Bleeding Reversal With Antifibrinolytics or Cryoprecipitate Following Thrombolysis for Acute Ischemic Stroke: A Case Series.

Patients who develop an intracerebral hemorrhage (ICH) following thrombolysis in acute ischemic stroke (AIS) have a mortality rate as high as 50%. Treatment options include blood products, such as cryoprecipitate, or antifibrinolytics, such as tranexamic acid (TXA) or ε-aminocaproic acid (EACA). Current guidelines recommend cryoprecipitate first-line despite limited data to support one agent over another. In addition, compared to antifibrinolytics, cryoprecipitate is higher in cost and requires thawing before use. This case series seeks to characterize the management of thrombolytic reversal at a single institution as well as provide additional evidence for antifibrinolytics in this setting. Patients were included for a retrospective review if they met the following criteria: presented between January 2011-January 2017, were >18 years of age, were admitted for AIS, received a thrombolytic, and received TXA EACA, or cryoprecipitate. Twelve patients met the inclusion criteria. Ten (83.3%) developed an ICH, one (8.3%) experienced gastrointestinal bleeding, and one (8.3%) had bleeding at the site of knee arthroscopy. Eleven patients received cryoprecipitate (median dose: 10 units), three received TXA (median dose: 1,000 mg), and one patient received EACA (13 g). TXA was administered faster than the first blood product at a mean time of 19 min and 137 min, respectively. Hemorrhagic expansion (N = 8, 66.67%) and inhospital mortality (N = 7, 58.3%) were high. While limited by its small sample size, this case series demonstrates significant variability in reversal strategies for thrombolysis-associated bleeding. It also provides additional evidence for the role of antifibrinolytics in this setting.

Pharmacological interventions for the prevention of bleeding in people undergoing elective hip or knee surgery: a systematic review and network meta-analysis.

BACKGROUND: Hip and knee replacement surgery is a well-established means of improving quality of life, but is associated with a significant risk of bleeding. One-third of people are estimated to be anaemic before hip or knee replacement surgery; coupled with the blood lost during surgery, up to 90% of individuals are anaemic postoperatively. As a result, people undergoing orthopaedic surgery receive 3.9% of all packed red blood cell transfusions in the UK. Bleeding and the need for allogeneic blood transfusions has been shown to increase the risk of surgical site infection and mortality, and is associated with an increased duration of hospital stay and costs associated with surgery. Reducing blood loss during surgery may reduce the risk of allogeneic blood transfusion, reduce costs and improve outcomes following surgery. Several pharmacological interventions are available and currently employed as part of routine clinical care. OBJECTIVES: To determine the relative efficacy of pharmacological interventions for preventing blood loss in elective primary or revision hip or knee replacement, and to identify optimal administration of interventions regarding timing, dose and route, using network meta-analysis (NMA) methodology. SEARCH METHODS: We searched the following databases for randomised controlled trials (RCTs) and systematic reviews, from inception to 18 October 2022: CENTRAL (the Cochrane Library), MEDLINE (Ovid), Embase (Ovid), CINAHL (EBSCOhost), Transfusion Evidence Library (Evidentia), ClinicalTrials.gov and WHO International Clinical Trials Registry Platform (ICTRP). SELECTION CRITERIA: We included RCTs of people undergoing elective hip or knee surgery only. We excluded non-elective or emergency procedures, and studies published since 2010 that had not been prospectively registered (Cochrane Injuries policy). There were no restrictions on gender, ethnicity or age (adults only). We excluded studies that used standard of care as the comparator. Eligible interventions included: antifibrinolytics (tranexamic acid (TXA), aprotinin, epsilon-aminocaproic acid (EACA)), desmopressin, factor VIIa and XIII, fibrinogen, fibrin sealants and non-fibrin sealants. DATA COLLECTION AND ANALYSIS: We performed the review according to standard Cochrane methodology. Two authors independently assessed trial eligibility and risk of bias, and extracted data. We assessed the certainty of the evidence using CINeMA. We presented direct (pairwise) results using RevMan Web and performed the NMA using BUGSnet. We were interested in the following primary outcomes: need for allogenic blood transfusion (up to 30 days) and all-cause mortality (deaths occurring up to 30 days after the operation), and the following secondary outcomes: mean number of transfusion episodes per person (up to 30 days), re-operation due to bleeding (within seven days), length of hospital stay and adverse events related to the intervention received. MAIN RESULTS: We included a total of 102 studies. Twelve studies did not report the number of included participants; the other 90 studies included 8418 participants. Trials included more women (64%) than men (36%). In the NMA for allogeneic blood transfusion, we included 47 studies (4398 participants). Most studies examined TXA (58 arms, 56%). We found that TXA, given intra-articularly and orally at a total dose of greater than 3 g pre-incision, intraoperatively and postoperatively, ranked the highest, with an anticipated absolute effect of 147 fewer blood transfusions per 1000 people (150 fewer to 104 fewer) (53% chance of ranking 1st) within the NMA (risk ratio (RR) 0.02, 95% credible interval (CrI) 0 to 0.31; moderate-certainty evidence). This was followed by TXA given orally at a total dose of 3 g pre-incision and postoperatively (RR 0.06, 95% CrI 0.00 to 1.34; low-certainty evidence) and TXA given intravenously and orally at a total dose of greater than 3 g intraoperatively and postoperatively (RR 0.10, 95% CrI 0.02 to 0.55; low-certainty evidence). Aprotinin (RR 0.59, 95% CrI 0.36 to 0.96; low-certainty evidence), topical fibrin (RR 0.86, CrI 0.25 to 2.93; very low-certainty evidence) and EACA (RR 0.60, 95% CrI 0.29 to 1.27; very low-certainty evidence) were not shown to be as effective compared with TXA at reducing the risk of blood transfusion. We were unable to perform an NMA for our primary outcome all-cause mortality within 30 days of surgery due to the large number of studies with zero events, or because the outcome was not reported. In the NMA for deep vein thrombosis (DVT), we included 19 studies (2395 participants). Most studies examined TXA (27 arms, 64%). No studies assessed desmopressin, EACA or topical fibrin. We found that TXA given intravenously and orally at a total dose of greater than 3 g intraoperatively and postoperatively ranked the highest, with an anticipated absolute effect of 67 fewer DVTs per 1000 people (67 fewer to 34 more) (26% chance of ranking first) within the NMA (RR 0.16, 95% CrI 0.02 to 1.43; low-certainty evidence). This was followed by TXA given intravenously and intra-articularly at a total dose of 2 g pre-incision and intraoperatively (RR 0.21, 95% CrI 0.00 to 9.12; low-certainty evidence) and TXA given intravenously and intra-articularly, total dose greater than 3 g pre-incision, intraoperatively and postoperatively (RR 0.13, 95% CrI 0.01 to 3.11; low-certainty evidence). Aprotinin was not shown to be as effective compared with TXA (RR 0.67, 95% CrI 0.28 to 1.62; very low-certainty evidence). We were unable to perform an NMA for our secondary outcomes pulmonary embolism, myocardial infarction and CVA (stroke) within 30 days, mean number of transfusion episodes per person (up to 30 days), re-operation due to bleeding (within seven days), or length of hospital stay, due to the large number of studies with zero events, or because the outcome was not reported by enough studies to build a network. There are 30 ongoing trials planning to recruit 3776 participants, the majority examining TXA (26 trials). AUTHORS' CONCLUSIONS: We found that of all the interventions studied, TXA is probably the most effective intervention for preventing bleeding in people undergoing hip or knee replacement surgery. Aprotinin and EACA may not be as effective as TXA at preventing the need for allogeneic blood transfusion. We were not able to draw strong conclusions on the optimal dose, route and timing of administration of TXA. We found that TXA given at higher doses tended to rank higher in the treatment hierarchy, and we also found that it may be more beneficial to use a mixed route of administration (oral and intra-articular, oral and intravenous, or intravenous and intra-articular). Oral administration may be as effective as intravenous administration of TXA. We found little to no evidence of harm associated with higher doses of tranexamic acid in the risk of DVT. However, we are not able to definitively draw these conclusions based on the trials included within this review.

