Kidney Stones Flashcards
What is the real name for kidney stones
Nephrotic-urolithiasis
What is a colic
Acute severe loin pain most commonly caused by an obstruction usually kidney stone
Due to peristalsis trying to push stone through
When is urgent intervention needed
Infection Obstruction Impending AKI Previous transplant Abnormality
What do you do as urgent intervention
ABCDE
Sepsis 6
Percutaneous nephrostomy or ureteric stent
What are different stone types
Calcium oxalate = 75% Calcium oxalate + phosphate Calcium phosphate Triple phosphate (infective) Uric acid Cysteine
What is most common type of stone
Calcium oxalate
- Radio-opaque
What can phosphate cause
Renal tubular acidosis
What causes uric acid stones
Metabolic disorder Children Tissue breakdown Malignancy Low pH as breakdown purine Gout Ileostomy (loss bicarb)
Will you see uric acid / xanthine stones on Xray
No
Radio-lucent so let X-ray pass to appear black
What causes cysteine stones
AR disorder of cysteine
What causes stag horn calculi and what type of urine
Proteus infection
Magnesium ammonium phosphate stones - Sturvie
Alkali urine
Where do stones present
VUJ
PUJ
Pelvic brim
Narrowest areas
How do renal stones present
Renal pain - colic Ureteric colic - radiates to groin As peristalsis pushes stone down urethra Restless N+V Dysuria Haematuria Proteinuria Sterile pyuria UTI Oliguria FUNI Sx - Frequency and urgency = most common - Nocturia / incontinence = less common
What suggests secondary infection and urgent RX
Pyrexia
Loin tenderness
Pyuria
What must you exclude
RUPTURED AAA Pulsatile mass Pulses BP mismatch CT
What are RF for developing stones
Recurrent UTI Metabolic - hyper Ca, uric, PTH Urinary tract abnormality - PKD / horse shoe kidney Foreign body Dehydration High protein diet Renal tubular acidosis Drugs FH
What drugs
Loop diuretic
Steroid
Theophylline
How do you Dx renal stone
USS often used as quick initial test but may miss small
Non contrast CT KUB = 1st line
X-Ray KUB or IVU = less sensitive
When do you do non-contrast CT KUB
Immediate if fever or 1 kidney or if uncertain over AAA
Within 14 hours otherwise
What other investigations do you do
Bloods - for infection and renal function
Split renal function
Urine Dipstick - blood, exclude infection / UTI
bhCG in all women with abdominal pain
MSSU
Blood culture of other septic signs
What bloods
FBC - infection U+E - renal function CRP - infection Coag if intervention Calcium / albumin / urate / bicarb / glucose / PTH for underlying cause
If CT shows hydronephrosis what does this suggest
Stone is obstructing so urgent Rx needed
What is analgesia of choice
NSAID
IM diclofenac as severe pain
Beware of CVS risk
When do you admit
If require IV analgesia Deranged U+E Hydronephrosis Complications Signs of infection - hypo / fever / tachy / raised WCC Surgical Rx required
What are general measures with kidney stones
Analgesia
Anti-emetic
IV fluid
Ax if infection
Can send home with medical if small stone, no pain and no complications
Nifedipine - CCB
Tamsulosin (a-blocker)
What does nifedipine do
Start expulsion
What do you do if stone <5mm
Should pass with fluid with 24 hours
What do you prescribe as analgesia
Morphine
Diclofenac
Anti-emetic (Cyclisine)
What does Rx depend on
Size
Site
Co-morbid
Renal function
What is 1st line
ESWL
Day Rx and non-invasive
When is ESWL CI
>2cm High BP Anti-coagulant Pregnancy Infection AAA
When would you do PCNL - percutaneous through back
Large stone PUJ stenosis Stricture MOrbid obese UTI Coagulopathy Fibrosis Small kidney High BP Pregnancy Staghorn EWSL resistant
When would you do utereoscopy + laser
<2cm but ESWL CI i.e. pregnancy
When would you do nephrectomy
Non-functioning infected kidney
Large stones
URGENT
What are indications for surgery
Obstruction Impending AKI Recurrent haematuria Recurrent pain and infection Loss of kidney function Occupation
What are complications of PCNL
Pseudoaneurysm AV fistula Ureteric injury Bowel injury Pneumothorax Sepsis MI
How do you prevent formation of calcium stones
Thiazide diuretic > loop to decrease Ca
High fluid
How do you prevent oxalate stones
CHolestyamine
How do you prevent uric acid stones
Allopurinol
Oral bicarb
What is the DDX of renal stone
Triple A Pyelonephritis Obstruction Malignncy Bowel Trauma - ureteric rupture
What makes pyelonephritis more likely
Septic
Urinary signs
Malignancy
More chronic
Ureteric rupture
Iatrogenic e.g. pelvic fracture
How do ureteric stones present
Bladder irritability
Pain in scrotum / penis / labia
Mimic appendicitis / diverticulitis
How do you Dx
CT = 1st line
IVU
How do you treat
ESWL 1st line
Uretereoscopy
When is ureteroscopy indicated
Obstruction Pain Fever Persistent haematuria Failed ESWL
Complications of ureteric stone
Infection
Complications of ureteroscopy
Perforation Haematuria Minor VUJ reflux Fever Uretral necrosis / stricture
What causes bladder stones
Usually 2 to bladder outflow obstruction
What are the symptoms of bladder stones
Suprapubic / groin pain Dysuria Strangury Frequency Haematuria UTI Sudden interruption of stream
How do you treat bladder stone
Cystolithoplaxy (endoscopic excision)
Surgery if large
When can you not do op
Septic
What can bladder stone do
Break of and obstruct catheter
What are unilateral causes of hydronephrosis
PACT Pelvic/ ureteric obstruction Aberrant renal vessel Calculi Tumour
What are bilateral causes
SUPER Stenosis urethra Urethral valve Prostatic enlragement Extensive bladder tumour Retroperitoneal fibrosis
How is hydronephrosis picked up
USS
How do you further investigate
CT
How do you treat
Remove obstruction e.g. catheter
Nephrostomy if acute
Stent / pyeloplasty if chronic
What is important to assess if bilateral kidney stone
U+E
What does a balatobale mass in abdominal suggest
Hydronephrosis
What is 1st line to investigate
USS to look for obstruction
Then CT for underlying cause
Infection
EMERGENCY
Why not contrast
As makes stone invisible as same colour
What has replaced IVU for renal stone
CT KUB
What needs urgent Rx with percutaneous nephrostomy or stent
Obstruction - bilateral or uni if single kidney
Infection / urosepsis
Intractable pain or vomit
Impending AKI
