O left in the tubule will be excreted
Aldosterone (from adrenal cortex)
• Reabsorption of Na+ and H2O
• In exchange for Na+, K+ ions are excreted
• Secretion of Aldosterone is influenced by:
– circulating blood volume
– plasma concentrations of Na+ and K+
Acid-Base Regulation
• Reabsorption of most of the HCO3
• Secreting excess H+
• pH 7.35-7.45
ANP (Atrial natriuretic peptide)
• Hormone from Right Atrium
– Response from atrial distention
• Increases Na+ excretion
• Inhibits renin, ADH, Angiotensin II
– Thereby suppresses Aldosterone secretion
• Results in large volume of dilute urine
• Increases GFR
Ca++ Balance
• PTH secreted in response to low serum Ca++
• Increases reabsorption of Ca++ ions
• Decreases reabsorption of PO4
Erythropoeitin
• Produced in response to hypoxia and
decreased renal flow
• Stimulates bone marrow to produce more
RBCs
• Deficiency occurs in renal failure
Vitamin D
•
Hormone obtained:
1. either in diet
2. or synthesized by ultraviolet radiation on
cholesterol in the skin
•
These forms of Vitamin D are inactive
–
To become metabolically active: must be
activated by the liver and the kidneys
Renin
• Regulates BP
• Secreted by juxtaglomerular cells of kidney
• In response to:
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Decreased renal perfusion
Decreased arterial blood pressure
Decreased ECF
Decreased Na+ ion concentration
Increased urinary Na+ concentration
Renin…how it works
• Catalyzes the splitting of the plasma protein
angiotensinogen (from the liver)
• Converts it to Angiotensin I
• Which is converted to Angiotensin II by ACE
(Angiotensin-converting enzyme)
• ACE is located in all blood vessels (and more
concentrated in vessels in lungs)
• Renin is inhibited when BP is up, plasma Na+ is
up
Diagnostic Studies
• UA (0-trace protein)
• Creatinine Clearance (24hr)
– Approximates the GFR (Normal 85-135)
• Serum BUN (10-30mg/dl)
– Some non-renal factors for elevation: GI bleed,
trauma, fever, infections, steroids, etc.
• Serum Creatinine (0.5-1.5mg/dl
– Best indicator of renal function
– Higher in men (normal)
Diagnostic Studies, cont…
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Serum K+ (3.5-5.0 mEq/l)
Serum Ca++ (9-11 mg/dl)
Serum Phosphorus (2.8-4.5 mg/dl)
Bicarbonate (HCO3 22-26 mEq/L)
Potentially Nephrotoxic Agents
• Gent, Tobra, Ibuprofen, Contrast medium…
The rest is just plumbing…
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Ureters
Bladder
Urethra
Meatus
℞ for Break?
Problems of Urinary Function
Predisposing Factors For UTI’s
• Urinary Stasis
– Stones, urethral strictures, BPH, tumors, neurogenic
bladder, renal impairment
• Foreign Bodies
– Calculi, catheters, ureteral stents, nephrostomy tubes,
cystoscopy
• Anatomic Factors
– Congenital defects (eg shorter urethras, meatus in
vagina), fistula formation, obesity
Predisposing Factors, con’t…
• Factors compromising immune response
– Aging, HIV, DM, etc.
• Functional Disorders
– Constipation, voiding dysfunction
• Pregnancy, low estrogen, multiple sex
partners, spermicidal agents, diaphragm,
poor hygiene
Urinary Tract Infection
Diagnostic Studies
• Urine for c and s
– Clean-catch sample preferred
– Specimen by catheterization or suprapubic needle
aspiration more accurate
• Imaging studies
– IVP or abdominal CT when obstruction suspected
Causative Microorganisms
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E. coli (80%)*
Enterococcus
Klebsiella
Enterobacter
Proteus
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Pseudomonas*
Staphylococcus
Serratia
Candida
* Nosocomial (31%
of all NI are UTIs)
Collaborative Care
Drug Therapy
• Antibiotics
– Selected on empiric therapy or results of
sensitivity testing
– Uncomplicated cystitis
• Short-term course (1 to 3 days)
– Complicated UTIs
• Requires longer-term treatment (7 to 14 days)
Acute Pyelonephritis
Inflammation
of the renal
parenchyma
& collecting
system
Symptoms?
• Sudden onset of chills, fever, vomiting,
malaise, flank pain, dysuria, urgency,
frequency…can lead to urosepsis (15% die)
• Can subside within a few days, even if
untreated, but bacteriuria and bacteremia
persist
Management
• AB treatment
• Fluids (8-10 glasses of water/day)
• Rest
• Pain control
• Prevention Education
Chronic Pyelonephritis
• Characterized by small, atrophic, shrunken
kidney r/t scarring or fibrosis
• Decreased renal function
• Leads to ESRD when both kidneys are
involved (even if underlying infection is
resolved)
Urethritis
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Trichomonas
Monilial infection
Chlamydia
Trichomonas
Gonorrhea
Bubble baths
Poor hygiene
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Flagyl
Clotrimazole
Diflucan
Doxycycline
Mycostatin
• Refrain from sex
Interstitial Cystitis
• Chronic painful inflammatory disease of the bladder
• Characterized by urgency/frequency/pain
– PBS (Painful Bladder Syndrome) (700,000 Americans)
• Suprapubic pain in absence of UTI or other path.
• Unknown etiology
• Treatment: pain control, dietary/lifestyle changes to
diminish voiding problems
– Low acidic foods, no coffee, tea, carbonation, ETOH
– Stress Reduction, antidepressants
– May distill DMSO, Lidocaine into bladder
DMSO (Dimethyl Sulfoxide)
• DRUG INFORMATIONDMSO is a widely used treatment
for interstitial cystitis (IC). It has both anti-inflammatory
and analgesic properties. It is believed to inhibit freeradical production, thus reducing pain and inflammation.