The effect of ε-aminocaproic acid on blood product requirement, outcome and thromboelastography parameters in severely thrombocytopenic dogs.

BACKGROUND: No treatment other than platelet administration is known to protect against spontaneous hemorrhage in thrombocytopenic dogs. OBJECTIVES: Primary: determine if treatment with ε-aminocaproic acid (EACA) decreases the requirement for blood transfusions and improves outcome in dogs with severe thrombocytopenia. Secondary: find evidence of hyperfibrinolysis and determine the effect EACA administration on rapid (rTEG) and tissue plasminogen activator-spiked (tPA-rTEG) thromboelastography parameters. ANIMALS: Twenty-seven dogs with severe thrombocytopenia were treated with EACA, and data from an additional 33 were obtained from the hospital database as historical control (HC) cohort. METHODS: Single arm clinical trial with HCs. The EACA group dogs received EACA (100 mg/kg IV followed by a constant-rate infusion [CRI] of 400 mg/kg/24 hours). Thromboelastography before and during EACA infusion, hospitalization days, number of transfusions, and mortality were compared. RESULTS: No difference was found in number of transfusions per dog (median, interquartile range; 1, 0-2.5 vs 0.9, 0-2; P = .5) and hospitalization days (4, 4-6 vs 4.5, 3.75-6; P = .83) between HC and EACA groups, respectively, and no difference in survival was identified by log-rank analysis (P = .15). Maximum amplitude on both rTEG and tPA-rTEG increased after EACA administration (rTEG baseline: 23.6, 9.6-38.9; post-EACA: 27.3, 19.8-43.2; P < .001; tPA-rTEG baseline: 23, 10.9-37.2; post-EACA: 24.7, 16.7-44.8; P < .002). CONCLUSIONS AND CLINICAL IMPORTANCE: Although EACA increased clot strength, there was no effect on outcome. Treatment with EACA at this dosage cannot be recommended as a routine treatment but may be considered for dogs with severe ongoing hemorrhage.

Comparison of efficacy between tranexamic acid and epsilon-aminocaproic acid for total knee arthroplasty: A meta-analysis of randomized controlled trials.

