Absent hematuria and expensive computerized tomography: case characteristics of emergency urolithiasis

We validated the descriptive characteristics of emergency cases presenting with urolithiasis, determined the incidence of normal urinalysis in such cases and compared the expense of diagnostic computerized tomography (CT) and excretory urography (IVP).

We retrospectively reviewed the charts of all consecutive patient visits to a community emergency department for 48 months. Explicit protocols for case selection, data abstraction and monitoring were used to maximize accuracy. Entry criteria were urolithiasis diagnosed by IVP, CT or stone passage, and urinalysis. Data analysis included descriptive statistics and the calculation of confidence intervals.

From 159,083 emergency visits during this period 397 met study entry criteria. Absent hematuria was noted in 9% (95% confidence interval 7% to 12%) of patients with proved urolithiasis. There was no correlation of the degree of obstruction with absent hematuria. Most patients presenting with painful urolithiasis were male (73%), in the fifth decade of life (mean age 47 years), had stones in the mid ureter (32%) or at the ureterovesicular junction (44%) and received opiates for pain control (91%). Of the patients 48% presented between 5 p.m. and 7 a.m. when the radiology department was available only for emergency imaging. The diagnosis was made by CT in half of the patients, who were charged $1,409. The maximal insurance reimbursement was $673. The diagnosis was made by IVP in half of the patients, who were charged $445. The maximal insurance reimbursement was $141.

Hematuria is not universally present in patients with painful urolithiasis and does not correspond to the degree of obstruction. Despite previous reports to the contrary, CT is significantly more expensive for patients than IVP.