The new oral anticoagulants in clinical practice

Studies on Atrial Fibrillation and Venous Thromboembolism in the Past 20 Years: A Bibliometric Analysis Via CiteSpace and VOSviewer

The conjunction of atrial fibrillation (AF) and venous thromboembolism (VTE) is common in clinical practice. Over the last 2 decades, a significant number of articles (2500) have been published about AF and VTE. To effectively analyze and present these vast amounts of information, this study uses bibliometric research methods to categorize and consolidate these publications. The number of publications has increased yearly, especially since 2012. The United States was the most prolific country, with 1054 studies published. The most productive institution was McMaster University. Gregory Y.H. Lip was the most prolific author. The keyword analysis identified that the research focuses from 2003 to 2014 were factor Xa inhibitor, dabigatran etexilate, direct thrombin inhibitor, double-blind, deep vein thrombosis, molecular weight heparin, stroke prevention, etc. From 2015 to 2016, research mainly focused on venous thromboembolism, antithrombotic therapy, anticoagulant, warfarin, atrial fibrillation, stroke, and pulmonary embolism. Studies during 2017 to 2022 focused on apixaban, direct oral anticoagulant, rivaroxaban, dabigatran, hemorrhage, edoxaban, medicine efficacy and safety, risk factors, clinical management, and vitamin K antagonists. Since 2018, novel oral anticoagulants have been the most commonly used keywords. On the whole, most studies of AF and VTE focus on pathogenesis and therapeutic drugs. The causal relationship between AF and VTE, the effectiveness and safety of novel oral anticoagulants in the treatments, the anticoagulant regimen of AF and VTE co-disease, and the treatment regimen for vulnerable populations such as the elderly or obese people were the focus of current research and will continue to be the central point of future research.

Antithrombotic Stewardship: Assessing Use of Computerized Clinical Decision Support Tools to Enhance Safe Prescribing of Direct Oral Anticoagulants in Hospitalized Patients

ABSTRACT

Prescribing patterns for oral anticoagulants in patients with nonvalvular atrial fibrillation and venous thromboembolism is shifting from vitamin K antagonists, such as warfarin to the direct oral anticoagulants (DOACs), such as dabigatran, rivaroxaban, and apixaban. Although many hospital systems have implemented clinical decision support or enhanced monitoring for patients prescribed warfarin, there is limited evidence to suggest similar levels of enhanced monitoring for DOACs. The antithrombotic stewardship team at our institution developed guidelines and implemented computerized clinical decision support (CCDS) tools to enhance medication and patient safety related to the DOACs. We sought to assess the safety and effectiveness of these CCDS tools available to clinicians upon DOAC prescription in hospitalized patients. We performed a retrospective review of 121 patients who received at least two doses of a DOAC from January 2013 to July 2014. We assessed dosing of the DOAC according to the CCDS provided upon order entry. Adherence to CCDS was 80% (n = 24), 75% (n = 46), and 87% (n = 27) in the dabigatran, apixaban, and rivaroxaban group, respectively. Our data demonstrate that implementing CCDS for DOACs into the electronic medical record may ensure safe prescribing of high-risk medications.

Effectiveness and Safety of Direct Oral Anticoagulants vs. Warfarin and Recurrence After Discontinuation in Patients With Acute Venous Thromboembolism in the Real World

BACKGROUND

The efficacy of direct oral anticoagulants (DOACs) compared with warfarin for the treatment of venous thromboembolism (VTE), and the recurrence of VTE after discontinuation of anticoagulation therapy in research are limited.Methods and Results:This retrospective study enrolled 893 patients with acute VTE between 2011 and 2019. The cohort was divided into the transient risk, unprovoked, continued cancer treatment, and cancer remission groups. The following were compared between DOACs and warfarin: composite outcome of all-cause death, VTE recurrence, bleeding and composite outcome of VTE-related death, recurrence and bleeding. In the continued cancer treatment group, more bleeding was seen in warfarin-treated patients than in patients treated with DOACs (53.2% vs. 31.2%, [P=0.048]). In addition, composite outcome of VTE-related death and recurrence after discontinuation of anticoagulation therapy (n=369) was evaluated. The continued cancer treatment group (multivariate analysis: HR: 3.62, 95% CI: 1.84-7.12, P<0.005) and bleeding-related discontinuation of therapy (HR: 2.60, 95% CI: 1.32-5.13, P=0.006) were independent predictors of the event after discontinuation of anticoagulation therapy. VTE recurrence after discontinuation of anticoagulation therapy in the cancer remission group was 1.6% and a statistically similar occurrence was found in the transient risk group (12.4%) (P=0.754).

CONCLUSIONS

DOACs may decrease bleeding incidence in patients continuing to receive cancer treatment. In patients with bleeding-related discontinuation of anticoagulation therapy, VTE recurrence may increase. Discontinuation of anticoagulant therapy might be a treatment option in patients who have completed their cancer treatment.

Supportive care in multiple myeloma: Current practices and advances

Supportive care in multiple myeloma (MM) can have a major impact on quality of life and the survival outcomes of MM patients. In this review, we will focus on disease and treatment related toxicities experienced by MM patients and what are the best approaches to date to help mitigate the effects. We will specifically focus on a practical approach to managing bone disease, thrombosis, infection risk, peripheral neuropathy, dermatologic complications, gastrointestinal and ocular toxicities, and fatigue in MM.

Meta-regression of randomized control trials with antithrombotics: weak correlation between net clinical benefit and all cause-mortality

This study aimed to explore the validity of the use of the net clinical benefit (NCB), i.e. the sum of major bleeding and thrombotic events, as a potential surrogate for all-cause mortality in clinical trials assessing antithrombotics. Published randomized controlled trials testing anticoagulants in the prevention or treatment of venous thromboembolism (VTE) and non-valvular atrial fibrillation (NVAF) were systematically reviewed. The validity of NCB as a surrogate endpoint was estimated by calculating the strength of correlation of determination (R²) and its 95% confidence interval (CI) between the relative risks of NCB and all-cause mortality. Amongst the 125 trials retrieved, the highest R²_trial values were estimated for NVAF (R²_trial = 0.41, 95% CI [0.03; 0.48]), and acute VTE (R²_trial = 0.30, 95% CI [0.04; 0.84]). Conversely, the NCB did not correlate with all-cause mortality in prevention studies with medical (R²_trial = 0.12, 95% CI [0.00; 0.36]), surgical (R²_trial = 0.05, 95% CI [0.00; 0.23]), and cancer patients (R²_trial = 0.006, 95% CI [0.00; 1.00]). A weak correlation between NCB and all cause-mortality was found in NVAF and acute VTE, whereas no correlation was observed in clinical situations where the mortality rate was low. Consequently, NCB should not be considered a surrogate outcome for all cause-mortality in anticoagulation trials.