BACKGROUND: Tranexamic acid (TXA) and epsilon-aminocaproic acid (EACA) have been demonstrated to reduce blood loss following total knee arthroplasty (TKA). This meta-analysis aimed to compare the efficacy and safety of TXA and EACA in reducing blood loss in primary TKA patients. METHODS: A search of the PubMed, Embase, and Cochrane Library databases identified all relevant studies published until December 2022. Randomized controlled trials (RCTs) reporting a comparison of TXA and EACA for TKA patients were selected. The main outcomes were total blood loss (TBL), hemoglobin (Hb) drop on postoperative day 3, intraoperative blood loss, operation time and the transfusion rate were evaluated. The weighted mean differences (WMD) and risk ratio (RR) with 95% confidence intervals (CI) were calculated using a fixed-effects or random-effects model. Stata 12.0 software was used for meta-analysis. RESULTS: Six studies involving 739 (TXA:372; EACA:367) patients were included in this meta-analysis. There was no significant difference in terms of intraoperative blood loss, Hb drop on postoperative day 3, operation time, tourniquet time (TT), transfusion rate and the occurrence of deep venous thrombosis (DVT) between the 2 treatments groups. However, compared with EACA, TXA significant reduced TBL (WMD, 174.60; 95% CI, -244.09 to -105.11). CONCLUSION: Our research did not demonstrate TXA to be superior to EACA in reducing need for transfusion and Hb drop. TXA was superior than EACA in reducing TBL in TKA patients. More RCTs with identical inclusion criteria and dose and duration of treatment, are required to confirm these findings.

Evaluation of Therapeutic Use of Antifibrinolytics in Cats.

Limited data are available regarding the use of the antifibrinolytic drugs tranexamic acid (TXA) and epsilon aminocaproic acid (EACA) in cats. This study aimed to evaluate the indications for the use of TXA and EACA in cats and to describe dosing regimens used, occurrence of adverse events, and patient outcomes. This was a retrospective multicenter study. Medical databases were searched for feline patients billed for TXA or EACA between 2015 and 2021. Thirty-five cats met the inclusion criteria; 86% received TXA and 14% received EACA. The most common indication was nontraumatic hemorrhage (54%), followed by traumatic hemorrhage (17%) and elective surgery (11%). The median dose was 10 mg/kg for TXA and 50 mg/kg for EACA. Overall, 52% of cats survived to discharge. Potential adverse events were noted in 7/35 (20%) patients. Of these, 29% survived to discharge. No standardized dosing regimen was identified; rather, dose, dosing interval, and duration of administration varied markedly between patients. Administration was potentially associated with severe adverse events, although the retrospective design makes it difficult to establish a causal association with antifibrinolytic use. This study provides a base for future prospective studies by giving an insight into the use of antifibrinolytic drugs in cats.

Medical interventions for traumatic hyphema.

BACKGROUND: Traumatic hyphema is the entry of blood into the anterior chamber, the space between the cornea and iris, following significant injury to the eye. Hyphema may be associated with significant complications that uncommonly cause permanent vision loss. Complications include elevated intraocular pressure, corneal blood staining, anterior and posterior synechiae, and optic nerve atrophy. People with sickle cell trait or disease may be particularly susceptible to increases in intraocular pressure and optic atrophy. Rebleeding is associated with an increase in the rate and severity of complications. OBJECTIVES: To assess the effectiveness of various medical interventions in the management of traumatic hyphema. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2022, Issue 3); MEDLINE Ovid; Embase.com; PubMed (1948 to March 2022); the ISRCTN registry; ClinicalTrials.gov; and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). The last date of the search was 22 March 2022. SELECTION CRITERIA: Two review authors independently assessed the titles and abstracts of all reports identified by the electronic and manual searches. We included randomized and quasi-randomized trials that compared various medical (non-surgical) interventions versus other medical interventions or control groups for the treatment of traumatic hyphema following closed-globe trauma. We applied no restrictions on age, gender, severity of the closed-globe trauma, or level of visual acuity at time of enrollment. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane and assessed the certainty of evidence using GRADE. MAIN RESULTS: We included 23 randomized and seven quasi-randomized studies with a total of 2969 participants. Interventions included antifibrinolytic agents (systemic and topical aminocaproic acid, tranexamic acid, and aminomethylbenzoic acid), corticosteroids (systemic and topical), cycloplegics, miotics, aspirin, conjugated estrogens, traditional Chinese medicine, monocular versus bilateral patching, elevation of the head, and bed rest. We found no evidence of an effect on visual acuity for any intervention, whether measured within two weeks (short term) or for longer periods. In a meta-analysis of two trials, we found no evidence of an effect of aminocaproic acid on long-term visual acuity (RR 1.03, 95% confidence interval (CI) 0.82 to 1.29) or final visual acuity measured up to three years after the hyphema (RR 1.05, 95% CI 0.93 to 1.18). Oral tranexamic acid appeared to provide little to no benefit on visual acuity in four trials (RR 1.12, 95% CI 1.00 to 1.25). The remaining trials evaluated the effects of various interventions on short-term visual acuity; none of these interventions was measured in more than one trial. No intervention showed a statistically significant effect (RRs ranged from 0.75 to 1.10). Similarly, visual acuity measured for longer periods in four trials evaluating different interventions was also not statistically significant (RRs ranged from 0.82 to 1.02). The evidence supporting these findings was of low or very low certainty. Systemic aminocaproic acid reduced the rate of recurrent hemorrhage (RR 0.28, 95% CI 0.13 to 0.60), as assessed in six trials with 330 participants. A sensitivity analysis omitting two studies not using an intention-to-treat analysis reduced the strength of the evidence (RR 0.43, 95% CI 0.17 to 1.08). We obtained similar results for topical aminocaproic acid (RR 0.48, 95% CI 0.20 to 1.10) in two trials with 131 participants. We assessed the certainty of the evidence as low. Systemic tranexamic acid had a significant effect in reducing the rate of secondary hemorrhage (RR 0.33, 95% CI 0.21 to 0.53) in seven trials with 754 participants, as did aminomethylbenzoic acid (RR 0.10, 95% CI 0.02 to 0.41), as reported in one study. Evidence to support an associated reduction in risk of complications from secondary hemorrhage (i.e. corneal blood staining, peripheral anterior synechiae, elevated intraocular pressure, and development of optic atrophy) by antifibrinolytics was limited by the small number of these events. Use of aminocaproic acid was associated with increased nausea, vomiting, and other adverse events compared with placebo. We found no evidence of an effect on the number of adverse events with the use of systemic versus topical aminocaproic acid or with standard versus lower drug dose.  The number of days for the primary hyphema to resolve appeared to be longer with the use of systemic aminocaproic acid compared with no use, but this outcome was not altered by any other intervention. The available evidence on usage of systemic or topical corticosteroids, cycloplegics, or aspirin in traumatic hyphema was limited due to the small numbers of participants and events in the trials. We found no evidence of an effect between a single versus binocular patch on the risk of secondary hemorrhage or time to rebleed. We also found no evidence of an effect on the risk of secondary hemorrhage between ambulation and complete bed rest. AUTHORS' CONCLUSIONS: We found no evidence of an effect on visual acuity of any of the interventions evaluated in this review. Although the evidence was limited, people with traumatic hyphema who receive aminocaproic acid or tranexamic acid are less likely to experience secondary hemorrhage. However, hyphema took longer to clear in people treated with systemic aminocaproic acid. There is no good evidence to support the use of antifibrinolytic agents in the management of traumatic hyphema, other than possibly to reduce the rate of secondary hemorrhage. The potentially long-term deleterious effects of secondary hemorrhage are unknown. Similarly, there is no evidence to support the use of corticosteroids, cycloplegics, or non-drug interventions (such as patching, bed rest, or head elevation) in the management of traumatic hyphema. As these multiple interventions are rarely used in isolation, further research to assess the additive effect of these interventions might be of value.

