What laboratory test should be performed for suspected bladder injury in blunt trauma?

In the context of suspected bladder injury resulting from blunt trauma, a urinalysis is the most relevant laboratory test to perform. When there is concern for potential bladder damage, analyzing the urine can provide critical information about the state of the bladder and the possibility of injury.

One of the primary objectives of performing a urinalysis in this scenario is to detect the presence of blood (hematuria) in the urine, which is a common indicator of an injury to the urinary tract, including the bladder. If the bladder is injured, blood may be present in the urine due to the disruption of blood vessels within or around the bladder. This information can help guide further management, which could include imaging studies like a CT scan or cystography to confirm the diagnosis of bladder injury.

Other tests, such as a complete blood count, liver function tests, and coagulation profile, are less specific for bladder injuries and would not provide immediate information about bladder integrity. While they might be necessary in the assessment of overall trauma or in managing other potential injuries, they do not directly address suspected bladder trauma. Thus, a urinalysis is the most pertinent test in this situation for evaluating potential bladder injury.