Using oral anticoagulants among chronic kidney disease patients to prevent recurrent venous thromboembolism: A systematic review and meta-analysis

INTRODUCTION

Chronic kidney disease (CKD) increases the risk of venous thromboembolism (VTE) among affected patients. Vitamin K antagonists (VKA) and warfarin remains the main stay of its treatment. Due to novelty and unclear risk-to-benefit ratio of direct oral anti-coagulants (DOAC), they remain underutilized in preventing VTE among CKD patients. We aim to assess the efficacy and safety of DOACs and other oral anticoagulants in preventing recurrent VTE among high-risk population.

MATERIAL METHODS

We conducted a literature search using PubMed, Embase, Cochrane, Web of Science and Clinicaltrials.gov for randomized controlled trials (RCTs) comparing anti-coagulants like DOAC, LMWH or VKA or any oral anti-coagulant (OAC) (This includes VKAs and DOACs) with either placebo or another anti-coagulant. Two independent reviewers screened the retrieved articles and extracted data using a piloted data extraction sheet. The primary outcome of interest was number of recurrent VTE and other side effects among CKD patients receiving respective treatment. Secondary outcomes were risk of major, non-major and intra-cranial bleed.

RESULTS

We retrieved 7244 titles on initial search, reviewed full text of 818 articles, and selected 10 phase III RCTS for quantitative meta-analysis. Out of 36,326 patients in these trials, only 10,840 (29.8%) were evaluable. We stratified patients into four categories based on severity of renal impairment using serum creatinine clearance (SCr) as the marker e.g. mild (>50 - <80) moderate (>30 - ≤50) severe (<30) and any level (from <30 to <80). There was no difference between DOACs vs VKA in decreasing the risk of recurrent VTE among patients with mild (RR:0.86, 95% CI:0.61-1.22, I² = 25%) moderate/severe (RR:0.72, 95% CI:0.44-1.17, I² = 0%) or any level of renal impairment (RR:0.83, 95% CI:0.60-1.14, I² = 34%). No difference in efficacy between LMWH vs VKA among patients with moderate (RR:2.40, 95% CI:0.44-12.96, I² = 76%) and any level (RR:2.59, 95% CI:0.66-10.16, I² = 71%) of renal impairment respectively. Similarly, no difference in efficacy between LMWH vs any OAC (This includes VKAs and edoxaban) among patients with (RR:2.16, 95% CI:0.66-7.-06, I² = 51%) and any level (RR:1.48, 95% CI:0.79-2.78, I² = 78%) of renal impairment. DOACs compared to VKAs had significantly lower risk of combined major and non-major bleeding (RR: 0.74, 95% CI:0.65-0.84, I² = 26%), major bleeding (RR: 0.51, 95% CI:0.38-0.69, I² = 7%) and non-major clinically relevant bleeding (RR: 0.73, 95% CI:0.57-0.94, I² = 45%) respectively. Risk of intracranial bleeding was comparable (RR: 0.68, 95% CI:0.19-2.44, I² = 0%). There was no difference in the risk of major bleeding between LMWH vs any OAC (RR: 0.83, 95% CI:0.46-1.51, I² = 0%).

CONCLUSION

DOACS and other anticoagulants (VKA and LMWH) showed no statistical difference in preventing recurrent VTEs among CKD patients but DOACs had significantly lower risk of major and non-major clinically relevant bleeding irrespective of the level of renal impairment compared to VKAs. There was no difference in risk of intra-cranial bleeding between DOACs and VKAs.

Extended DOAC therapy in patients with VTE and potential risk of recurrence: A systematic review and meta-analysis

BACKGROUND

Guidelines recommend at least 3 months of anticoagulation for venous thromboembolism (VTE). Evidence supporting indefinite anticoagulation exists in certain conditions; however, for many patients, uncertainty regarding when to discontinue anticoagulation persists.

OBJECTIVE

We aimed to investigate the efficacy and safety of extended direct oral anticoagulants (DOAC) therapy in patients with VTE and clinical uncertainty regarding extended anticoagulation.

METHODS

We searched EMBASE, MEDLINE, PubMed, and Cochrane Central Register of Controlled Trials databases for randomized control trials examining extended anticoagulation with DOACs as compared to non-extended therapy for the treatment of VTE.

RESULTS

Of 560 citations identified by the search, three studies were eligible. Extended anticoagulation reduced VTE recurrence (relative risk [RR] 0.18, 95% confidence interval [CI] 0.12 to 0.25), and mortality (RR 0.39, 95% CI 0.19 to 0.80) with a low total number of deaths in the DOAC group (n = 12) versus placebo (n = 18). Extended anticoagulation increased clinically relevant non-major bleedings (RR 2.51, 95% CI 1.37 to 4.59). There was no difference in rates of major bleeding (RR 1.87, 95% CI 0.19 to 17.85); however, there was a low number of major bleeding events in both DOAC (n = 9) and placebo groups (n = 4). The results were mostly driven by one study (AMPLIFY-EXT), with significant heterogeneity between studies noticed when assessing bleeding outcomes.

CONCLUSION

Extended DOAC therapy for 1 year in patients with clinical uncertainty for ongoing anticoagulation can reduce VTE recurrence and mortality; however, it could increase clinically relevant non-major bleeding events.

Recent evidence for direct oral anticoagulants in chronic kidney disease

PURPOSE OF REVIEW

The direct oral anticoagulants (DOACs) have emerged as an effective and safe alternative to vitamin K antagonists (VKAs) for stroke and venous thromboembolism (VTE) prevention. However, patients with chronic kidney disease (CKD) experience an increase in the risk of both thromboembolism and bleeding, and the risk-benefit profile of DOACs, particularly in advanced CKD remains a source of ongoing debate. This review summarizes the recent evidence on the effects of DOACs in CKD across a range of clinical indications including newly emerging indications.

