Key messages
• It is possible that TEG (thromboelastography) and ROTEM (thromboelastometry, which give guidance on the need for transfusion, may reduce the risk of death, amount of blood lost and the need for blood products, as well as additional surgery, but this is very unclear. This finding mainly applied to people undergoing heart surgery
• We had no information on unwanted events from this guidance.
• The evidence is very uncertain, and more studies are needed in a greater number of people, particularly children and people in other settings than heart surgery.
What are TEG and ROTEM?
Thromboelastography (TEG) and thromboelastometry (ROTEM) are bedside (point-of-care) blood analysers used to monitor blood clotting and guide blood product transfusions. Severe bleeding and blood-clotting problems are serious clinical conditions that are associated with a high number of deaths.
Blood products include red blood cells, fresh frozen plasma (FFP), cryoprecipitate, platelets, or clotting factor concentrates.
Why is this important for people with severe bleeding?
Problems with severe bleeding and blood clotting can be caused by a number of factors, each needing to be treated in different ways. In people with bleeding caused by surgery, trauma (physical distress) or childbirth, the ability of the blood to clot can be followed with TEG and ROTEM tests. These are performed at the bedside to provide real-time information.
What did we want to find out?
We wanted to know the benefits and risks of TEG- or ROTEM-guided use of blood products in the treatment of people with severe bleeding and blood clotting problems. This was compared to the use of standard laboratory tests and doctors’ clinical judgement.
We were interested in the effects on:
• deaths from any cause;
• the use of blood products;
• the amount of blood lost;
• need for further surgery;
• how long they stayed in the hospital; and
• any unwanted effects.
What did we do?
We searched for studies that investigated whether blood clotting analysers (TEG or ROTEM) to guide the transfusion of blood products in adults or children with severe bleeding in hospital reduced the risk of death. The analysers were used with or without other laboratory tests and compared with transfusions guided by clinical judgement, standard laboratory tests, or both.
We compared and summarised the studies' results and rated our confidence in the evidence, based on factors such as study methods and the number of participants.
What did we find?
We found 35 studies (randomised controlled trials) that included 3096 adults. Most of these people had severe bleeding following elective heart surgery.
Main results
Using TEG or ROTEM-guided treatment in people with severe bleeding was linked to:
• A lower chance of dying (19 studies, 1868 people).
• A lower need to use blood products: fresh frozen plasma (18 studies, 1536 people), or platelets (20 studies, 1607 people).
• No difference in the amount of packed red blood cells (21 studies, 2003 people).
• Fewer repeat surgeries (13 studies, 1204 people).
• Less bleeding (19 studies, 1523 people).
None of the studies examined the risks of TEG- or ROTEM-guided treatment.
We are very uncertain about these results.
What are the limitations of the evidence?
• TEG or ROTEM-guided treatment needs to be studied in a greater number of people, including children, and with different causes of bleeding, for us to be more certain about the results.
• The number of deaths (mortality) was the main outcome for this review, yet none of the individual studies had enough people to show benefits for this outcome, as it is not common.
• Many of the studies involved patients who had elective heart surgery (where circulation of the blood outside the body is needed during the surgery). The results could differ depending on the cause of severe bleeding.
How up-to-date is this evidence?
The evidence is up-to-date as of January 2025.
Vollständige Zusammenfassung lesen
Severe bleeding and coagulopathy are serious clinical conditions that are associated with high mortality. Thromboelastography (TEG) and thromboelastometry (ROTEM) are increasingly used to guide transfusion strategy, but their roles remain disputed. This is an update of a review that was first published in 2011 and updated in January 2016.
Zielsetzungen
The objective was to evaluate the benefits and harms of TEG-/ROTEM-guided transfusion strategies for bleeding in adults and children by comparing TEG-ROTEM-guided transfusion with standard treatment.
