What should I do for intermittent renal pain?

Management of Intermittent Kidney Pain

For intermittent kidney pain, immediately administer intramuscular diclofenac 75 mg to achieve pain relief within 30 minutes, then assess for red-flag features requiring urgent hospital admission. 1

Immediate Clinical Assessment (Within 30 Minutes)

Your first priority is to determine if this represents acute renal colic versus a life-threatening alternative diagnosis:

• Check vital signs immediately: Measure pulse, blood pressure, and temperature to exclude shock or systemic infection 1, 2
• Examine the abdomen: Establish the site of maximal tenderness and exclude peritonitis 1
• Assess pain characteristics: Renal colic presents as abrupt onset of severe unilateral flank pain radiating to the groin or genitals 1, 2

Critical Red Flags Requiring Immediate Hospital Admission

Admit immediately if any of the following are present:

• Fever or signs of systemic infection – suggests obstructive pyelonephritis, a surgical emergency requiring urgent decompression 1, 2, 3
• Shock or hemodynamic instability – requires immediate admission 2, 4
• Age >60 years – must exclude leaking abdominal aortic aneurysm 1, 2
• Women with delayed menses – must exclude ectopic pregnancy 1, 2

First-Line Pain Management

Administer intramuscular diclofenac 75 mg immediately – this is the preferred agent and route with Grade A evidence, providing pain relief within 30 minutes 1, 3. Oral and rectal routes are unreliable in acute settings 1, 3.

If NSAIDs Are Contraindicated

Use morphine sulfate combined with cyclizine (antiemetic) if the patient has: 1

• Renal impairment
• Cardiovascular disease
• History of gastrointestinal bleeding
• Allergy to NSAIDs

Important caveat: In patients with renal impairment, avoid morphine, codeine, or tramadol due to accumulation of active metabolites; fentanyl is the safest opioid choice 1, 4, 5

Failure of Analgesia = Immediate Admission

If pain is not controlled within 60 minutes of appropriate analgesia, arrange immediate hospital admission by telephone without further consultation. 1, 3 Do not wait for a second visit – check response by phone 1.

Urinalysis Consideration

While over 80% of renal colic cases show hematuria, urinalysis is often impractical as patients cannot void on demand 1, 4. The absence of hematuria does not exclude renal colic 1. If practical, test the urine to support the diagnosis, but never delay analgesia while waiting for urinalysis 2.

Home Management Criteria

Patients can be managed at home if they meet ALL of the following: 2

• Adequate pain control achieved and maintained for at least 6 hours
• No fever or signs of infection
• Hemodynamically stable
• No red-flag features present

Instructions for Home Management

• Maintain high fluid intake (approximately 2 liters per day) 1, 2, 4
• Strain all urine through a tea strainer or gauze to catch any passed calculus for analysis 1, 2
• Telephone follow-up at 1 hour after initial assessment to verify sustained pain control 1, 2

Fast-Track Investigation Pathway

All patients with suspected renal colic require imaging to identify the calculus and determine if intervention is needed: 1

• Arrange renal imaging within 7 days of symptom onset (ultrasound or non-contrast CT) 1, 2, 4
• Urgent urology referral within 1 week if imaging shows a calculus requiring intervention 1, 2
• Send imaging results to the primary care physician immediately 2

Common Pitfalls to Avoid

• Never delay analgesia while waiting for diagnostic tests or imaging 2
• Do not discharge before ensuring 6 hours of adequate pain control 2
• Missing obstructive pyelonephritis (infected obstructed kidney) is catastrophic – any fever with obstruction requires urgent decompression via percutaneous nephrostomy or ureteral stenting 2, 3, 4
• NSAIDs may worsen renal function in patients with pre-existing kidney disease – use the lowest effective dose and monitor carefully 3, 5

Recurrent Pain Management

If pain recurs after initial control, consider providing a limited supply of oral or rectal analgesics for self-administration, though there are concerns about potential drug misuse 1. Abrupt recurrence of severe pain warrants immediate hospital admission arranged by telephone 1.