Does tranexamic acid reduce desmopressin-induced hyperfibrinolysis?

A multicenter study of DDAVP versus platelet transfusions for antiplatelet agent reversal in patients with traumatic brain injury

BACKGROUND

Antiplatelet agents have been shown to worsen outcomes following traumatic injury. Research on desmopressin (DDAVP) and platelet transfusion for antiplatelet reversal is limited. We aimed to evaluate the effect of these agents on patients taking pre-injury antiplatelet medications who experienced traumatic brain injury (TBI) after blunt trauma.

METHODS

This is a retrospective cohort study of adult trauma patients from 2014 to 2021 on aspirin and/or a P2Y12 inhibitor. Patients were stratified into groups based on if they received DDAVP, platelets, both agents, or neither.

RESULTS

Of 5525 included patients, 4696 (85.4%) were not reversed, 461 (8.4%) received platelets, 173 (3.1%) received DDAVP, and 172 (3.1%) received both reversals. There was no statistically significant difference in length of stay between, but patients who received platelets or both reversals were more likely to have hospital complications (p < 0.05), longer hospital length of stay (p < 0.001), and longer ICU length of stay (p < 0.001) compared to those who did not receive reversal. A subgroup analysis of patients with a head AIS of 4 or 5 confirmed these findings.

CONCLUSIONS

Patients who received platelets or both reversals had a longer length of hospital stay and length of ICU stay. It is difficult to recommend one treatment over another based on our results alone. Further studies are needed to help clarify the risks and benefits of reversal agents in this patient population.

Dose-response relationships of intravenous and perineural dexamethasone as adjuvants to peripheral nerve blocks: a systematic review and model-based network meta-analysis

BACKGROUND

Superiority of perineural over intravenous dexamethasone at extending nerve block analgesia has been suggested but without considering the dose-response relationships for each route of administration.

METHODS

Randomised control studies that evaluated intravenous or perineural dexamethasone as an adjuvant to unilateral peripheral nerve blocks in adults were searched up to October 2023 in MEDLINE, Central, Google Scholar, and reference lists of previous systematic reviews. The Cochrane Risk-of-Bias tool was used. A maximum effect (Emax) model-based network meta-analysis was undertaken to evaluate the dose-response relationships of dexamethasone.

RESULTS

A total of 118 studies were selected (9284 patients; 35 with intravenous dexamethasone; 106 with perineural dexamethasone; dose range 1-16 mg). Studies with unclear or high risk of bias overestimated the effect of dexamethasone. Bias-corrected estimates indicated a maximum fold increase in analgesia duration of 1.7 (95% credible interval (CrI) 1.4-1.9) with dexamethasone, with no difference between perineural and intravenous routes. Trial simulations indicated that 4 mg of perineural dexamethasone increased the mean duration of analgesia for long-acting local anaesthetics from 11.1 h (95% CrI 9.4-13.1) to 16.5 h (95% CrI 14.0-19.3) and halved the rate of postoperative nausea and vomiting. A similar magnitude of effect was observed with 8 mg of intravenous dexamethasone.

CONCLUSIONS

Used as an adjuvant for peripheral nerve block, intravenous dexamethasone can be as effective as perineural dexamethasone in prolonging analgesic duration, but is less potent, hence requiring higher doses. The evidence is limited because of the observational nature of the dose-response relationships and the quality of the included studies.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO CRD42020141689.

Desmopressin to reduce periprocedural bleeding and transfusion: a systematic review and meta-analysis

We systematically reviewed the literature to investigate the effects of peri-procedural desmopressin in patients without known inherited bleeding disorders undergoing surgery or other invasive procedures. We included 63 randomized trials (4163 participants) published up to February 1, 2023. Seven trials were published after a 2017 Cochrane systematic review on this topic. There were 38 trials in cardiac surgery, 22 in noncardiac surgery, and 3 in non-surgical procedures. Meta-analyses demonstrated that desmopressin likely does not reduce the risk of receiving a red blood cell transfusion (25 trials, risk ratio [RR] 0.95, 95% confidence interval [CI] 0.86 to 1.05) and may not reduce the risk of reoperation due to bleeding (22 trials, RR 0.75, 95% CI 0.47 to 1.19) when compared to placebo or usual care. However, we demonstrated significant reductions in number of units of red blood cells transfused (25 trials, mean difference -0.55 units, 95% CI - 0.94 to - 0.15), total volume of blood loss (33 trials, standardized mean difference - 0.40 standard deviations; 95% CI - 0.56 to - 0.23), and the risk of bleeding events (2 trials, RR 0.45, 95% CI 0.24 to 0.84). The certainty of evidence of these findings was generally low. Desmopressin increased the risk of clinically significant hypotension that required intervention (19 trials, RR 2.15, 95% CI 1.36 to 3.41). Limited evidence suggests that tranexamic acid is more effective than desmopressin in reducing transfusion risk (3 trials, RR 2.38 favoring tranexamic acid, 95% CI 1.06 to 5.39) and total volume of blood loss (3 trials, mean difference 391.7 mL favoring tranexamic acid, 95% CI - 93.3 to 876.7 mL). No trials directly informed the safety and hemostatic efficacy of desmopressin in advanced kidney disease. In conclusion, desmopressin likely reduces periprocedural blood loss and the number of units of blood transfused in small trials with methodologic limitations. However, the risk of hypotension needs to be mitigated. Large trials should evaluate desmopressin alongside tranexamic acid and enroll patients with advanced kidney disease.

