Argyropoulos A et al. (2004) The presence of microscopic hematuria detected by urine dipstick test in the evaluation of patients with renal colic. Urol Res 32: 294–297

A negative urinalysis for microscopic hematuria is reported in up to 18% of cases of urolithiasis. Argyropoulos and colleagues have carried out a single-center, retrospective study to investigate whether testing in the emergency department with a urine dipstick test (UDT) gives similar results.

The authors reviewed the records of patients who had been diagnosed with renal colic and who had been examined in the emergency department. A urine sample from each patient was tested with a UDT. This was followed by a formal urinalysis if the UDT result was negative or showed only traces of blood.

A subset of patients (n = 609) with at least one ureteral or renal stone >3 mm in diameter were included in the analysis. Hematuria was detected by dipstick testing in 566 patients (92.9%). Formal urinalysis was positive for hematuria in a further 12 (2.0%) patients whose UDT was negative. A positive urinalysis was observed in all patients whose UDT showed only traces of blood.

The authors suggest that UDT should be used as a first-line, low cost approach in patients presenting with symptoms of renal colic in the emergency department, and that formal urinalysis should be reserved for those cases in which the UDT is negative or ambiguous.