RECENT FINDINGS

Data on early-to-moderate stage CKD derived from pivotal randomized controlled trials in broader atrial fibrillation and VTE populations support the favorable risk-benefit ratio of DOACs compared with VKAs in patients in these groups. However, safety data from observational studies comparing DOACs with VKAs in patients with atrial fibrillation and CKD (moderate to advanced) have been conflicting. Recent trials have evaluated the efficacy of low-dose DOACs on major cardiovascular outcomes, showing promising risk-benefit ratios in high-risk populations with concurrent CKD.

SUMMARY

Current data on patients with CKD derived from trials in the broader population suggest that DOACs are an effective alternative to VKAs in patients with early-to-moderate stage CKD. However, studies on patients with advanced CKD are lacking. Further randomized controlled trials, particularly those evaluating the risk of any clinically relevant bleeding as part of a more accurate assessment of the risk-benefit profile of DOACs in people with CKD, are needed.

Poor response to rivaroxaban in nephrotic syndrome with acute deep vein thrombosis: A case report

RATIONALE

Hypercoagulability can lead to thromboembolic events that are a life-threatening complication of nephrotic syndrome (NS). Conventional anticoagulants are first-line treatment in the presence of demonstrated thrombosis in NS. Direct-acting oral anticoagulants (DOACs) have provided useful alternatives for the prevention and treatment of thromboembolic events.

PATIENT CONCERNS

A 59-year-old male developed lower limbs deep vein thrombosis (DVT) during the early course of NS but presented poor response to oral therapeutic doses of rivaroxaban. The decision was made to switch from rivaroxaban to heparin and subsequently bridged to warfarin. The patient presented significant clinical symptom improvement.

DIAGNOSIS

NS with Lower limbs DVT.

INTERVENTIONS

Rivaroxaban was discontinued and switch to heparin and subsequently bridged to warfarin.

OUTCOMES

Venography result of both lower limb vein showed the venous wall was smooth without obvious stenosis or obstruction. Edema of the patient's lower limbs gradually improved and disappeared.

LESSONS

The existing published data on the application of DOACs in NS are limited. DOACs have an immediate anticoagulant effect and have demonstrated safety and efficacy and required no routine monitoring, however, application of these agents in NS likely requires further investigation before widespread adoption.

An Efficient Modular One-Pot Synthesis of Heparin-Based Anticoagulant Idraparinux

Idraparinux is a fully O-sulfated α-methyl glycoside of heparin pentasaccharide motif known to interact with the antithrombin III domain and act as anticoagulant. The current most effective synthesis of Idraparinux is complicated and nonstereoselective, requiring numerous stepwise procedures with low yields. We report here an efficient modular one-pot synthesis of Idraparinux involving the use of a glycosyl phosphate with 6- O- tert-butyl diphenyl silyl group and a d-glucuronic acid-containing disaccharide thioglycoside with 6- O-acetyl group as donor building blocks for the α-directing one-pot glycosylations with an l-iduronic acid-containing disaccharide acceptor building block. The uronic acid was incorporated in a disaccharide module used in the one-pot synthesis to avoid the complicated late-stage installation of these acidic sugars. The one-pot synthesis of Idraparinux demonstrated here is an effective strategy and should be applicable to the modular assembly of other heparan sulfates with regiodefined sulfation pattern for functional study.

Antithrombotic Dilemmas after Left Atrial Appendage Occlusion Watchman Device Placement

Antithrombotic therapy for stroke prevention in patients with atrial fibrillation (AF) has dramatically shifted from warfarin, a vitamin K antagonist, to the direct oral anticoagulants (DOACs) such as dabigatran, apixaban, and rivaroxaban. In patients with contraindications to oral anticoagulation, left atrial appendage occlusion (LAAO) devices, such as the Watchman™ device, may be considered; however, temporary postimplantation antithrombotic therapy is still a recommended practice. We present a case of complex antithrombotic management, post LAAO device implantation, designed to avoid drug interactions with concomitant rifampin use and remained necessary secondary to subsequent device leak. This case highlights the challenges of antithrombotic therapy post LAAO device placement in a complex, but representative, patient.

Viral receptors for flaviviruses: Not only gatekeepers

Arboviruses have been a huge threat for human health since the discovery of yellow fever virus in 1901. Arboviruses are arthropod born viruses, mainly transmitted by mosquitoes and ticks, responsible for more than thousands of deaths annually. The Flavivirideae family is probably the most clinically relevant, as it is composed of very important agents, such as dengue, yellow fever, West Nile, Japanese encephalitis, and, recently, Zika virus. Intriguingly, despite their structural and genomic similarities, flaviviruses may cause conditions ranging from mild infections with fever, cutaneous rash, and headache, to very severe cases, such as hemorrhagic fever, encephalitis, Guillain-Barré syndrome, and microcephaly. These differences may greatly rely on viral burden, tissue tropism, and mechanisms of immune evasion that may depend on both viral and host genetic factors. Unfortunately, very little is known about the biology of these factors, and how they orchestrate these differences. In this context, viral structural proteins and host cellular receptors may have a great relevance, as their interaction dictates not only viral tissue tropism, but also a plethora on intracellular mechanisms that may greatly account for either failure or success of infection. A great number of viral receptors have been described so far, although there is still a huge gap in understanding their overall role during infection. Here we discuss some important aspects triggered after the interaction of flaviviruses and host membrane receptors, and how they change the overall outcome of the infection.

Factors influencing the recruitment of lactating women in a clinical trial involving direct oral anticoagulants: a qualitative study

Background Robust human data on medication use during lactation is scarce. With increasing medication use in postpartum women, it is important to conduct clinical lactation studies measuring the excretion of drugs in human milk and generate evidence. We plan to conduct a clinical lactation study, involving the direct oral anticoagulants (DOACs). Objective This study aimed to identify factors influencing lactating women's clinical trial participation and to improve the design of a proposed DOACs clinical lactation study. Setting Lactating women in London, UK. Methods Three focus groups were conducted in lactating women with differing experiences of being prescribed anticoagulants during puerperium. Main outcome measures Thematic framework approach was used to analyse and identify key themes, using NVivo version 11. Results Eight breastfeeding mothers participated. Women's decision-making on clinical trial participation was largely influenced by the lactation stage and previous breastfeeding experience. The concern of harm to their infant caused by the test medication or interruption of lactation were the predominant barriers to potential participation. Around 6 months following the birth of their infant and second-time mothers appeared to be more amenable to clinical trial participation. The provision of home visits for the execution of the study was highly recommended. Conclusion Our findings suggest that lactating women would participate in a clinical trial during the breastfeeding period, if the timing is right and if the woman is an experienced mother. Home visits will be provided in our proposed DOACs clinical lactation study.