Myocardial infarction after craniotomy for asymptomatic meningioma

A man in his 40s with a history of coronary artery disease previously treated with a drug-eluting stent presented for elective craniotomy and resection of an asymptomatic but enlarging meningioma. During his craniotomy, he received desmopressin and tranexamic acid for surgical bleeding. Postoperatively, the patient developed chest pain and was found to have an ST-elevation myocardial infarction (MI). Because of the patient's recent neurosurgery, standard post-MI care was contraindicated and he was instead managed symptomatically in the intensive care unit. Echocardiogram on postoperative day 1 demonstrated no regional wall motion abnormalities and an ejection fraction of 60%. His presentation was consistent with thrombosis of his diagonal stent. He was transferred out of the intensive care unit on postoperative day 1 and discharged home on postoperative day 3.

Point-of-care platelet function testing for guided transfusion in neurosurgical management of intracranial hemorrhage: a systematic review

Given the rising prevalence of antiplatelet therapy, rapid preoperative identification of patients with bleeding diathesis is necessary for the guidance of blood product administration. This is especially relevant in neurosurgery for intracranial hemorrhage (ICH), where indiscriminate transfusions may lead to further hemorrhagic or thromboembolic injury. Point-of-care (POC) testing of platelet function is a promising solution to this dilemma, as it has been proven effective in cardiac surgery. However, to date, POC platelet function testing in neurosurgery has not been extensively evaluated. This systematic review appraises the use of POC platelet function test (PFT) in emergency neurosurgery in terms of its impact on patient outcomes.

A comprehensive search was conducted on four electronic databases (Pubmed, MEDLINE, Embase, and Cochrane) for relevant English language articles from their respective inceptions until 1 June 2022. We included all randomized controlled trials and cohort studies that met the following inclusion criteria: (i) involved adult patients undergoing neurosurgery for ICH; (ii) evaluated platelet function via POC PFT; (iii) reported a change in perioperative blood loss; and/or (iv) reported data on treatment-related adverse events and mortality. Assessment of study quality was conducted using the Newcastle Ottawa Quality Assessment Scale for Cohort Studies and Case–Control Studies, and the JBI Critical Appraisal Checklist for Case Series.

The search yielded 2,835 studies, of which seven observational studies comprising 849 patients met the inclusion criteria for this review. Overall, there is evidence that the use of POC PFT to assess bleeding risk reduced bleeding events, thromboembolic adverse outcomes, and the length of hospitalization. However, there is currently insufficient evidence to suggest that using POC PFT improves blood product use, functional outcomes or mortality.

The effect of tranexamic acid to reduce blood loss and transfusion on off-pump coronary artery bypass surgery: A systematic review and cumulative meta-analysis

STUDY OBJECTIVE

To assess the safety and efficacy of tranexamic acid (TA) on off-pump coronary artery bypass (OPCAB) surgery.

DESIGN

Meta-analysis.

SETTING

Operating room, OPCAB surgery, all surgeries were elective measurements. Searching the following data sources respectively: PubMed/MEDLINE, the Cochrane Library, EMBASE and reference lists of identified articles, we performed a meta-analysis of postoperative 24h blood loss, postoperative allogeneic transfusion, re-operation for massive bleeding, postoperative mortality, and postoperative thrombotic complications.

