Viscoelastic haemostatic assays to guide therapy in elective surgery: an updated systematic review and meta-analysis

Background: Patients undergoing major surgery frequently experience major uncontrolled bleeding. The aim of this systematic review and meta-analysis was to evaluate the clinical efficacy of using viscoelastic haemostatic assays to manage peri-operative bleeding in elective surgery.

Methods: We searched PubMed/MEDLINE and Embase databases for randomised controlled trials according to pre-determined criteria. The primary outcomes were blood product requirements; duration of stay in the operating theatre or ICU; and surgical reintervention rate.

Results: We included 20 randomised controlled trials. The overall risk of bias was low to moderate. Twelve studies used thromboelastography-based transfusion algorithms, while eight used thromboelastometry. Viscoelastic haemostatic assay-guided therapy was associated with a statistically significant reduction in transfusion of red blood cells (standardised mean difference (95%CI) 0.16 (-0.29 to 0.02)), platelets (standardised mean difference (95%CI) -0.33 (-0.56 to -0.10)) and fresh frozen plasma (standardised mean difference (95%CI) -0.64 (-1.01 to -0.28)). There was no evidence of an effect of viscoelastic haemostatic assay-guided therapy on surgical reintervention (relative risk (95%CI) 1.09 (0.70-1.69)). Viscoelastic haemostatic assay-guided therapy was associated with lower blood loss and shorter ICU duration of stay. There was no evidence of any effect on total duration of stay and all-cause mortality.

Conclusions: Viscoelastic haemostatic assay-guided therapy may reduce peri-operative blood product transfusion requirements and blood loss during major elective surgery, with no discernible effect on patient-centred outcomes. The overall quality of evidence was modest.