A nomogram to predict arterial bleeding in patients with pelvic fractures after blunt trauma: a retrospective cohort study.

Background: Pelvic bone fractures are one of the biggest challenges faced by trauma surgeons. Especially, the presence of bleeding and hemodynamic instability features is associated with high morbidity and mortality in patients with pelvic fractures. However, prediction of the occurrence of arterial bleeding causing massive hemorrhage in patients with pelvic fractures is difficult. Therefore, the aim of this study was to develop a nomogram to predict arterial bleeding in patients with pelvic bone fractures after blunt trauma.

Methods: The medical records of 1404 trauma patients treated between January 2013 and August 2017 were retrospectively reviewed. Patients older than 15 years with a pelvic fracture due to blunt trauma were enrolled (n = 148). The pelvic fracture pattern on anteroposterior radiography was classified according to the Orthopedic Trauma Association/Arbeitsgemeinschaft fur Osteosynthesefragen (OTA/AO) system. Multivariable logistic regression modeling was used to determine the independent risk factors for arterial bleeding. A nomogram was constructed based on the identified risk factors.

Results: The most common pelvic fracture pattern was type A (58.8%), followed by types B (34.5%) and C (6.7%). Of the 148 patients, 28 (18.9%) showed pelvic arterial bleeding on contrast-enhanced computed tomography or angiography, or in the operative findings. The independent risk factors for arterial bleeding were a type B or C pelvic fracture pattern, body temperature < 36 °C, and serum lactate level > 3.4 mmol/L. A nomogram was developed using these three parameters, along with a systolic blood pressure < 90 mmHg. The area under the receiver operating characteristic curve of the predictive model for discrimination was 0.8579. The maximal Youden index was 0.1527, corresponding to a cutoff value of 68.65 points, which was considered the optimal cutoff value for predicting the occurrence of arterial bleeding in patients with pelvic bone fractures.

Conclusions: The developed nomogram, which was based on the initial clinical findings identifying risk factors for arterial bleeding, is expected to be helpful in rapidly establishing a treatment plan and improving the prognosis for patients with pelvic bone fractures.