Combination of Intravenous and Intra-Articular Application of Tranexamic Acid and Epsilon-Aminocaproic Acid in Primary Total Knee Arthroplasty: A Prospective Randomized Controlled Trial.

OBJECTIVE: There were limited randomized controlled trials (RCTs) of epsilon-aminocaproic acid (EACA) versus tranexamic acid (TXA) in total knee arthroplasty (TKA). The aim of the study was to compare the efficacy and safety of TXA and EACA in the combination of intravenous (IV) and intra-articular (IA) administration on reducing blood loss in patients following primary TKA. METHODS: From January 2020 to January 2021, a total of 181 patients undergoing a primary unilateral TKA were enrolled in this prospective randomized controlled trial. Patients in the TXA group (n = 90) received 20 mg/kg of intravenous TXA preoperatively, 1 g of intra-articular TXA intraoperatively, and three doses of 20 mg/kg intravenous TXA at 0, 3, 6 h postoperatively. Patients in the EACA group (n = 91) received 120 mg/kg of intravenous EACA preoperatively, 2 g of intra-articular EACA intraoperatively, and three doses of 40 mg/kg intravenous EACA at 0, 3, 6 h postoperatively. The primary outcomes were total blood loss (TBL), transfusion rates and drop of hemoglobin (HB) level. The secondary outcomes included postoperative hospital stays and postoperative complications. The chi-square tests and Fisher's exact tests were utilized to compare categorical variables, while the independent-samples t-tests and Mann-Whitney tests were used to compare continuous variables. RESULTS: The patients who received TXA averaged less TBL than the patients who received EACA (831.83 ml vs 1065.49 ml, P = 0.015), and HB drop in TXA group was generally less than that of EACA group on postoperative day 1 and 3 (20.84 ± 9.48 g/L vs 24.99 ± 9.40 g/L, P = 0.004; 31.28 ± 11.19 vs 35.46 ± 12.26 g/L, P = 0.047). The length of postoperative stays in EACA group was 3.66 ± 0.81 day, which is longer than 2.62 ± 0.68 day in TXA group (P < 0.001). No transfusions were required in either group. The risk of nausea and vomiting in TXA group was significantly higher than that in EACA group (11/90 vs 0/91, P < 0.01). CONCLUSION: Although the TBL and HB drop were slightly greater in EACA group, these results were not clinically important, given that no transfusions were required. EACA could be an alternative to TXA, especially for patients with severe nausea and vomiting after using TXA postoperatively. Further studies are needed to adjust dosage of EACA to make better comparison of the two drugs.

1,2,3-Triazole Derivatives as Novel Antifibrinolytic Drugs.

Fibrinolysis is a natural process that ensures blood fluidity through the removal of fibrin deposits. However, excessive fibrinolytic activity can lead to complications in different circumstances, such as general surgery or severe trauma. The current antifibrinolytic drugs in the market, aminocaproic acid (EACA) and tranexamic acid (TXA), require high doses repetitively to maintain their therapeutic effect. These high doses are related to a number of side effects such as headaches, nasal symptoms, or gastrointestinal discomfort and severely limit their use in patients with renal impairment. Therefore, the discovery of novel antifibrinolytics with a higher specificity and lower dosage could vastly improve the applicability of these drugs. Herein, we synthesized a total of ten compounds consisting of a combination of three key moieties: an oxadiazolone, a triazole, and a terminal amine. The IC50 of each compound was calculated in our clot lysis assays, and the best candidate (1) provided approximately a 2.5-fold improvement over the current gold standard, TXA. Molecular docking and molecular dynamics were used to perform a structure-activity relationship (SAR) analysis with the lysine binding site in the Kringle 1 domain of plasminogen. This analysis revealed that 1,2,3-triazole was crucial for the activity, enhancing the binding affinity through pi-pi stacking and polar interactions with Tyr72. The results presented in this work open the door to further investigate this new family as potential antifibrinolytic drugs.

