Download Renal System

Renal System
Overview of renal System:
While bladder is contracted to urinate—ureters clamp off so there is no backflow of urine into
the ureters.
Urethra—Women short, 2-3” Men longer 8”
Urinary meatus—outside
Ureters, bladder and urethra, meatus—all innervated, can feel pain,
Right kidney is a little lower than the left because the liver places it down.
Kidneys are surrounded by a capsule. They will not feel pain unless the capsule is stretched.
Kidney pain is flank pain.
Kidneys need 20% of cardiac output in order to function—that is about 1200 ml of blood in a
minute.
Biggest cause of kidney failure—HTN, Diabetes, ETOH and drug abuse
Functional unit of kidney—nephrons—there are over 1 million nephrons in each kidney
Nephrons—glomelular filtration, Bowman’s capsule surrounds glomelular capillaries.
Less than 1% of the blood filtered is excreted.
Renal Pelvis—only holds 5 mL of urine.
ADH (Vasopressin)—causes reabsorption of water/fluids—concentrated.
Functions of Kidneys:
1. Fluid and electrolyte balance
2. acid and base balance
3. Excretion of wastes
4. BP regulation—renin—angiotension—aldosterone cycle
5. Formation of RBC—erythropoetin is a renal hormone that stimulates the formation of
RBC from the bone marrow.
6. Vit. D—prohormone is converted to an active form by the kidneys. Helps with calcium
reabsorption and use by the bones.
Assessing the kidneys:
1. Creatinine—0.7-1.3 norms
 the end product of muscle metabolism.
 Solely excreted by the kidney.
 Used as a gauge of kidney function.
 If kidney failure—decreases in fct—increase of creatinine in blood.
Can’t pull it across the glomerular filter to excrete.
2. BUN—blood urea nitrogen— Norm. 10-20.
 end product of protein metabolism.
 Solely excreted by the kidney.
 Elevated levels—fail or decreases kidney function. Cannot pull it out to
excrete.
3. IUP—intravenous pyelogram
 determines size, shape, and excretory function.
 A dye is injected through vein
 Caution—allergic to iodine or shellfish.
 Bowel must be prepped—empty the bowel so you can see the kidneys
4. Retrograde urography
 Cath the urinary tract
 Inject a dye into the ureters.
 Renal pelvis—ureters—bladder
 After test have pt push fluids.

Pg 1158—table of drugs that are nephrotoxic.
-mycin antibiotics esp. when given IV. Administer over an hour.
Pg 1163 tests
UTI
Most common pathogen—E coli
 Pyelonephritis—infection in the kidneys
 Cystitis—infection in the bladder
 Urethritis—infection in the urethra, more common in men usually from gonorrhea
Pathophysiology—UTI
 Most common route for UTI is organism comes from urethra or bladder, come from
below. Vagina or perineum—wipe front to back.
 Other routes—through the blood stream, or the lymphatic system sits in kidneys or
Uriniary tract. Very uncommon, usually down and moves up.
Risk factors for UTI—
 Aging—more underlying diseases. Everything slows down. Impaired immune response
 Females—short urethra, void after sex, wipe front to back
 Males—prostatic hypertrophy—enlargement of prostate—normal with aging, prevents
urine flow
 Urinary tract obstruction—stone. Scarring
 Sex—void after sex, honeymoon cystitis, now 8th grade cystitis?? :)
Signs and Symptoms
 Dysuria
 Frequency
 Urgency
 Hesitancy
 Suprapubic discomfort
 US—cloudy, foul odor
 Flank pain—kidney—there will be pyuria (pus in urine) Pyelonephritis—increased temp.
Diagnostics
 H and P
 UA—clean catch, or straight cath
 Urine culture and sensitivity
Treatment for cystitis
 Antibiotics—short therapy Bactrim—sulfa drug antiinfective.
