Renal and urology · Easy
This case is fictional and exists for study. It describes no real patient.
38 years · male
A 38-year-old male presents to the emergency department with a two-hour history of severe, sudden-onset right loin pain that radiates down into his right groin. The pain comes in waves, and he is visibly distressed and writhing, unable to lie still on the examination couch. He reports accompanying nausea and two episodes of non-bilious vomiting. He has no fever, dysuria, or visible haematuria. On physical examination, he has marked tenderness at the right costovertebral angle, but his abdomen is soft, non-distended, and non-tender with normal bowel sounds. A urine dipstick performed in the department shows microscopic haematuria (+++) but is negative for leukocytes and nitrites.
Vital signs
- HR
- 102 bpm
- BP
- 135/85 mmHg
- RR
- 18/min
- Temp
- 36.7 °C
- SpO₂
- 99%
Examination findings
- Marked right costovertebral angle (renal angle) tenderness
- Soft, non-tender abdomen without peritonitis
- Patient writhing in discomfort, unable to find a comfortable position
Investigations
| Urine dipstick blood | +++ scale | reference: Negative |
| Urine dipstick leukocytes | Negative scale | reference: Negative |
| Urine dipstick nitrites | Negative scale | reference: Negative |
| White blood cell count (WBC) | 7.2 10^9/L | reference: 4.0-11.0 |
| Serum Creatinine | 85 µmol/L | reference: 60-110 |
Question 1 of 3
What is the most likely diagnosis?
The classic clinical presentation of renal colic consists of sudden-onset, severe, spasmodic loin-to-groin pain accompanied by restlessness (patient unable to lie still) and microscopic haematuria. Acute appendicitis typically starts with periumbilical pain radiating to the right iliac fossa with localized abdominal tenderness and fever. Acute pyelonephritis presents with fever, rigors, flank pain, and signs of urinary infection (positive leukocytes/nitrites). Ruptured abdominal aortic aneurysm usually occurs in older patients with vascular risk factors, presenting with hypotension, back/abdominal pain, and a pulsatile abdominal mass.
Teaching point: Renal colic typically presents with severe loin-to-groin spasmodic pain, restlessness, costovertebral angle tenderness, and microscopic haematuria.
Question 2 of 3
Which investigation is the definitive imaging modality of choice to confirm the diagnosis in this patient?
Non-contrast CT KUB (NCCT KUB) is the gold standard imaging modality for diagnosing urolithiasis in adult non-pregnant patients due to its high sensitivity and specificity for detecting urinary tract stones. Plain abdominal radiography misses uric acid and small stones and has low sensitivity. Renal ultrasound is useful in pregnancy or when CT is contraindicated, but has lower sensitivity for small stones and ureteric calculus detection. Contrast-enhanced CT is unnecessary and contrast can obscure intraluminal urinary stones.
Teaching point: Non-contrast CT KUB (NCCT KUB) is the initial imaging modality of choice for confirming suspected renal colic in adult non-pregnant patients.
Question 3 of 3
What is the most appropriate initial pharmacological agent for pain management in this patient?
First-line pain management for acute renal colic is a non-steroidal anti-inflammatory drug (NSAID), such as diclofenac, ketorolac, or ibuprofen (intravenous, intramuscular, or rectal/oral), as NSAIDs inhibit prostaglandin synthesis, reducing ureteric spasm and renal capsular pressure. Oral paracetamol is insufficient for severe acute renal colic pain. Codeine is an ineffective weak opioid for severe renal colic pain and causes smooth muscle constriction. Antispasmodics like hyoscine butylbromide are not recommended first-line therapies as they are less effective than NSAIDs or opioids.
Teaching point: NSAIDs (e.g., diclofenac) administered parenterally or rectally are the first-line choice for analgesia in acute renal colic.
Key learning points
- Renal colic presents classically with severe, colicky loin-to-groin pain, restlessness, costovertebral tenderness, and microscopic haematuria.
- Non-contrast CT KUB is the imaging investigation of choice for confirming urolithiasis in non-pregnant adults.
- NSAIDs (e.g., diclofenac or ibuprofen) are the first-line treatment for pain relief in acute renal colic.
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