Acute Management of Renal Colic
NSAIDs (diclofenac, ibuprofen, or metamizole) are the first-line treatment for renal colic pain, superior to opioids in reducing the need for additional analgesia. 1
Analgesia
First-Line: NSAIDs
- Use NSAIDs as primary analgesics for renal colic 1
- Specific agents: diclofenac, ibuprofen, or metamizole
- NSAIDs reduce inflammation and lower pressure within the urinary collecting system 2
- Use the lowest effective dose to minimize cardiovascular and gastrointestinal risks 1
Important caveat: NSAIDs may impair renal function in patients with low glomerular filtration rate—screen for contraindications including renal failure and peptic ulcer disease 1, 3
Second-Line: Opioids
- Reserve opioids when NSAIDs are contraindicated or insufficient 1
- Avoid pethidine due to high rates of vomiting and need for additional analgesia 1
- Preferred opioid alternatives: hydromorphine, pentazocine, or tramadol 1
- In elderly patients, use downward-adjusted doses and monitor for confusion and respiratory depression 3
Imaging
Standard Approach
- Start with ultrasound (US) as first-line imaging 1
- Follow with low-dose non-contrast CT if US doesn't provide sufficient information 1
- Low-dose CT maintains high diagnostic accuracy (93.1% sensitivity, 96.6% specificity) while reducing radiation exposure 1
- CT assesses stone location, burden, density, and anatomy 1
Special Populations
- Pregnant women: US first → MRI second → low-dose CT as last resort 1
- Children: US first → KUB or low-dose CT if needed 1
Laboratory Workup
All emergency patients require: 1
- Urine dipstick
- Blood tests: creatinine, uric acid, ionized calcium, sodium, potassium, blood cell count, CRP
- Urine microscopy and culture before any stone treatment 1
Medical Expulsive Therapy (MET)
Alpha-blockers are efficacious for ureteral stones amenable to conservative management, with greatest benefit for stones >5 mm in the distal ureter. 1
Indications
- Ureteral stones suitable for conservative management
- Maximum benefit: stones >5 mm in distal ureter 1
- Note: This is an off-label use (class effect) 1
Post-Operative Use
- Prescribe alpha-blockers after shockwave lithotripsy to improve stone-free rates and reduce post-operative pain 4
Criteria for Urgent Urologic Intervention
Absolute Emergencies (Immediate Decompression Required)
Urgent decompression via percutaneous nephrostomy or ureteral stenting is mandatory for: 1
- Sepsis in an obstructed kidney
- Anuria in an obstructed kidney
Management protocol for obstructive pyelonephritis/sepsis: 1, 5
- Collect urine for culture before and after decompression
- Start antibiotics immediately
- Re-evaluate antibiotic regimen based on culture results
- Delay definitive stone treatment until sepsis resolves
- Intensive care may be necessary
Relative Indications for Intervention
- High-grade obstruction
- Failure of oral analgesics to control pain (may require hospitalization) 6
- Stones >10 mm (less likely to pass spontaneously) 7
- Persistent symptoms despite conservative management
Conservative Management Strategy
For stones likely to pass spontaneously (approximately 90% of stones causing renal colic): 6
- Pain control with NSAIDs ± opioids
- Alpha-blocker therapy for stones >5 mm 1
- Follow-up imaging within 14 days to monitor stone position and assess for hydronephrosis 7
- Instruct patient to strain urine to recover stone for analysis 6
- Watchful waiting for 2-4 weeks for small, distal ureteral stones 3
Special Considerations
Uric Acid Stones
Oral chemolysis is strongly recommended 1
- Alkalinization with citrate or sodium bicarbonate (target pH 7.0-7.2)
- Patients should monitor urine pH and adjust medication accordingly
- Success rate: 80.5%, with 15.7% requiring further intervention 1
Anticoagulation/Antiplatelet Therapy
- Ureteroscopy may be performed in patients requiring continued AC/AP therapy 4
- Continuation increases bleeding complications but may be necessary based on thrombotic risk
- Refer to internist for appropriate perioperative management 1