Higher enhanced computed tomography attenuation value of the aorta is a predictor of massive transfusion in blunt trauma patients

Abstract

Objective: Several scoring systems have been developed to identify patients who require massive transfusion (MT) after major trauma to improve survival. The primary goal of this study was to investigate the usefulness of enhanced computed tomography attenuation values (CTAVs) of major vessels to determine the need for MT in patients with major blunt trauma.

Methods: This single-center retrospective cohort study evaluated patients aged 16 years or older who underwent contrast-enhanced computed tomography scan of the torso after major blunt trauma. The CTAVs of six major vessel points in both the arterial and portal venous phases at initial computed tomography examination were assessed and compared between the MT and the no MT group. The capability of enhanced CTAVs to predict the necessity for MT was estimated based on the area under the receiver operating characteristic curve.

Results: Of the 254 eligible patients, 36 (14%) were in the MT group. Patients in the MT group had significantly higher CTAVs at all sites except the inferior vena cava in both the arterial and portal venous phases than that in the no MT group. The descending aorta in the arterial phase had the highest accuracy for predicting MT, with an AUROC of 0.901 (95% confidence interval, 0.855 to 0.947; P<0.001).

Conclusion: Initial elevation of enhanced CTAV of the aorta is a predictor for the need for MT. A higher CTAV of the aorta should alert the trauma surgeon or emergency physician to activate their MT protocol.

Keywords: Computed tomography attenuated value; Massive transfusion; Wounds and injuries.

Fig. 1.

Six points of measurement of enhanced computed tomography attenuation values: 1) main pulmonary artery at the level of its bifurcation, 2, 3) ascending aorta and descending aorta at the same level (A), 4) abdominal aorta at the left renal artery branching level (B), 5) common femoral artery on the right (C), and 6) inferior vena cava 25 mm above the right renal vein (D).

Fig. 2.

Correlation between computed tomography attenuation values of the ascending aorta in the arterial phase and heart rate (HR) (A), systolic blood pressure SBP (B), lactate level on arrival (C), or requirement of red blood cells (RBCs) within 24 hours after arrival (D). Filled circles show the massive transfusion group (n=36) and open circles show the no massive transfusion group (n=218). The diagonal line represents a linear fit of the data. AsA_A, ascending aorta in the arterial phase.

Fig. 3.

Receiver operating characteristic curve of absolute computed tomography attenuation values at the descending aorta in the arterial phase for prediction of massive transfusion (A) and receiver operating characteristic curve of computed tomography attenuation values adjusted according to the iodine dose per body weight at the ascending aorta in the arterial phase for prediction of massive transfusion (B). AUROC, area under the receiver operating characteristic curve.