Ask an answerable question (PICO)：
As the population ages, the number of patients undergoing total knee arthroplasty (TKA) increases year by year. Studies shows that about 11-21% of blood transfusion are received in the surgery and blood transfusions may present some potential risks, such as infection, renal failure and even death. Tranexamic acid (TXA) is a synthetic anti-fibrinolytic agent that inhibits fiber lysis and plasmin activation to achieve hemostasis. Clinically, TXA is used in local and intravenous injections. The effect of local injection on reducing blood loss and blood transfusion rate is better than that of intravenous injection. The purpose of this study is to investigate whether local injection of TXA in total knee arthroplasty can reduce postoperative bleeding volume and blood transfusion rate.
The Method and Analysis of Literature Review：
Use P, I, C, O related Chinese and English keywords, synonyms, cut-off words, MeSH terms, use Boolean Logic "AND", "OR" to search the database, exclude the disagreement with the theme and repeat the article, select five Articles in accordance with PICO, one for systematic review (SR) and four for randomized controlled trial (RCT).
The Critical Appraisal Skills Programme(CASP, 2013) and level of Evidence published by CEBM(Oxford University, 2011) was used to appraise the quality of the reviewed studies. The SR literature is Level 1, and the four RCTs are For Leve 2, the searched literature supports local use of TXA to effectively reduce TKA bleeding and transfusion rates, as well as reduce the proportion of postoperative drainage tube blood and hemoglobin, Especially the high concentration is better than low concentration.
Clinical Application of Evidence：
The team examined 146 patients who performed TKA surgery in 104 years. Those who received TXA had a significant decrease in total drainage amount and transfusion rate compared with those who did not receive TXA, which was consistent with the literature. Based on SR inference, The high concentration group was TXA 6 ampoules+20c.c. N/S (30mg/mL), and the low concentration group was TXA 3 ampoules+35c.c. N/S (15mg/mL) to compare the postoperative blood loss and blood transfusion rate. Patients were randomly allocated in a double-blind manner. All patients underwent the same anesthesia and surgical procedures during the operation. During the hospitalization, the three-shift nursing staff recorded the Hb values, drainage amount, number of blood transfusions.
Evaluation of Effectiveness：
The total number of people collected was 174, with an average age of 70.3 years old. High concentration group had a total of 91 (52.3%) patients with 25 males and 66 females. low concentration group had a total of 83 (48.7%) patients with 23 males and 60 females. On the first day after operation, the drainage amount of high concentration group was significantly less than that of low concentration group (133±129.4ml, 182.4±161.6ml, p<0.01), and there was no significant difference between the two groups in terms of the drainage amount on the second day after operation (175.5±103.2ml, 183.2±112.0ml, p=0.63), total drainage amount(308.6±210.1ml, 365.6±250.7ml, p=0.05) and total blood loss (618.3±282.5ml, 641.6±275.6ml, p=0.28). 6 patients (6.6%) in high concentration group received 14 bags of blood transfusion, 9 patients in low concentration group (10.8%) received a total of 18 bags of blood transfusion, and the number people with blood transfusions (p<0.01) and the number of blood transfusion units (p<0.01) were significantly different.
Conclusions and Recommendations：
For patients with TKA, it is recommended that intraoperative local injection of TXA can reduce postoperative bleeding and blood transfusion rate. In particular, local injection of high-concentration TXA can reduce drainage amount on the first postoperative day, transfusion rate, and number of transfusion units. It can reduce the cost of medical care, the burden of nursing care, and the patient's and family's concerns about adverse reactions to blood transfusion, but in the future, need more samples can be included and further confirmation of different concentrations or doses of TXA use in TKA surgery the effect of reduction postoperative blood loss blood transfusion rate.