Perioperative Blood Conservation: Guidelines to Practice

The Optimal Dose, Efficacy and Safety of Tranexamic Acid and Epsilon-Aminocaproic Acid to Reduce Bleeding in TKA: A Systematic Review and Bayesian Network Meta-analysis

OBJECTIVE

The optimal dose and efficacy of tranexamic acid (TXA) and epsilon-aminocaproic acid (EACA) in total knee arthroplasty (TKA) were under controversial, and we aimed to make comparisons between different doses of TXA and EACA in intravenous (IV) or intra-articular (IA) applications in patients undergoing TKA.

METHODS

This network meta-analysis was guided by the Priority Reporting Initiative for Systematic Assessment and Meta-Analysis (PRISMA). According to the administrations of antifibrinolytic agents, patients in eligible studies were divided into three subgroups: (i) IA applications of TXA and EACA; (ii) IV applications (g) of TXA and EACA; (iii) IV applications (mg/kg) of TXA and EACA. Total blood loss (TBL), hemoglobin (HB) drops and transfusion rates were the primary outcomes, while drainage volume, pulmonary embolism (PE) or deep vein thrombosis (DVT) risk were the secondary outcomes. A multivariate Bayesian random-effects model was adopted in the network analysis.

RESULTS

A total of 38 eligible trials with different regimens were assessed. Overall inconsistency and heterogeneity were acceptable. Taking all primary outcomes into account, 1.0-3.0 g TXA were most effective in IA applications, 1-6 g TXA and 10-14 g EACA were most effective in IV applications (g), while 30 mg/kg TXA and 150 mg/kg EACA were most effective in IV applications (mg/kg). None of the regimens showed increasing risk for pulmonary embolism (PE) or deep vein thrombosis (DVT) compared with placebo.

CONCLUSION

0 g IA TXA, 1.0 g IV TXA or 10.0 g IV EACA, as well as 30 mg/kg IV TXA or 150 mg/kg IV EACA were most effective and enough to control bleeding for patients after TKA. TXA was at least 5 times more potent than EACA.

Combination of Intravenous and Intra-Articular Application of Tranexamic Acid and Epsilon-Aminocaproic Acid in Primary Total Knee Arthroplasty: A Prospective Randomized Controlled Trial

OBJECTIVE

There were limited randomized controlled trials (RCTs) of epsilon-aminocaproic acid (EACA) versus tranexamic acid (TXA) in total knee arthroplasty (TKA). The aim of the study was to compare the efficacy and safety of TXA and EACA in the combination of intravenous (IV) and intra-articular (IA) administration on reducing blood loss in patients following primary TKA.

METHODS

From January 2020 to January 2021, a total of 181 patients undergoing a primary unilateral TKA were enrolled in this prospective randomized controlled trial. Patients in the TXA group (n = 90) received 20 mg/kg of intravenous TXA preoperatively, 1 g of intra-articular TXA intraoperatively, and three doses of 20 mg/kg intravenous TXA at 0, 3, 6 h postoperatively. Patients in the EACA group (n = 91) received 120 mg/kg of intravenous EACA preoperatively, 2 g of intra-articular EACA intraoperatively, and three doses of 40 mg/kg intravenous EACA at 0, 3, 6 h postoperatively. The primary outcomes were total blood loss (TBL), transfusion rates and drop of hemoglobin (HB) level. The secondary outcomes included postoperative hospital stays and postoperative complications. The chi-square tests and Fisher's exact tests were utilized to compare categorical variables, while the independent-samples t-tests and Mann-Whitney tests were used to compare continuous variables.

RESULTS

The patients who received TXA averaged less TBL than the patients who received EACA (831.83 ml vs 1065.49 ml, P = 0.015), and HB drop in TXA group was generally less than that of EACA group on postoperative day 1 and 3 (20.84 ± 9.48 g/L vs 24.99 ± 9.40 g/L, P = 0.004; 31.28 ± 11.19 vs 35.46 ± 12.26 g/L, P = 0.047). The length of postoperative stays in EACA group was 3.66 ± 0.81 day, which is longer than 2.62 ± 0.68 day in TXA group (P < 0.001). No transfusions were required in either group. The risk of nausea and vomiting in TXA group was significantly higher than that in EACA group (11/90 vs 0/91, P < 0.01).

CONCLUSION

Although the TBL and HB drop were slightly greater in EACA group, these results were not clinically important, given that no transfusions were required. EACA could be an alternative to TXA, especially for patients with severe nausea and vomiting after using TXA postoperatively. Further studies are needed to adjust dosage of EACA to make better comparison of the two drugs.

Blood Conservation and Hemostasis in Cardiac Surgery: A Survey of Practice Variation and Adoption of Evidence-Based Guidelines

BACKGROUND

Blood conservation and hemostasis are integral parts of reducing avoidable blood transfusions and the associated morbidity and mortality. Despite the publication of blood conservation guidelines for cardiac surgery, evidence suggests persistent variability in practice patterns. Members of the Society of Cardiovascular Anesthesiologists (SCA) created a survey to audit conformance to existing guidelines and use the results to help narrow the evidence-to-practice gap.

METHODS

Members of the SCA and its Continuous Practice Improvement (CPI)- Blood Conservation Work Group developed a 48-item Blood Conservation and Hemostasis in Cardiac Surgery (BCHCS) survey. The questionnaire included the components of the Anesthesia Quality Institute's (AQI) composite measure AQI49. The survey was distributed to the entire SCA membership by e-mail via the Research Electronic Data Capture (REDCap) Consortium between the fall of 2017 and early 2018.

RESULTS

Of 3152 SCA members, 536 returned surveys for a response rate of 17%. Most responders worked at academic institutions. The median transfusion trigger after cardiopulmonary bypass was hemoglobin (Hgb) 7.0 to 8.0 g/dL. There are 4 components to AQI49, and the composite conformance to all of them was low due to 1 specific component: the use of transfusion algorithms supplemented with point-of-care (POC) testing. There was good conformance to the other 3 components of AQI49: use of antifibrinolytics, minimization of hemodilution and use of red cell salvage. Overall, practices with a multidisciplinary patient blood management (PBM) team were the most successful in meeting all 4 AQI49 criteria.

CONCLUSIONS

The survey demonstrated widespread adoption of several best practices, including the tolerance of lower hemoglobin transfusion triggers, use of antifibrinolytics, minimization of hemodilution, and use of red cell salvage. The survey also confirms that gaps remain in preoperative anemia management and the use of transfusion algorithms supplemented with POC hemostasis testing. Serial use of this survey can be used to identify barriers to implementation and audit the effectiveness of interventions described in this article. This instrument could also help harmonize local, regional, and national efforts and become an essential component of an implementation strategy for PBM in cardiac surgery.