What are the typical presentation and initial management of renal colic?

How Renal Colic Presents

Renal colic presents with abrupt onset of severe unilateral flank pain radiating into the groin or genitals, often accompanied by nausea, vomiting, and hematuria. 1, 2

Classic Clinical Presentation

Pain Characteristics:

• Sudden, severe unilateral flank pain that radiates from loin to groin or external genitalia 1, 2, 3
• Renal pelvic or upper ureteric stones cause more flank pain and costovertebral angle tenderness 3
• Lower ureteric stones produce pain radiating toward the ipsilateral testicle or labia 3
• Pain is typically colicky in nature, with waves of intensity 4

Associated Symptoms:

• Nausea and vomiting occur commonly 3, 4
• Hematuria is present in >80% of cases, though its absence does not exclude the diagnosis 2, 3
• Irritative lower urinary tract symptoms may occur 3
• Patients are typically restless and unable to find a comfortable position 4

Critical Initial Assessment

Immediate Evaluation (within 30 minutes):

• Assess vital signs including pulse, blood pressure, and temperature to exclude shock and systemic infection 1
• Perform abdominal examination to exclude peritonitis and other acute abdominal conditions 1
• Patients with fever or signs of systemic infection require immediate hospital admission 1, 5
• Patients with shock or hemodynamic instability require immediate hospital admission 2, 5

Important Diagnostic Caveats

Red Flags Requiring Alternative Diagnosis Consideration:

• Patients over 60 years old: consider leaking abdominal aortic aneurysm 1
• Women with delayed menses: consider ectopic pregnancy 1, 5
• Elderly patients may have atypical presentations with minimal fever or leukocytosis despite serious infection 2

Diagnostic Accuracy:

• Symptoms of renal colic plus positive dipstick for hematuria have 84% sensitivity and 99% specificity 3
• However, absence of hematuria does not exclude renal colic 2, 3
• Urinalysis is often impractical in the acute setting as patients are frequently unable to void on demand 1

Initial Management Approach

Analgesia (Grade A recommendation):

• Intramuscular diclofenac 75 mg is first-line treatment, providing pain relief within 30 minutes 1, 5, 6
• Oral and rectal routes are unreliable in acute settings 1, 6
• When NSAIDs are contraindicated, use morphine sulfate combined with cyclizine (antiemetic) 1, 5
• If pain is not controlled within 60 minutes, immediate hospital admission is required 1, 5, 6

Home Management Criteria:

• Approximately 90% of stones pass spontaneously, making home management appropriate for most patients 2, 3
• Patients should maintain high fluid intake and attempt to strain urine to catch any passed calculus 1
• Follow-up telephone call should occur one hour after initial assessment 1, 5

Mandatory Follow-up Imaging:

• All patients require renal tract imaging within 7 days to identify the calculus and rule out obstruction 1, 3
• Ultrasound should be considered as the primary imaging modality as it is non-invasive, non-expensive, and avoids radiation 7
• CT urography is the gold standard when diagnosis is uncertain or complications are suspected 4

Critical Pitfalls to Avoid

• Never delay analgesia while waiting for diagnostic tests 5
• Do not discharge patients before ensuring adequate pain control for at least 6 hours 5
• Missing an infected obstructed kidney (obstructive pyelonephritis) is a surgical emergency requiring urgent decompression 5, 6, 4
• Abrupt recurrence of severe pain warrants immediate hospital admission 1