Urology: renal colic and stones Flashcards
What is renal colic?
a presenting complaint associated with kidney stones.
Renal colic- unilateral loin to groin pain
Colicky- fluctuating in severity as the stone settles
What is the most common renal stone composition?
Calcium- calcium oxalate
What are struvite stones associated with?
Infection
What are the symptoms of renal stones?
Restless movement
Haematuria
Nausea and vomiting
Reduced urine output
Symptoms of sepsis if there is an infection
What non imaging investigations would you do for a patient presenting with renal colic?
Bedside:
* Urinalysis to detect blood and assist in stone identification for further follow-up. Urinalysis frequently reveals haematuria, although a negative result doesn’t exclude renal colic.
* Urine MC+S as there may be a co-existing infection/precipitant.
* Observations to look for any signs of sepsis which may indicate an infected obstruction, which is a urological emergency.
Blood tests:
- Full Blood Count to detect any inflammatory response hinting at an infected system.
- Urea and Electrolytes to assess any impairment in renal function.
- Calcium & Uric acid to identify underlying metabolic conditions predisposing to stone formation.
What is the gold standard imaging for kidney stones?
Non- contrast CT scan KUB
A 46 male patient comes in with intense pain in the left lower loin, he has not passed urine 8 hours, and has vomited 4 times, what are your differentials?
Ruptured AAA, appendicitis, kidney stone, AKI due to obstruction?
Define renal colic
Unilateral loin to groin pain that is excruciating.
If a pt has “colicky” pain due to renal stones, what does this mean?
Pain fluctuates in severity as the stone moves and settles.
Where do renal stones most commonly get stuck?
Vesico-ureteric junction
Name the most common type of renal stone?
Calcium oxalate.
What are risk factors for getting calcium oxalate renal stones?
Hypercalcaemia, low urine output
Name three types of renal stones?
Calcium oxalate, calcium phosphate, uric acid, struvite, cystine.
Where can renal stones be found in the urinary system?
Pelvi-ureteric junction, crossing the pelvic brim and vesicoureteric junction.
How do renal stones present?
Pt moving restlessly due to pain. Haematuria. N&V, reduced urine output, Sx of sepsis if infected.
Name 2 differentials for renal stones presentation
Ectopic pregnancy, pyelonephritis, ruptured AAA, biliary pathology, appendicitis.
Name a complication of renal stones
Obstruction —> lead to AKI. Infection can result with obstructive pyelonephritis.
What investigations would you do for suspected renal stones?
Urine dip - helps exclude infection, and may show haematuria. Blood tests - FBC, U+Es, calcium levels, eGFR. Abdo XR. Non contrast CT KUB. US if pregnant
What is the gold standard for suspected renal stones?
Non-contrast CT scan KUB within 24hours.!!
What initial management may be part of your plan after confirming a pt with renal stones?
1) Pt is dehydrated - may need fluid resuscitation. 2) Analgesia - IM or rectal diclofenac (or IV para if NSAIDs not tolerated). 3)Anti-emetic if nauseas/vomiting. 4) Abx if infection or septic signs. 5) Tamsulosin may help pass stone. 6) If stone is in lower ureter or <5mm, may pass.
What surgical management would you think about for renal stones?
Extracorporeal shock wave lithotripsy if smaller than 2mm.
Percutaneous nephrolithotomy.
Ureteroscopy and laser lithotripsy.
Stent insertion or nephrostomy.
What advice would you give a patient about recurrent renal stones?
They can happen! Need to: 1) increase oral intake - add fresh lemon, avoid carbonated drinks, reduce salt, maintain normal Ca2+ intake.
A patient has calcium oxalate stones. What would you tell them to avoid in their diet?
Oxalate rich foods - spinach, beetroot, nuts, rhubarb, black tea.
A pt has uric acid stones. What should they avoid in their diet?
Kidney, liver, anchovies, spinach, sardines.
Analgesia for renal colic as per guidelines?
IM diclofenac
RF for renal colic
Non-modifiable:
- Previous stone disease. The risk of developing a second stone is 30-40% over 5 years.
- Anatomical abnormalities of the collecting system
- Family history
- Underlying medical conditions. These include:
Hyperparathyroidism
Renal tubular acidosis
Myeloproliferative disorders
All chronic diarrhoeal conditions
Modifiable:
- Obesity
- Dehydration
- Diet
Blood test investigations for renal colic?
FBC - for inflammation and infection
CRP - inflammation
U+Es - impaired renal function which needs management
Calcium and uric acid - ID any underlying metabolic condition which is causing stone formation
Bedside investigations for renal colic?
Urinalysis - will likely show the presence of blood in the urine, and may help with stone identification and subsequent follow up in stone clinic.
Radiological investigations for renal colic?
Non-contrast helical CT KUB
XR - useful for planning management if CT confirms stone. XR is also needed for ESWL (extracorporeal shockwave lithotripsy)
Infection and organism most commonly linked to struvite calculi in renal colic?
Recurrent UTIs with Proteus spp.
