Effect of different factors on predicting patient mortality beyond the NACA classification: a multivariate analysis of more than 2,000 polytrauma patients

Background The National Advisory Committee for Aeronautics (NACA) score is widely used to assess polytrauma patients. NACA scores of 4 and 5 indicate severe and potentially life-threatening injuries. However, these two categories are rather broad, with a large variety of conditions within each level. Aim of this study was to investigate a large cohort of NACA 4 and NACA 5 trauma patients and quantify the impact of individual factors on the mortality risk. Methods The polytrauma registry of the Lugano Regional Hospital affiliated to the National Swiss Trauma Registry (STR) was retrospectively analysed to investigate all patients admitted between 2015 and 2023 with a NACA score of 4 or 5. Out of 2,152 patients, 1,684 were NACA 4 and 468 were classified as NACA 5. Extracted parameters included age, mechanism of injury, NACA score, prehospital variables and hospital variables, and patient diagnoses. Univariate and multivariate analyses were performed for all patients combined and separately for NACA 4 and NACA 5 subgroups. Results A total of 121 patients died during hospitalization. The multivariate analysis of the prehospital variables showed that NACA score (OR 2.96), age (OR 1.11), Glasgow Coma Scale (GCS) (OR 0.78), reanimation (OR 7.22), and administration of vasoactive drugs (OR 2.38) were statistically significant independent risk factors for all included patients (p < 0.05). In the NACA 4 subgroup analysis only age (OR 1.13) and GCS (OR 0.69) emerged as statistically significant predictors of mortality (p < 0.05). In the NACA 5 subgroup, age (OR 1.09), GCS (OR 0.28), and administration of vasoactive drugs (OR 2.40) emerged as statistically significant predictors of mortality (p < 0.05). Conclusion This study demonstrated that different factors can influence the mortality risk of polytrauma patients beyond the mere NACA 4 and 5 classification, including reanimation, administration of vasoactive drugs, GCS, and age. These findings highlight the association between specific clinical parameters and the mortality risk, whose early identification is paramount for a more targeted management of polytrauma patients. Level of Evidence (LoE): III