Effect of different doses of low molecular weight heparin on coagulation mechanism in thoracic cancer surgery

Objective To study the effect of different doses of low molecular weight heparin on coagulation mechanism after thoracic surgery. Methods A prospective randomized controlled study was conducted to select patients who underwent thoracic cancer surgery (lung cancer, esophageal cancer, cardiac cancer) from February 2015 to October 2018. According to the Caprini risk assessment model, 101 patients with high risk of deep venous thrombosis were randomly assigned to groups A, B and C. Control group A (34 cases) did not use low molecular weight heparin; group B (34 cases) used prophylactic low molecular weight heparin calcium after operation; group C (33 cases) used therapeutic low molecular weight heparin calcium after operation. The platelet count (PLT), fibrinogen (FIB), prothrombin time (PT), D-dimer (D-D), postoperative thoracic drainage and lower extremity deep vein ultrasound were observed before and after operation. Results The incidence of deep venous thrombosis (DVT) was 11.76% in group A, 2.94% in group B and 3.03% in group C, with significant difference between group B and C and group A (P 0.05). The levels of FIB and D-D after operation were significantly higher than those before operation (P<0.05), but the levels of indexes in group B and C were significantly lower than those in group A (P<0.05). Conclusions Low molecular weight heparin calcium does not increase bleeding and thoracic drainage, which is beneficial to improve the hypercoagulable state of patients and has good safety. However, the use of low molecular weight heparin calcium in different doses (prevention amount and treatment amount) has no significant effect on the occurrence of lower extremity deep vein thrombosis and coagulation index. Key words: Thoracic neoplasms; Thoracic surgical procedures; Heparin, low-molecular-weight; Blood coagulation tests