What is the appropriate management for a patient with left lower flank pain and hematuria?

Management of Left Lower Flank Pain with Hematuria

Non-contrast CT of the abdomen and pelvis is the recommended initial imaging study for patients with left lower flank pain and hematuria, as it has the highest sensitivity and specificity (95-100% and 94% respectively) for detecting urolithiasis and other urinary tract pathologies. 1

Diagnostic Approach

Initial Assessment

• Evaluate urinalysis findings:
  • Presence of hematuria (80 Ery/ul or 2+ blood)
  • Ketonuria (2+)
  • Bilirubinuria (1+)
  • Leukocyte esterase (negative)
  • Nitrite (negative)
  • Specific gravity (1.030)

Primary Differential Diagnosis

1. Urolithiasis - Most common cause of flank pain with hematuria
2. Pyelonephritis - Though typically presents with positive leukocyte esterase/nitrites
3. Renal/ureteral mass - Less common but important to exclude
4. Nutcracker syndrome - Compression of left renal vein causing venous hypertension 2
5. Page kidney - Subcapsular hematoma causing compression of renal parenchyma 3

Imaging Recommendations

First-Line Imaging

• Non-contrast CT abdomen and pelvis
  • Gold standard for detecting urinary stones with sensitivity and specificity near 100% 4
  • Can identify complications such as obstruction, infection, and alternative diagnoses
  • Provides information about stone size, location, and degree of obstruction

Alternative Imaging Options

• Ultrasound of kidneys and bladder

  • Consider if CT is contraindicated (pregnancy, radiation concerns)
  • Less sensitive than CT, particularly for ureteral stones (only 38% sensitivity for ureteral stones) 4, 1
  • Can detect hydronephrosis, larger stones, and some complications

• CT Urography (CTU)

  • Consider if initial non-contrast CT is negative but symptoms persist
  • Includes unenhanced images followed by contrast-enhanced nephrographic and excretory phases 4
  • Better evaluates the collecting system and ureter

Management Algorithm

1. If urolithiasis is confirmed:

   • Assess stone size, location, and degree of obstruction
   • Stones <5mm in distal ureter typically pass spontaneously
   • Pain management with NSAIDs or other analgesics
   • Hydration and medical expulsive therapy if appropriate
   • Urologic consultation for stones >5mm, complete obstruction, or infection

2. If pyelonephritis is diagnosed:

   • Appropriate antibiotic therapy based on culture results
   • Consider urologic intervention if evidence of obstruction

3. If abscess or other complication is identified:

   • Urologic or interventional radiology consultation for possible drainage
   • Broadened antibiotic coverage

4. If initial imaging is negative:

   • Consider CT urography or MR urography to evaluate for less common causes
   • Comprehensive urologic evaluation including cystoscopy and urine cytology 4, 1
   • Consider rare causes like nutcracker syndrome or loin pain hematuria syndrome 2, 5

Important Clinical Considerations

• Gross hematuria has a higher association with malignancy (30-40%) compared to microscopic hematuria (2.6-4%) 4
• The presence of ketonuria (2+) in this patient may suggest metabolic derangement or starvation ketosis
• Bilirubinuria (1+) is unusual and may indicate liver dysfunction or hemolysis
• High specific gravity (1.030) suggests dehydration, which can contribute to stone formation

Follow-up Recommendations

• Repeat urinalysis after treatment to confirm resolution of hematuria
• If hematuria persists despite treatment of identified cause, consider additional evaluation
• Patients with persistent hematuria require continued surveillance to exclude underlying malignancy or other conditions 1

Pitfalls to Avoid

• Don't assume all flank pain with hematuria is due to urolithiasis; consider the full differential diagnosis
• Don't delay imaging in patients with significant pain or signs of infection
• Don't forget to assess renal function before administering contrast for CT urography
• Don't overlook the possibility of rare conditions like nutcracker syndrome or Page kidney when common causes are ruled out 3, 2