MAIN RESULTS

Using electronic databases, we selected 15 randomized control trials (RCTs), carried out between 2003 and 2016, with a total of 1250 patients for our review. TA significantly reduced the postoperative 24h blood loss (mean difference -213.32ml, 95% confidence intervals, -247.20ml to -179.43ml; P<0.0001). And, TA also significantly reduced the risk of packed red blood cell (PRBCs) transfusion (risk ratio 0.62; 95% confidence intervals 0.51 to 0.76; P<0.0001) and fresh frozen plasma (FFP) transfusion (0.65; 0.52 to 0.81; P<0.001). There were no statistical significance on platelet transfusion (risk difference -0.00, 95% confidence interval -0.02 to 0.02; P=0.73) and re-operation (0.00, -0.02 to 0.02; P=1.00). No association was found between TA and morbility (risk difference -0.00, 95% confidence interval -0.02 to 0.02; P=0.99) and thrombotic complications (-0.01, -0.01 to 0.02; P=0.70).

CONCLUSIONS

TA reduced the probability of receiving a PRBCs and FFP transfusion during OPCAB surgery. And no association with postoperative death and thrombotic events was found. However, further trials with an appropriate sample size are required to confirm TA safety in OPCAB surgery.

Reducing risk of spinal haematoma from spinal and epidural pain procedures

Background and aims:

Central neuraxial blocks (CNB: epidural, spinal and their combinations) and other spinal pain procedures can cause serious harm to the spinal cord in patients on antihaemostatic drugs or who have other risk-factors for bleeding in the spinal canal. The purpose of this narrative review is to provide a practise advisory on how to reduce risk of spinal cord injury from spinal haematoma (SH) during CNBs and other spinal pain procedures. Scandinavian guidelines from 2010 are part of the background for this practise advisory.

Methods:

We searched recent guidelines, PubMed (MEDLINE), SCOPUS and EMBASE for new and relevant randomised controlled trials (RCT), case-reports and original articles concerning benefits of neuraxial blocks, risks of SH due to anti-haemostatic drugs, patient-related risk factors, especially renal impairment with delayed excretion of antihaemostatic drugs, and specific risk factors related to the neuraxial pain procedures.

Results and recommendations:

Epidural and spinal analgesic techniques, as well as their combination provide superior analgesia and reduce the risk of postoperative and obstetric morbidity and mortality. Spinal pain procedure can be highly effective for cancer patients, less so for chronic non-cancer patients. We did not identify any RCT with SH as outcome. We evaluated risks and recommend precautions for SH when patients are treated with antiplatelet, anticoagulant, or fibrinolytic drugs, when patients’ comorbidities may increase risks, and when procedure-specific risk factors are present. Inserting and withdrawing epidural catheters appear to have similar risks for initiating a SH. Invasive neuraxial pain procedures, e.g. spinal cord stimulation, have higher risks of bleeding than traditional neuraxial blocks. We recommend robust monitoring routines and treatment protocol to ensure early diagnosis and effective treatment of SH should this rare but potentially serious complication occur.

Conclusions:

When neuraxial analgesia is considered for a patient on anti-haemostatic medication, with patient-related, or procedure-related risk factors, the balance of benefits against risks of bleeding is decisive; when CNB are offered exclusively to patients who will have a reduction of postoperative morbidity and mortality, then a higher risk of bleeding may be accepted. Robust routines should ensure appropriate discontinuation of anti-haemostatic drugs and early detection and treatment of SH.

Implications:

There is an on-going development of drugs for prevention of thromboembolic events following surgery and childbirth. The present practise advisory provides up-to-date knowledge and experts’ experiences so that patients who will greatly benefit from neuraxial pain procedures and have increased risk of bleeding can safely benefit from these procedures. There are always individual factors for the clinician to evaluate and consider. Increasingly it is necessary for the anaesthesia and analgesia provider to collaborate with specialists in haemostasis. Surgeons and obstetricians must be equally well prepared to collaborate for the best outcome for their patients suffering from acute or chronic pain. Optimal pain management is a prerequisite for enhanced recovery after surgery, but there is a multitude of additional concerns, such as early mobilisation, early oral feeding and ileus prevention that surgeons and anaesthesia providers need to optimise for the best outcome and least risk of complications.

Desmopressin use for minimising perioperative blood transfusion

BACKGROUND

Blood transfusion is administered during many types of surgery, but its efficacy and safety are increasingly questioned. Evaluation of the efficacy of agents, such as desmopressin (DDAVP; 1-deamino-8-D-arginine-vasopressin), that may reduce perioperative blood loss is needed.

OBJECTIVES

To examine the evidence for the efficacy of DDAVP in reducing perioperative blood loss and the need for red cell transfusion in people who do not have inherited bleeding disorders.

