Thromboelastography (TEG) or rotational thromboelastometry (ROTEM) to monitor haemostatic treatment in bleeding patients: a systematic review with meta-analysis and trial sequential analysis.

Coagulopathy and severe bleeding are associated with high mortality. We evaluated haemostatic treatment guided by the functional viscoelastic haemostatic assays, thromboelastography or rotational thromboelastometry in bleeding patients. We searched for randomised, controlled trials irrespective of publication status, publication date, blinding status, outcomes published or language from date of inception to 5 January 2016 in six bibliographic databases. We included 17 trials (1493 participants), most involving cardiac surgery. Thromboelastography or rotational thromboelastometry seemed to reduce overall mortality compared to any of our comparisons (3.9% vs. 7.4%, RR (95% CI) 0.52 (0.28-0.95); I2 = 0%, 8 trials, 717 participants). However, the quality of evidence is graded as low due to the high risk of bias, heterogeneity, imprecision and low event rate. Thromboelastography or rotational thromboelastometry significantly reduced the proportion of patients transfused with red blood cells (RR (95% CI) 0.86 (0.79-0.94); I2 = 0%, 10 trials, 832 participants), fresh frozen plasma (RR (95% CI) 0.57 (0.33-0.96); I2 = 86%, 10 trials, 832 participants) and platelets (RR (95% CI) 0.73 (0.60-0.88); I2 = 0%, 10 studies, 832 participants). There was no difference in proportion needing surgical re-interventions (RR (95% CI) 0.75 (0.50-1.10); I2 = 0%, 9 trials, 887 participants). Trial sequential analysis of mortality suggests that only 54% of the required information size has been reached so far. Transfusion strategies guided by thromboelastography or rotational thromboelastometry may reduce the need for blood products in patients with bleeding, but the results are mainly based on trials of elective cardiac surgery involving cardiopulmonary bypass, with low-quality evidence.