Test 2 - Nephrolithiasis

Nephrolithiasis

Kidney stone disease

how many people in US have nephrolithiasis

1-2 million people

Who are stone disorders more common in

Men
20-55 years old
More frequent in whites and if there is a family history

Percent of people stones reoccur in

50%
More in summer due to dehydration

Struvite stones

magnesium ammonium phosphate

Which stone is more common in women

struvite stones
Associated with urinary tract infection

Etiology of nephrolithiasis

metabolic
dietary
genetic
climatic
lifestyles
occupations

Crystals and stone formation

When really concentrated, this can turn into a stone

Perks of keeping urine dilute and free flowing

reduces risks of recurring stones

Genetic factors that contribute to stones

Cystinuria

Cystinuria

autosomal recessive
Increase excretion of cystine

What affects stone formation

urinary pH
Solute load
Inhibitors in urine

High pH (alkaline)

The less soluble calcium and phosphate are

Lower pH (Acidic)

uric acid and cystine are less soluble

What happens when a substance is not soluble in fluid

it is more likely to precipitate out of solution

What can infected stones lead to

Staghorn configuration as it occupies more of the collecting system
Renal infection, hydronephrosis, loss of kidney function

Calculus

...

Lithiasis

formation of stone

Five categories of stones

calcium phosphate
calcium oxalate
uric acid
cystine
struvite

Most common stone

Calcium

Renal colic

sharp severe pain, which results from the stretching, dilation, and spasm of the ureter in response to obstructing stone

Pain is determined by what

location of stone if if it is obstructing

Obstruction at UPJ S/S

may experience dull costovertebral flank pain or renal colic
Pain resulting from passage of calculus down the ureter is intense and colicky
Patient with renal colic have a hard time being still
-Known as a kidney stone dance

What happens if stone is non-obstructing

pain may be absent

common sites of stone obstruction

1. UreteroPelvic Junction (UPJ)
2. UreteroVesicular Junction (UVJ)

Pain manifestations

sharp pain in flank area, back, or lower abdomen

S/S as stone nears UVJ

pain moves toward back of abdomen and down toward the lower quadrant
Men can have testicular pain
Women may have labial pain
Both men and women experience pain in the groin

Diagnostic studies for nephrolithiasis

Non-contrast helical (spiral) CT scan
Ultrasound
Urinalysis
Retrieval and removal of stones
Labs
Health history
Urine pH
24 hour urinary measurement

health history for nephrolithiasis

previous stone formations
Prescribed and OTC medications
Dietary supplements
family history

Why measure urine pH

diagnosis of struvite stones and renal tubular acidosis (tendency to alkaline or high pH) and uric acid (tendency to be acidic or low pH)

24 hour urinary measurement

used for patients who have recurring stone formation
Measure calcium, phosphorus, sodium, oxalate, citrate, sulfate, potassium, uric acid, and total volume

Labs that are measured

Calcium
Phosphorus
Sodium
Potassium
Bicarbonate
Uric acid
BUN
Creatinine

First approach of care

Managing attack, pain, infection and obstruction
Opioids given to relieve renal colic pain
Stones are 4mm and pass easily-Can take weeks
Tamsulosin (Flomax) or terazosinr

Tamsulosin (Flomax) or terazosin

A-adrenergic blocker that relaxes smooth muscle in ureter
Can help with passage of stone
Relaxes muscle with BPH

Second approach to treatment

Evaluation of cause of stone formation and prevention of future stones
History of genetics/family, geographic residence, nutritional assessment intake of vitamins A and D), activity pattern, history of prolonged dehydration and immobility, and history of

Therapy for active stones

adequate hydration, dietary sodium restriction, dietary changes, drugs used to minimize stone formation

Purpose of drugs in nephrolithiasis

Drugs can alter urine pH, prevent excessive urinary excretion of a substance, and correct primary disease (hyperparathyroidism)

Treatment of struvite stones

Control of infection
Antibiotics and acetohydroxamic

Why are antibiotics and acetohydroxamic used

treat kidney infections that result in continual formation of struvite stones

Acetohydroxamic acid use

inhibits chemical action caused by persistent bacteria and thus retards struvite stone formation

