What is the recommended initial assessment and treatment for an adult patient with colicky pain, potentially due to kidney stones, and considering their medical history and renal function?

Management of Colicky Pain in Adults

For adult patients presenting with colicky pain suggestive of renal colic, initiate immediate pain control with NSAIDs (diclofenac, ibuprofen, or metamizole) as first-line therapy, followed by ultrasound as the primary diagnostic tool, with non-contrast CT reserved for cases where ultrasound is negative or equivocal and clinical suspicion remains high. 1, 2

Immediate Pain Management

NSAIDs are superior to opioids for renal colic and should be administered first-line. 1

• Diclofenac, ibuprofen, or metamizole reduce the need for additional analgesia compared to opioids and should be given at the lowest effective dose 1
• NSAIDs carry cardiovascular and gastrointestinal risks, and may impact renal function in patients with reduced glomerular filtration rate, so use cautiously in these populations 1
• If NSAIDs are contraindicated or ineffective, use opioids as second-line agents—specifically hydromorphine, pentazocine, or tramadol rather than pethidine, which has higher rates of vomiting 1, 3

Initial Diagnostic Workup

Ultrasound is the primary diagnostic tool and should not delay emergency care. 1, 2

Immediate Laboratory Assessment

• Perform urine dipstick to assess for hematuria and infection 1, 4
• Obtain blood tests: creatinine, uric acid, ionized calcium, sodium, potassium, complete blood count, and C-reactive protein 1
• Send urine culture if infection is suspected 3

Imaging Strategy

Use a conditional imaging approach to minimize radiation while maintaining diagnostic accuracy: 2, 5

• Start with ultrasound, which has 45% sensitivity but 94% specificity for ureteral stones and 88% specificity for renal stones 1
• Ultrasound effectively identifies hydronephrosis, which has 77% positive predictive value for ureteral stones 1
• If ultrasound shows no stone but clinical suspicion remains high (STONE score ≥10), proceed to non-contrast CT 5
• This conditional strategy maintains >95% sensitivity and specificity while reducing CT use by 76% 5

When to Use CT Immediately

Non-contrast CT of abdomen and pelvis is the gold standard with 94% sensitivity and 94% specificity, and should be performed urgently in these situations: 1, 2

• Ultrasound is negative or equivocal with moderate-to-high clinical suspicion 1
• Moderate-to-severe hydronephrosis on ultrasound requiring treatment planning 6, 7
• Need to assess stone size, location, density, and anatomy for intervention decisions 1, 2
• Always use low-dose protocols (93.1% sensitivity, 96.6% specificity) to minimize radiation 1

Risk Stratification and Urgent Conditions

Immediate Emergency Intervention Required

Urgent decompression via percutaneous nephrostomy or ureteral stenting is mandatory if any of the following are present: 1, 7

• Signs of sepsis (fever, hypotension, elevated CRP) with obstructed kidney 1, 7
• Anuria in an obstructed kidney 1
• Collect urine for culture before and after decompression, start empiric antibiotics immediately, and adjust based on antibiogram 1
• Delay definitive stone treatment until sepsis resolves 1

High-Risk Features Requiring Urological Consultation

• Moderate-to-severe hydronephrosis (97% sensitivity for requiring intervention) 6, 7
• Stones >10 mm (unlikely to pass spontaneously) 4, 3
• Solitary kidney with elevated creatinine 7
• Intractable pain despite adequate analgesia 2

Conservative Management for Appropriate Candidates

Medical expulsive therapy (MET) with alpha-blockers is first-line for uncomplicated distal ureteral stones ≤10 mm. 1, 4

Patient Selection Criteria

• Stone size ≤10 mm in distal ureter 1, 4
• Controlled symptoms with analgesia 6, 3
• No signs of infection 1, 7
• Normal or near-normal renal function 7

Monitoring During Conservative Management

• Alpha-blockers show greatest benefit for stones >5 mm in the distal ureter 1
• Arrange follow-up imaging within 14 days to monitor stone position and hydronephrosis 3
• Counsel patients that if stone does not pass within 28 days or symptoms worsen, urological intervention will be required 6, 7
• Periodic imaging is necessary to assess stone progression 6, 7

Critical Pitfalls to Avoid

• Do not assume absence of hydronephrosis on ultrasound rules out significant stones—negative predictive value is only 65% 2, 7
• Do not delay urological referral if infection is suspected—untreated bacteriuria with obstruction leads to urosepsis 6
• Do not assume all small stones will pass spontaneously—presence of hydronephrosis indicates higher risk of passage failure 6
• Do not rely solely on ultrasound for treatment decisions, as it significantly overestimates stone size in the 0-10 mm range 7

Special Populations

Pregnant Patients

Ultrasound is first-line imaging with an appropriateness rating of 8. 2, 7

• Use MRI without contrast as second-line if ultrasound is inconclusive 2, 7
• Reserve low-dose non-contrast CT as absolute last resort 2, 7

Patients with Recurrent Stones

• Review previous imaging to understand stone history 2
• Consider ultrasound combined with KUB radiography for follow-up to reduce radiation exposure 2, 7
• Refer high-risk patients for metabolic assessment after acute episode resolves 4, 3