Renal colic

Question 1

What is it

Answer 1

SYMPTOM

usually caused by renal calculi (kidney stones)

Question 2

3 common sites where stones get stuck

Answer 2

Pelvi-ureteric junction
Pelvic brim
Vesico-ureteric junction

Question 3

Epidemiology of renal colic

Answer 3

men 3xs more common

Question 4

Describe the different compositions of renal colic

Answer 4

Calcium oxalate 75%, 
Struvite, 
Uric acid, 
Cystine
Caused by supersaturation of urine with salt/minerals

Question 5

Clinical presentation

Answer 5

Many stones are asymptomatic and discovered by chance
Sudden severe pain (unilateral)
Other symptoms: Rigors, Dysuria, Haematuria, Urinary retention, nausea and vomiting
Patient writhers around in agony
Normally pyrexial in uncomplicated renal colic

Question 6

Describe the sudden severe pain in presentation of renal colic

Answer 6

Unilateral
Pain starts in the loin and moves to the groin, sometimes with haematuria
Pain radiated down to the testis, labia
Pain of renal colic is quite constant but often periods of relief or dull ache before it returns

Question 7

Risk factors

Answer 7

Anatomical anomalies
FH
Hypertension
Gout
Hyperparathyroidism
Immobilisation
Dehydration

Question 8

Differentials

Answer 8

Ruptured AAA
Diverticulitis, appendicitis
Pyelonephritis
Acute pancreatitis
Testicular torsion
MSK

Question 9

How do most stones get picked up in hospital?

Answer 9

Incidentally on X-ray or CT

Question 10

How would you differentiate this from peritonitis

Answer 10

Movement makes it much worse in peritonitis

Question 11

Investigations

Answer 11

Bloods including calcium, phosphate and urate
Urinalysis, MSU if +ve
CT scan picks up 99% of stones
KUB (Kidney, ureter, bladder) Xray picks up between 60-70%

Question 12

Management of stones <5mm diameter

Answer 12

Pain relief e.g. diclofenac or opioids; abx if infection suspected
Stones <5mm diameter: 90%+ pass spontaneously
If obstruction + infection - ureteric stent may be needed
Prevention: drink plenty

Question 13

Management of stones >5mm diameter

Answer 13

Pain relief e.g. diclofenac or opioids; abx if infection suspected
Stones >5mm diameter: medical therapy (nifedipine or tamsulosin); Extracorporeal shockwave lithotripsy, percutaneous nephrolithotomy
If obstruction + infection - ureteric stent may be needed
Prevention: drink plenty

Question 14

What is Nifedipine

Answer 14

Calcium channel blocker

Question 15

What is ESWL

Answer 15

extracorporeal shockwave lithotripsy

uses sound waves to break up the stone

Question 16

What is PCNL

Answer 16

percutaneous nephrolithotomy
entering the kidney through a small incision in the back and using a miniature fiberoptic camera and other small instruments to remove the stone