TAKE ENTIRE COURSE OF MEDICATION TO PREVENT RESISTANCE
 Urinary analgesics—pyridium will turn urine orange. Dyrenium
 Force fluids—caffeine is irritant, suppresses ADH, take cranberry juice
 Wipe front to back
 Void after sex
 Avoid harsh soaps like bubble bath
 Void frequently
10/11/04
Neophrostomy tube—
Pyelostomy tube—diverts the urine from the ureter.
~ Renal pelvis only hold 5 mLs of urine.
~ Cannot irrigate with 30 mLs only 2-3
First sign or symptom of bladder or kidney cancer is gross hematuria.
Kidneys—maintain fluid and electrolyte balance, regulated BP, begins formation of RBC
(Erythropoetin) allows Ca to be absorbed from the gut, they maintain acid/base balance.
Oliuria—less than 400 mL of urine output.
Auria—less than 100 mL of urine output.
I. Acute renal failure:
Rapid decline in kidney function.—leads to azotemia
Azotemia (nitrogenous waste in the blood) BUN and creatinine. Not symptomatic.
Progresses to Uremia—(urine in the blood) person is symptomatic. Urine output of less than 400
mL in one day.
Causes:
1. Pre-renal
 hypovolemia
 ACE inhibitors
 Severe burns
 excessive diuresis
 MI—decreased CO
2. Intrarenal
 Nephrotoxins—gentomycin
 Transfusion rx.—Hemolysis of RBC
 Amphotericin B
3. Post-renal
 Prostatic Ca or hypertrophy
 leads to obstructions
 Stones
 Hydronephrosis—kidney keeps making urine even if it is blocked.
All of these things lead to ischemic changes in the kidneys.
Clinical Course:
1. oliguric phase—1-7 days after injury.
2. GFR—15 mL/min
3. leads to anuria
4. specific gravity test—ability to diulute or concentrate an Urine. Normals 1.003-1.030
Low is dilute, high is concentrated.
Signs and symptoms—
1. UA—output of less than 100 mL ?WBC in the urine?
2. Fluid volume excess—kidneys can’t get rid of urine—leads to overload.
~ increased BP, bounding pulse, Neck vein distention, edema, CHF
3. kidneys can’t synthesize ammonia—needed for Hydrogen ion excretion—results in
metabolic acidosis.
4. Sodium imbalance—decreased sodium level—confusion
5. potassium excess—hyperkalemia. (3.5-5.0 normals)
 BIG CAUTION is when you get to 6—prone to life-threatening arrythmias—the kidneys
can’t excrete K+. Will also have peaked T-waves, may have ST depression.
 Metabolic acidosis—causes K+ release from the cells.
 Tissue death from trauma causes release of K.
Treatment for hyperkalemia—greater than 6.
1. IV insulin—regular is only type that can be given IV.
 Moves K+ back into the cells
 Dextrose IV solution (D5)—to prevent hypoglycemia from the insulin.
2. Sodium Bicarbinate IV
 Moves K+ into cells
3. Kaexylate enema
 Exchange resin K+ for Na
 Should have stool after enema to get rid of K+.
4. increased BUN (norm 10-20) and creatinine levels (norms .07-.03)
5. Decreased Ca levels, because of decreased GI absorption—Vit. D def.
II. Diruretic phase—kidneys beginning to work again.
 Lasts 1-3 weeks
 Gradual increase in urinary output—1-3 L a day. Up to 5 L/day—can result in
hypovolemia.
 Decreased BP
 Decreased K+
 Recovery is evident when BUN and creatinine return to normal.
III. Diagnostics Pg 1214 table 45-3
 H and P—causative factor.
 UA—specific gravity and osmolatity—
 BUN and creatinine levels
 Electrolytes—K, Na,Mg
 IVP—
 MRI
 CT scan
IV. Collaborative Care
 Fluid restriction—add 600 mLs to yesterdays output—total fluid allowed for the day.
