[2] Urinary Tract Stones Flashcards
What are urinary tract stones also known as?
Urolithiasis
What is urolithiasis?
When a solid piece of material occurs in the kidney tract
Where do urinary tract stones form?
Typically in the kidney
How to urinary tract stones typically leave the body?
In the urine stream
When can kidney stones pass in the urine stream without causing symptoms?
When it is small (under 5mm)
What may happen when a stone is bigger than 5mm?
It can cause blockage of the ureter resulting in severe pain and other symptoms
When are renal calculi formed?
When the urine is supersaturated with salt and minerals.
The other factor that leads to stone production is the formation of Randall’s plaque
What salt and minerals might the urine become supersaturated with?
- Calcium oxalate
- Struvite
- Uric acid
- Cysteine
What causes Randall’s plaques?
The precipitation of calcium oxalate in the basement membrane of the thin loops of Henle, which eventually accumulate in the subepithelial space on renal papillae
What does the formation of Randall’s plaques eventually lead to?
The formation of a calculus
What % of urinary tract stones are bladder stones?
Around 5%
What do bladder stones usually occur due to?
- Foreign bodies
- Obstruction
- Infection
What is the most common cause of bladder stones?
Urinary stasis due to failure of emptying the bladder completely on urination
Which gender do bladder stones occur most commonly in?
Men (95% of cases)
What are bladder stones in women usually associated with?
- Sutures
- Synthetic tapes or meshes
- Urinary stasis
What are the risk factors for urinary tract stones?
- Anatomical anomalities in kidneys and/or urinary tract
- Family history of stones
- Hypertension
- Gout
- Hyperparathyroidism
- Immobilisation
- Relative dehydration
- Metabolic disorders that cause an increased excretion of solute
- Deficiency of citrate in urine
- Cystinuria
- Drugs
What anatomical abnormalities in the kidneys and/or urinary tract increase the risk of urinary tract stones?
- Horseshoe kidney
- Urethral stricture
What metabolic disorders cause an increased excretion of solute?
- Chronic metabolic acidosis
- Hypercalciuria
- Hyperuricosuria
What drugs can increase the risk of urinary tract stones?
- Diuretics such as triamterene
- Calcium/vitamin D supplements
How are most urinary tract stones discovered?
During investigations for other conditions, as many are asymptomatic
What is the classic symptom of urinary colic?
Sudden severe pain
What causes the pain in urinary tract stones?
Stones in the kidney, renal pelvis, or ureter, which causes dilation, stretching, and spasm of the ureter
Other than pain, what symptoms may be present with urinary tract stones?
- Rigors and fever
- Dysuria
- Haematuria
- Urinary retention
- Nausea and vomiting
Where does the pain in renal colic start?
In the loin, at about the level of the costovertebral angle
Where does the pain in renal colic move too?
Moves to the groin, with tenderness of the loin or renal angle
When do urinary tract stones cause pain in the loin?
When the stone is high and distends the renal capsule
When do urinary stones cause pain in the flank?
As it moves anteriorly and down the urinary system
What is more painful, a stone that is moving or a stone that is static?
A stone that is moving
Where might renal colic pain radiate?
- Testis
- Scrotum
- Labia
- Anterior thigh
Describe the pattern of pain in renal colic?
It is fairly constant, but there are often periods of relief, or just a dull ache before it returns
How will a patient with renal colic appear from the end of the bed?
They will be writing around in agony, in contrast to a patient with peritoneal irritation who lies still
When will a renal colic patient be apyrexical?
When it is uncomplicated