Replacement of the L-iduronic acid unit of the anticoagulant pentasaccharide idraparinux by a 6-deoxy-L-talopyranose - Synthesis and conformational analysis

One critical part of the synthesis of heparinoid anticoagulants is the creation of the L-iduronic acid building block featured with unique conformational plasticity which is crucial for the anticoagulant activity. Herein, we studied whether a much more easily synthesizable sugar, the 6-deoxy-L-talose, built in a heparinoid oligosaccharide, could show a similar conformational plasticity, thereby can be a potential substituent of the L-idose. Three pentasaccharides related to the synthetic anticoagulant pentasaccharide idraparinux were prepared, in which the L-iduronate was replaced by a 6-deoxy-L-talopyranoside unit. The talo-configured building block was formed by C4 epimerisation of the commercially available L-rhamnose with high efficacy at both the monosaccharide and the disaccharide level. The detailed conformational analysis of these new derivatives, differing only in their methylation pattern, was performed and the conformationally relevant NMR parameters, such as proton-proton coupling constants and interproton distances were compared to the corresponding ones measured in idraparinux. The lack of anticoagulant activity of these novel heparin analogues could be explained by the biologically not favorable 1C4 chair conformation of their 6-deoxy-L-talopyranoside residues.

Reversible covalent direct thrombin inhibitors

INTRODUCTION

In recent years, the traditional treatments for thrombotic diseases, heparin and warfarin, are increasingly being replaced by novel oral anticoagulants offering convenient dosing regimens, more predictable anticoagulant responses, and less frequent monitoring. However, these drugs can be contraindicated for some patients and, in particular, their bleeding liability remains high.

METHODS

We have developed a new class of direct thrombin inhibitors (VE-DTIs) and have utilized kinetics, biochemical, and X-ray structural studies to characterize the mechanism of action and in vitro pharmacology of an exemplary compound from this class, Compound 1.

RESULTS

We demonstrate that Compound 1, an exemplary VE-DTI, acts through reversible covalent inhibition. Compound 1 inhibits thrombin by transiently acylating the active site S195 with high potency and significant selectivity over other trypsin-like serine proteases. The compound inhibits the binding of a peptide substrate with both clot-bound and free thrombin with nanomolar potency. Compound 1 is a low micromolar inhibitor of thrombin activity against endogenous substrates such as fibrinogen and a nanomolar inhibitor of the activation of protein C and thrombin-activatable fibrinolysis inhibitor. In the thrombin generation assay, Compound 1 inhibits thrombin generation with low micromolar potency but does not increase the lag time for thrombin formation. In addition, Compound 1 showed weak inhibition of clotting in PT and aPTT assays consistent with its distinctive profile in the thrombin generation assay.

CONCLUSION

Compound 1, while maintaining strong potency comparable to the current DTIs, has a distinct mechanism of action which produces a differentiating pharmacological profile. Acting through reversible covalent inhibition, these direct thrombin inhibitors could lead to new anticoagulants with better combined efficacy and bleeding profiles.

Perioperative Management of New Oral Anticoagulants in Urological Surgery

New oral anticoagulants (NOACs) are increasingly replacing the use of warfarin in clinical practice. Their use has now also been extended to thromboprophylaxis in many orthopedic surgeries. This, in addition to an increasingly aging population with many complex comorbidities means that these medications will be ever more frequently encountered by urologists. Thus, a clear understanding of the mechanism of action of NOACs, their time to peak action and half-life is essential for the purpose of managing these patients perioperatively. This article demonstrates the patient and procedural variability that must be taken into account in the perioperative management of the anticoagulated patient. While the time to peak onset and half-life of NOACs can aid in determining the interval of interruption of anticoagulation, the risks of thrombosis and bleeding must be assessed before the decision to stop anticoagulation. This article takes into account the evidence available on NOACs in urological surgery in order to inform the perioperative management of these medications and to propose guidelines to aid in clinical decision making. In attempting this, we address the issue of the lack of high-level evidence surrounding NOACs in urological surgery given their relative novelty and the need for further research to better guide practice.

The impact of direct oral anticoagulants in traumatic brain injury patients greater than 60-years-old

Background

Traumatic brain injury (TBI) is the leading cause of death among trauma patients. Patients under antithrombotic therapy (ATT) carry an increased risk for intracranial haematoma (ICH) formation. There is a paucity of data about the role of direct oral anticoagulants (DOACs) among TBI patients.

Methods

In this retrospective study, we investigated all TBI patients ≥60-years-old who were admitted to the intensive care unit (ICU) from January 2014 until May 2017. Patients were grouped into those receiving vitamin K antagonists (VKA), platelet inhibitors (PI), DOACs and no antithrombotic therapy (no-ATT).

Results

One-hundred-eighty-six, predominantly male (52.7%) TBI patients with a median age of 79 years (range: 70–85 years) were enrolled in the study. Glasgow Coma Scale and S-100β were not different among the groups. Patients on VKA and DOACs had a higher Charlson Comorbidity Index compared to the PI group and no-ATT group (p = 0.0021). The VKA group received reversal agents significantly more often than the other groups (p < 0.0001). Haematoma progression in the follow-up cranial computed tomography (CCT) was lowest in the DOAC group. The number of CCT and surgical interventions were low with no differences between the groups. No relevant differences in ICU and hospital length of stay were observed. Mortality in the VKA group was significantly higher compared to DOAC, PI and no-ATT group (p = 0.047).

Discussion

Data from huge registry studies displayed higher efficacy and lower fatal bleeding rates for DOACs compared to VKAs. The current study revealed comparable results. Despite the fact that TBI patients on VKAs received reversal agents more often than patients on DOACs (84.4% vs. 24.2%, p < 0.001), mortality rate was significantly higher in the VKA group (p = 0.047).

Conclusion

In patients ≥60 years suffering from TBI, anticoagulation with DOACs appears to be safer than with VKA. Anti-thrombotic therapy with VKA resulted in a worse outcome compared to DOACs and PI. Further studies are warranted to confirm this finding.

