In patients with multiple injuries, potentially fatal injuries are treated first. Early internal fixation needs to adhere to the principle of the preservation of life as the first goal.8 After the patient's vital signs are initially stable, other treatments can be initiated. Epiphyseal growth is rapid in patients with brain trauma. A large number of epiphyses in the subclavian region may compress the subclavian structure, stimulate the brachial plexus nerve, and cause traumatic arthritis. The internal fixation of fractures should be performed early.9 However, the incidence of venous thromboembolism (VTE) in patients with trauma is high and can be life-threatening after trauma and cause various complications. Therefore, the prevention of DVT is very important in the treatment of trauma patients. DVT and pulmonary embolism (PE) are collectively referred to as VTE events.10 In clinical experience, chest fractures, pelvic fractures and limb fractures, craniocerebral trauma and bed rest are high risk factors for VTEs.11 This study analyzed various factors in trauma patients and provides a theoretical basis for the formulation of clinical anticoagulation strategies.
In patients with multiple traumatic injuries, most deaths are caused by traumatic brain injury (TBI). According to the GCS, clinical TBI can be divided into mild, moderate and severe. The related permanent disability rates are 10%, 60% and 100%, respectively.12 The inclusion criteria in this study were patients with mild injuries, with a GCS score of 13 or higher. The incidence of VTE and its related complications increases the length of hospital stay and medical costs; it is also the most common preventable cause of death in hospitals.13 The prevalence of DVT in trauma and orthopedic patients is estimated to be 1.16%. With the continuous improvement of medical knowledge and treatment methods, DVT can be controlled and prevented.14 In this study, some patients experienced a DVT of the lower limbs. Despite drug and mechanical anticoagulation, craniocerebral injury, chest trauma, and bed rest are still high risk factors for DVT. Hospitalization for acute trauma is an independent risk factor for incident VTE; however, VTE preventive measures increase the risk of bleeding in patients with acute trauma.15 According to previous experience, there is concern regarding the worsening of intracranial hemorrhage in patients with brain trauma, and drugs are not usually used in the early stage after injury.16 According to a 2011 study by Scudday with 812 patients with craniocerebral trauma, the incidence of VTE was lower in patients receiving preventive drugs than in those not receiving preventive drugs.17 Shelan proposed in 2012 that low-risk TBI patients start enoxaparin treatment within 24 hours after injury.18 In this study, based on the Caprini risk scores of patients admitted to the hospital and the BTF recommendations,19 if the injury is stable and the benefit of prevention outweighs the risk of bleeding progression, then preventive drugs should be administered. All patients at high and very high risk were treated with anticoagulation drugs in this study.
Many risk factors have been identified for venous thrombosis that alter blood flow, activate the endothelium, and increase blood coagulation. Three important factors affecting thrombosis are blood flow, blood composition and blood vessels. Severe trauma often leads to the emergence of the triad of Virchow, with hypercoagulability, endothelial damage, and venous stasis, which increases the risk of thromboembolism.20 Prolonged bed rest and limb fractures in the patients in this study promoted venous stasis. Increased hematocrit levels, increased FIB levels, and shortened clotting time in patients with trauma can lead to the local accumulation of coagulation activation products and cause hypercoagulability in patients.21 In this study, patients’ blood coagulation was monitored to determine whether there was thrombosis in the blood.
The contraindications caused by brain trauma often limit the choice of strategies to prevent VTE in trauma patients. This study mainly explores the choice of methods to prevent DVT in trauma patients. The available methods for thrombosis prevention in trauma patients are divided into pharmacological anticoagulation, mechanical prevention and inferior vena cava filters (IVCs).22 LMWH was used for anticoagulation in this study. Its advantages are fast pharmacokinetics, convenient administration and few side effects; it has strong activity against Xa because of its low molecular weight and charge.23 LMWH became the most (or only) effective method for preventing DVT in trauma patients in the late 1990s.24 Several studies in recent years have shown that LMWH reduces the incidence of DVT in trauma patients.25 Due to the need for safer and more effective preventive measures in patients with high-risk trauma, the experimental group in our study used drugs and mechanical anticoagulation. Conventional mechanical prevention includes graded compression socks (GCS), sequential pneumatic compression equipment (PCD), and pneumatic sole (A-V) foot pumps.26 These devices reduce the risk of thrombosis and related bleeding by reducing the luminal diameter of the veins, which leads to an increase in venous blood flow velocity; they are often used in the treatment of trauma patients.27 Kurtoglu prospectively randomized 120 trauma patients and compared PCDs and LMWH with regard to the prevention of VTE; the authors concluded that PCDs can be safely used to prevent DVT.28 It is recommended to combine LMWH in with intermittent pneumatic pressure devices. Based on the results and conclusions of this study, the combination of PCD and LMWH appears to be an advantageous way to prevent DVT in patients with multiple traumatic injuries.
According to the American College of Chest Physicians (ACCP) guidelines for the prevention of VTE in 2008,29 LMWH should be administered as soon as possible to patients with severe trauma; an acceptable alternative is to combine LMWH with the best mechanical methods. For patients with severe trauma, ACCP recommends therapy to prevent thrombosis until discharge, and patients in this study received therapy for the duration of hospitalization. The Eastern Trauma Surgery Association (EAST) recommends secondary LMWH for patients with multiple traumatic injuries as an anticoagulation therapy. The level III recommendation is that PCD alone can be used in patients with partial head injuries.30 The 9th ACCP guidelines only suggest the “use of low dose unfractionated heparin (LDUH), LMWH, or mechanical prophylaxis over no prophylaxis” in major trauma patients and give this recommendation the lowest grade of evidence.31 Based on the latest guidelines for the prevention of traumatic DVT, in this study, the clinical effectiveness of LMWH combined with PCD was analyzed and compared with that of LMWH alone; the results show that LMWH should be used in trauma patients.32 Obviously, VTE is one of the main problems in trauma patients. As demonstrated in the extensive literature on preventing VTE in trauma patients, there is currently a lack of high-quality clinical studies supporting the selection of VTE preventions methods by clinicians for this group of patients. Although there is no preventive method that can completely prevent VTE, it is clear that without precautionary measures, the incidence of DVT is higher, which may increase the risk of VTE-related morbidity and mortality. Although LMWH anticoagulation was used in all patients in this study, the best VTE prevention strategy in trauma patients remains controversial. Large-scale, randomized prospective clinical studies are needed to provide evidence regarding the optimal clinical VTE prevention measures in clinical practice.
This study has some limitations, including the retrospective data collection of case records from outpatient databases, a small sample size, and a short study period. Further research with a longer study period is needed to collect more cases. Multicenter follow-up in a prospective study is needed. In addition, the changes in index values at multiple time points, the risk of thrombosis over a long period of time, and different doses of drugs need to be investigated. Embedding the VTE risk assessment scale in electronic medical records and guiding intervention based on those scores can effectively improve VTE prevention and control strategies and reduce the incidence of VTE in the hospital. Although angiography is the gold standard for diagnosing DVT, vascular Doppler ultrasound was used in this study because of its noninvasive nature and relatively low cost. In addition, our records allowed the calculation of infection rates during hospitalization. The advantage of this study is that the results provide clinical evidence for clinicians selecting anticoagulation regimens for patients with multiple traumatic injuries.