Tranexamic acid (an antifibrinolytic agent) for reducing mortality in emergency and urgent surgery

Emergency or urgent surgery, which can be defined as surgery which must be done promptly to save life, limb, or functional capacity, is associated with a high risk of bleeding and death. Antifibrinolytic drugs, such as tranexamic acid, promote blood clotting by preventing blood clots from breaking down. Previous studies have shown that this drug reduces the need for blood transfusion in patients undergoing elective surgery. The authors of this review searched for randomised controlled trials assessing the effects of tranexamic acid in patients undergoing urgent or emergency surgery. 

The results of this review show that tranexamic acid reduces the probability that a patient will receive a blood transfusion by around 30%. The effect of tranexamic acid on other important outcomes, such as death, remains uncertain. The authors conclude that larger studies should be done to assess the effects of tranexamic acid on relevant outcomes such as death in patients undergoing all types of emergency and urgent surgery.

Authors' conclusions: 

There is evidence that tranexamic acid reduces blood transfusion in patients undergoing emergency or urgent surgery. There is a need for a large pragmatic clinical trial to assess the effects of routine use of tranexamic acid on mortality in a heterogeneous group of patients receiving urgent and emergency surgery.

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Background: 

Emergency or urgent surgery, which can be defined as surgery which must be done promptly to save life, limb or functional capacity, is associated with a high risk of bleeding and death. Antifibrinolytic agents, such as tranexamic acid, inhibit blood clot breakdown (fibrinolysis) and can reduce perioperative bleeding. Tranexamic acid has been shown to reduce the need for a blood transfusion in adult patients undergoing elective surgery but its effects in patients undergoing emergency or urgent surgery are unclear.  

Objectives: 

To assess the effects of tranexamic acid on mortality, blood transfusion and thromboembolic events in adults undergoing emergency or urgent surgery.

Search strategy: 

We searched the following electronic databases: the Cochrane Injuries Group Specialised Register (22 August 2012); Cochrane Central Register of Controlled Trials (2012, Issue 8 of 12); MEDLINE (OvidSP) (1950 to week 2 August 2012); PubMed (1 June 2012 to 22 August 2012); EMBASE (OvidSP) (1980 to Week 33 2012); ISI Web of Science: Conference Proceedings Citation Index-Science (CPCI-S) (1990 to 22 August 2012); ISI Web of Science: Science Citation Index Expanded (SCI-EXPANDED) (1970 to 22 August 2012). We also searched online trials registers on 22 August 2012 to identify unpublished studies.

Selection criteria: 

Randomised controlled trials comparing tranexamic acid with no tranexamic acid or placebo in adults undergoing emergency or urgent surgery.

Data collection and analysis: 

Two authors examined titles, abstracts and keywords of citations from the electronic databases for eligibility and extracted data for analysis and risk of bias assessment. Outcome measures of interest were mortality, receipt of a blood transfusion, units of blood transfused, reoperation, seizures and thromboembolic events (myocardial infarction, stroke, deep vein thrombosis and pulmonary embolism).

Main results: 

We identified five trials involving 372 people that met the inclusion criteria. Three trials (260 patients) contributed data to the analyses. The effect of tranexamic acid on mortality (RR 1.01; 95% CI 0.14 to 7.3) was uncertain. However, tranexamic acid reduced the probability of receiving a blood transfusion by 30% although the estimate was imprecise (RR 0.70; 95% CI 0.52 to 0.94). The effects on deep venous thrombosis (RR 2.29; 95% CI 0.68 to 7.66) and stroke (RR 2.79; 95% CI 0.12 to 67.10) were uncertain. There were no events of pulmonary embolism or myocardial infarction. None of the trials reported units of blood transfused, reoperation or seizure outcomes.