Back Pain OSCE - Renal Colic

Case Overview

• Age/Sex: 34-year-old female
• Occupation: Office worker (administrative assistant)
• Setting: Emergency department / urgent care
• Chief complaint: "Back pain"

Patient Script

Who I Am

I'm a 34-year-old office worker who sits at a computer most of the day.

What Brings Me In

"My right side is in agony — it started suddenly and I can't get comfortable."

My Story

About 6 hours ago I suddenly got a very bad sharp pain on the right side of my lower back. It comes in waves of really intense pain that make me double over. The pain radiates down towards my groin and I felt nauseous and vomited once this morning. I haven't been able to find a position that helps — lying down, standing, nothing really eases it. I noticed my urine looked a bit pink earlier today.

I thought at first I might have just pulled a muscle at work because I moved some heavy boxes at home two days ago, and I had a mild back ache last month after lifting some furniture, but this is much worse. I don't have a fever and I haven't had any severe urinary burning, just a bit of discomfort when I pee. My dad had kidney stones a few years ago.

My Medical Background

• Past medical history: none of significance; one uncomplicated urinary tract infection about 2 years ago
• Medications: combined oral contraceptive pill (started years ago), ibuprofen occasionally for headaches
• Allergies: none known
• Social: drinks a couple of caffeinated drinks a day, drinks alcohol socially, does not smoke
• Family: father had kidney stones

What I Think & Worry About

• I think maybe I pulled a muscle when I moved the boxes, but this pain feels different and much worse.
• I'm worried it might be something serious with my kidneys or that I might need surgery.
• I mainly want strong pain relief and to know if I need to see a specialist.

If You Ask Me About Other Symptoms...

• Pain: "It's on the right side, sharp, and comes in waves. It goes down to my groin."
• Urine: "I saw a bit of pink in the toilet this morning — not a lot, but definitely not normal."
• Fever/chills: "I don't feel hot or have chills."
• Vaginal/menstrual: "My last period was about 10 days ago. No unusual vaginal bleeding or discharge."
• Bowel: "No diarrhoea, but I felt a bit bloated earlier."
• Neurological: "No numbness or weakness in my legs."
• Recent travel / sick contacts: "None."
• Anxiety/stress: "I've been really stressed at work recently and felt anxious — but I don't think that's causing this level of pain."

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Clinical Summary

Examination

• General: alert, sweaty, visibly distressed and repeatedly changing position, clutching right flank
• Vitals: HR 110 bpm; BP 138/86 mmHg; RR 20/min; Temp 37.2°C; SpO2 98% on air
• Abdomen: soft, no guarding or rebound, focal tenderness in the right lower quadrant on deep palpation
• Costovertebral angle: right-sided percussion tenderness
• Genital/pelvic: no external bleeding noted; pelvic exam not performed in ED (pregnancy test done)
• Neuro / MSK: normal lower limb power and sensation

Investigations

• Urine pregnancy test: negative (hCG negative) (pregnancy excluded prior to imaging)
• Urine dipstick: blood +++ ; nitrite negative; leukocyte esterase trace (consistent with hematuria)
• Urine microscopy: red blood cells >50/hpf (confirming hematuria)
• Serum creatinine: 110 µmol/L (slightly above normal range, mild renal impairment/possible obstruction effect)
• Serum Na+/K+: Na 139 mmol/L, K 4.2 mmol/L (electrolytes within normal limits)
• WBC: 9.3 x10^9/L (normal)
• CRP: 4 mg/L (normal/low)
• Non-contrast CT KUB: 6 mm calculus located in the right distal ureter at the ureterovesical junction with mild right-sided hydroureter and hydronephrosis (obstructing ureteric stone)

Diagnosis

• Primary diagnosis: Renal colic due to an obstructing right distal ureteric calculus (6 mm) with mild hydronephrosis.

  • Evidence: acute onset severe colicky right flank pain radiating to groin, visible/microscopic hematuria, CT demonstrating a 6 mm distal ureteric stone with proximal dilatation.

• Differential diagnoses considered:

  • Acute pyelonephritis — less likely (absent fever, nitrite negative, WBC/CRP not elevated)
  • Right-sided appendicitis — less likely (pain radiating to groin, CT confirms ureteric stone; abdomen soft without peritonism)
  • Ovarian torsion / ruptured ovarian cyst — considered because of female pelvic pain, but location/radiation and CT findings support ureteric stone; pelvic exam/US could be done if clinical doubt
  • Musculoskeletal back strain — red herring from recent lifting; pain quality (colicky, radiating to groin) and hematuria point away from simple strain
  • Ectopic pregnancy — excluded by negative pregnancy test and history

Management

• Immediate measures in ED:
  • Analgesia: IV NSAID (e.g., ketorolac or diclofenac) unless contraindicated; titrated IV opioid (e.g., morphine) if pain remains severe
  • Antiemetic: IV ondansetron for nausea
  • IV fluids: maintenance and to aid hydration unless contraindicated
  • Monitor vitals and urine output
• Investigations and safety checks:
  • Send urine for culture (to detect infection prior to definitive intervention)
  • Confirm pregnancy status before any radiologic imaging (already done)
• Definitive/next-step management:
  • Urology consultation: stone is 6 mm (distal ureter) with mild hydronephrosis — discuss early urological intervention (ureteroscopy with stone extraction or laser lithotripsy) because spontaneous passage is less likely and patient has severe pain and obstruction
  • Consider medical expulsive therapy (tamsulosin) if pain controlled and urology deems appropriate, but counsel that success for 6 mm stones is limited
  • If evidence of infection with obstruction (fever, positive nitrite/leukocytosis), urgent decompression (stent or nephrostomy) would be required — not indicated currently
  • Arrange follow-up with urology and outpatient imaging if discharged; advise on indications for return (fever, worsening pain, reduced urine output)
• Disposition:
  • Admit or arrange same-day urology review depending on local resources and patient's analgesic requirements

Key Learning Points

• Acute severe flank-to-groin colicky pain with visible or microscopic hematuria should prompt consideration of ureteric colic; non-contrast CT KUB is the diagnostic gold standard when pregnancy excluded.

• Initial ED priorities are rapid and effective analgesia, antiemesis, assessment for infection or renal impairment, pregnancy test before imaging, and urgent urology referral for obstructing stones >5 mm or if infection is present.

• Not all loin pain after lifting is musculoskeletal — consider alternate causes (renal stone, appendicitis, gynecological pathology) and use history, urinalysis, and imaging to differentiate.