URETERIC STONES

Ureteric stones: presentation
Ureteric stones usually present with sudden onset of severe flank pain which is colicky (waves of increasing severity are followed by a reduction in severity, but it seldom goes away completely). It may radiate to the groin as the stone passes into the lower ureter. ~50% of patients with classic symptoms for a ureteric stone do not have a stone confirmed on subsequent imaging studies, nor do they physically ever pass a stone.

Examination
Spend a few seconds looking at the patient. Ureteric stone pain is colicky the patient moves around, trying to find a comfortable position. They may be doubled-up with pain. Patients with conditions causing peritonitis (e.g. appendicitis, a ruptured ectopic pregnancy) lie very still: movement and abdominal palpation are very painful.

Pregnancy test
Arrange a pregnancy test in pre-menopausal women (this is mandatory in any pre-menopausal woman who is going to undergo imaging using ionizing radiation). If +ve, refer to a gynaecologist; if negative, arrange imaging to determine whether they have a ureteric stone.

Dipstick or microscopic haematuria
Many patients with ureteric stones have dipstick or microscopic haematuria (and, more rarely, macroscopic haematuria), but 10 - 30% have no blood in their urine.18,19 The sensitivity of dipstick haematuria for detecting ureteric stones presenting acutely is ~95% on the first day of pain, 85% on the second day, and 65% on the third and fourth days.19 Therefore, patients with a ureteric stone whose pain started 3 - 4 days ago may not have blood detectable in their urine. Dipstick testing is slightly more sensitive than urine microscopy for detecting stones (80% versus 70%) because blood cells lyse, and therefore disappear, if the urine specimen is not examined under the microscope within a few hours. Both ways of detecting haematuria have roughly the same specificity for diagnosing ureteric stones (~60%).
Remember, blood in the urine on dipstick testing or microscopy may be a coincidental finding because of non-stone urological disease (e.g. neoplasm, infection) or a false +ve test (no abnormality is found in ~70% of patients with microscopic haematuria, despite full urological investigation).

Temperature
The most important aspect of examination in a patient with a ureteric stone confirmed on imaging is to measure their temperature. If the patient has a stone and a fever, they may have infection proximal to the stone. A fever in the presence of an obstructing stone is an indication for urine and blood culture, intravenous fluids and antibiotics, and nephrostomy drainage if the fever does not resolve within a matter of hours.