SEARCH METHODS

We searched for randomised controlled trials (RCTs) in the Cochrane Central Register of Controlled Trials (2017, issue 3) in the Cochrane Library, MEDLINE (from 1946), Embase (from 1974), the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (from 1937), the Transfusion Evidence Library (from 1980), and ongoing trial databases (all searches to 3 April 2017).

SELECTION CRITERIA

We included randomised controlled trials comparing DDAVP to placebo or an active comparator (e.g. tranexamic acid, aprotinin) before, during, or immediately after surgery or after invasive procedures in adults or children.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane.

MAIN RESULTS

We identified 65 completed trials (3874 participants) and four ongoing trials. Of the 65 completed trials, 39 focused on adult cardiac surgery, three on paediatric cardiac surgery, 12 on orthopaedic surgery, two on plastic surgery, and two on vascular surgery; seven studies were conducted in surgery for other conditions. These trials were conducted between 1986 and 2016, and 11 were funded by pharmaceutical companies or by a party with a commercial interest in the outcome of the trial.The GRADE quality of evidence was very low to moderate across all outcomes. No trial reported quality of life. DDAVP versus placebo or no treatmentTrial results showed considerable heterogeneity between surgical settings for total volume of red cells transfused (low-quality evidence) and for total blood loss (very low-quality evidence) due to large differences in baseline blood loss. Consequently, these outcomes were not pooled and were reported in subgroups.Compared with placebo, DDAVP may slightly decrease the total volume of red cells transfused in adult cardiac surgery (mean difference (MD) -0.52 units, 95% confidence interval (CI) -0.96 to -0.08 units; 14 trials, 957 participants), but may lead to little or no difference in orthopaedic surgery (MD -0.02, 95% CI -0.67 to 0.64 units; 6 trials, 303 participants), vascular surgery (MD 0.06, 95% CI -0.60 to 0.73 units; 2 trials, 135 participants), or hepatic surgery (MD -0.47, 95% CI -1.27 to 0.33 units; 1 trial, 59 participants).DDAVP probably leads to little or no difference in the total number of participants transfused with blood (risk ratio (RR) 0.96, 95% CI 0.86 to 1.06; 25 trials; 1806 participants) (moderate-quality evidence).Whether DDAVP decreases total blood loss in adult cardiac surgery (MD -135.24 mL, 95% CI -210.80 mL to -59.68 mL; 22 trials, 1358 participants), orthopaedic surgery (MD -285.76 mL, 95% CI -514.99 mL to -56.53 mL; 5 trials, 241 participants), or vascular surgery (MD -582.00 mL, 95% CI -1264.07 mL to 100.07 mL; 1 trial, 44 participants) is uncertain because the quality of evidence is very low.DDAVP probably leads to little or no difference in all-cause mortality (Peto odds ratio (pOR) 1.09, 95% CI 0.51 to 2.34; 22 trials, 1631 participants) or in thrombotic events (pOR 1.36, 95% CI, 0.85 to 2.16; 29 trials, 1984 participants) (both low-quality evidence). DDAVP versus placebo or no treatment for people with platelet dysfunctionCompared with placebo, DDAVP may lead to a reduction in the total volume of red cells transfused (MD -0.65 units, 95% CI -1.16 to -0.13 units; 6 trials, 388 participants) (low-quality evidence) and in total blood loss (MD -253.93 mL, 95% CI -408.01 mL to -99.85 mL; 7 trials, 422 participants) (low-quality evidence).DDAVP probably leads to little or no difference in the total number of participants receiving a red cell transfusion (RR 0.83, 95% CI 0.66 to 1.04; 5 trials, 258 participants) (moderate-quality evidence).Whether DDAVP leads to a difference in all-cause mortality (pOR 0.72, 95% CI 0.12 to 4.22; 7 trials; 422 participants) or in thrombotic events (pOR 1.58, 95% CI 0.60 to 4.17; 7 trials, 422 participants) is uncertain because the quality of evidence is very low. DDAVP versus tranexamic acidCompared with tranexamic acid, DDAVP may increase the volume of blood transfused (MD 0.6 units, 95% CI 0.09 to 1.11 units; 1 trial, 40 participants) and total blood loss (MD 142.81 mL, 95% CI 79.78 mL to 205.84 mL; 2 trials, 115 participants) (both low-quality evidence).Whether DDAVP increases or decreases the total number of participants transfused with blood is uncertain because the quality of evidence is very low (RR 2.42, 95% CI 1.04 to 5.64; 3 trials, 135 participants).No trial reported all-cause mortality.Whether DDAVP leads to a difference in thrombotic events is uncertain because the quality of evidence is very low (pOR 2.92, 95% CI 0.32 to 26.83; 2 trials, 115 participants). DDAVP versus aprotininCompared with aprotinin, DDAVP probably increases the total number of participants transfused with blood (RR 2.41, 95% CI 1.45 to 4.02; 1 trial, 99 participants) (moderate-quality evidence).No trials reported volume of blood transfused or total blood loss and the single trial that included mortality as an outcome reported no deaths.Whether DDAVP leads to a difference in thrombotic events is uncertain because the quality of evidence is very low (pOR 0.98, 95% CI 0.06 to 15.89; 2 trials, 152 participants).

