【Objective】 To compare the hemostatic effect and safety of single infusion of tranexamic acid with different loading dose before spinal surgery. 【Methods】 150 patients with scoliosis orthopaedic surgery were randomly divided into group C, group H and group L with 50 cases in each group. Before skin incision, group H and group L received intravenous loading dose TXA of 20 mg/kg and 10 mg/kg, respectively, followed by continuous intravenous pumping of TXA of 10 mg/kg/h until the end of the operation. Group C received intravenous infusion of 0.9% sodium chloride injection at the same time. Intraoperative infusion volume, blood loss, red blood cell transfusion volume, urine volume and postoperative drainage volume were recorded. Prothrombin time (PT), activated partial prothrombin time (APTT), D-dimer (D-D), blood platelet count (BPC), hemoglobin (Hb), hematocrit (HCT), tissue plasminogen activator (t-PA) and plasminogen activator inhibitor -1(PAI-1) were detected before and after surgery. Adverse events such as lower extremity deep vein thrombosis (DVT), pulmonary embolism, acute kidney injury (AKI), epilepsy and myocardial infarction were followed. 【Results】 The amount of blood loss and transfusion in group H and group L was lower than that in group C (P<0.05), and that in group H was lower than that in group L (P<0.05). The drainage volume of the three groups decreased gradually from 1 to 3 days after the operation. The drainage volume of group H and group L at different time points was lower than that of group C(P<0.05), and that of group H at different time points was lower than that of group L(P<0.05). Compared with the preoperative results, the postoperative BPC, Hb and HCT in the three groups decreased (P<0.05), and the postoperative D-D and t-PA increased (P<0.05). The postoperative changes of the above indexes in group H and group L were lower than those in group C(P<0.05), and the postoperative changes of the above indexes in group H were lower than those in group L(P<0.05). There was no significant change in PAI-1 in group H and group L (P>0.05), while there was a significant decrease in PAI-1 in group C (P<0.05). B-ultrasonography of both lower limbs showed no DVT formation on 1d, 7d and 28d after surgery, and no adverse events such as pulmonary embolism, AKI, epilepsy and myocardial infarction were found after 28 d follow-up. 【Conclusion】 The application of high load dose of TXA in spinal surgery produces better hemostasis, and it has no effect on the incidence of near and long term postoperative adverse events.

【Objective】 To investigate the effect of adequate amount of tranexamic acid(TXA)before operation on blood loss and safety in posterior lumbar fusion with multiple segments. 【Methods】 A retrospective analysis was conducted on 105 patients with lumbar spinal stenosis, submitted to our hospital for multilevel PLIF, from March 2017 to December 2019. According to the intervention method, they were divided into control group, group A and group B (n =30, 39 and 36, respectively). TXA was not used in the control group. Dripping of saline solution(100 mL) containing TXA 2g and 1g was given in Group A and Group B, and extra intravenous pumping of TXA [10 mg/(kg·h)] during surgery was conducted in Group B besides the pre-operation dripping of TXA. Total blood loss, dominant blood loss, recessive blood loss, intraoperative blood loss, postoperative drainage volume, transfusion rate and hemoglobin (Hb), hematocrit (Hct), prothrombin time international standardized ratio (PT - INR), platelet count (Plt), D - dimer (D - D), C-reactive protein (CRP), neutrophil percentage (NP), alanine aminotransferase (ALT), and blood urea nitrogen (BUN) before and after operation were compared in the three groups. Postoperative drug-related adverse events were traced. 【Results】 1)The total blood loss, dominant blood loss(mL), intraoperative blood loss(mL), drainage volume(mL) within and after 24h after surgery, and the transfusion rate(%) in group A and B were 892.6±193.5 vs 887.7±320.8, 409.1±109.2 vs, 408.6±98.3, 193.7±69.3 vs 189.6±65.6, 130.5±53.4 vs 128.3±53.5, 63.1±17.6 vs 60.9±13.5 and 7.7 (3/39) vs 8.3 (3/36), respectively, which were significantly lower than that in group C as 1 296.8±329.2, 807.6±231.5, 270.9±65.5, 365.4±127.8, 172.3±66.4 and 36.7(11/30), respectively (P< 0.05). There were no significant differences in the above indexes between group A and group B (P < 0.05). The differences in recessive blood loss was not significant by groups(P<0.05). 2) Compared with pre-operation, the levels of Hb, Hct and Plt in the three groups at 3d after operation decreased: Hb(g/L) 91.5±14.0, 107.6±16.4 and 105.9±17.1; Hct(%) 25.6±3.1, 31.2±3.9 and 30.5±4.4; Plt(×10⁹/L)146.6±31.8, 172.8 ±40.1 and 169.7±39.5(P < 0.05); while D-D, CRP and NP increased: D-D(mmol/L)365.6±67.1, 280.9±50.5 and 286.1±53.1; CRP(mg/L): 65.4±22.0, 53.4±19.6 and 56.8±17.7; NP(%): 87.3±15.6, 73.1±13.7, and 71.9±11.8(P < 0.05), and Pt-INR, ALT and BUN showed no significant changes (P > 0.05). The changes of Hb, Hct, Plt, D-D, CRP and NP in group A and B were significantly lower than those in group C at 3 days after operation [Hb (g/L) : 107.6±16.4, 105.9±17.1, 91.5±14.0; Hct (%) : 31.2±3.9, 30.5±4.4, 25.6±3.1; Plt (×10⁹/L) : 172.8 ±40.1, 169.7±39.5, 146.6±31.8; D-D (mmol/L) : 280.9±50.5, 286.1±53.1, 365.6±67.1; CRP (mg/L) : 53.4±19.6, 56.8±17.7, 65.4±22.0; NP (%) : 73.1±13.7, 71.9±11.8, 87.3±15.6] (P < 0.05), and no significant differences in the above index were noticed between group A and B(P> 0.05).3)No lower limb deep vein thrombosis nor pulmonary embolism were found in group A and group B after operation, and all the incisions were healed in the first stage, and no serious complications such as drug allergy, cardiovascular and cerebrovascular accident, epidural hematoma, epilepsy occurred. 【Conclusion】 The preoperative TXA administration with sufficient single dose showed equivalent hemostatic effect in comparison with intraoperative continuous administration additional to preoperative dripping, which is simple and convenient and does not increase the risk of thrombosis.

Key requirements of successful animal behavior research in the laboratory are robustness, objectivity, and high throughput, which apply to both the recording and analysis of behavior. Many automatic methods of monitoring animal behavior meet these requirements. However, they usually depend on high-performing hardware and sophisticated software, which may be expensive. Here, we describe an automatic infrared behavior-monitor (AIBM) system based on an infrared touchscreen frame. Using this, animal positions can be recorded and used for further behavioral analysis by any PC supporting touch events. This system detects animal behavior in real time and gives closed-loop feedback using relatively low computing resources and simple algorithms. The AIBM system automatically records and analyzes multiple types of animal behavior in a highly efficient, unbiased, and low-cost manner.