Suchstrategie
In this updated review, we identified randomised controlled trials (RCTs) from the following electronic databases: Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE(R) ALL; Embase; Web of Science Core Collection and Biosis Previews via Clarivate; CINAHL EBSCO; and the WHO Global Index Medicus incl. LILACS (from 2015 up to 5 January 2025). We searched for ongoing clinical trials and unpublished studies in the following registries during the aforementioned period: ISRCTN, ClinicalTrials.gov, CentreWatch, and UMIN-CTR. We contacted trial authors, authors of previous reviews, and manufacturers in the field. The original searches were run in October 2010 and January 2016.
Auswahlkriterien
We included all RCTs, irrespective of blinding or language, that compared transfusion guided by TEG or ROTEM to transfusion guided by clinical judgement, guided by standard laboratory tests, or a combination. We also included interventional algorithms including both TEG and ROTEM in combination with standard laboratory tests or other devices. The primary analysis included trials on TEG or ROTEM versus any comparator.
Datensammlung und ‐analyse
Two review authors independently abstracted data; we resolved any disagreements by discussion. We presented pooled estimates of the intervention effects on dichotomous outcomes as risk ratios (RRs) with 95% confidence intervals (CIs). Due to skewed data, meta-analysis was not provided for continuous outcome data. Our primary outcome measure was all-cause mortality. We performed subgroup and sensitivity analyses to assess the effect of a TEG- or ROTEM-guided algorithm in adults and children on various clinical and physiological outcomes. We evaluated potential bias by examining trial methodological components using the Cochrane Risk of Bias 1 and assessed the risk of random error through Trial Sequential Analysis (TSA).
Hauptergebnisse
This systematic review included 35 randomised trials (n = 3096), with most involving patients undergoing elective cardiac surgery. Hence, 18 trials and 1603 participants were added since the previous update of this review. TEG-/ROTEM-guided transfusion algorithms may be associated with a reduction in mortality (RR 0.76, 95% CI 0.63 to 0.92; 19 trials; 1865 participants, I2 = 0%; random-effects model; very low-certainty evidence), but the evidence is very uncertain. This aligns with results from a previous update of this review. Additionally, TEG-/ROTEM-guided transfusion algorithms may reduce bleeding volume (standardised mean difference -0.31, 95% CI -0.51 to -0.11; 19 trials; 1523 participants, I² = 72%, random-effects model; very low-certainty evidence), but the evidence is very uncertain. No effects on the need for packed red blood cells were seen; RR 0.94 (95% CI 0.87 to 1.01; 21 trials, 2003 participants; I2 = 91%; random-effects model; very low-certainty evidence), but the evidence is very uncertain. Furthermore, reductions may be observed in the use of fresh frozen plasma (RR 0.52, 95% CI 0.35 to 0.76; 18 trials; 1536 participants; I2 = 94%, random-effects model; very low-certainty evidence), platelet transfusions (RR 0.69, 95% CI: 0.55 to 0.87; 20 trials; 1607 participants; I2 = 60%; random-effects model; very low-certainty evidence), and in the risk of surgical re-intervention (RR 0.63, 95% CI 0.45 to 0.88; 13 trials; 1204 participants; I² = 0%; fixed-effect model; very low-certainty evidence), but the evidence is very uncertain.
Using the GRADE framework, the certainty of the evidence was judged to be very low across all outcomes. TSA for mortality indicated that 64% of the required information size had been reached, with the monitoring boundary for benefit crossed.
Schlussfolgerungen der Autoren
TEG-/ROTEM-guided transfusion algorithms may reduce the risk of mortality, bleeding volume, and the need for fresh frozen plasma, platelets, and surgical re-intervention, but the evidence is very uncertain. Furthermore, the results were primarily based on the adult population undergoing elective cardiac surgery. Hence, the conclusion remains unchanged from the previous update of this review.
There is a need for large, low risk of bias randomised controlled trials evaluating TEG/ROTEM across diverse clinical settings, including paediatric and neonatal populations, sepsis, trauma, obstetrics, and high-risk surgical and critically ill cohorts requiring major transfusion. Future studies should be adequately powered and prioritise patient-centred outcomes such as long-term survival, adverse events, cost-effectiveness, and the role of TEG/ROTEM in coagulopathy and severe haemorrhage.