Prophylactic Use of Antifibrinolytics During Pediatric Cardiac Surgery With Cardiopulmonary Bypass on Postoperative Bleeding and Transfusion: A Systematic Review and Meta-Analysis.

OBJECTIVES: To determine the effect of intraoperative antifibrinolytics, including tranexamic acid (TXA), aminocaproic acid (EACA), or aprotinin, on bleeding in children undergoing cardiac surgery with cardiopulmonary bypass (CPB). DATA SOURCES: Relevant articles were systematically searched from Ovid MEDLINE, Ovid EMBASE, CINAHL, Cochrane Library, and Web of Science to November 15, 2021. STUDY SELECTION: Abstracts were screened, and full texts were reviewed using predetermined inclusion and exclusion criteria using the Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline. DATA EXTRACTION: A standardized data extraction tool was used. DATA SYNTHESIS: Sixty-eight studies including 28,735 patients were analyzed. TXA compared with placebo resulted in a mean decrease in chest tube output of 9.1 mL/kg (95% CI, 6.0-12.3 mL/kg), I2 equals to 65.2%, p value of less than 0.001, platelet requirement of 2.9 mL/kg (95% CI, 0.1-5.8 mL/kg), I2 =72.5%, p value less than 0.001 and plasma requirement of 4.0 mL/kg (95% CI, 0.6-7.2 mL/kg), I2 equals to 94.5%, p value less than0.001. Aprotinin compared with placebo resulted in a mean decrease in chest tube output of 4.3 mL/kg (2.4-6.2 mL/kg), I2 equals to 66.3%, p value of less than 0.001, platelet transfusion of 4.6 mL/kg (95% CI, 0.6-8.6 mL/kg), I2 equals to 93.6%, p value of less than 0.001, and plasma transfusion of 7.7 mL/kg (95% CI, 2.1-13.2 mL/kg), I2 equals to 95.3%, p value of less than 0.001. EACA compared with placebo resulted in a mean decrease in chest tube output of 9.2 mL/kg (2.3-21.0 mL/kg), I2 equals to 96.4%, p value of less than 0.001, RBC transfusion of 7.2 mL/kg (95% CI, 2.4-12.1 mL/kg), I2 equals to 94.5%, p value equals to 0.002, and platelet transfusion of 10.7 mL/kg (95% CI, 2.9-18.5 mL/kg), I2 equals to 0%, p value of less than 0.001. No statistical difference was observed in chest tube output when TXA was compared with aprotinin. Subgroup analysis of cyanotic patients showed a significant decrease in chest tube output, platelet requirement, and plasma requirement for patients receiving aprotinin. Overall, the quality of evidence was moderate. CONCLUSIONS: Antifibrinolytics are effective at decreasing blood loss and blood product requirement in children undergoing cardiac surgery with CPB although the quality of evidence is only moderate.

Ultrasmall polymer-coated cerium oxide nanoparticles as a traumatic brain injury therapy.

No medication has been approved for secondary injuries after traumatic brain injury (TBI). While free radicals are considered a major mediator of secondary injury, conventional antioxidants only have modest clinical efficacy. Here, we synthesized CX201 consisting of core cerium oxide nanoparticles coated with 6-aminocaproic acid and polyvinylpyrrolidone in aqueous phase. CX201 with 3.49 ± 1.11 nm of core and 6.49 ± 0.56 nm of hydrodynamic diameter showed multi-enzymatic antioxidant function. Owing to its excellent physiological stability and cell viability, CX201 had a neuroprotective effect in vitro. In a TBI animal model, an investigator-blinded randomized experiment showed a single intravenously injected CX201 significantly improved functional recovery compared to the control. CX201 reduced lipid peroxidation and inflammatory cell recruitment at the damaged brain. These suggest ultrasmall CX201 can efficiently reduce secondary brain injuries after TBI. Given the absence of current therapies, CX201 may be proposed as a novel therapeutic strategy for TBI.

[Hemostatic efficacy of tranexamic acid and ε-aminocaproic acid in hip and knee arthroplasty:a Meta-analysis].

