What is the best approach for managing renal colic due to renal stones?

Management of Renal Colic Due to Renal Stones

Intramuscular diclofenac 75 mg is the first-line treatment for renal colic when the diagnosis is clear and there are no signs of complications. 1

Diagnosis and Initial Assessment

• Diagnosis is primarily based on:

  • Abrupt onset of severe unilateral flank pain radiating into the groin or genitals
  • Examination of abdomen to establish site of maximal tenderness
  • Exclusion of other conditions such as peritonitis
  • Assessment of vital signs to exclude shock and systemic infection 1

• Red flags requiring immediate hospital referral:

  • Presence of shock
  • Fever (suggests infection)
  • Oligoanuria
  • Age over 60 years (consider leaking abdominal aortic aneurysm)
  • Women with delayed menses (consider ectopic pregnancy) 2, 1

• Diagnostic support:

  • Haematuria (present in >80% of cases)
  • Alternative diagnoses should be considered if urinalysis is negative 1

Treatment Algorithm

1. First-line analgesia:

   • Intramuscular diclofenac 75 mg when diagnosis is clear and no complications 2, 1
   • Intramuscular route preferred over oral/rectal administration for reliable absorption 2
   • Research shows diclofenac is significantly more effective than morphine (OR 1.35,95% CI 1.05-1.73) 3

2. Alternative analgesia (if NSAIDs contraindicated):

   • Opiate combined with antiemetic (e.g., morphine sulfate and cyclizine) 2, 1
   • Intravenous paracetamol 1g can be effective (comparable to morphine in studies) 3

3. Pain reassessment after 60 minutes:

   • If pain not alleviated → immediate hospital admission 2, 1
   • If pain controlled → manage at home with follow-up 2

4. Home management instructions:

   • High fluid intake
   • Void urine into container/through strainer to catch any passed calculus
   • Contact doctor if pain worsens or new symptoms develop 2, 1

Follow-up and Investigation

• Telephone follow-up one hour after initial assessment and analgesia 2

• All patients (whether managed at home or hospital) should receive:

  • Fast-track investigation within 7 days of symptom onset
  • Urgent urology outpatient appointment within a week if imaging shows problems requiring intervention 2, 1

• Investigations should determine:

  1. Whether a calculus was identified (size and location)
  2. If intervention is needed for existing calculus
  3. If alternative diagnoses should be considered
  4. Patient's risk for developing further episodes 2

Indications for Immediate Hospital Admission

1. Failure to respond to analgesia within one hour
2. Abrupt recurrence of severe pain
3. Presence of shock or fever
4. Signs of peritonitis or systemic infection
5. Septic shock
6. Unclear diagnosis 2, 1, 4

Prevention of Recurrence

• Maintain copious fluid intake (>2 L/day) to reduce urine concentration
• Reduce salt intake (ideally <2g/day)
• Reduce animal protein in diet 4
• Risk of recurrence is high (40% in 5 years, 50% in 10 years) but can be reduced with proper prevention 5

Common Pitfalls to Avoid

1. Delayed analgesia administration - Pain relief should be immediate and complete
2. Inadequate follow-up - All patients need imaging within 7 days
3. Missing red flags - Fever with renal colic requires immediate hospital admission
4. Overreliance on haematuria - While common (>80%), absence doesn't rule out stones
5. Unnecessary hospital admissions - Most stones (90%) pass spontaneously 4
6. Inadequate hydration advice - Essential for both acute management and prevention

By following this evidence-based approach, clinicians can provide effective pain relief while ensuring appropriate investigation and definitive treatment for patients with renal colic.