Significance of the vacuum phenomenon in patients with trauma evaluated by whole-body computed tomography.

Background: Severely traumatized patients undergo whole-body computed tomography (WCT) to detect lethal anatomical injuries. When checking the images, we have sometimes recognized minute gas (the vacuum phenomenon [VP]) near the traumatized lesions. Accordingly, we investigated the significance of the VP in patients with trauma.

Basic Procedures: From April to October 2013, a medical record review was retrospectively performed for all patients with trauma. The exclusion criteria included an age more than 60 years, patients who did not receive the WCT, scan and those in cardiopulmonary arrest on arrival. The subjects were divided into 2 groups: a VP group (n=19), which included patients who had the VP, and a control group (n=49).

Main Findings: There were no significant differences between the 2 groups with regard to age, the mechanism of injury, or the survival rate. In contrast, the ratio of women, the Injury Severity Score, and the duration of hospitalization in the VP group were significantly higher than those in the control group. The greatest number of the VP was located at or near rib fractures, followed by joint spaces that experienced a traumatic impact.

Principal Conclusion: This study demonstrated that the VP tended to be observed most often in severely traumatized female cases. The VP is observed at locations that experience a traumatic impact, so an analysis of the VP may be useful to elucidate the mechanism of injuries. The presence of traumatic VP itself does not influence the final outcome.