Stones Flashcards
Key history features in acute renal colic
sudden, severe flank pain radiating to the groin/scrotum (loin to groin pain)
in a low stone can be pain at the end of penis or testicles
constant or colicky pain
spasmodic/intermittent in nature
nausea and vomitting sometimes
previous Hx of stones
sometimes mild pyrexia
Common differentials with flank pain
Ruptured AAA Pancreatitis Biliary Colic Appendicitis Gynae path (ectopics, ovarian cyst, testicular/ovarian torsion, etc)
What are the features of sepsis in a patient with suspected/confirmed renal colic and why is it significant?
Signs of sepsis (eg. Very high WBC) + fever can indicate an obstructed kidney = Urological emergency!!!
Results in irreversible loss of renal function, multiorgan failure, death.
Management:
- sepsis 6
- emergency decompression/ drainage via percutaneous nephrostomy or cystoscopy and retrograde JJ ureteric stent
Key investigations in suspected renal colic
Urine dip (haematuria in 85%)
FBC, U&Es, Calcium and urate, LFT, Amylase to exclude diff
CTKUB is gold standard (non-contrast)
- high sensitivity and specificity
- Can be done regardless of renal function unlike CT urogram (post-contrast CT used to look for malignancy)
Follow up CTKUB with XRay as need to visualise stone before ESWL
Ultrasound scans often used in cases of known stones to assess for hydronephrosis
- no radiation risk
what are the appropriate analgesia for pain relief in renal colic?
NSAID = pr diclofenac or paracetamol
Opiates as required = morphine, oral or IM/IV
however opiates tend to worsen spasmodic colicky pain
What is a JJ stent?
a thin tube inserted into the ureter with the aid of a cystoscope, to clear obstruction or aid flow. the ends are coiled to prevent it moving out of place.
What is a nephrostomy?
An opening between the kidney and skin.
A nephrostomy tube is passed from the back through the skin directly into the renal pelvis and collecting system, relieving obstruction proximally.
What are the definitive treatment options for a ureteric stone?
Conservative
- allow stone to pass (<5mm)
- give analgesia and advice
- follow up in 28 days with plain KUB xray
Extracorporeal Shock Wave Lithotripsy (ESWL)
- <2cm stone
- Xray or US guidance
- stone must be radio-opaque to target it
Rigid ureteroscopy and Laser Lithotripsy
What are the treatment options for a stone in the kidney? (non-obstructive)
ESWL
Flexible ureteroscopy and laser lithotripsy
Percutaneous nephrolithotomy for Larger stones eg. staghorn calculi
Open or laparoscopic surgery is rarely required.
(nephrectomy only after renogram shows you one kidney function is less than 20%)
What are the common types of urinary stones and who forms them? and which ones are seen on plain radiographs?
Calcium oxalate (most common)
Calcium phosphate (seen in hyperparathyroidism)
Urate (seen on CT, radiolucent on plain films)
(seen in obesity, T2DM, acidic urine)
Triple phsophate stones (form staghorn calculi, associated with urea splitting oragnisms like proteus)
Cystine stones (seen in cystinuria patients)
Indinavir stones (invisible on CT) (seen in HIV treatment)
Who is predisposed to forming urinary stones?
- dehydrated (oversaturation of urine)
- High BMI
- people with low flow urine eg. pregnant people
- sedentary occupations
- hyperparathyroidism
- meat eaters
- younger to middle aged
What is some general preventative advice given to patients who form stones?
advice 2-3 litres of water a day (keep urine pale)
avoid excessive salt or red meat
citrate is beneficial (lemon juice in water, apple juice)
maintain normal calcium intake
What is ESWL
for 5mm-2cm stones
Shockwaves targeted at stone causing it to fragment and be passed.
3 sessions for kidney stones, 2 sessions for stones in ureter.
Paracetamol or tramadol to tolerate it
Where can stones generally occur?
Pelvoureteric junction
Vesicoureteric junction
mid ureter coming over pelvic brim
renal stones
When is ESWL contraindicated
High skin to kidney ratio
Pregnancy
Patients on blood thinner
AAA
Uncorrected infection
