Association of Intravenous Tranexamic Acid With Thromboembolic Events and Mortality: A Systematic Review, Meta-analysis, and Meta-regression.

IMPORTANCE: Tranexamic acid (TXA) is an efficient antifibrinolytic agent; however, concerns remain about the potential adverse effects, particularly vascular occlusive events, that may be associated with its use. OBJECTIVE: To examine the association between intravenous TXA and total thromboembolic events (TEs) and mortality in patients of all ages and of any medical disciplines. DATA SOURCE: Cochrane Central Register of Controlled Trials and MEDLINE were searched for eligible studies investigating intravenous TXA and postinterventional outcome published between 1976 and 2020. STUDY SELECTION: Randomized clinical trials comparing intravenous TXA with placebo/no treatment. The electronic database search yielded a total of 782 studies, and 381 were considered for full-text review. Included studies were published in English, German, French, and Spanish. Studies with only oral or topical tranexamic administration were excluded. DATA EXTRACTION AND SYNTHESIS: Meta-analysis, subgroup and sensitivity analysis, and meta-regression were performed. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline. MAIN OUTCOMES AND MEASURES: Vascular occlusive events and mortality. RESULTS: A total of 216 eligible trials including 125 550 patients were analyzed. Total TEs were found in 1020 (2.1%) in the group receiving TXA and 900 (2.0%) in the control group. This study found no association between TXA and risk for total TEs (risk difference = 0.001; 95% CI, -0.001 to 0.002; P = .49) for venous thrombosis, pulmonary embolism, venous TEs, myocardial infarction or ischemia, and cerebral infarction or ischemia. Sensitivity analysis using the risk ratio as an effect measure with (risk ratio = 1.02; 95% CI, 0.94-1.11; P = .56) and without (risk ratio = 1.03; 95% CI, 0.95-1.12; P = .52) studies with double-zero events revealed robust effect size estimates. Sensitivity analysis with studies judged at low risk for selection bias showed similar results. Administration of TXA was associated with a significant reduction in overall mortality and bleeding mortality but not with nonbleeding mortality. In addition, an increased risk for vascular occlusive events was not found in studies including patients with a history of thromboembolism. Comparison of studies with sample sizes of less than or equal to 99 (risk difference = 0.004; 95% CI, -0.006 to 0.014; P = .40), 100 to 999 (risk difference = 0.004; 95% CI, -0.003 to 0.011; P = .26), and greater than or equal to 1000 (risk difference = -0.001; 95% CI, -0.003 to 0.001; P = .44) showed no association between TXA and incidence of total TEs. Meta-regression of 143 intervention groups showed no association between TXA dosing and risk for venous TEs (risk difference, -0.005; 95% CI, -0.021 to 0.011; P = .53). CONCLUSIONS AND RELEVANCE: Findings from this systematic review and meta-analysis of 216 studies suggested that intravenous TXA, irrespective of dosing, is not associated with increased risk of any TE. These results help clarify the incidence of adverse events associated with administration of intravenous TXA and suggest that TXA is safe for use with undetermined utility for patients receiving neurological care.

Comparison of common perioperative blood loss estimation techniques: a systematic review and meta-analysis.

Estimating intraoperative blood loss is one of the daily challenges for clinicians. Despite the knowledge of the inaccuracy of visual estimation by anaesthetists and surgeons, this is still the mainstay to estimate surgical blood loss. This review aims at highlighting the strengths and weaknesses of currently used measurement methods. A systematic review of studies on estimation of blood loss was carried out. Studies were included investigating the accuracy of techniques for quantifying blood loss in vivo and in vitro. We excluded nonhuman trials and studies using only monitoring parameters to estimate blood loss. A meta-analysis was performed to evaluate systematic measurement errors of the different methods. Only studies that were compared with a validated reference e.g. Haemoglobin extraction assay were included. 90 studies met the inclusion criteria for systematic review and were analyzed. Six studies were included in the meta-analysis, as only these were conducted with a validated reference. The mixed effect meta-analysis showed the highest correlation to the reference for colorimetric methods (0.93 95% CI 0.91-0.96), followed by gravimetric (0.77 95% CI 0.61-0.93) and finally visual methods (0.61 95% CI 0.40-0.82). The bias for estimated blood loss (ml) was lowest for colorimetric methods (57.59 95% CI 23.88-91.3) compared to the reference, followed by gravimetric (326.36 95% CI 201.65-450.86) and visual methods (456.51 95% CI 395.19-517.83). Of the many studies included, only a few were compared with a validated reference. The majority of the studies chose known imprecise procedures as the method of comparison. Colorimetric methods offer the highest degree of accuracy in blood loss estimation. Systems that use colorimetric techniques have a significant advantage in the real-time assessment of blood loss.

Health economics of Patient Blood Management: a cost-benefit analysis based on a meta-analysis.

BACKGROUND AND OBJECTIVES: Patient Blood Management (PBM) is the timely application of evidence-based medical and surgical concepts designed to improve haemoglobin concentration, optimize haemostasis and minimize blood loss in an effort to improve patient outcomes. The focus of this cost-benefit analysis is to analyse the economic benefit of widespread implementation of a multimodal PBM programme. MATERIALS AND METHODS: Based on a recent meta-analysis including 17 studies (>235 000 patients) comparing PBM with control care and data from the University Hospital Frankfurt, a cost-benefit analysis was performed. Outcome data were red blood cell (RBC) transfusion rate, number of transfused RBC units, and length of hospital stay (LOS). Costs were considered for the following three PBM interventions as examples: anaemia management including therapy of iron deficiency, use of cell salvage and tranexamic acid. For sensitivity analysis, a Monte Carlo simulation was performed. RESULTS: Iron supplementation was applied in 3·1%, cell salvage in 65% and tranexamic acid in 89% of the PBM patients. In total, applying these three PBM interventions costs €129·04 per patient. However, PBM was associated with a reduction in transfusion rate, transfused RBC units per patient, and LOS which yielded to mean savings of €150·64 per patient. Thus, the overall benefit of PBM implementation was €21·60 per patient. In the Monte Carlo simulation, the cost savings on the outcome side exceeded the PBM costs in approximately 2/3 of all repetitions and the total benefit was €1 878 000 in 100·000 simulated patients. CONCLUSION: Resources to implement a multimodal PBM concept optimizing patient care and safety can be cost-effectively.