Therapy with activated prothrombin complex concentrate is effective in reducing dabigatran-associated blood loss in a porcine polytrauma model

Clinical use of non-vitamin K antagonist oral anticoagulants is increasingly well established. However, specific agents for reversal of these drugs are not currently available. It was to objective of this study to investigate the impact of activated prothrombin complex concentrate (aPCC) on the anticoagulant effects of dabigatran in a randomised, controlled, porcine trauma model. Twenty-one pigs received oral and intravenous dabigatran, resulting in supratherapeutic plasma concentrations. Twelve minutes after injury (standardised bilateral femur fractures and blunt liver injury), animals (n=7/group) received 25 or 50 U/kg aPCC (aPCC25 and aPCC50) or placebo (control) and were followed for 5 hours. The primary endpoint was total volume of blood loss (BL). Haemodynamic and coagulation variables (prothrombin time [PT], activated partial thromboplastin time, diluted thrombin time, thrombin–antithrombin complexes, thromboelastometry, thrombin generation and D-dimers) were measured. Twelve minutes post-injury, BL was similar between groups. Compared with control (total BL: 3807 ± 570 ml) and aPCC25 (3690 ± 454 ml; p=0.77 vs control), a significant reduction in total BL (1639 ± 276 ml; p< 0.0001) and improved survival (p< 0.05) was observed with aPCC50. Dabigatran’s anticoagulant effects were effectively treated in the aPCC50 group, as measured by several parameters including EXTEM clotting time (CT) and PT. In contrast, with aPCC25, laboratory values were initially corrected but subsequently deteriorated due to ongoing blood loss. Thromboembolic or bleeding effects were not detected. In conclusion, blood loss following trauma in dabigatran-anticoagulated pigs was successfully reduced by 50 U/kg aPCC. Optimal methodology for measuring amelioration of dabigatran anticoagulation by aPCC is yet to be determined.

Dose requirements for idarucizumab reversal of dabigatran in a lethal porcine trauma model with continuous bleeding

Idarucizumab is licensed for emergency reversal of dabigatran. A single 5 g dose is usually sufficient, but higher doses may sometimes be required and optimum dosing has not been defined. It was the aim of this study to investigate the effect of idarucizumab, given once or as a split dose, after double trauma in pigs anticoagulated with dabigatran. Dabigatran etexilate (30 mg/kg bid) was given to 18 male pigs orally for 3 days. On day 4, animals were randomised 1:1:1 to receive idarucizumab 60+0, 60+60 or 120+0 mg/kg. Doses were administered 15 and 75 minutes after initial liver trauma. At 60 minutes, a second liver injury was undertaken. Animals were monitored for 5 hours after initial trauma or until death. Blood loss during the first hour was 990 ± 109 ml, 988 ± 84 ml and 964 ± 75 ml in the 60+0, 60+60 and 120+0 groups, respectively. In the 120+0 and 60+60 groups, total blood loss was 1659 ± 346 and 1426 ± 106 ml, respectively, and survival at 5 hours was 100 %. However, in the 60+0 group, total blood loss was 3561 ± 770 ml and survival was 50 %. Analysis of dabigatran plasma concentrations showed that equimolar concentrations of idarucizumab are necessary to bind all dabigatran and achieve sufficient thrombin generation. At sufficient doses, idarucizumab rapidly reduced blood loss and improved survival in this lethal porcine model of double trauma with dabigatran anticoagulation. In clinical practice, should bleeding continue after initial treatment with the approved 5 g dose of idarucizumab, a second dose may potentially be effective to control bleeding caused by redistribution of unbound dabigatran.

Supplementary Material to this article is available online at www.thrombosis-online.com.

Risk of Gastrointestinal Bleeding in Patients Taking Non-Vitamin K Antagonist Oral Anticoagulants: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Non-vitamin K antagonist oral anticoagulants (NOACs) are convenient and effective in the prevention and treatment of venous thromboembolism and the prevention of stroke in patients with atrial fibrillation. However, these drugs have been associated with an increased risk of gastrointestinal (GI) bleeding. We conducted a systematic review and meta-analysis to determine the risk of GI bleeding in patients receiving these drugs.

METHODS

We searched the EMBASE, Medline, Cochrane, and ISI Web of knowledge databases through January 2016 for randomized trials that compared NOACs with conventional anticoagulants for approved indications. We conducted a meta-analysis, reporting odds ratios (ORs) with 95% confidence intervals (CIs). The primary outcome was major GI bleeding. Secondary outcomes included clinically relevant nonmajor bleeding and upper and lower GI bleeding. We performed a priori subgroup analyses by individual drug.

RESULTS

Our analysis included a total of 43 randomized trials, comprising 166,289 patients. There was no difference between NOACs and conventional anticoagulants in the risk of major bleeding (1.5% vs 1.3%, respectively; OR, 0.98; 95% CI, 0.80-1.21), clinically relevant nonmajor bleeding (0.6% vs 0.6%, respectively; OR, 0.93; 95% CI, 0.64-1.36), upper GI bleeding (1.5% vs 1.6%, respectively; OR, 0.96; 95% CI, 0.77-1.20), or lower GI bleeding (1.0% vs 1.0%, respectively; OR, 0.88; 95% CI, 0.67-1.15). Dabigatran (2.0% vs 1.4%, respectively; OR, 1.27; 95% CI, 1.04-1.55) and rivaroxaban (1.7% vs 1.3%, respectively; OR, 1.40; 95% CI, 1.15-1.70) were associated with increased odds of major GI bleeding compared with conventional anticoagulation, whereas no difference was found for apixaban (0.6% vs 0.7%, respectively; OR, 0.81; 95% CI, 0.64-1.02) or edoxaban (1.9% vs 1.6%, respectively; OR, 0.93; 95% CI, 0.78-1.11). These subgroup findings were not observed in other sensitivity analyses.

CONCLUSIONS

In a systematic review and meta-analysis, we found risk of major GI bleeding to be similar between NOACs and conventional anticoagulation. Dabigatran and rivaroxaban, however, may be associated with increased odds of major GI bleeding. Further high-quality studies are needed to characterize GI bleeding risk among NOACs.

Reversing Dabigatran Anticoagulation with Prothrombin Complex Concentrate versus Idarucizumab as Part of Multimodal Hemostatic Intervention in an Animal Model of Polytrauma

BACKGROUND

Although idarucizumab is the preferred treatment for urgent dabigatran reversal, it is not always available. Prothrombin complex concentrate (PCC) may be an alternative and, with bleeding in trauma, additional hemostatic therapy may be required. The authors investigated multimodal treatment in a preclinical polytrauma model.

