Contemporary management of isolated free fluid on computed tomography scan in blunt abdominal trauma-experience from a Level 1 trauma centre in New Zealand

AIMS: The management of patients with blunt abdominal trauma (BAT) who have isolated free fluid (IFF) with no solid organ injury (SOI) on computed tomography (CT) remains controversial. This study aims to determine if the volume of free fluid (FF) is a predictor of the need for operative management of traumatic intra-abdominal injuries, by reviewing the local cumulative experience with IFF at a major trauma centre in New Zealand. METHODS: A retrospective study was undertaken over nine years at a Level 1 trauma centre in New Zealand. Patients aged over 15 years who sustained BAT and had IFF with no SOI demonstrated on CT were included. All CT scans and patient notes were reviewed. The volume of free fluid was classified by the local interpreting radiologist on the CT report. RESULTS: Eighty-two out of 1,177 BAT patients (7%) had IFF with no SOI on CT. Thirty-eight percent were males, with a median age of 31 years. Nineteen (23%) underwent immediate operative management (OM) at the time of presentation. The remaining 63 patients had a trial of non-operative management (NOM), 10 (16%) of which were unsuccessful and required an operation. Overall, 29 patients (35%) required operative management. Eighty-nine percent of the OM group and 90% who failed NOM had positive operative findings, giving an overall true positive of 32%. CONCLUSIONS: The presence of IFF in itself is not an absolute indication for operative exploration and many patients with trace IFF can be managed non-operatively. Small amounts of IFF should be regarded with suspicion, and moderate or large amounts of fluid are likely to require operative exploration. Further work must make use of clinical scoring systems and laparoscopy or laparotomy to assess patients at high risk of surgically remediable intra-abdominal injury post BAT.