OBJECTIVE: To systematically evaluate the hemostatic efficacy of tranexamic acid and ε-aminocaproic acid in total hip arthroplasty (THA) and total knee arthroplasty (TKA). METHODS: Randomized controlled trials (RCT) and retrospective case-control studies about tranexamic acid and ε-aminocaproic acid for the comparison of THA or TKA were searched electronically in PubMed, EMbase, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang, VIP from the time of building databases to July 2020. Two investigators carried out literature screening and data extraction according to the inclusion and exclusion criteria respectively. The methodological quality of the included randomized controlled studies was evaluated through the Cochrane Handbook, and the methodological quality of the included retrospective case-control studies was evaluated through the NOS scale. Blood loss, the incidence of thrombosis complications, per capita input of hemoglobin were Meta-analyzed by Review Manager 5.3 software. RESULTS: A total of 6 articles were included, including 4 RCTs and 2 retrospective case-control studies. A total of 3 174 patients, including 1 353 in the tranexamic acid group and 1 821 in the ε-aminocaproic acid group. Meta-analysis results showed that there were no difference statistical significance in blood loss [MD=-88.60, 95%CI(-260.30, 83.10), P=0.31], blood transfusion rate [OR=1.48, 95%CI(0.96, 2.27), P=0.08], thrombotic complications [OR=0.80, 95%CI(0.07, 8.83), P=0.85], per capita hemoglobin input [MD=0.04, 95%CI(-0.02, 0.10), P=0.18] between tranexamic acid group and ε-aminocaproic acid group during THA. While in TKA, the blood loss of the tranexamic acid group was less than that of the ε-aminocaproic acid group [MD=-147.13, 95%CI(-216.52, -77.74), P<0.0001], the difference was statistically significant. The blood transfusion rate [OR=1.30, 95%CI(0.74, 2.28), P=0.37], thrombotic complications [OR=0.95, 95%CI(0.38, 2.36), P=0.92], per capita hemoglobin input [MD=-0.00, 95%CI(-0.05, 0.06), P=0.48], tourniquet time [MD=1.54, 95%CI(-2.07, 5.14), P=0.40] were similar between two groups, the difference was not statistically significant. CONCLUSION: In THA, tranexamic acid and ε-aminocaproic acid have similar hemostatic effects, while in TKA, tranexamic acid can effectively reduce the patient's blood loss and has a better hemostatic effect. Tranexamic acid is recommended as one of the first choice hemostatic drugs for TKA.

Effects of antifibrinolytics on systemic and cerebral inflammation after traumatic brain injury.

BACKGROUND: Administration of antifibrinolytic medications, including tranexamic acid (TXA), may reduce head injury-related mortality. The effect of these medications on post-traumatic brain injury (TBI) inflammatory response is unknown. The goal of this study was to investigate the role of available antifibrinolytic medications on both systemic and cerebral inflammation after TBI. METHODS: An established murine weight drop model was used to induce a moderate TBI. Mice were administered 1, 10, or 100 mg/kg of TXA, 400 mg/kg of aminocaproic acid (Amicar, Hospira, Lake Forest, IL), 100 kIU/kg of aprotonin, or equivalent volume of normal saline (NS) 10 minutes after recovery. Mice were euthanized at 1, 6, or 24 hours. Serum and cerebral tissue were analyzed for neuron-specific enolase and inflammatory cytokines. Hippocampal histology was evaluated at 30 days for phosphorylated tau accumulation. RESULTS: One hour after TBI, mice given TXA displayed decreased cerebral cytokine concentrations of tumor necrosis factor α (TNF-α) and, by 24 hours, displayed decreased concentrations of cerebral TNF-α, interleukin (IL)-6, and monocyte chemoattractant protein 1 compared with TBI-NS. However, serum concentrations of TNF-α and macrophage inflammatory protein 1α (MIP-1α) were significantly elevated from 1 to 24 hours in TBI-TXA groups compared with TBI-NS. The concentration of phosphorylated tau was significantly decreased in a dose-dependent manner in TBI-TXA groups compared with TBI-NS. By contrast, Amicar administration increased cerebral cytokine levels of IL-6 1 hour after TBI, with serum elevations noted in TNF-α, MIP-1α, and monocyte chemoattractant protein 1 at 24 hours compared with TBI-NS. Aprotonin administration increased serum TNF-α, IL-6, and MIP-1α from 1 to 24 hours without differences in cerebral cytokines compared with TBI-NS. CONCLUSION: Tranexamic acid administration may provide acute neuroinflammatory protection in a dose-dependent manner. Amicar administration may be detrimental after TBI with increased cerebral and systemic inflammatory effects. Aprotonin administration may increase systemic inflammation without significant contributions to neuroinflammation. While no antifibrinolytic medication improved systemic inflammation, these data suggest that TXA may provide the most beneficial inflammatory modulation after TBI.

Antifibrinolytic Drugs for the Prevention of Bleeding in Pediatric Cardiac Surgery on Cardiopulmonary Bypass: A Systematic Review and Meta-analysis.

BACKGROUND: Bleeding is one of the commonest complications affecting children undergoing cardiac surgery on cardiopulmonary bypass. Antifibrinolytic drugs are part of a multifaceted approach aimed at reducing bleeding, though sufficiently sized pediatric studies are sparse, and dosing algorithms are heterogeneous. Our objective was to evaluate the efficacy and safety of antifibrinolytic agents as well as the effectiveness of different dosing regimens in pediatric cardiac surgery using cardiopulmonary bypass. METHODS: We performed a systematic review and meta-analysis evaluating randomized controlled trials published between 1980 and 2019, identified by searching the databases MEDLINE, EMBASE, PubMed, and CENTRAL. All studies investigating patients <18 years of age without underlying hematological disorders were included. The primary outcome was postoperative bleeding; secondary end points included blood product transfusion, mortality, and safety (thromboses, anaphylaxis, renal or neurological dysfunction, and seizures). Different dosing regimens were compared. Studies were dual appraised, outcomes were reported descriptively and, if appropriate, quantitatively using the Review Manager 5 (REVMAN 5) software (The Cochrane Collaboration). RESULTS: Thirty of 209 articles were included, evaluating the following drugs versus control: aprotinin n = 14, tranexamic acid (TXA) n = 12, and epsilon-aminocaproic acid (EACA) n = 4. The number of participants per intervention group ranged from 11 to 100 (median, 25; interquartile range [IQR], 20.5) with a wide age span (mean, 13 days to 5.8 years) and weight range (mean, 3.1-26.3 kg). Methodological quality was low to moderate.All agents reduced mean 24-hour blood loss compared to control: aprotinin by 6.0 mL/kg (95% confidence interval [CI], -9.1 to -3.0; P = .0001), TXA by 9.0 mL/kg (95% CI, -11.3 to -6.8; P < .00001), and EACA by 10.5 mL/kg (95% CI, -21.1 to 0.0; P = .05). Heterogeneity was low for TXA (I2 = 29%; P = .19), moderate for aprotinin (I2 = 41%; P = .11), and high for EACA (I2 = 95%; P < .00001). All agents also reduced 24-hour blood product transfusion. There was no clear dose-response effect for TXA nor aprotinin. Studies were underpowered to detect significant differences in mortality, thromboses, anaphylaxis, and renal or neurological dysfunction. CONCLUSIONS: The available data demonstrate efficacy for all 3 antifibrinolytic drugs. Therefore, the agent with the most favorable safety profile should be used. As sufficient data are lacking, large comparative trials are warranted to assess the relative safety and appropriate dosing regimens in pediatrics.

