344.4 ð ç« æ«éèš Summary
344.4.1 ð äžå¥è©±çžœçµ
Nephrolithiasis å šççè¡çäžå (~ 12% ç·, ~ 6% 女 lifetime), å°ç£é«çŒïŒäºå€§ stone typesïŒ(1) calcium oxalate ~ 70-80% (most) + calcium phosphate 5-10%ïŒ(2) uric acid 5-10% â é žæ§ urine + gout + hyperuricosuriaïŒ(3) struvite 5-10% â magnesium ammonium phosphate + urease-producing bacteria (Proteus, Klebsiella, Pseudomonas, S. aureus) + é¹Œæ§ urine + staghorn calculiïŒ(4) cystine 1% â autosomal recessive cystinuria (SLC3A1/SLC7A9)ïŒ(5) drug-induced (acyclovir, indinavir, sulfonamide, triamterene, topiramate)ïŒacute presentation = renal colic (severe flank pain â groin radiation, hematuria, nausea)ïŒdiagnosis = non-contrast CT gold standard (> 95% sensitive); US for pregnancy/pediatric/follow-upïŒstone passage by size: < 5 mm 80% / 5-10 mm 50% / > 10 mm < 25%ïŒacute management: NSAIDs (ketorolac) first-line + opioids backup + hydration + anti-emetics + MET (tamsulosin α-blocker for 5-10 mm ureteral â SUSPEND 2015 mixed evidence)ïŒurgent intervention indications: obstruction + infection (urosepsis emergency!) + AKI + solitary functional kidney + severe pain; procedures: ureteroscopy + laser lithotripsy (most < 2 cm) + ESWL (small upper urinary) + PCNL (> 2 cm, staghorn) + ureteral stent (bridging)ïŒprevention strategies by stone typeïŒcalcium oxalate (thiazide for hypercalciuria + K citrate for hypocitraturia + calcium with meals for hyperoxaluria), uric acid (alkalinize urine pH 6.5-7.0 + allopurinol), struvite (antibiotics + surgical removal), cystine (hydration > 4 L/d + alkalinize pH > 7.5 + tiopronin/penicillamine); emerging: lumasiran (Oxlumo, FDA 2020) + nedosiran for primary hyperoxaluria (siRNA AGXT)ã
344.4.2 ð æ²»ç粟èŠ
- acute painïŒketorolac IV/IM/PO first-line + opioid backup + hydration + anti-emetics
- MET (medical expulsive therapy)ïŒtamsulosin 0.4 mg daily for 5-10 mm distal ureteral stones (SUSPEND 2015 negative overall, some benefit subgroups)
- urgent interventionïŒurosepsis + AKI + solitary kidney + severe persistent pain + pregnancy complications
- calcium oxalate preventionïŒthiazide (hypercalciuria) + potassium citrate (hypocitraturia + alkalinize) + calcium with meals (hyperoxaluria) + maintain adequate dietary calcium (donât restrict!)
- uric acid preventionïŒalkalinize urine (potassium citrate to pH 6.5-7.0) + allopurinol + low purine + hydration
- struvite preventionïŒlong-term antibiotics targeting urease bacteria + surgical removal (PCNL for staghorn) + treat underlying chronic infection
- cystine preventionïŒheavy hydration > 4 L/d + alkalinize (potassium citrate pH > 7.5) + tiopronin (preferred) or penicillamine + low Na + low protein
- primary hyperoxaluria type 1ïŒlumasiran (Oxlumo, FDA 2020) siRNA against AGXT
- diet generalïŒhydration > 2.5 L urine + low Na + moderate protein + adequate dietary Ca (binds oxalate in gut, paradoxically reduces stones) + low oxalate + citrus juices
344.4.3 ð¯ ç§é«åž«çèåæé
- stone composition äºå€§ïŒcalcium oxalate (most ~ 70-80%) + calcium phosphate (alkaline urine, RTA-1) + uric acid (acid urine) + struvite (urease bacteria, staghorn) + cystine (autosomal recessive)
- non-contrast CT gold standard > 95% sensitive for all stone types; HU helps composition: < 600 (uric acid), 600-1000 (cystine), 1000-1500 (struvite, Ca phosphate), > 1500 (calcium oxalate densest)
- stone passage by size: < 5 mm 80%, 5-10 mm 50%, > 10 mm < 25% â guides decision for spontaneous vs intervention
- SUSPEND trial (2015): tamsulosin vs placebo for ureteral stones â no overall benefit; some benefit in distal 5-10 mm; still commonly tried
- urosepsis with obstruction = emergencyïŒobstruction + infection (positive UA + signs of sepsis) â emergent decompression (stent or nephrostomy) + antibiotics (donât delay)
- calcium oxalate prevention paradoxïŒmaintain adequate dietary calcium (DO NOT restrict) â calcium binds oxalate in gut, reduces oxalate absorption + stone formation
- struvite stones = âinfection stonesâïŒurease-producing bacteria (Proteus mirabilis, Klebsiella, Pseudomonas, S. aureus) â alkaline urine + Mg + NH4 + PO4 crystals; staghorn calculi (filling renal pelvis); need PCNL + long-term antibiotics
- uric acid stonesïŒacid urine (pH < 5.5) + gout + high purine + TLS + DKD; alkalinize urine with potassium citrate to pH 6.5-7.0 + allopurinol â stones can dissolve!
- cystinuriaïŒautosomal recessive (SLC3A1, SLC7A9) + faint sweet odor of cysteine + recurrent + young onsetïŒtreatment heavy hydration > 4 L/d + alkalinize > 7.5 + tiopronin (better tolerated than penicillamine)
- lumasiran (Oxlumo, FDA 2020) for primary hyperoxaluria type 1ïŒsiRNA against AGXT (alanine glyoxylate aminotransferase) â reduces urinary oxalate; preventing ESKD; nedosiran emerging