Thromboelastography or rotational thromboelastometry for bleeding management in adults undergoing cardiac surgery: a systematic review with meta-analysis and trial sequential analysis

Background: Severe bleeding and massive transfusion of blood products may be associated with increased morbidity and mortality of cardiac surgery. A transfusion algorithm incorporating thromboelastography (TEG) or rotational thromboelastometry (ROTEM) can help to determine the appropriate time and target for the use of hemostatic blood products, which may thus reduce the quantity of blood loss as well as blood products transfused. Methods: We conducted meta-analysis and trial sequential analysis to evaluate the effects of TEG or ROTEM-guided transfusion algorithms vs. standard treatments for patients undergoing cardiac surgery with cardiac pulmonary bypass. Results: Nineteen studies with a total of 15,320 participants, including 13 randomized controlled trials (RCTs), were included. All-cause mortality was not reduced either in overall studies or in RCTs. Blood loss volume was reduced by 132 mL in overall studies [mean difference (MD): -132.46, 95% CI: -207.49, -57.43; I-2 = 53%, P<0.01], and by 103 mL in RCTs (MD: -103.50, 95% CI: -156.52, -50.48; I-2 = 0%, P<0.01). The relative risks (RRs) in RCTs were 0.89 (95% CI: 0.80-0.98; I-2 = 0%, P=0.02) for red blood cells transfusion, 0.59 (95% CI: 0.42-0.82; I-2 = 55%, P<0.01) for fresh frozen plasma transfusion, and 0.81 (95% CI: 0.74-0.90; I-2 = 0%, P<0.01) for platelet transfusion, respectively. Trial sequential analysis of continuous data on blood loss and dichotomous outcomes on transfusion of blood products suggested the benefits of a TEG/ROTEM-guided algorithm. Conclusions: TEG or ROTEM-guided transfusion strategies may reduce blood loss volume and the transfusion rates in adult patients undergoing cardiac surgery.