METHODS

Dabigatran etexilate (30 mg/kg twice daily) was given orally to 45 male pigs for 3 days. On day 4, animals received a dabigatran infusion before blunt liver injury and bilateral femur fractures. After injury, animals were randomized 1:1:1:1:1 to receive placebo (control), tranexamic acid (TXA; 20 mg/kg) plus human fibrinogen concentrate (FCH; 80 mg/kg) (TXA-FCH group), PCC (25 U/kg or 50 U/kg) plus TXA plus FCH (PCC25 and PCC50 groups), or 60 mg/kg idarucizumab (IDA) plus TXA plus FCH (IDA group). Animals were monitored for 240 min after trauma, or until death.

RESULTS

The degree of injury was similar in all animals before intervention. Control and TXA-FCH animals had the highest total postinjury blood loss (3,652 ± 601 and 3,497 ± 418 ml) and 100% mortality (mean survival time 96 and 109 min). Blood loss was significantly lower in the PCC50 (1,367 ± 273 ml) and IDA (986 ± 144 ml) groups, with 100% survival. Thrombin-antithrombin levels and thrombin generation were significantly elevated in the PCC50 group.

CONCLUSIONS

Idarucizumab may be considered the optimal treatment for emergency reversal of dabigatran anticoagulation. However, this study suggests that PCC may be similarly effective as idarucizumab and could therefore be valuable when idarucizumab is unavailable. (Anesthesiology 2017; 127:852-61).

Comparative safety of direct oral anticoagulants and warfarin in venous thromboembolism: multicentre, population based, observational study

Objective To determine the safety of direct oral anticoagulant (DOAC) use compared with warfarin use for the treatment of venous thromboembolism.Design Retrospective matched cohort study conducted between 1 January 2009 and 31 March 2016.Setting Community based, using healthcare data from six jurisdictions in Canada and the United States.Participants 59 525 adults (12 489 DOAC users; 47 036 warfarin users) with a new diagnosis of venous thromboembolism and a prescription for a DOAC or warfarin within 30 days of diagnosis.Main outcome measures Outcomes included hospital admission or emergency department visit for major bleeding and all cause mortality within 90 days after starting treatment. Propensity score matching and shared frailty models were used to estimate adjusted hazard ratios of the outcomes comparing DOACs with warfarin. Analyses were conducted independently at each site, with meta-analytical methods used to estimate pooled hazard ratios across sites.Results Of the 59 525 participants, 1967 (3.3%) had a major bleed and 1029 (1.7%) died over a mean follow-up of 85.2 days. The risk of major bleeding was similar for DOAC compared with warfarin use (pooled hazard ratio 0.92, 95% confidence interval 0.82 to 1.03), with the overall direction of the association favouring DOAC use. No difference was found in the risk of death (pooled hazard ratio 0.99, 0.84 to 1.16) for DOACs compared with warfarin use. There was no evidence of heterogeneity across centres, between patients with and without chronic kidney disease, across age groups, or between male and female patients.Conclusions In this analysis of adults with incident venous thromboembolism, treatment with DOACs, compared with warfarin, was not associated with an increased risk of major bleeding or all cause mortality in the first 90 days of treatment.Trial registration Clinical trials NCT02833987.

Novel Oral Anticoagulants in the Peri-Endoscopic Period

Millions of patients in the United States are currently prescribed some form of anticoagulation therapy. Recently, novel oral anticoagulants (NOACs), including direct thrombin inhibitors and direct factor Xa inhibitors, have begun to replace warfarin as the drugs of choice for anticoagulation. As the use of these medications becomes more widespread, it is increasingly important for gastroenterologists to understand the risks associated with performing endoscopic procedures on patients who are taking NOACs. In this review, we provide an overview of the NOACs and current guidelines from international societies regarding the management of patients scheduled to undergo endoscopic procedures who are prescribed these medications. Finally, we offer a perspective on future studies required to adequately investigate and characterize the effects that these drugs have on a patient's risk for bleeding in the peri- and/or postprocedural timeframes.

International clinical practice guidelines including guidance for direct oral anticoagulants in the treatment and prophylaxis of venous thromboembolism in patients with cancer

Venous thromboembolism (VTE) is the second leading cause of death in patients with cancer. These patients are at an increased risk of developing VTE and are more likely to have a recurrence of VTE and bleeding while taking anticoagulants. Management of VTE in patients with cancer is a major therapeutic challenge and remains suboptimal worldwide. In 2013, the International Initiative on Thrombosis and Cancer (ITAC-CME), established to reduce the global burden of VTE in patients with cancer, published international guidelines for the treatment and prophylaxis of VTE and central venous catheter-associated thrombosis. The rapid global adoption of direct oral anticoagulants for management of VTE in patients with cancer is an emerging treatment trend that needs to be addressed based on the current level of evidence. In this Review, we provide an update of the ITAC-CME consensus recommendations based on a systematic review of the literature ranked according to the Grading of Recommendations Assessment, Development, and Evaluation scale. These guidelines aim to address in-hospital and outpatient cancer-associated VTE in specific subgroups of patients with cancer.

Managing Nonoperable Intracranial Bleeding Associated With Apixaban: A Series of 2 Cases

OBJECTIVE

To report 2 cases of nonoperable intracranial bleeding associated with apixaban managed by 3-factor prothrombin complex concentrate (PCC3).

CASE SUMMARIES

Case 1 presented with a 1.3-cm left parieto-occipital hemorrhage and a thin subdural hematoma (SDH) on the left tentorium of the brain about 6 hours after his last dose of apixaban. Case 2 presented with a 4-mm left parafalcine SDH with time of most recent apixaban dose unknown. The patients received 24.9 to 25.5 U/kg of PCC3 with none to 1 U fresh frozen plasma (FFP) and demonstrated minimal or no progression in lesions measured by repeat computed tomography (CT) after treatment. One patient was discharged to a skilled nursing facility after 8 days; the other patient was discharged to home after 18 days.

DISCUSSION

Apixaban has no specific antidote. Current bleeding management strategies are based on expert opinion. The risks and benefits for differing strategies are unclear, and little clinical experience for managing apixaban-associated intracranial bleeding has been reported to date. These cases describe the clinical use of PCC3 to manage parieto-occipital and subdural hemorrhage associated with apixaban in events not requiring surgical intervention.

CONCLUSION

In these 2 cases, 25 U/kg PCC3, with none to one unit FFP, ceased apixaban-associated intracranial bleeding without apparent thrombogenic complications.