Use of Antifibrinolytics in Pediatric Life-Threatening Hemorrhage: A Prospective Observational Multicenter Study.

OBJECTIVES: To assess the impact of antifibrinolytics in children with life-threatening hemorrhage. DESIGN: Secondary analysis of the MAssive Transfusion epidemiology and outcomes In Children study dataset, a prospective observational study of children with life-threatening bleeding events. SETTING: Twenty-four children's hospitals in the United States, Canada, and Italy. PATIENTS: Children 0-17 years old who received greater than 40 mL/kg of total blood products over 6 hours or were transfused under activation of massive transfusion protocol. INTERVENTION/EXPOSURE: Children were compared according to receipt of antifibrinolytic medication (tranexamic acid or aminocaproic acid) during the bleeding event. MEASUREMENTS AND MAIN RESULTS: Patient characteristics, medications administered, and clinical outcomes were analyzed using Cox proportional hazard and Kaplan-Meier survival analysis. The primary outcome was 24-hour mortality. Of 449 patients analyzed, median age was 7 years (2-15 yr), and 55% were male. The etiology of bleeding was 46% traumatic, 34% operative, and 20% medical. Twelve percent received antifibrinolytic medication during the bleeding event (n = 54 unique subjects; n = 18 epsilon aminocaproic acid, n = 35 tranexamic acid, and n = 1 both). The antifibrinolytic group was comparable with the nonantifibrinolytic group on baseline demographic and physiologic parameters; the antifibrinolytic group had longer massive transfusion protocol duration, received greater volume blood products, and received factor VII more frequently. In the antifibrinolytic group, there was significantly less 6-hour mortality overall (6% vs 17%; p = 0.04) and less 6-hour mortality due to hemorrhage (4% vs 14%; p = 0.04). After adjusting for age, bleeding etiology, Pediatric Risk of Mortality score, and plasma deficit, the antifibrinolytic group had decreased mortality at 6- and 24-hour postbleed (adjusted odds ratio, 0.29 [95% CI, 0.09-0.93]; p = 0.04 and adjusted odds ratio, 0.45 [95% CI, 0.21-0.98]; p = 0.04, respectively). CONCLUSIONS: Administration of antifibrinolytic medications during the life-threatening event was independently associated with improved 6- and 24-hour survivals in bleeding children. Consideration should be given to use of antifibrinolytics in pediatric patients with life-threatening hemorrhage.

Blood Loss and Transfusion in a Pediatric Scoliosis Surgery Cohort in the Antifibrinolytic Era.

Children and adolescents undergoing posterior spinal fusion for scoliosis experience high rates of bleeding and blood product transfusion. Antifibrinolytic therapy is one key strategy to decrease blood loss and transfusion in pediatric scoliosis surgery. Here we review 172 pediatric scoliosis patients (birth to 21 y) who underwent posterior spinal fusion at our institution from 2017 to 2018. We reported rates of blood loss and transfusion, compared patients receiving tranexamic acid to a ε-aminocaproic acid, and evaluated antifibrinolytic agent and laboratory parameters as predictors of blood loss and transfusion. Intraoperatively, 62% received tranexamic acid and 38% received ε-aminocaproic acid. Overall, blood loss (mean intraoperative estimated blood loss=14.9±9.7 mL/kg, 22% with clinically significant blood loss [>20 mL/kg], and mean calculated hemoglobin mass loss=175.9±70.1 g) and transfusion rates (15% with intraoperative allogeneic red blood cell transfusion and mean intraoperative allogeneic red blood cell transfusion volume=12.5±7.1 mL/kg) were similar to previous cohorts studying intraoperative antifibrinolytics. There was no difference in intraoperative estimated blood loss, clinically significant blood loss, calculated hemoglobin mass loss, or transfusion rates between the antifibrinolytic groups. Antifibrinolytic choice was not predictive of blood loss or transfusion. Routine hematologic laboratory parameters and antifibrinolytic choice were insufficient to predict blood loss or other outcomes. Future prospective laboratory-based studies may provide a more comprehensive model of surgical-induced coagulopathy in scoliosis surgery and provide a better tool for predicting blood loss and improving outcomes.

ε-Aminocaproic acid versus tranexamic acid in children undergoing complex cranial vault reconstruction for repair of craniosynostosis.