• It also aids in the absorption of other bladder-instilled
medication. Its liquid form, Rimso-50, was approved by
the FDA for use in treating IC in 1978. Oral and topical
forms of DMSO have not been formally studied in the
treatment of IC and should therefore be used with
caution. INSTILLATIONSA 50% solution of DMSO is
instilled intravesically, meaning that the drug is placed, via
catheter, directly into the bladder. It is then held in the
bladder for 10-20 minutes. This procedure is typically
performed in a physician’s office.
Renal TB
• Usually 2ndary to Pulmonary TB
• Asymptomatic (5-8yrs)
• Then, low-grade fever, lesions ulcerate,
infection spreads
Glomerulonephritis
• 3rd leading cause of renal failure
– Affects BOTH kidneys equally
– Can spread to tubules, interstitial, vascular areas
• Divided into classifications:
– Diffuse or focal
– Initial causes: systemic lupus, systemic sclerosis or
scleroderma, streptococcal infection, hepatitis,
Goodpasture Syndrome, etc.
– Extent of changes: minimal or widespread
Glomerulonephritis, Symptoms
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Hypertension/Edema?
RBC’s, WBC’s, casts, and protein in urine
Elevated serum BUN, Creatinine
1. Expect a full recovery in MOST acute
cases (not with Goodpastures)
2. If progressive involvement…destruction
of renal tissue and thus renal insufficiency
Glomerulonephritis, Treatment
• Prompt diagnosis
• Correction of fluid overload, hypertension,
uremia, inflammatory injury
• Viral (fluids)
• Bacterial (AB)
• Autoimmune (corticosteroids, cytotoxic
agents, plasmapheresis)
Chronic Glomerulonephritis
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Acute
Rapidly Progressive
Chronic
Mostly leads to ESRD
Often found “by coincidence”
Pt will have no recollection of nephritis hx
• Diagnostics: Ultrasound, CT, Renal biopsy
• Treatment: Supportive and Symptomatic
Nephrotic Syndrome
• Characterized by the glomerulus being
excessively permeable to plasma protein
• Thus tissue edema, ascites, anasarca
(massive generalized edema)
• Hypertension
• Hyperlipidemia
• Hypoalbuminemia
• Hypercoagulability (thrombus usually
forms in renal vein)
Nursing Management
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Daily weights
I&O
Meticulous skin care
Maintain a low to moderate protein diet
Small frequent meals (pt often anorexic)
Emotional support
HIV and ESRD
• 10% of HIV—highest among IV drug users
Common Causes of Obstruction
Obstruction complications
• Hydroureter (reflux)
• Hydronephrosis
pyelo, atrophy
• Nephrolithiasis (calculi)
• The higher the pH—the less soluble are Ca++ PO3
• The lower the pH—the less soluble are uric acid &
cystine
Nutritional Therapy (Calculi)
• Purine (Uric acid is a waste product of this)
– Sardines, herring, mussels, liver, kidney, goose,
venison, meat soups, sweetbreads
• Calcium (Phosphate)
– Dairy, all beans (except green beans), lentils, fish with
fine bones (sardines, kippers, herring, salmon), dried
fruits & nuts, chocolate
• Oxalate (Calcium)
– Dark roughage, spinach, rhubarb, asparagus, cabbage,
tomatoes, beets, nuts, celery, parsley, chocolate, coffee,
tea, Worcestershire sauce
Renal Calculi
•
Diagnostics: U/A, C&S, IVP, Retrograde
pyelogram, Ultrasound, Cystoscopy
• Manage pain, treat infection, pass
spontaneously (if < 4 mm), high fld intake
(output at least 2 L/day)
1. Evaluation of cause, further prevention
2. Endo, Lithotripsy, Surgery = too large,
unable to contain infection, impaired renal
function, pain control, ineffective medical
approach, pt with only 1 kidney
Renal Vascular Problems
• Renal Trauma (Symptomology)
• Nephrosclerosis (BP control)
• Renal Artery Stenosis (BP control, perfusion control, revascularization)
• Renal Vein Thrombosis (anticoags, steroids, thrombectomy)
Polycystic Kidney Disease
• The most common
life-threatening
genetic disease in the
world
• 2 types (Childhood
and Adult)
• Adult type—50%
chance of child
having it.
PKD
Metabolic & Connective Tissue Diseases
• Diabetic Nephropathy
– Primary cause of ESRD
– Microangiopathic changes, diffuse glomerulosclerosis
• Gout
– Hyperuricemia (deposits of uric acid crystals)
• Amyloidosis
– Infiltration of tissues with a hyaline substance (amyloid)
• Systemic Lupus Erythematosus
– Connective tissue disorder (similar to glomerulonephritis)
• Systemic Sclerosis (Scleroderma)
– Vascular lesions
Cancer
• Kidney Adenocarcinoma (Renal cell) most common type
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Will need nephrectomy, chemo
Risk factors: smoking, genetics, obesity,
hypertension, asbestos, cadmium, gasoline, polycystic
disease
• Bladder Transitional and Squamous cell (rad + chemo)
1.
2.
3.
4.
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Transurethral Resection (with cauterization)
Laser photocoagulation
Open loop resection (snaring of polyp types of
lesions)
Partial or Radical Cystectomy (if invasive)
Risk factors: Smoking, dyes, rubber industry,
phenacetin-containing analgesics (1st NSAID)
Urinary Incontinence and Retention
• Types:
– Stress
– Urge
– Overflow
– Reflex
– Trauma
– Functional
Catheters
• Urethral
• Ureteral (Cystoscopic or surgical placement)
• Suprapubic
• Nephrostomy Tubes
Urinary Diversion Devices