Tranexamic acid in cardiac surgery: Are low doses enough?

OBJECTIVES: Tranexamic acid is used to prevent hyperfibrinolysis and reduce postoperative bleeding and blood transfusions in on-pump cardiac surgery. We evaluate the efficacy of low or high dose tranexamic acid in a prospective cohort study conducted in Valencia. MATERIALS AND METHODS: A total of 427 patients were recruited between January 2019 and January 2020, 207 in the Hospital General Universitario (low dose [LD]) and 220 in the Hospital Universitario y Politécnico La Fe (high dose [HD] and intermediate dose [ID]). We recorded the presence of hyperfibrinolysis on rotational thromboelastometry, intra- and postoperative administration of blood products, chest tube output within the first 12 h, and incidence of convulsions. Univariate and multivariate comparisons were performed. Univariate analysis of all categories was performed after propensity score matching between LD and HD and between LD and ID. RESULTS: There were no statistically significant differences in: appearance of hyperfibrinolysis, administration of blood products, postoperative chest tube output within the first 12 h, or occurrence of convulsions. Group LD received less fibrinogen than group HD (P = .014) and ID (P = .040) but more fresh frozen plasma than group ID (P = .0002). CONCLUSIONS: Administration of low-dose tranexamic acid is as effective as higher doses in hyperfibrinolysis prophylaxis and the prevention of postoperative bleeding in cardiac surgery.

Tranexamic acid in cardiac surgery: Are low doses enough? / Ácido tranexámico en cirugía cardíaca: ¿las dosis bajas son suficientes?

OBJECTIVES: Tranexamic acid is used to prevent hyperfibrinolysis and reduce postoperative bleeding and blood transfusions in on-pump cardiac surgery. We evaluate the efficacy of low or high dose tranexamic acid in a prospective cohort study conducted in Valencia. MATERIALS AND METHODS: A total of 427 patients were recruited between January 2019 and January 2020, 207 in the Hospital General Universitario (low dose [LD]) and 220 in the Hospital Universitario y Politécnico La Fe (high dose [HD] and intermediate dose [ID]). We recorded the presence of hyperfibrinolysis on rotational thromboelastometry, intra- and postoperative administration of blood products, chest tube output within the first 12h, and incidence of convulsions. Univariate and multivariate comparisons were performed. Univariate analysis of all categories was performed after propensity score matching between LD and HD and between LD and ID. RESULTS: There were no statistically significant differences in: appearance of hyperfibrinolysis, administration of blood products, postoperative chest tube output within the first 12h, or occurrence of convulsions. Group LD received less fibrinogen than group HD (P=.014) and ID (P=.040) but more fresh frozen plasma than group ID (P=.0002). CONCLUSIONS: Administration of low-dose tranexamic acid is as effective as higher doses in hyperfibrinolysis prophylaxis and the prevention of postoperative bleeding in cardiac surgery.

Can regional cerebral oxygen saturation guide red blood cell transfusion in high risk cardiac surgery? / ¿Puede la saturación regional de oxígeno cerebral guiar la transfusión de hematíes en cirugía cardiaca en pacientes de alto riesgo? Estudio prospectivo observacional.

INTRODUCTION: Cardiac surgery (CS) is associated with a significant use of blood products. The aim of this study was to evaluate the effect of red blood cells concentrates (RBC) transfusion on regional cerebral oxygen saturation (SrO2) in patients undergoing CS with additive EuroSCORE I > 6. MATERIAL AND METHODS: This is a prospective descriptive study. Patients with additive EuroSCORE I > 6 undergoing CS with extracorporeal circulation were included in the study. The demographic values, perioperative complications, hospital/ICU length of stay (LOS), as well as the preinduction baseline SrO2values, the lowest SrO2 value during surgery, number of blood products transfused, hemoglobine (HB) and pre and postransfusional SrO2 values were recorded, and events of significant decrease in SrO2 below 20% of basal value or decrease below 50%. We considered responders those who had an increase post-transfusion SrO2 at least 20% of pre-transfusion value, an increase of standar deviation (7.9) or an increase up to basal SrO2. RESULTS: Data from 57 patients were collected. The average additive EuroSCORE I was 7.4 (SD 2.6) and the EuroSCORE II was 6.1 (SD 7.4). 52% were male. 35.1% of patients received intraoperative transfusion of at least one unit of RBC. The overall mortality was 8.7% (N = 5). During surgery 29.8% of the overall sample presented a decrease of more than 20% of baseline SrO2 or a value lower than 50%. Patients with a significant decrease in SrO2 presented a higher rate of perioperative complications (P=0.04) and longer ICU-LOS 4.3 (SD 3.6) vs. 6.8 (SD 8.2) days (P=0.01) and hospital LOS 10.1 (SD 3.1) vs. 14.2 (SD 9.4) days (P=0.01). Pretransfusional HB was 7.4 (SD 0.8) mg/dl and postransfusional value was 8.4 (SD 0.8) (P =0.00). Pretransfusional SrO2 was 59 (SD 8.6) and increased non- significantly after RBC transfusion to 61.1 (SD 7.9) (P=0.1). Only 6 patients out of 21 could be considered responders. There were no significant differences in morbidity, mortality or LOS between responders and non-responders. DISCUSSION: In our population a non statistically significant increase in SrO2 was observed after RBC transfusion. When considering responders few patients were identified by SrO2. In conclusion SrO2 might not be reliable triger to decide transfusion.