AUTHORS' CONCLUSIONS

Most of the evidence derived by comparing DDAVP versus placebo was obtained in cardiac surgery, where DDAVP was administered after cardiopulmonary bypass. In adults undergoing cardiac surgery, the reduction in volume of red cells transfused and total blood loss was small and was unlikely to be clinically important. It is less clear whether DDAVP may be of benefit for children and for those undergoing non-cardiac surgery. A key area for researchers is examining the effects of DDAVP for people with platelet dysfunction. Few trials have compared DDAVP versus tranexamic acid or aprotinin; consequently, we are uncertain of the relative efficacy of these interventions.

Utility of rotational thromboelastometry for the diagnosis of asymptomatic hyperfibrinolysis secondary to anaphylaxis

We present a case of hyperfibrinolysis induced by oxaliplatin-derived anaphylactic shock, which was diagnosed with rotational thromboelastometry (ROTEM). A 57-year-old male patient underwent a second course of oxaliplatin (126 mg/m/course)-based chemotherapy for stage IV metastatic rectal cancer. Two minutes after the infusion of oxaliplatin, the patient lost consciousness and developed generalized urticarial lesions, followed by hemodynamic instability and respiratory insufficiency. He was diagnosed anaphylactic shock and transported to emergency department (ED) after intramuscular injection of 0.2 mg of adrenaline, an intravenous injection of 100 mg of hydrocortisone, and 500 mg of methylprednisolone. After arriving in the ED, the patient remained in shock and early resuscitation with administration of 5 mg of D-chlorpheniramine maleate and 20 mg of famotidine was performed. He recovered from his state of shock 30 min after the resuscitation. ROTEM findings showed fulminant hyperfibrinolysis with minimal changes in standard coagulation tests (SCTs) and no remarkable coagulopathy. Seven hours after the attack, he became asymptomatic and follow-up ROTEM revealed values within normal limits with the exception of sustained slight abnormalities of SCTs. He was discharged the next day without any signs of spontaneous bleeding and has continued his outpatient chemotherapy uneventfully. A review of the literature on anaphylaxis-induced hyperfibrinolysis and a discussion of the mechanism between anaphylactic shock and hyperfibrinolysis were performed. Although administration of tissue-type plasminogen activator can play a vital role in anaphylactic shock-induced hyperfibrinolysis, early effective resuscitation is imperative to prevent severe hemorrhagic complications. Therefore, ROTEM is a useful tool that can detect these dynamic changes faster and more accurately than SCTs.

The European guideline on management of major bleeding and coagulopathy following trauma: fourth edition

BACKGROUND

Severe trauma continues to represent a global public health issue and mortality and morbidity in trauma patients remains substantial. A number of initiatives have aimed to provide guidance on the management of trauma patients. This document focuses on the management of major bleeding and coagulopathy following trauma and encourages adaptation of the guiding principles to each local situation and implementation within each institution.

METHODS

The pan-European, multidisciplinary Task Force for Advanced Bleeding Care in Trauma was founded in 2004 and included representatives of six relevant European professional societies. The group used a structured, evidence-based consensus approach to address scientific queries that served as the basis for each recommendation and supporting rationale. Expert opinion and current clinical practice were also considered, particularly in areas in which randomised clinical trials have not or cannot be performed. Existing recommendations were reconsidered and revised based on new scientific evidence and observed shifts in clinical practice; new recommendations were formulated to reflect current clinical concerns and areas in which new research data have been generated. This guideline represents the fourth edition of a document first published in 2007 and updated in 2010 and 2013.

RESULTS

The guideline now recommends that patients be transferred directly to an appropriate trauma treatment centre and encourages use of a restricted volume replacement strategy during initial resuscitation. Best-practice use of blood products during further resuscitation continues to evolve and should be guided by a goal-directed strategy. The identification and management of patients pre-treated with anticoagulant agents continues to pose a real challenge, despite accumulating experience and awareness. The present guideline should be viewed as an educational aid to improve and standardise the care of the bleeding trauma patients across Europe and beyond. This document may also serve as a basis for local implementation. Furthermore, local quality and safety management systems need to be established to specifically assess key measures of bleeding control and outcome.

