Renal and urology · Moderate
This case is fictional and exists for study. It describes no real patient.
42 years · male
A 42-year-old male presents to the emergency department with a two-hour history of severe, agonizing right flank pain that radiates down into his groin and right scrotum. The pain is sharp, excruciating, and comes in waves. He is visibly restless, constantly shifting position on the examination trolley to find relief, and has vomited twice since the onset of pain. He denies fever, chills, dysuria, or visible blood in his urine, but reports urinary frequency. Physical examination demonstrates marked tenderness over the right costovertebral angle, but his abdomen is soft, non-distended, and non-tender. Dipstick urinalysis demonstrates non-visible haematuria (+++) with negative nitrites and leucocyte esterase.
Vital signs
- HR
- 102 bpm
- BP
- 138/84 mmHg
- RR
- 18/min
- Temp
- 36.8 °C
- SpO₂
- 98%
Examination findings
- Marked right costovertebral angle tenderness
- Abdomen soft and non-tender
- Patient unable to lie still due to severe colicky pain
Investigations
| Haemoglobin | 14.8 g/dL | reference: 13.0-17.0 |
| White Blood Cell Count | 8.5 10^9/L | reference: 4.0-11.0 |
| Serum Creatinine | 88 µmol/L | reference: 60-110 |
| Serum Urea | 5.2 mmol/L | reference: 2.5-7.8 |
| Urine Dipstick Blood | +++ scale | reference: Negative |
Question 1 of 3
Which of the following is the definitive initial imaging modality of choice to confirm the diagnosis in this patient?
Non-contrast CT KUB is the gold standard imaging modality for suspected acute renal colic and is recommended by UK guidelines to be performed within 24 hours of presentation. It has high sensitivity and specificity for detecting stone location, size, and secondary signs of obstruction. Contrast-enhanced CT is unnecessary and increases the risk of contrast-induced nephropathy. Ultrasound KUB is useful in pregnant women or children, but less sensitive for small ureteric stones in adult males. Plain KUB X-ray misses radiolucent stones (e.g., uric acid) and small distal stones.
Teaching point: Non-contrast CT KUB is the initial imaging modality of choice for adult patients presenting with suspected acute renal colic.
Question 2 of 3
Which of the following is the most appropriate first-line medication for pain relief in this patient?
NICE guidelines recommend NSAIDs (e.g., IV/IM/PR diclofenac or ketorolac) as first-line analgesia for patients with acute renal colic unless contraindicated (e.g., renal impairment, active peptic ulcer disease). NSAIDs inhibit prostaglandin synthesis, reducing ureteric spasm and local capsular distension. Pethidine is no longer recommended due to neurotoxicity risks. Oral codeine and oral paracetamol are inadequate for severe acute renal colic pain.
Teaching point: NSAIDs are first-line analgesics for acute renal colic because they target prostaglandin-mediated ureteric spasm.
Question 3 of 3
An NCCT KUB confirms a 3 mm stone in the distal right ureter with mild proximal hydronephrosis and no signs of infection. What is the single most appropriate initial management strategy for this stone?
Ureteric stones smaller than 5 mm pass spontaneously in up to 80-90% of cases. Uncomplicated small stones (< 5 mm) without features of sepsis or severe renal impairment are appropriately managed conservatively with oral analgesia, adequate fluid intake, and medical expulsive therapy using an alpha-blocker like tamsulosin. Surgical interventions (ureteroscopy, ESWL) or decompression (nephrostomy, stent) are reserved for larger stones (> 5-10 mm), intractable pain, severe failure to pass after conservative care, or obstructed/infected systems.
Teaching point: Uncomplicated ureteric stones < 5 mm should initially be managed conservatively with medical expulsive therapy (tamsulosin) and analgesia.
Key learning points
- Acute renal colic typically presents with sudden-onset severe flank pain radiating to the groin/scrotum, accompanied by non-visible or visible haematuria.
- Non-contrast CT KUB is the gold-standard diagnostic imaging modality for renal colic in adults.
- NSAIDs are first-line analgesics, and uncomplicated distal stones smaller than 5 mm are managed conservatively with medical expulsive therapy (e.g., tamsulosin).
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