Tranexamic Acid Plus Low-dose Epinephrine Reduces Blood Loss in Total Knee Arthroplasty: A Systematic Review and Meta-analysis.

The present study assessed the effectiveness of the combined administration of tranexamic acid (TXA) plus low-dose epinephrine in primary total knee arthroplasty (TKA). We searched the following Chinese electronic databases: China National Knowledge Infrastructure and WanFang Data. We also searched the following English electronic databases: PubMed, Embase, Web of Science, and Central Register of Controlled Trials. To search for additional eligible studies, we also used Google's search engine. All randomized controlled trials (RCT) comparing TXA plus low-dose epinephrine (Combined group) and TXA alone in TKA were systematically searched. The primary outcomes were total blood loss, hidden blood loss, the requirement for transfusion, maximum hemoglobin (Hb) drop, and deep venous thrombosis (DVT). Drainage volume, operation time, length of stay, hospital for special surgery (HSS) score, and range of motion (ROM) were considered as secondary outcomes. Subgroup analyses were performed to assess the benefits of using a tourniquet and the application routes of topical or intravenous TXA between the two groups. Statistical analysis was assessed using RevMan 5.3 software. Four independent RCT were included involving 426 patients, with 213 patients in the Combined group and 213 patients in the TXA alone group. In the Combined group there was significant reduction in total blood loss (MD, 204.70; 95% CI, -302.76 to -106.63; P < 0.0001), hidden blood loss (MD, 185.63; 95% CI, -227.56 to -143.71; P < 0.00001), drainage volume (MD, 93.49; 95% CI, -117.24 to -69.74; P < 0.00001), and maximum Hb drop (MD, 5.33, 95% CI, -6.75 to -3.91; P < 0.00001). No statistical differences were found postoperatively in terms of the requirement for transfusion (risk ratio, 0.52; 95% CI, 0.26-1.04; P = 0.06), operation time (MD, 0.85; 95% CI, -2.62 to 4.31; P = 0.63), length of stay (MD, -0.02; 95% CI, -0.52 to 0.47; P = 0.93), HSS score (MD, 0.78; 95% CI, -0.36 to 1.92; P = 0.18), and ROM (MD, 1.40; 95% CI, -1.01 to 3.81; P = 0.26), and not increasing the risk of DVT (risk ratio, 1.00; 95% CI, 0.33 to 3.02; P = 1.00) in the two groups. This meta-analysis demonstrated that the administration of tranexamic acid plus low-dose epinephrine is a safe and efficacious treatment to reduce total blood loss, hidden blood loss, drainage volume, and maximum Hb drop in primary TKA, without increasing the risk of DVT in primary THA.