When would endourology, lithotripsy, or open surgical stone removal be used

Stone too large for spontaneous passage (usually 7mm)
Stones associated with bacteriuria or symptomatic infection
Stones causing impaired renal function
Stones causing persistent pain/nausea/paralytic ileus
Inability of patient to be treated medically
Pat

Endourologic Procedures

Cystoscopy
Cystolitholapaxy
Cystoscopic lithotripsy

Cystoscopy

if stone is in bladder
Removes small stones

Cystolitholapaxy

Used for larger stones
Broken up with lithotrite (stone crusher)
Bladder is washed out

Cystoscopic Lithotripsy

Uses ultrasonic lithotrite to break up stones

Complications of cystoscopic lithotripsy

Hemorrhage, retained stone fragments, and infection

Flexible uretoscopes

Used to remove stones from renal pelvis and upper urinary tract
Ultrasonic, laser, or electrohydraulic lithotripsy can be used in conjunction with the ureteroscope to pulverize the stone

Percutaneous nephrolithotomy

Nephroscope is inserted into the kidney pelvis through a track (using a sheath) in the skin
Track is created in the patient's back
Kidney stones can be fragmented using ultrasound, electrohydraulic, or laser lithotripsy
Stone fragments are removed, and pe

Complications of Percutaneous nephrolithotomy

bleeding, injury to surrounding structures, and infection

Lithotripsy procedures

Used to eliminate calculi from urinary tract
Lase lithotripsy
Extracorporeal shock wave lithotripsy (ESWL)
Percutaneous Ultrasonic lithotripsy
Electrohydraulic lithotripsy

What is left after lithotripsy

a stent is placed and kept for about 2 weeks to facilitate passage of sand and prevent buildup

What is common after lithotripsy

Hematuria

Complications of electrohydraulic lithotripsy

Rare but include hemorrhage, sepsis, and abscess formation
Postoperatively, usually there is severe colicky pain
First few urinations can be bright red
Antibiotics are given to reduce infection

Electrohydraulic lithotripsy

Probe placed directly onto stone but breaks stone into small fragments that are removed by suction or forceps
Continuous saline infusion flushes out stones
Calculi can also be removed by basket extraction

Percutaneous ultrasonic lithotripsy

Ultrasonic probe is placed in renal pelvis
inserted through a small incision in the flank and placed against the stone
General or spinal anesthesia
waves break up stone into sand like material

Laser lithotripsy steps

To access ureteral stones, a ureteroscope is used to get close to the stone
Small fiber is inserted up the endoscope so the tip (which emits laser energy) can come in contact with the stone
Holmium laser in direct contact with the stone is commonly used
N

Anesthesia for laser lithotripsy

general

Purpose of laser lithotripsy

Used to break up large and ureteral stones

Extracorporeal shock wave lithotripsy (ESWL)

Noninvasive
Fluoroscopy or ultrasound is used
Stone is broken into fine sand (steinstrasse) and excreted in the urine

Why is a fluoroscopy or ultrasound used with extracorporeal shock wave lithotripsy

to focus the lithotripter on affected kidney, and high voltage spark creates shock waves that break up the stone without damaging surrounding tissue

Anesthesia for extracorporeal shock wave lithotripsy

general or spinal
to ensure they stay in the same position

Indications of surgical therapy

pain, infection, obstruction

Type of open surgery depends on what

location of stone

Types of surgical therapy

Nephrolithotomy
Pyelolithotomy
Ureterolithotomy
Cystotomy

Nephrolithotomy

incision in kidney to remove stone

Pyelolithotomy

incision into renal pelvis for stone removal

Ureterolithotomy

incision into the ureter to remove a stone
Done if stone is in the ureter

Cystotomy

used for bladder calculi

Incision for open surgery

flank incision directly below the diaphragm and across the side is used

Complications of open surgery

hemorrhage

Benefits of hydration for people who

live in dry climate
active in sports
exercise
have family history of stone formation
work outside

What can increase risk of recurring urinary calculi

colas, coffee, and tea

Purpose of low sodium diet

increases calcium excretion in urine

How much fluid should you have after urolithiasis

high fluid intake
about 3L to have 2L of urine output

What can happen if you force fluids

can increase pain and precipitate development of renal colic