The flatness index of inferior vena cava is useful in predicting hypovolemic shock in severe multiple-injury patients.
BACKGROUND
Computed tomography (CT) signs of hypovolemic shock have been reported previously. Whether these signs can be used to clinically predict hypovolemic shock remains unclear.


OBJECTIVE
To investigate the predictive value of CT signs for hypovolemic shock in severe multiple-injury patients.


METHODS
The clinical and multi-slice spiral CT (MSCT) data from 63 severe multiple-injury patients admitted to our trauma center from January 2008 to December 2011 were reviewed. The caliber of the inferior vena cava (IVC) and abdominal aorta, and mean CT value of the abdominal organs in both the early and the delayed phases were measured. The patients were divided into two groups, a shock group (n = 34) and a stable group (n = 29), based on the occurrence of hypovolemic shock within 24 h after the CT scan. Receiver operating characteristic curve (ROC) analysis was performed to assess the predictive accuracy of these signs for hypovolemic shock.


RESULTS
The shock group, compared to the stable group, had a higher Injury Severity Score (30 ± 8 vs. 22 ± 6, respectively, p < 0.001), shock index (1.17 ± 0.37 vs. 0.96 ± 0.33, respectively, p = 0.019), and lactate level (3.27 ± 0.69 mmol/L vs. 2.56 ± 0.89 mmol/L, respectively, p = 0.001). Among all the CT signs, the flatness index of IVC had the largest area under the curve (0.833) in ROC analysis, with sensitivity of 73.5% and specificity of 86.2%, higher than traditional indices and other CT signs. The optimal diagnostic cutoff value for the flatness index of IVC was 3.02.


CONCLUSIONS
MSCT can provide useful information for predicting hyovolemic shock in severe multiple-injury patients. An IVC flatness index > 3.02 suggests the presence of hypovolemic shock in severe multiple-injury patients.
State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing, China.
Yang
Y
Li
Lian-yang
LY
Zhang
Yi
Y
Wang
Wei-guo
WG
Zhang
D000293:Adolescent; D000328:Adult; D000368:Aged; D019540:Area Under Curve; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009104:Multiple Trauma / Q000000981:diagnostic imaging*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012769:Shock / Q000000981:diagnostic imaging*; D036542:Tomography, Spiral Computed / Q000379:methods*; D014682:Vena Cava, Inferior / Q000000981:diagnostic imaging*; D055815:Young Adult
diagnosis; hypovolemic shock; multi-slice spiral computed tomography; multiple injury; trauma