Factors associated with lower extremity deep venous thrombosis in elderly patients with hip fracture before surgery and their anesthetic characteristics: An analysis of 258 cases

  Background   Hip fracture is one of the main causes of disability in elderly patients. Deep vein thrombosis of the lower extremity following a fracture can significantly increase the length of hospital stay and mortality.

  Objective  To analyze the risk factors of preoperative deep venous thrombosis (DVT) in elderly hip fracture patients over 70 years old, as well as the characteristics of coexisting diseases and anesthesia.

  Methods  From January 2012 to December 2018, clinical data about 258 hip fracture patients over 70 years old admitted to department of anesthesiology, Hainan Hospital of Chinese PLA General Hospital were retrospectively collected and analyzed. The patients were divided into DVT group and non DVT group (NDVT group) according to whether they had DVT before operation. The risk factors of DVT before operation were analyzed by multivariate analysis, and the characteristics of coexisting diseases and anesthesia were statistically analyzed.

  Results  Of the 258 cases, 15 patients (5.8%) had DVT before operation, and 3 of them had inferior vena cava filter before operation. Among the two groups, 152 (58.9%) patients had preoperative ASA grade III - IV, 135 (52.3%) patients received nerve block anesthesia, and 48 (18.6%) patients received general anesthesia. Seventeen patients (6.6%) underwent surgery within 48 hours after fracture. Univariate analysis showed that there were statistically significant differences in anemia 12 (80.0%) vs 116 (48.5%), fracture to operation 14.0 (7.3, 31.8) d vs 9.0 (6.0, 11.0) d between the DVT group and the NDVT group (all P < 0.05). Anemia (OR: 0.296; 95% CI: 0.075-1.170; P=0.083) and fracture to operation time (OR: 1.020; 95% CI: 0.997-1.044; P=0.094) was not independently associated with the occurrence of preoperative deep vein thrombosis.

  Conclusion  This study has not found that preoperative anemia and the time from fracture to operation are independent risk factors for preoperative lower extremity DVT in elderly patients with hip fracture. Nerve block anesthesia is the main anesthesia characteristics for patients with high preoperative ASA and basic disease.