The use of viscoelastic haemostatic assays in non-cardiac surgical settings: a systematic review and meta-analysis

Abstract

Background. Thrombelastography (TEG) and rotational thromboelastometry (ROTEM) are viscoelastic haemostatic assays (VHA) which exploit the elastic properties of clotting blood. The aim of this systematic review and meta-analysis was to evaluate the usefulness of these tests in bleeding patients outside the cardiac surgical setting.
Materials and methods. We searched the Cochrane Library, MEDLINE, EMBASE and SCOPUS. We also searched clinical trial registries for ongoing and unpublished studies, and checked reference lists to identify additional studies.
Results. We found 4 randomised controlled trials (RCTs) that met our inclusion criteria with a total of 229 participants. The sample size was small (from 28 to 111 patients) and the follow-up periods very heterogenous (from 4 weeks to 3 years). Pooled data from the 3 trials reporting on mortality (199 participants) do not show any effect of the use of TEG on mortality as compared to standard monitoring (based on the average treatment effect from a fixed-effects model): Risk Ratio (RR) 0.71; 95% Confidence Interval (CI): 0.43 to 1.16. Likewise, the use of VHA does not reduce the need for red blood cells (mean difference –0.64; 95% CI: –1.51 to 0.23), platelet concentrates (mean difference –1.12; 95% CI: –3.25 to 1.02), and fresh frozen plasma (mean difference –0.91; 95% CI: –2.02 to 0.19) transfusion. The evidence on mortality and other outcomes was uncertain (very low-certainty evidence, down-graded due to risk of biases, imprecision, and inconsistency).
Conclusions. Overall, the certainty of the evidence provided by the trials was too low for us to be certain of the benefits and harms of viscoelastic haemostatic assay in non-cardiac surgical settings. More, larger, and better-designed RCTs should be carried out in this area.