Ureteral or Renal Calculi

• • Costovertebral angle/ flank pain

  • Pain may radiate to the ipsilateral lower abdominal quadrant

  • Hematuria

  • Nausea, vomiting, intestinal ileus

  • Radiographic evidence of renal or ureteral calculus

  • Fever, if proximal infection present

Epidemiology

• • Many affected patients have history of prior renal calculi

  • -Roughly 50% chance of developing second stone within 5 years of the first calculi

  • Hypercalcuria is a metabolic risk factor for stone formation, seen in:

  • -Hyperparathyroidism

    -Excess calcium and vitamin D intake

    -Immobilization osteoporosis

    -Paget disease

    -Sarcoidosis

    -Dehydration

  • Urea-splitting bacteria create magnesium-ammonium phosphate (struvite) stones

  • Metabolic stones form from the hypersecretion of uric acid or cystine

  • Other metabolic risk factors include:

  • -Hyperuricosuria

    -Hypocitraturia

    -Hypomagnesuria

    -Hyperoxaluria

Symptoms and Signs

• • Moderate to severe costovertebral angle/flank pain that does not improve with change in position

  • Pain may radiate to ipsilateral lower abdominal quadrant depending on location of calculus

  • Often nausea and vomiting, associated with an intestinal ileus

  • Gross hematuria occurs more often than microscopic

  • Symptoms of pyelonephritis with proximal infection (costovertebral angle tenderness, high fever, chills, dysuria)

  • Nonobstructive calculi are typically asymptomatic

Laboratory Findings

• • Evidence of hematuria

  • Pyuria, bacturia, and leukocytosis with secondary infection

  • Urine pH > 7.6 suggests presence of urea-splitting organisms

  • Urine pH < 5.5 suggests metabolic stone formation (uric acid and cystine)

  • Hypercalcemia and hypophosphatemia consistent with hyperparathyroidism

  • Hyperchloremic metabolic acidosis consistent with renal tubular acidosis with secondary renal calcifications

Imaging Findings

• • 90% of stones are radiopaque (calcium, cystine, and struvite) and seen on plain films

  • Uric acid stones are non-radiopaque, but can be seen on spiral CT

  • Spiral CT without contrast demonstrates entire urinary tract and can distinguish between stones, tumor, and blood clots

  • Excretory urography will verify stone location and provides qualitative information on renal function

• • Acute pyelonephritis

  • Renal adenocarcinoma (hematuria)

  • Transitional cell tumors (obstruction)

  • Renal papillary necrosis

  • Renal infarction

  • Acute pancreatitis

  • Psoas abscess

  • Symptomatic abdominal aortic aneurysm (AAA)

  • Acute appendicitis

  • Acute salpingitis

  • Herpes zoster

Rule Out

• • Symptomatic/ruptured AAA

  • Proximal infection

  • Presence of a urologic neoplasm

• • CBC

  • Basic chemistries

  • UA

  • Urine culture and sensitivities

  • Qualitative urine cystine

  • Abdominal x-ray

  • Spiral CT without contrast ("stone protocol") diagnostic test of choice

  • Calculi composition analysis if recovered

When to Admit

• • Fever and leukocytosis

  • Severe ureterorenal colic requiring parenteral analgesics

  • Inability to tolerate PO fluids or analgesia

  • Obstruction complicated by infection, requiring percutaneous nephrostomy tube or ureteral stent for drainage

When to Refer

• • All patients should be managed by a urologist

• • ...