This patient is presenting with his first kidney stone. Following discharge from the hospital, the most important recommendation is to encourage hydration in order to reduce the risk of recurrence, and in-depth metabolic evaluation is not indicated after just one episode of nephrolithiasis.
General initial treatment for nephrolithiasis includes aggressive hydration, analgesia, and waiting for spontaneous passage of the stone. For larger stones or stones that fail to pass with conservative measures, lithotripsy and/or surgical removal may be necessary. Work-up should be conducted with imaging and urine analysis to determine the type of stone causing the obstruction, as management and future prevention measures often differ based on the type of stone present.
Frassetto and Kohlstadt discuss the treatment and prevention of kidney stones. The prevention of recurrent nephrolithiasis varies by the type of the initial stone. For calcium oxalate, cysteine, and uric acid stones, urine can be alkalinized to prevent stones by eating high amounts of fruits and vegetables, supplementing with citrate, or drinking alkaline mineral water. For calcium phosphate and struvite stones, urine can be acidified to prevent stones by consuming cranberry juice or betaine.
Fink et al. conducted a meta-analysis assessing medical management strategies to prevent recurrent nephrolithiasis. For patients with a single prior calcium stone, increased hydration reduced risk of recurrence. For patients with multiple (>1) prior stones, addition of citrate, thiazide diuretic, or allopurinol further reduced the recurrence risk.
Figure A displays a CT scan confirming the presence of a kidney stone in the right kidney. Illustration A summarizes a management strategy for patients after a resolved kidney stone. Illustration B discusses the imaging work-up of a suspected kidney stone. Illustration C displays a management algorithm for acute renal colic.
Answer 1: For a patient presenting with their first renal stone, only aggressive hydration should be recommended. An in-depth metabolic evaluation should only be pursued if there is another episode of nephrolithiasis.
Answer 3: Loop diuretics such as furosemide may increase the risk of future kidney stones by increasing the amount of calcium lost in urine.
Answer 4: Antibiotics can be helpful to treat an underlying infection that may be present with a struvite stone; the urine sediment analysis results above showing envelope-shaped crystals are more consistent with a calcium oxalate stone.
Answer 5: Ultrasound is not utilized to screen for kidney stones in asymptomatic individuals, regardless of their prior nephrolithiasis history.
Frassetto L, Kohlstadt I. Treatment and prevention of kidney stones: an update. Am Fam Physician. 2011 Dec 1;84(11):1234-42.
PMID:22150656 (Link to Abstract)
Fink HA, Wilt TJ, Eidman KE, Garimella PS, MacDonald R, Rutks IR, Brasure M, Kane RL, Ouellette J, Monga M. Medical management to prevent recurrent nephrolithiasis in adults: a systematic review for an American College of Physicians Clinical Guideline. Ann Intern Med. 2013 Apr 2;158(7):535-43. doi: 10.7326/0003-4819-158-7-201304020-00005.
PMID:23546565 (Link to Abstract)