Disproportionate Acidosis After Traumatic Bladder Rupture: A Case-Control Study

Abstract

Background: Traumatic bladder injury is rare and often missed on initial evaluation. We sought to identify early markers of bladder injury with a high sensitivity.

Methods: A retrospective review from 1999 to 2008.

Results: There were 28 patients diagnosed with traumatic bladder injury. The most common mechanism was car accidents with pelvic fractures. 93% (26) of the patients presented with significant metabolic acidosis, without evidence of hemorrhagic shock. For intra- and extraperitioneal bladder ruptures, the mean hemoglobin level on arrival was 12.4 + 2.0 (range 9.0-16.0) and 11.4 + 1.9 (range 8.2-14.7). The average pH on arrival for intraperitoneal ruptures was 7.22 + 0.16 (range 6.86-7.37) and for extraperitoneal ruptures, 7.22 + 0.16 (range 6.85-7.37). The pH improved in all patients with intraperitoneal rupture after surgical repair, up to a mean of 7.27 + 0.11 (range 7.06-7.36, p = 0.5) within 12 h. Extraperitoneal ruptures recovered more quickly with a pH after catheter drainage of 7.34 + 0.04 (range 7.27-7.37, p = 0.1) within 12 h. The ISS for intraperitoneal and extraperitoneal ruptures were similar, 30 + 12 (range 13-57) and 32 + 13 (range 13-57, p = 0.7). A cohort of trauma patients, matched by ISS, age, and pelvic fracture, but without bladder rupture, was used for comparison. Their mean ISS was 30 + 10 (range 14-57). The average pH for this group on arrival was 7.33 + 0.11 (range 7.16-7.42), and 47% of these patients had a normal pH. There was a significant difference between the pH on arrival in the ruptured compared to the nonruptured cohort (intraperitoneal pH 7.22, p = 0.008, extraperitoneal pH 7.22, p = 0.02). Three patients died (mortality 10.7%).

Conclusions: Disproportionate acidosis in the trauma patient is a sensitive indicator of bladder injury, especially with a pelvic fracture or hematuria. Fully resuscitated patients with persistent acidosis and an appropriate mechanism should be evaluated for bladder injury.

Keywords: Acidosis; Bladder injury; Bladder rupture; Pelvic fracture.