The Conundrum of "Warfarin Hypersensitivity": Prolonged Partial Thromboplastin Time From Factor IX Propeptide Mutation

Carboxylation of glutamic acid residues of vitamin K dependent clotting factors (II, VII, IX, and X) is essential to their biological functioning. Binding of these factors to γ-glutamyl carboxylase enzyme for carboxylation reaction is mediated by wild-type propeptide, a small sequence of amino acids that precede the actual polypeptide. Missense mutations at certain residue severely decrease the affinity of mutated propeptide for the enzyme. Such mutations are reported to occur at codon-10 of factor IX propeptide, a clinically silent metabolic event in normal conditions. However in the presence of warfarin, such mutations and resultant decrease affinity of factor IX propeptide for the enzyme that causes severe selective decrease in factor IX activity. This can potentially leads to life-threatening bleeding complications and known as one of the causes of warfarin hypersensitivity. It is imperative to recognize such cases early on to avoid additional warfarin therapy. Recurrent bleeding episodes, subtherapeutic to therapeutic range international normalized ratio values with relatively prolong partial thromboplastin time should raise the suspicion of underlying factor IX propeptide mutations.

Non-vitamin K antagonist oral anticoagulants and heart failure

Thromboembolism contributes to morbidity and mortality in patients with heart failure (HF), and atrial fibrillation (AF) is one of the main factors promoting this complication. As they share many risk factors, HF and AF frequently coexist, and patients with both conditions are at a particularly high risk of thromboembolism. Non-vitamin K antagonist oral anticoagulants (NOACs) are direct antagonists of thrombin (dabigatran) and factor Xa (rivaroxaban, apixaban and edoxaban), and were designed to overcome the limitations of vitamin K antagonists. Compared with warfarin in non-valvular AF, NOACs demonstrated non-inferiority with better safety, most particularly for intracranial haemorrhages. Therefore, the European Society of Cardiology guidelines recommend NOACs for most patients with non-valvular AF. Subgroups of patients with both AF and HF from the pivotal studies investigating the safety and efficacy of NOACs have been analysed and, for each NOAC, results were similar to those of the total analysis population. A recent meta-analysis of these subgroups has confirmed the better efficacy and safety of NOACs in patients with AF and HF - particularly the 41% decrease in the incidence of intracranial haemorrhages. The prothrombotic state associated with HF suggests that patients with HF in sinus rhythm could also benefit from treatment with NOACs. However, in the absence of clinical trial data supporting this indication, current guidelines do not recommend anticoagulant treatment of patients with HF in sinus rhythm. In conclusion, recent analyses of pivotal studies support the use of NOACs in accordance with their indications in HF patients with non-valvular AF.

Novel Oral Anticoagulants in Atrial Fibrillation: Update on Apixaban

Almost 800,000 new or recurrent strokes occur every year. Atrial fibrillation, the most common cardiac arrhythmia, is a major risk factor for stroke, accounting for 15-20% of ischemic strokes. Apixaban is a direct inhibitor of Factor Xa that was approved in December 2012 by the US Food and Drug Administration (FDA) for the prevention of stroke in patients with non-valvular atrial fibrillation. It is part of a family of novel oral anticoagulants (NOACs) which has advantage over warfarin of less dosing variability, rapid onset of action and no INR monitoring required. Apixaban showed superiority to warfarin in both primary efficacy and primary safety outcomes by simultaneously showing both significantly lower rates of strokes and systemic embolism and a reduced risk of major clinical bleeding in clinical trials. Warfarin remains the anticoagulant of choice for patients with prosthetic heart valves and significant mitral stenosis. There are currently no head-to-head studies that directly compare the different NOACs with one another, but it is expected that there will be more trials in the future that will explore this comparison. Dabigatran is the only NOAC with an FDA approved reversal agent. However, a reversal agent for apixaban is being developed and was successful in recent clinical trials. This review summarizes the clinical trial data on apixaban for atrial fibrillation, compares apixaban to other NOACs and discusses apixaban use in clinical practice.

Risk of Thromboembolic Events in Patients with Non-Valvular Atrial Fibrillation After Dabigatran or Rivaroxaban Discontinuation - Data from the Ljubljana Registry

Background and Aim

Interruption of anticoagulant treatment with warfarin or non-vitamin K antagonist oral anticoagulants (NOAC) represents a vulnerable period with an increased risk of thromboembolic events. What is the incidence of thromboembolic events in real-life patients with non-valvular atrial fibrillation treated with NOAC who had a discontinuation or cessation of treatment in comparison to patients on continuous treatment?

Patients and Methods

Registry data from 866 patients with non-valvular atrial fibrillation, aged 74.3 (SD 9.8) years, with an average CHADS₂ score of 2.1 (SD 1.2), who were started on dabigatran or rivaroxaban, were analysed for thromboembolic events and survival. Patients who had temporary or permanent discontinuation of NOAC were compared to patients on continuous NOAC treatment.

Results

Among 866 patients started on NOAC, 705 were treated without interruption, 84 patients had temporary interruption (69 because of planned invasive procedures, 10 due to bleeding, 5 for other causes) and 77 had permanent cessation of NOAC treatment. In patients without interruptions, the incidence of thromboembolic events was 1.0 (95% CI 0.4–2.1) per 100 patient-years, while in patients with interruption/cessation the rate of thromboembolic events was 21.6 (95% CI 10.3–45.2) per 100 patient-years, p < 0.001. There was a distinct clustering of thromboembolic events in the first weeks of NOAC discontinuation with the median occurring on day 14 (range 1–37 days) after discontinuation.

Conclusion

Dabigatran and rivaroxaban offered good protection against thromboembolic events during treatment, but interruption of NOAC treatment increased the short-term thromboembolic risk more than 20-fold.

Quality Control Approach to Anticoagulants and Transfusion

Quality can be defined by processes of care and by the characteristics of the care and its outcomes. In terms of blood loss and transfusion, otolaryngologists should be aware of available guidelines, standards for use of blood products, devices and hemostatic agents, outcomes metrics relevant to patients, and tools for implementing quality improvements. This article reviews the definition of health care quality, and discusses the data regarding anticoagulant medications (particularly new oral anticoagulants) and guidelines for blood product transfusion. A brief outline of quality tools is provided to help otolaryngologists create quality plans for themselves and their institutions/systems.

Suboptimal Use of Oral Anticoagulants in Atrial Fibrillation: Has the Introduction of Direct Oral Anticoagulants Improved Prescribing Practices?

