Renal colic Flashcards
What is renal colic?
Refers to acute severe loin pain that occurs secondary to a urinary stone.
What is another name for urinary stones?
urolithiasis
What is the peak incidence age for symptomatic urinary stones in men and women?
Between 40-60 years in males and late 20’s in females
Why do patients experience pain (renal colic) when they have a urinary stones?
Obstruction to urinary flow within the ureter due to the urinary stones. Also spasms that occur in ureter
What are the signs and symptoms of renal stones?
Symptoms
Loin-to-groin pain (sever, sudden onset pain not relived by pain medication- pain is constant but can vary in severity)
(this means pain can radiate from the flank to groin)
Nausea and vomiting
Haematuria
Dysuria (painful urination)
Urgency
Patient is restless to obtain relief from pain
Some are asymptomatic
Signs Flank tenderness Haematuria (typically microscopic) Fever chills, Rigors
List the different types of renal stones
Calcium Oxalate Calcium phosphate Urate Magnesium Ammonium Phosphate (Struvite) Cysteine
Others
- Xanthine
- Idinavir
- Matrix
Describe the properties of calcium oxalate stones and how they are formed
- Most common type of stone
- Calcium oxalate is insoluble.
- Not forming this type of stone depend upon
inhibitors (citrate, magnesium) Loss of these inhibitors can promote stone formation - Shows up on Xrays
Formation -
- Calcium phosphate crystals accumulate in the Interstitium
- This leads to the formation of Randall’s plaques (calcification) at the loop of Henle
- This creates a surface for renal stones to form
- Renal stones formed in the tubules get stuck at the ducts of Bellini (collecting duct) at the papillary surface (most distal part of the duct)
There are 2 types of calcium oxalate stones what are they?
Dihydrate which are softer (700HU)
Monohydrate which are extremely hard (1500 HU)
Describe the properties of calcium phosphate crystals
Associated with 3 conditions:
- Hyperparathyroidism
- Distal Renal Tubular Acidosis (Type1)
• Medullar Sponge Kidney
(MSK)
Also associated with urinary stasis & partly with infection
Show up reasonably well on x ray, and are usually quite hard (1200HU)
Describe the properties of urate crystals. Colour, shape, urinary conditions for production.
- Bright yellow stones formed from uric acid in the urine
- Needle shaped
- Formation is strongly associated with low PH and high uric acid concentration in the kidneys (idiopathic gout, increased cell turnover in myeloproliferative disease, dehydration)
- So (400HU) and, dissolvable
What are the different causes of uric acid stones?
Metabolic syndromes e.g diabetes
Gout
Dehydration due to malabsorption or chronic diarrhoea
Hyperuricaemia and, therefore, hyperuricosuria which can be caused by -
Myeloproliferative disorders such as leukaemia (increased cell turn over)
Chemotherapy (increased cell turn over)
Haemolytic anaemia (increased cell turn over
Describe the properties of Magnesium Ammonium Phosphate crystals (struvite)?
- Associated with infections
- Shows up slightly on X rays
- Usually relatively soft
(200-‐600HU) - Often has associations with calcium phosphate crystals
- usually associated with Staghorn Calculi (due to growing rapidly)
- Coffine lid appearance
Which microorganisms are associated with Magnesium Ammonium Phosphate crystals (struvite) and how?
Protease-producing microorganisms including Proteus and Klebsiella.
microorganisms are able to convert urea into ammonia which reacts with water increasing the pH of the urine. Increased ammonia and alkaline urine promote stone formation.
What are the properties of Cysteine crystals?
- Associated with Cysteinuria
– gene disease - Poorly visible on x-‐ray & are Hard (1400HU)
- Produce a white smoke and rotten egg smell when lasered (Hydrogen sulphide)
- Hexegan shape
How are Cysteine crystals treated?
medical dissolution
therapy
What is a key feature of the matrix urinary stones?
Proteinaceous material - a lot like chewing gum
What is a key feature of the Idinavir urinary stones?
Do not show up on CT
What is the free theory associated the stone formation?
The presence of stone constituents in the right amount, and without enough inhibitors, will form stones . Formation is effected by: - Concentration of solutes - Urine acidity - Presence of formation inhibitors
What is the fixed theory regarding renal stone formation?
The energy to form a crystal lattice is lower if there is a surface to form them on
Formation effected by:
- Surface to form lattice on
- Crystals (other crystals like urate can form a surface)
- Randall’s plaques (sub urothelial deposits which form a surface)
What are the main inhibitors in renal stone formation? (5)
Citrate (calcium citrate is soluble)
Magnesium (magnesium oxalate is soluble)
They prevent calcium oxalate crystals from forming
osteopontin
Nephrocalcin
Tamm Horsfall Protein (THP) (uromodulin)