CONCLUSIONS

A multidisciplinary approach and adherence to evidence-based guidance are key to improving patient outcomes. The implementation of locally adapted treatment algorithms should strive to achieve measureable improvements in patient outcome.

Evaluations of topical application of tranexamic acid on post-operative blood loss in off-pump coronary artery bypass surgery

Objective:

One of the major complications of cardiac surgery is the presence of post-operative bleeding. The aim of the present study was to investigate the topical application of tranexamic acid in the pericardial cavity on post-operative bleeding in off-pump coronary artery bypass graft (CABG) surgery.

Materials and Methods:

This study was on 71 patients who underwent off-pump CABG. The anesthesia and surgery methods were the same for all patients. Patients were assigned to two equal groups. In the first group, 1 g of tranexamic acid in 100 mL of normal saline solution (NSS) was applied to pericardium and mediastinal cavity at the end of surgery. In the second group, only 100 mL of NSS was applied. Chest drainage of the patients after 24 h and the amounts of blood and blood products transfusion were also recorded during this time.

Results:

Patients were the same regarding demographic information and surgery. The average volume of blood loss after 24 h was 366 mL for the first group and 788 mL for the control group. There was a statistically significant difference between the two groups (P < 0.001). The amount of packed red blood cells transfusion in the first group was less than that of the control group, which was not statistically significant. There was no statistically significant difference between the amount of hemoglobin, hematocrit, platelets, prothrombin time and partial thromboplastin time in the post-operative stage in the two groups.

Conclusion:

The topical application of tranexamic acid in off-pump CABG patients leads to a decreased post-operative blood loss.

Systematic review, meta-analysis and meta-regression of the effect of tranexamic acid on surgical blood loss

Background

Tranexamic acid (TXA) reduces blood transfusion in surgery but the extent of the reduction in blood loss and how it relates to the dose of TXA is unclear.

Methods

A systematic review of randomized trials was performed. Data were extracted on blood loss from trials comparing intravenous TXA with no TXA or placebo in surgical patients. A Bayesian linear regression was used to describe the relationship between the reduction in blood loss with TXA and the extent of bleeding as measured by the mean blood loss in the control group. A meta-analysis of the log-transformed data was conducted to quantify the effect of TXA on blood loss, stratified by type of surgery, timing of TXA administration and trial quality. Meta-regression was used to explore the effect of TXA dosage.

Results

Data from 104 trials were examined. Although the absolute reduction in blood loss with TXA increased as surgical bleeding increased, the percentage reduction was similar. TXA reduced blood loss by 34 per cent (pooled ratio 0·66, 95 per cent confidence interval 0·65 to 0·67; P &lt; 0·001). The percentage reduction in blood loss with TXA differed by type of surgery, timing of TXA administration and trial quality, but the differences were small. The effect of TXA on blood loss did not vary over the range of doses assessed (5·5–300 mg/kg).

Conclusion

TXA reduces blood loss in surgical patients by about one-third. A total dose of 1 g appears to be sufficient for most adults. There is no evidence to support the use of high doses.

Initial experiences with Multiplate® for rapid assessment of antiplatelet agent activity in neurosurgical emergencies

OBJECTIVE

As the population ages, physicians encounter a growing number of patients who are treated with antiplatelet agents and present with severe conditions requiring urgent neurosurgical therapy. Standard laboratory investigations are insufficient to evaluate platelet activity and furthermore, it is difficult to evaluate effects of haemostatic measures on platelet function. In this article we report our initial experiences with the point-of-care device Multiplate® for assessment of platelet activity in neurosurgical emergencies on patients with a reported intake of antiplatelet medication.

METHODS

Multiplate® assessment of antiplatelet activity was carried out in 21 non-consecutive patients with a reported intake of antiplatelet medication (aspirin: n=21, clopidogrel: n=3, ticragrelor: n=1) and urgent admission to our hospital because of conditions such as intracranial haemorrhage requiring urgent neurosurgical therapy. Analysis was repeated in order to evaluate the effectiveness of haemostatic drugs and platelet concentrate transfusion on platelet activity in six patients.

RESULTS

No technical difficulties occurred and in all cases, results were obtained within 15 min. On admission, patients' arachidonic acid induced platelet activity was reduced by 44.4±33.5% (range: -79.7% to +44.3%) compared to the lower reference limit. Two patients had a normal platelet activity despite a reported intake of aspirin. Haemostatic measures significantly increased arachidonic acid induced platelet activity by 100±66% (p<0.005).

