What is the management approach for an adult patient with no significant medical history presenting with right kidney pain?

Management of Right Kidney Pain

For an adult with no significant medical history presenting with right kidney pain, immediately administer intramuscular diclofenac 75 mg for analgesia while simultaneously evaluating for renal colic with obstructive uropathy, which is the most likely diagnosis requiring urgent assessment within 30 minutes. 1, 2, 3

Immediate Assessment (Within 30 Minutes)

Evaluate for red flags requiring immediate hospital admission:

• Shock or hemodynamic instability (check pulse and blood pressure immediately) 1, 3
• Fever or signs of systemic infection (check temperature) 1, 3
• Age >60 years (consider leaking abdominal aortic aneurysm) 1, 3
• Anuria in the setting of suspected obstruction (surgical emergency) 2, 3

Obtain urinalysis for hematuria, which is present in >80% of renal colic cases, though absence does not exclude the diagnosis 1

Pain Management Protocol

First-Line Analgesia

Administer intramuscular diclofenac 75 mg immediately as this provides pain relief within 30 minutes and is superior to opioids for renal colic 1, 2, 3. NSAIDs reduce the need for additional analgesia compared to opioids 2.

Critical timing rule: If pain is not controlled within 60 minutes of appropriate analgesia, immediate hospital admission is required 2, 3

Second-Line Analgesia (If NSAIDs Contraindicated)

If the patient has contraindications to NSAIDs (renal impairment, cardiovascular disease, gastrointestinal bleeding history):

• Use fentanyl as the preferred opioid because it does not accumulate active metabolites 2
• Avoid morphine, codeine, or tramadol as these accumulate toxic metabolites 1, 2
• Consider hydromorphine or pentazocine as alternatives 2
• Never use pethidine due to highest rate of vomiting and need for additional analgesia 2

Diagnostic Workup

Order non-contrast CT scan or renal ultrasound to confirm urolithiasis and assess for obstruction 1. MRI is not appropriate for detecting renal calculi 4.

If imaging confirms urinary obstruction with infection (obstructive pyelonephritis), this is a surgical emergency requiring urgent decompression via percutaneous nephrostomy or ureteral stenting 1, 2

Outpatient Management Criteria

Approximately 90% of stones pass spontaneously, making home management appropriate if:

• Pain is adequately controlled for at least 6 hours 1, 3
• No red flags are present 1, 3
• Patient is hemodynamically stable without fever 1, 3

Discharge instructions:

• Drink copious fluids 3
• Void urine through a strainer to catch calculus for analysis 1, 3
• Arrange imaging within 7 days if managed as outpatient 1
• Urgent urology consultation within 1 week if intervention is needed 1

Medical Expulsive Therapy

For stones >5 mm in the distal ureter, prescribe tamsulosin (alpha-blocker) to facilitate spontaneous passage 2

Critical Pitfalls to Avoid

• Never delay analgesia while waiting for diagnostic tests 1, 3
• Do not discharge patients before ensuring adequate pain control for at least 6 hours 1, 3
• Missing an infected obstructed kidney is a surgical emergency—any patient with fever and suspected obstruction requires immediate intervention 1, 3
• In elderly patients, always consider abdominal aortic aneurysm as a life-threatening mimic of renal colic 1, 3

Alternative Diagnoses to Consider

If imaging does not reveal urolithiasis and pain persists, consider:

• Autosomal dominant polycystic kidney disease (ADPKD) with cyst-related pain, which requires investigation to determine if pain is kidney-related 5
• For ADPKD-related chronic pain, a multidisciplinary approach is needed with nonpharmacologic interventions initially, followed by pharmacologic treatment, and referral to a center of expertise when invasive intervention is considered 5
• Cyst aspiration or aspiration sclerotherapy may be considered when pain can be attributed to a single or several dominant cysts 5