 Sodium restriction—so it doesn’t conserve more fluid
 Diuretics—lasix, bumix, (osmotic diuretics) Manitol.
 ACE inhibitors—prinivil
 Ca channel blockers—causes venous dilation—renoprotectant—cardizem
 Beta blockers—lopressor
 Dialysis—artificial kidney, peritoneal or hemo-dialysis.
 Monitor I and O, and weight.
Leading cause of death in acute renal failure—infection
 Use meticulous skin care and aseptic technique.
I. Chronic Renal failure
 Progressive irreversible destruction of nephrons in both kidneys.
 Scar tissue forms.
 Most common causes are HTN, and diabetes. (African American and American Indians
more prone to)
A. Signs and Symptoms:
1. Elevated BUN
 Nausea and vomiting
 Lethargy
 Coma
 Sezieres.
2. Elevated triglycerides
3. Increased K+
4. Metabolic Acidosis—dyspneic—Kussmaul’s respirations (deep resp)
5. Anemia—decreased erythropoetin
 yellowish, pale skin.
 uremic frost—skin is trying to excrete waste.
 Pruiritis—crawling, itching from down deep.
6. Platelets function is altered—bleeding tendencies.
7. Infection—WBC function is altered—diminished immune response.
8. Cardiovascular, increased BP, CHF, arrhythmias.
9. Stomatitis—mouth ulcerations, breath smells like urine. Infertility
 Anorexia
 N/V and diarrhea.
10. Infertility
Diagnotic studies—same as acute
 UA—for creatinine clearance. 24 hr urine collection. Starts and ends with an empty
bladder.
B. Medicines—a lot same as acute
1. increased BP—diuretics, ACE inhibitors, Ca channel blockers, Beta blockers.
Think about toxicity, not being excreted sufficiently.
2. Hyperkalemia—tx same as acute
3. Anemia—transfusions—overload and incompatibility don’t usually give. Usually
give Procrit—stimulates formation of RBC (Erythropoetin).
4. Diet must be done by a nutritionist, protein, Na etc. restriction. Very complicated.
5. Will always have fluid restriction even they have dialysis.
6.
III. Dialysis—Movement of fluid and particles across a semi-permeable membrane.
 Movement from blood or peritoneal membrane and into the dialysate (dialysis fluid).
Types of dialysis
a) peritoneal
b) Hemodialysis.
Principles of dialysis:
a) Osmosis—movement of water from greater to lower
b) Diffusion—movement of solutes from greater to lower.
c) Ultrafiltration—adding an artificial pressure gradient—artificial pull, done by
machine.
Peritoneal dialysis—pg 1229 and 1230 pictures.
 Dialysate pulls excess fluids, electrolytes and waste etc. out across the peritoneal
membrane by osmosis.
 Can maintain some independence—can do at home etc.
3 steps: qid
a) instill dialysate into the abdomen—2-3 liters.
b) Dwell time—30 min.
c) Drain--gravity
Hemodialysis—
 Vascular access device
Types:
a) arteriovenous shunt—fistula (abnormal opening between two things) pg 1233.
Leaves through the artery and comes back through a vein.
 Rate of flow is 200-500 mL/min. diasylate pulls waste from blood.
 Takes 4-6 hours to complete
 Must be done 3 times a week.
 Premedicate with heparin to prevent clotting.
b) Subclavian catheter—3 lumen
Complications from dialysis—
 Hypotension—0.9% NaCl
 Disequalibrium syndrome
 Blood loss
 Sepsis—infection throughout system
Kidney transplants
Types:
a) Cadaver—90% success rate
b) Live donor—95% success rate.
 Biggest complication is rejection: hyperacute—in OR, or long-term—1 yr later.
 The old kidneys are not removed unless there is severe uncontrolled HTN or severe
infections.
 Must be on anti-rejection drugs for life. Immuran
 Steroids—prednisone chronic antiinflammatory drugs
 Preventative ulcer meds--amphajel