What is the initial treatment for a patient presenting with kidney stones?

Initial Treatment for Kidney Stones

For acute kidney stone presentation, immediately administer intramuscular diclofenac 75 mg as first-line analgesia, which should provide pain relief within 30 minutes, while simultaneously assessing for life-threatening conditions requiring hospital admission. 1

Immediate Pain Management

NSAIDs are superior to opioids for acute kidney stone pain because they directly decrease ureteral smooth muscle tone and spasm, have fewer side effects, and carry no dependence risk. 1

• Administer diclofenac 75 mg intramuscularly as the preferred agent for acute renal colic, with pain relief expected within 30 minutes. 1
• Intramuscular injection is the only reliable route in acute settings; oral and rectal routes are unreliable. 1
• Reserve opioids (morphine sulfate with cyclizine) only when NSAIDs are contraindicated due to cardiovascular disease, gastrointestinal comorbidities, hypertension, renal insufficiency, heart failure, or peptic ulcer disease risk. 1

Critical Assessment Within 30 Minutes

Immediately admit to hospital if any of the following are present:

• Shock or fever (suggests infected obstructed kidney—a urologic emergency). 1
• Failure to respond to analgesia within one hour. 1
• Abrupt recurrence of severe pain after initial relief. 1
• Age over 60 years (consider leaking abdominal aortic aneurysm). 1
• Women with delayed menses (consider ectopic pregnancy). 1

Initial Diagnostic Workup

Obtain the following tests immediately:

• Urinalysis with dipstick and microscopy to assess pH, detect infection indicators, and identify pathognomonic crystals. 2, 3
• Urine culture if urinalysis suggests infection or patient has recurrent UTI history. 2, 3
• Serum chemistries including electrolytes, calcium, creatinine, and uric acid to identify underlying metabolic conditions. 3
• Imaging within 7 days with renal ultrasonography as first-line modality to quantify stone burden and guide treatment decisions. 3, 1

Immediate Supportive Care for Outpatient Management

For patients managed at home after pain control:

• Instruct patients to drink large amounts of fluids targeting urine output of at least 2.5 liters daily to promote stone passage. 1, 2
• Have patients void through a tea strainer to catch any passed stone for analysis, as stone composition directs preventive therapy. 1, 3
• Follow up by telephone within one hour to verify adequate pain control; inadequate response mandates hospital admission. 1

Conservative Management vs. Intervention

Conservative management is appropriate for uncomplicated ureteral stones up to 10 mm. 3

• Prescribe medical expulsive therapy with tamsulosin (alpha-blocker), particularly for stones >5 mm in the distal ureter. 3
• Maximum duration of conservative treatment is 4-6 weeks from initial presentation; stones failing to pass require intervention. 3

Metabolic Evaluation Timing

Obtain stone analysis at least once when stone is available, as composition (uric acid, cystine, struvite) implicates specific metabolic abnormalities. 2, 3

Perform metabolic testing with 24-hour urine collection (measuring volume, pH, calcium, oxalate, uric acid, citrate, sodium, potassium, creatinine) in high-risk or recurrent stone formers. 2

Check serum intact parathyroid hormone if primary hyperparathyroidism is suspected (high or high-normal serum calcium). 2

Common Pitfalls to Avoid

• Never use opioids as first-line therapy—NSAIDs are superior and avoid dependence risks. 1
• Never delay admission for patients with fever and obstruction—this represents a urologic emergency requiring immediate drainage. 1
• Never fail to reassess pain control within one hour—inadequate response mandates hospital admission. 1
• Never prescribe oral or rectal analgesics as primary therapy in acute settings—absorption is unreliable. 1