CONCLUSION

The Multiplate® device allowed rapid assessment of antiplatelet agent activity and evaluation of haemostatic measures on platelet activity. Further studies with larger patient numbers are needed, but this device may represent a valuable tool to improve treatment modalities in patients treated with antiplatelet medication and conditions requiring urgent neurosurgical therapy.

Tranexamic acid: a review of its use in the treatment of hyperfibrinolysis

Tranexamic acid, a synthetic derivative of the amino acid lysine, is an antifibrinolytic agent that acts by binding to plasminogen and blocking the interaction of plasmin(ogen) with fibrin, thereby preventing dissolution of the fibrin clot. Tranexamic acid (Transamin®) is indicated in Japan for use in certain conditions with abnormal bleeding or bleeding tendencies in which local or systemic hyperfibrinolysis is considered to be involved. This article reviews the efficacy and tolerability of tranexamic acid in conditions amenable to antifibrinolytic therapy and briefly overviews the pharmacological properties of the drug. In large, randomized controlled trials, tranexamic acid generally significantly reduced perioperative blood loss compared with placebo in a variety of surgical procedures, including cardiac surgery with or without cardiopulmonary bypass, total hip and knee replacement and prostatectomy. In many instances, tranexamic acid also reduced transfusion requirements associated with surgery. It also reduced blood loss in gynaecological bleeding disorders, such as heavy menstrual bleeding, postpartum haemorrhage and bleeding irregularities caused by contraceptive implants. Tranexamic acid significantly reduced all-cause mortality and death due to bleeding in trauma patients with significant bleeding, particularly when administered early after injury. It was also effective in traumatic hyphaema, gastrointestinal bleeding and hereditary angioneurotic oedema. While it reduces rebleeding in subarachnoid haemorrhage, it may increase ischaemic complications. Pharmacoeconomic analyses predicted that tranexamic acid use in surgery and trauma would be very cost effective and potentially life saving. In direct comparisons with other marketed agents, tranexamic acid was at least as effective as ε-aminocaproic acid and more effective than desmopressin in surgical procedures. It was more effective than desmopressin, etamsylate, flurbiprofen, mefenamic acid and norethisterone, but less effective than the levonorgestrel-releasing intra-uterine device in heavy menstrual bleeding and was as effective as prednisolone in traumatic hyphaema. Tranexamic acid was generally well tolerated. Most adverse events in clinical trials were of mild or moderate severity; severe or serious events were rare. Therefore, while high-quality published evidence is limited for some approved indications, tranexamic acid is an effective and well tolerated antifibrinolytic agent.

Effect of tranexamic acid on surgical bleeding: systematic review and cumulative meta-analysis

OBJECTIVE

To assess the effect of tranexamic acid on blood transfusion, thromboembolic events, and mortality in surgical patients.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Cochrane central register of controlled trials, Medline, and Embase, from inception to September 2011, the World Health Organization International Clinical Trials Registry Platform, and the reference lists of relevant articles.

STUDY SELECTION

Randomised controlled trials comparing tranexamic acid with no tranexamic acid or placebo in surgical patients. Outcome measures of interest were the number of patients receiving a blood transfusion; the number of patients with a thromboembolic event (myocardial infarction, stroke, deep vein thrombosis, and pulmonary embolism); and the number of deaths. Trials were included irrespective of language or publication status.

RESULTS

129 trials, totalling 10,488 patients, carried out between 1972 and 2011 were included. Tranexamic acid reduced the probability of receiving a blood transfusion by a third (risk ratio 0.62, 95% confidence interval 0.58 to 0.65; P<0.001). This effect remained when the analysis was restricted to trials using adequate allocation concealment (0.68, 0.62 to 0.74; P<0.001). The effect of tranexamic acid on myocardial infarction (0.68, 0.43 to 1.09; P = 0.11), stroke (1.14, 0.65 to 2.00; P = 0.65), deep vein thrombosis (0.86, 0.53 to 1.39; P = 0.54), and pulmonary embolism (0.61, 0.25 to 1.47; P=0.27) was uncertain. Fewer deaths occurred in the tranexamic acid group (0.61, 0.38 to 0.98; P = 0.04), although when the analysis was restricted to trials using adequate concealment there was considerable uncertainty (0.67, 0.33 to 1.34; P = 0.25). Cumulative meta-analysis showed that reliable evidence that tranexamic acid reduces the need for transfusion has been available for over 10 years.

