Internal Medicine

0521779407-18 CUNY1086/Karliner 0 521 77940 7 June 13, 2007 8:1

Renal Calculi 1281

■creatinine: assess before contrast imaging study

■Ca

Basic Urine Tests

■urinalysis: pH, microhematuria, pyuria, crystals; red blood cells

absent in 10–25% of patients with a stone

■urine culture

Imaging

■non-enhanced, thin-cut (3 mm) helical CT of kidneys and ureters:

study of choice for acute flank pain

■plain abdominal radiograph (KUB): to determine if stone seen on CT

is radiopaque

■intravenous urogram or CT urogram: to assess degree of obstruction

and define anatomy for consideration of treatment

■renal sonogram: may detect hydronephrosis, renal calculi, and some

distal ureteral calculi, but less sensitive than CT

differential diagnosis

■appendicitis, perforated ulcer, colitis, diverticulitis, pelvic inflam-

matory disease, ectopic pregnancy, urinary tract infection

■no peritoneal signs or high fever with stone as is typical with acute

abdomen

■non-enhanced CT scan highly sensitive for diagnosing stone; may

also demonstrate appendicitis, free air, secondary signs of divertic-

ulitis

management

What to Do First

■relieve pain with narcotic analgesics: morphine sulfate or meperi-

dine

■hydration; may use ketorolac with caution, but avoid in patients with

renal insufficiency

■if obstruction with clinical signs of infection, immediately decom-

press collecting system with percutaneous nephrostomy or ureteral

stent

Indications for Hospital Admission

■obstruction with signs of infection

■persistent vomiting and inability to retain fluids

■pain not relieved by oral narcotics

■solitary kidney