BACKGROUND AND OBJECTIVES

Atrial fibrillation (AF) and the associated risk of stroke are emerging epidemics throughout the world. Suboptimal use of oral anticoagulants for stroke prevention has been widely reported from observational studies. In recent years, direct oral anticoagulants (DOACs) have been introduced for thromboprophylaxis. We conducted a systematic literature review to evaluate current practices of anticoagulation in AF, pharmacologic features and adoption patterns of DOACs, their impacts on proportion of eligible patients with AF who receive oral anticoagulants, persisting challenges and future prospects for optimal anticoagulation.

LITERATURE SOURCE AND SELECTION CRITERIA

In conducting this review, we considered the results of relevant prospective and retrospective observational studies from real-world practice settings. PubMed (MEDLINE), Scopus (RIS), Google Scholar, EMBASE and Web of Science were used to source relevant literature. There were no date limitations, while language was limited to English. Selection was limited to articles from peer reviewed journals and related to our topic.

RESULTS

Most studies identified in this review indicated suboptimal use of anticoagulants is a persisting challenge despite the availability of DOACs. Underuse of oral anticoagulants is apparent particularly in patients with a high risk of stroke. DOAC adoption trends are quite variable, with slow integration into clinical practice reported in most countries; there has been limited impact to date on prescribing practice.

CONCLUSION

Available data from clinical practice suggest that suboptimal oral anticoagulant use in patients with AF and poor compliance with guidelines still remain commonplace despite transition to a new era of anticoagulation featuring DOACs.

Direct-Acting Oral Anticoagulants: Practical Considerations for Emergency Medicine Physicians

Nonvalvular atrial fibrillation- (NVAF-) related stroke and venous thromboembolism (VTE) are cardiovascular diseases associated with significant morbidity and economic burden. The historical standard treatment of VTE has been the administration of parenteral heparinoid until oral warfarin therapy attains a therapeutic international normalized ratio. Warfarin has been the most common medication for stroke prevention in NVAF. Warfarin use is complicated by a narrow therapeutic window, unpredictable dose response, numerous food and drug interactions, and requirements for frequent monitoring. To overcome these disadvantages, direct-acting oral anticoagulants (DOACs)—dabigatran, rivaroxaban, apixaban, and edoxaban—have been developed for the prevention of stroke or systemic embolic events (SEE) in patients with NVAF and for the treatment of VTE. Advantages of DOACs include predictable pharmacokinetics, few drug-drug interactions, and low monitoring requirements. In clinical studies, DOACs are noninferior to warfarin for the prevention of NVAF-related stroke and the treatment and prevention of VTE as well as postoperative knee and hip surgery VTE prophylaxis, with decreased bleeding risks. This review addresses the practical considerations for the emergency physician in DOAC use, including dosing recommendations, laboratory monitoring, anticoagulation reversal, and cost-effectiveness. The challenges of DOACs, such as the lack of specific laboratory measurements and antidotes, are also discussed.

Trombose induzida pelo calor endovenoso: relato de dois casos tratados com rivaroxabana e revisão da literatura

Define-se trombose induzida pelo calor endovenoso como a propagação do trombo a partir de uma veia superficial em direção a uma veia mais profunda. Em geral, é considerada clinicamente insignificante quando não há propagação do trombo para o sistema venoso profundo. Essa condição pode ser tratada com terapia anticoagulante, embora a observação pareça ser suficiente, principalmente para graus menores. Neste estudo, relatamos dois casos de trombose induzida pelo calor endovenoso que teriam indicação de heparina de baixo peso molecular até a resolução do quadro. Porém, optou-se pelo uso da rivaroxabana (15 mg de 12 em 12h), com resolução completa do trombo em 4 semanas (caso 1) e em 7 dias (caso 2). A rivaroxabana pode ser uma alternativa promissora no tratamento da trombose induzida pelo calor endovenoso avançada, pela simplicidade da posologia, sem comprometimento da eficácia ou da segurança. São necessários estudos prospectivos, randomizados e controlados que possibilitem melhor entendimento da condição e o desenvolvimento de recomendações mais definitivas sobre opções de prevenção e tratamento.

Novel anticoagulants - an update on the latest developments and management for clinicians treating patients on these drugs

There are several novel anticoagulant agents that are being increasingly used as an alternative to warfarin, with these drugs being reported to be at least as effective if not better. Their increased use means that oral care clinicians should have a sound understanding of the mechanism of action, pharmacology, reversal strategies and management of bleeding in patients taking these drugs. Surprisingly, there is little published in the current literature specific to professionals involved in oral health care. In this review, we provide an overview of these drugs and discuss the management of patients who need an oral procedure based on currently available literature and clinical trials.

Edoxaban: A Comprehensive Review of the Pharmacology and Clinical Data for the Management of Atrial Fibrillation and Venous Thromboembolism

Historically, vitamin K antagonists have been the only class of oral anticoagulants available. Despite our experience with warfarin over the past 60 years, its use is associated with several pharmacokinetic and clinical disadvantages including unpredictable dosing, frequent monitoring, and delayed onset and offset. Edoxaban, an oral direct Xa inhibitor, may provide clinicians with an additional option in patients requiring chronic anticoagulation. This review examines the pharmacology and clinical data of edoxaban as a therapeutic alternative.

Quick Response Tracheotomy: A Novel Surgical Procedure

Quick response tracheostomy (QRT) is a novel open surgical technique to emergently establish an airway. The method is simple; the skills necessary to perform this procedure are rapidly acquired; and it is expedient, minimally traumatic, and remarkably devoid of complications often encountered with percutaneous dilatational tracheotomies, including those complications seen with cricothyroidotomies. Unlike all other tracheotomies in which considerable blunt dissection is required, QRT avoids tissue crushing because sharp dissection alone is used to acquire surgical access to the trachea. The QRT does not entail inserting a guidewire into the trachea, a standard feature for percutaneous tracheal access; it avoids any risk of unintended laceration of the posterior tracheal wall and proximal subjacent esophagus. The technique averts tracheal ring fracture and tracheoesophageal fistula complications. The QRT has a uniquely low incidence of inducing hemorrhage, and it requires no steps that cause temporary tracheal occlusion and will therefore not facilitate hypoxia. The QRT contributes minimally to conditions favorable for generating subglottic stenosis, and the procedure is swiftly executed with very low probability for external tracheal placement of the tracheostomy tube. The QRT is not a blind procedure. No special instruments are required for its execution nor is concurrent tracheoscopy required at any stage while performing a QRT as is specified for percutaneous tracheotomies.