DVT is classically caused by stasis, hypercoagulability, and endothelial injury, called Virchow's Triad, which occurs frequently in polytrauma patients[24]. Meanwhile, in cases of multiple traumatic injuries, bleeding can result in the activation of blood clotting factors, potentially resulting in DVT [25]. Following the initial survival of the acute phase on day one, the primary worries for these individuals involve severe complications that could be dangerous to life, such as DVT[26]. The occurrence of DVT in trauma cases ranges from 7–60%, varying based on patient characteristics, detection techniques, and preventive measures[27, 28]. In our literature, the incidences of DVT were 32.1% in polytrauma patients with TBI. In our previous literature, significant difference in the DVT rate between polytrauma patients with TBI and those with isolated TBI (31.9% vs 20.2%, P < 0.05), despite similar GCS scores. Polytrauma patients with TBI had a higher DVT rate than polytrauma patients without TBI (31.9 versus 22.0%, P < 0.05), even though ISS was not different[1].A possible explanation for this might be that many people who suffer TBIs have immobility, weakness, and bed rest, as well as other injuries that can increase their risk of venous stasis[12]. DVT is three to four times more likely to occur in people suffering from traumatic brain injury (TBI) according to a 2009 study [29].
Our research identified older age, smoking, elevated D-dimmer levels, higher ISS scores, lower GCS scores, mechanical ventilation, and increased use of vasoactive drugs as risk factors for DVT in polytrauma patients with TBI. DVT is commonly seen as a condition that affects older individuals more, with a much higher chance of developing DVT in individuals aged 40 and above than in younger patients [30].Additionally, the likelihood of developing DVT increases by about two times for each additional ten years of age [30]. D-dimer serves as an indicator of both the creation and breakdown of fibrin [31]. A bioinformatics study was done to look back and find neurosurgical patients who were tested for serum D-dimer levels and had a VDU to check for DVT. The research determined that the D-dimer procedure was successful in detecting DVT in patients who were hospitalized[14]. A clear connection has been found between DVT and the duration of ventilator use, as extended use of a ventilator leads to more time spent lying flat [32].
A nomogram was created and validated internally to predict DVT on an individual basis in polytrauma patients with TBI. The nomogram incorporates seven items of the Age, Smoking, ISS, GCS, D-dimer, MV and AVD. The risk score's performance was deemed satisfactory in the training cohort, achieving an accuracy of 0.78 based on AUC. Utilize the nomogram for predicting DVT to assess the likelihood of DVT in a patient admitted to the hospital. Typically, the seven necessary variables for assessing the risk of DVT are easily accessible. As showed in Fig. 1, the nomogram aligns well with our everyday clinical practice and is user-friendly. The calibration graphs and decision curve analysis of the nomogram for predicting DVT showed promise for practical use in clinical settings. In cases where the patient's likelihood of developing DVT is deemed low, the healthcare provider may opt for observation, while high-risk assessments could warrant intensive treatment or hospitalization in the ICU
The research has some restrictions, particularly due to its retrospective nature that limits the study's design. During our investigation, the detection of DVT was mainly based on ultrasound tests performed while the patient was in the hospital, which could result in missing DVT cases after discharge and minor DVT incidents. Furthermore, the inclusion of both surgical and non-surgical patients in the study may introduce an additional source of bias. Moreover, while the nomogram demonstrated strong performance, it is essential to conduct multicenter clinical validation to assess the external applicability of our nomogram.