Routine urinalysis in patients with a blunt abdominal trauma mechanism is not valuable to detect urogenital injury.

OBJECTIVE: To investigate whether the routine performance of urinalysis in patients with a blunt trauma mechanism is still valuable.

METHODS: Consecutive patients aged ≥16 years, admitted to a Dutch Level 1 trauma centre between January 2008 and August 2011, were included in this retrospective cohort study. Results of urinalysis (erythrocytes per µL) were divided into no, microscopic or macroscopic haematuria. Patients were divided into four groups based on whether a urinalysis was performed or not, with or without imaging for urogenital injury. Main outcome measures were the presence of urogenital injury and whether the findings on urine specimen and/or imaging led to clinical consequences.

RESULTS: A total of 1815 patients were included. The prevalence of intra-abdominal and urogenital injuries was 13% and 8%, respectively. In 1363 patients (75%), urinalysis was performed and 1031 patients (57%) underwent imaging for urogenital injury as well. The presence of macroscopic haematuria (n=16) led to clinical consequences in 73% of the patients (11 out of 15), regardless of the findings on imaging. Microscopic haematuria on urinalysis in combination with no findings on imaging led to clinical consequences in 8 out of 212 patients (4%). Microscopic haematuria on urinalysis in patients who did not have imaging for urogenital injury did not lead to clinical consequences (0 out of 54 patients; 0%). All the 8 patients who underwent an intervention had positive findings on imaging.

CONCLUSIONS: The results do not support the routine performance of urinalysis in patients admitted with a blunt trauma mechanism. Although urinalysis could be valuable in specific patient populations, we should consider omitting this investigation as a routine part of the assessment of trauma patients.