What is the best treatment approach for a patient presenting with renal colic?

Management of Renal Colic

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

Initial Assessment and Diagnosis

The diagnosis of renal colic is primarily based on:

• Abrupt onset of severe unilateral flank pain radiating into the groin or genitals
• Patients typically present with intense, colicky pain that may be accompanied by nausea and vomiting
• Haematuria is present in over 80% of cases and supports the diagnosis

Key examination elements:

• Examination of the abdomen to establish site of maximal tenderness
• Assessment of vital signs to exclude shock and systemic infection
• Urinalysis for blood (if practicable)

Red Flags Requiring Immediate Hospital Admission

• Shock
• Fever
• Age over 60 years (consider leaking abdominal aortic aneurysm)
• Women with delayed menses (consider ectopic pregnancy)

Treatment Algorithm

Step 1: Rapid Pain Control

• First-line therapy: Intramuscular diclofenac 75 mg 1

  • Provides rapid pain relief within 30 minutes
  • NSAIDs directly interfere with the pathophysiology of renal colic 2
  • Complete or acceptable pain control should be maintained for six hours or longer

• Alternative if NSAIDs contraindicated: Morphine with an antiemetic (e.g., morphine sulfate and cyclizine) 1, 3

  • NSAIDs should be avoided in:
    • Pregnancy
    • Heart failure
    • Renal artery stenosis
    • Dehydration
    • Existing renal impairment
    • Patients on nephrotoxic drugs
    • Very elderly patients

Step 2: Follow-up Assessment

• Follow initial assessment with telephone call one hour after analgesia administration
• If pain not alleviated within 60 minutes, arrange immediate hospital admission
• Abrupt recurrence of severe pain also warrants immediate admission

Step 3: Home Management Instructions

• Encourage high fluid intake
• Have patient void urine into a container or through a tea strainer to catch any calculus
• Instruct patient to contact doctor if pain worsens or new symptoms develop

Comparative Efficacy of Analgesics

Research shows that:

• NSAIDs and strong opioids have comparable efficacy for pain relief 3
• NSAIDs are associated with fewer adverse effects than opioids (6% vs 20% vomiting rate) 3
• Diclofenac and ketorolac appear equally effective for pain management 4
• In some cases (approximately 10% of patients), a combination of morphine and NSAID provides greater analgesic effect than either agent alone 3

Integrated Care Pathway

For patients managed at home:

• Fast-track investigation initiated by hospital upon receipt of completed template from GP
• Radiology appointment within seven days of symptom onset
• Urgent urology outpatient appointment within a week if imaging shows a problem requiring intervention

Common Pitfalls to Avoid

1. Delayed analgesia administration: Pain control should be prioritized and administered quickly
2. Overreliance on hydration: Intensive hydration is not currently recommended 5
3. Failure to recognize complications: Always check for fever, shock, or other concerning symptoms
4. Missing alternative diagnoses: Consider other serious conditions in atypical presentations
5. Unnecessary hospital admissions: Many patients can be managed effectively at home with proper follow-up

Special Populations

Pregnant women: Morphine carries a lower risk of adverse effects than NSAIDs, which should never be used during pregnancy 3

By following this evidence-based approach, patients with renal colic can receive prompt and effective pain relief while avoiding unnecessary hospital admissions and ensuring appropriate follow-up care.