OnlineMedEd: Nephrology - "Kidney Stones" Flashcards
Describe the presentation of kidney stones.
- Colicky flank pain that radiates to the groin
- Hematuria
- No fever
Review the workup for suspected kidney stone.
• Patient presents with colicky flank pain that radiates to the groin and doesn’t have fevers
- First, do a UA: if there is no microscopic hematuria, then they do not have a kidney stone (the contractions of the ureter will almost always lead to bleeding in the urine).
- Second, if they have microscopic hematuria then do a non-contrast CT of the abdomen (which is the best test).
Note: if the patient is pregnant, do an ultrasound instead of the NC CT.
Go through the management of kidney stones by size of stone.
- Less than 5 mm: IVF and pain medication
- 5 mm - 7 mm: medical expulsive therapy (CCBs, terazosin)
- 7 mm - 1.5 cm: lithotripsy for proximal stones, ureteroscopy for distal stones
- Greater than 1.5 cm: surgery (distal = percutaneous anterograde nephroscopy; proximal = laparoscopy)
For stones that are expelled, review the follow-up protocol.
- Modify risk factors: drink more water
- Strain urine to definitively identify the stone
- Have them come back in 6 weeks to screen urine for blood and stones.
Go through the following for calcium oxalate stones:
•Radiolucency:
•Risk factors:
•Preventive management:
- Radiolucency: opaque
- Risk factors: increased protein intake
- Preventive management: decrease oxalate (less protein, less spinach); increase citrate (more fruits and veggies), and thiazide diuretics
Go through the following for struvite (MAP) stones:
•Radiolucency:
•Risk factors:
•Preventive management:
- Radiolucency: opaque
- Risk factors: Proteus infection
- Preventive management: surgery and antibiotics
Go through the following for uric acid stones:
•Radiolucency:
•Risk factors:
•Preventive management:
- Radiolucency: lucent
- Risk factors: gout, tumor lysis syndrome
- Preventive management: allopurinol for gout or TLS; rasburicase for treatment
Go through the following for cystine stones:
•Radiolucency:
•Risk factors:
•Preventive management:
- Radiolucency: lucent
- Risk factors: cystinuria
- Preventive management: ???