Complex cranial vault reconstruction (CCVR) for pediatric craniosynostosis is a high blood loss surgery, for which antifibrinolytic agents have been shown to reduce bleeding and transfusion requirements. The relative efficacy of ε-aminocaproic acid (EACA) versus tranexamic acid (TXA) has not yet been evaluated in this population. The aim of this retrospective study was to compare perioperative blood loss and transfusion in CCVR patients receiving EACA versus TXA. In a CCVR cohort of 95 children, 47 received EACA and 48 received TXA. We found no differences in demographics, adverse outcomes, calculated blood loss (CBL), or transfusion requirements between the two antifibrinolytic groups.

Tranexamic acid versus aminocapróic acid in multiple doses via the oral route for the reduction of postoperative bleeding in total primary hip arthroplasty: a prospective, randomized, double-blind, controlled study.

To compare the effects of oral ε-aminocaproic acid (EACA) as a hemostatic agent versus the use of oral tranexamic acid (TXA) administered in multiple doses pre and postsurgery in patients undergoing elective primary total hip arthroplasty (THA). We enrolled 102 patients that were randomly divided into two groups: received three oral doses of EACA (2000 mg per dose) or three oral doses of TXA (1300 mg per dose). The medication was given according to the following schedule: 2 h before surgery and 6 and 12 h after surgery. The variables analyzed to compare the effectiveness of the hemostatic agents were total blood loss, hidden blood loss, external blood loss, transfusion rate, intraoperative blood loss, decreases in hemoglobin and hematocrit values, surgical drainage output, visual analog scale, and surgical complications. There were no significant differences between any of the study variables for the group receiving oral TXA and the group receiving oral EACA (P > 0.05). Our study showed that the use of oral EACA was similar to its counterpart TXA regarding the evaluated parameters. TXA did not have superior blood conservation effects, safety profile, or differences in functional scales compared with EACA in THA. We consider the use of multiple oral doses of aminocaproic acid at the selected dose to be effective as a standard protocol to achieve less blood loss and a lower rate of transfusion and adverse events related to the medication in patients undergoing a THA.

Real-world cohort study of adult and pediatric patients treated for hereditary angioedema in the United States.

Background: There is limited real-world evidence on hereditary angioedema (HAE) patient characteristics and health-care resource utilization (HCRU); in addition, pediatric patients have been described in small cohorts. Objective: To describe patient characteristics, treatment patterns, and HCRU among adult and pediatric patients treated for HAE in a large U.S. cohort. Methods: This retrospective cohort study used an administrative claims data base (January 2006 to September 2015). Eligible patients with either ≥1 pharmacy claim for HAE-indicated therapies (C1 inhibitors, ecallantide, icatibant) or ≥2 medical claims with codes associated with HAE (per medical billing codes), and ≥1 claim for androgens, fresh frozen plasma, tranexamic acid, or ε-aminocaproic acid formed a "treated cohort." Three nonexclusive treated cohorts were assessed: overall, pediatric, and HCRU (≥2 years of continuous enrollment during 2010-2015). Results: Overall, 1429 patients received treatment (mean ± standard deviation [SD] age, 38.8 ±15.7 years; 62.4% female patients; mean ± SD Charlson Comorbidity Index of 1.4 ± 2.4). Common comorbidities were allergy or anaphylaxis (51.4%) and anxiety or depression (35.8%). Diagnoses indicative of HAE attacks included swelling and/or angioedema (78.5%), abdominal pain (55.6%), and asphyxiation (27.2%). Use of HAE-indicated medication rose between 2006 and 2015 to 81.8%, whereas androgen use declined (from 91.5% to 24.9%). Similar trends were observed in the pediatric treated cohort (n = 143). In the HCRU treated cohort (n = 538), HAE-related claims for emergency department and inpatient admissions were observed for 36.6% and 22.3% of patients, respectively. Conclusion: In a large U.S. cohort of adult and pediatric patients who received treatments indicated or used for HAE, common comorbidities and trends in resource use denoted the substantial burden of attacks, which reflected a continued need that recently approved long-term prophylactic treatments may help to address.

Bronchoscopic delivery of aminocaproic acid as a treatment for pulmonary bleeding: A case series.

OBJECTIVE: Bronchoscopy is an essential therapeutic modality in the treatment of pulmonary bleeding. Although numerous endoscopic treatments exist, topical ε-aminocaproic acid has not been described in the literature. This study documents the use of this novel treatment for pulmonary bleeding and compares it to available evidence for tranexamic acid, a similar anti-fibrinolytic agent. DESIGN: Case-series study. SETTING: ICU and general inpatient floors of a tertiary medical center. PATIENTS: Forty-six patients receiving endobronchial ε-aminocaproic acid for the treatment or prevention of pulmonary bleeding. MEASUREMENTS AND MAIN RESULTS: Of the 46 patients included in the study, 41.6% and 13% presented with non-massive and massive hemoptysis, respectively. In patients with active pulmonary bleeding, endobronchial application of ε-aminocaproic acid and accompanying therapies resulted in cessation of bleeding in 94.7% of cases. A total of six patients received ε-aminocaproic acid monotherapy; in three patients with active bleeding, 100% achieved hemostasis after treatment. Of the 36 patients successfully treated for active pulmonary bleeding, 27.8% had recurrent bleeding within 30 days. Thirty-day adverse events were as follows: death (10 patients), deep vein thrombosis (2 patients), renal failure (2 patients), and stroke (2 patients). CONCLUSIONS: Endobronchial administration of ε-aminocaproic acid during bronchoscopy may be a safe and efficacious option in the treatment and prevention of pulmonary bleeding. Further studies are necessary to better define ε-aminocaproic acid's safety profile, optimal routes of administration, and comparative effectiveness to tranexamic acid.