CONCLUSIONS

Strong evidence that tranexamic acid reduces blood transfusion in surgery has been available for many years. Further trials on the effect of tranexamic acid on blood transfusion are unlikely to add useful new information. However, the effect of tranexamic acid on thromboembolic events and mortality remains uncertain. Surgical patients should be made aware of this evidence so that they can make an informed choice.

Management of bleeding following major trauma: an updated European guideline

INTRODUCTION

Evidence-based recommendations are needed to guide the acute management of the bleeding trauma patient, which when implemented may improve patient outcomes.

METHODS

The multidisciplinary Task Force for Advanced Bleeding Care in Trauma was formed in 2005 with the aim of developing a guideline for the management of bleeding following severe injury. This document presents an updated version of the guideline published by the group in 2007. Recommendations were formulated using a nominal group process, the Grading of Recommendations Assessment, Development and Evaluation (GRADE) hierarchy of evidence and based on a systematic review of published literature.

RESULTS

Key changes encompassed in this version of the guideline include new recommendations on coagulation support and monitoring and the appropriate use of local haemostatic measures, tourniquets, calcium and desmopressin in the bleeding trauma patient. The remaining recommendations have been reevaluated and graded based on literature published since the last edition of the guideline. Consideration was also given to changes in clinical practice that have taken place during this time period as a result of both new evidence and changes in the general availability of relevant agents and technologies.

CONCLUSIONS

This guideline provides an evidence-based multidisciplinary approach to the management of critically injured bleeding trauma patients.

Meta-analysis comparing the effectiveness and adverse outcomes of antifibrinolytic agents in cardiac surgery

BACKGROUND

Since the 1980s, antifibrinolytic therapies have assisted surgical teams in reducing the amount of blood loss. To date, however, serious questions remain regarding the safety and effectiveness of these agents.

METHODS AND RESULTS

We conducted a meta-analysis to compare aprotinin, epsilon-aminocaproic acid, and tranexamic acid with placebo and head to head on 8 clinical outcomes from 138 trials. Published randomized controlled trial data were collected from OVID/PubMed. Outcomes included total blood loss, transfusion of packed red blood cells, reexploration, mortality, stroke, myocardial infarction, dialysis-dependent renal failure, and renal dysfunction (0.5-mg/dL increase in creatinine from baseline). All agents were effective in significantly reducing blood loss by 226 to 348 mL and the proportion of patients transfused with packed red blood cells over placebo. Only high-dose aprotinin reduced the rate of reexploration (relative risk, 0.49; 95% CI, 0.33 to 0.73). There were no significant risks or benefits for any agent for mortality, stroke, myocardial infarction, or renal failure. However, high-dose aprotinin significantly increased the risk of renal dysfunction (relative risk, 1.47; 95% CI, 1.12 to 1.94), 12.9% versus 8.4%. Compared head to head, high-dose aprotinin demonstrated significant reduction in total blood loss over epsilon-aminocaproic acid (-184 mL; 95% CI, -256 to -112) and tranexamic acid (-195 mL; 95% CI, -286 to -105). There were no significant differences among any agent when compared head to head on other outcomes.

CONCLUSIONS

All antifibrinolytic agents were effective in reducing blood loss and transfusion. There were no significant risks or benefits for mortality, stroke, myocardial infarction, or renal failure. However, high-dose aprotinin was associated with a statistically significant increased risk of renal dysfunction.

Evaluation of hemorrhage depressors on blood loss during orthognathic surgery: a retrospective study

PURPOSE

Correction of dentofacial deformities by orthognathic surgery may cause significant bleeding and therefore hypotensive anesthesia is often used to reduce the blood loss. The main objective of the present clinical study was to determine whether the addition of hemorrhage depressors to other medication during orthognathic surgery would further reduce the blood loss.

PATIENTS AND METHODS

Thirty patients, consecutively operated on with standardized Le Fort I osteotomies in 1998 (n = 15, control group) and 1999 (n = 15, treatment group), were included in the study. Both groups received hypotension anesthesia during surgery and the treatment group received additional hemorrhage depressors; tranexamic acid and desmopressin.

RESULTS

The mean blood loss was 740 +/- 410 mL (11.3 mL/kg) in the control group and 400 +/- 210 mL (5.7 mL/kg) in the treatment group. The results showed a statistically significant reduction of blood loss in the treatment group (P <.01).

CONCLUSIONS

This study shows that blood loss during orthognathic surgery under hypotensive anesthesia can be significantly reduced when a combination of tranexamic acid and desmopressin is added.