What is the initial management for a patient presenting with colicky pain suspected to be due to renal colic?

Initial Management of Renal Colic

Administer intramuscular diclofenac 75 mg immediately as first-line treatment when the diagnosis is clear and there are no contraindications. 1, 2

Immediate Assessment (Within 30 Minutes)

The diagnosis centers on recognizing the classic presentation: 1, 2

• Abrupt onset of severe unilateral flank pain radiating to the groin or genitals
• Often accompanied by nausea or vomiting (occurs in approximately 50% of cases) 3

Critical examination components include: 1, 2

• Abdominal assessment to exclude peritonitis
• Vital signs (pulse, blood pressure, temperature) to identify shock or systemic infection
• Assessment for red flag conditions requiring immediate hospital admission

Red Flags Requiring Immediate Hospital Admission

Do not attempt outpatient management if any of the following are present: 2

• Age over 60 years (consider leaking abdominal aortic aneurysm) 1, 2
• Women with delayed menses (consider ectopic pregnancy) 1, 2
• Shock or signs of systemic infection 2
• Fever suggesting infection with obstruction 2
• Anuria with obstruction 2
• Renal impairment or acute kidney injury secondary to obstruction 2

First-Line Analgesia

The intramuscular route is superior to oral or rectal administration because these routes are unreliable in acute colic, and IV administration may be impractical in primary care settings. 2, 4

Dosing: 1, 2

• Diclofenac 75 mg intramuscularly
• Goal: Pain relief within 30 minutes of administration 4

When NSAIDs are contraindicated (renal impairment, heart failure, pregnancy, peptic ulcer disease): 2, 5

• Administer an opiate combined with an antiemetic
• Example: morphine sulfate plus cyclizine 2
• Use downward-adjusted doses in elderly patients to prevent confusion and respiratory depression 5

Mandatory One-Hour Reassessment

Follow up by telephone call exactly one hour after initial analgesia administration. 1, 2

If pain is NOT alleviated within 60 minutes: 1, 2

• Immediately arrange hospital admission by telephone
• Do not schedule another consultation—admit directly

If pain is adequately controlled: 1, 2

• Instruct patient to drink large volumes of fluids
• Have patient void urine through a tea strainer or gauze to catch any stone
• Contact physician immediately if pain worsens or unexpected symptoms develop

Follow-Up Investigation (All Patients)

Even if symptoms resolve, all patients require investigation: 1, 2

• Arrange renal imaging within 7 days of symptom onset 1, 2
• Schedule urgent urology outpatient appointment within 7-14 days if imaging identifies a calculus requiring intervention 1, 2

Evidence Supporting NSAIDs Over Other Options

NSAIDs demonstrate superior efficacy compared to alternatives: 6

• Versus placebo: NSAIDs are 2.28 times more likely to achieve 50% pain reduction within one hour
• Versus antispasmodics: NSAIDs reduce pain by an additional 13 points on the visual analogue scale and are 2.44 times more effective at achieving adequate pain control
• Versus opioids alone: Comparable efficacy but NSAIDs cause vomiting in only 6% versus 20% with opioids 7

Adding antispasmodics to NSAIDs provides no additional benefit and should be avoided. 6

Critical Pitfalls to Avoid

Do not: 2, 4

• Delay analgesia while waiting for diagnostic tests
• Issue limited quantities of oral or rectal analgesics for recurrent pain (risk of drug misuse)
• Fail to recognize infection with obstruction (fever + obstruction = surgical emergency)
• Discharge patients before ensuring adequate pain control and ability to maintain hydration
• Use morphine, codeine, or tramadol as first-line agents in patients with renal impairment 8