Qualitative study of the consequences of vaccine-induced immune thrombocytopenia and thrombosis: the experiences of family members

OBJECTIVES

To explore the experiences of family members of patients who died or survived following a diagnosis of vaccine-induced immune thrombocytopenia and thrombosis (VITT).

DESIGN

A semistructured qualitative study, conducted via Zoom.

SETTING

Participants discussed their experiences during hospitalisation and following discharge.

PARTICIPANTS

Sixteen family members of patients with VITT (survivors=11; bereaved=5), recruited via a Facebook support group and advertising on Twitter.

RESULTS

Analysis identified two themes common to both groups of participants: the stress of hospitalisation and the experience of multiple losses. A third theme, living with VITT, was unique to the survivor group and a fourth, battling against the system, was predominantly reported by bereaved participants.

CONCLUSIONS

This is a significantly challenged group of people, with multiple emotional, financial, social and psychological losses. These losses have been compounded by experiences of limited governmental and societal recognition of the problems they face.

REVISE: Re-Evaluating the Inhibition of Stress Erosions in the ICU: a randomised trial protocol

INTRODUCTION

The Re-Evaluating the Inhibition of Stress Erosions (REVISE) Trial aims to determine the impact of the proton pump inhibitor pantoprazole compared with placebo on clinically important upper gastrointestinal (GI) bleeding in the intensive care unit (ICU), 90-day mortality and other endpoints in critically ill adults. The objective of this report is to describe the rationale, methodology, ethics and management of REVISE.

METHODS AND ANALYSIS

REVISE is an international, randomised, concealed, stratified, blinded parallel-group individual patient trial being conducted in ICUs in Canada, Australia, Saudi Arabia, UK, US, Kuwait, Pakistan and Brazil. Patients≥18 years old expected to remain invasively mechanically ventilated beyond the calendar day after enrolment are being randomised to either 40 mg pantoprazole intravenously or an identical placebo daily while mechanically ventilated in the ICU. The primary efficacy outcome is clinically important upper GI bleeding within 90 days of randomisation. The primary safety outcome is 90-day all-cause mortality. Secondary outcomes include rates of ventilator-associated pneumonia, Clostridioides difficile infection, new renal replacement therapy, ICU and hospital mortality, and patient-important GI bleeding. Tertiary outcomes are total red blood cells transfused, peak serum creatinine level in the ICU, and duration of mechanical ventilation, ICU and hospital stay. The sample size is 4800 patients; one interim analysis was conducted after 2400 patients had complete 90-day follow-up; the Data Monitoring Committee recommended continuing the trial.

ETHICS AND DISSEMINATION

All participating centres receive research ethics approval before initiation by hospital, region or country, including, but not limited to - Australia: Northern Sydney Local Health District Human Research Ethics Committee and Mater Misericordiae Ltd Human Research Ethics Committee; Brazil: Comissão Nacional de Ética em Pesquisa; Canada: Hamilton Integrated Research Ethics Board; Kuwait: Ministry of Health Standing Committee for Coordination of Health and Medical Research; Pakistan: Maroof Institutional Review Board; Saudi Arabia: Ministry of National Guard Health Affairs Institutional Review Board: United Kingdom: Hampshire B Research Ethics Committee; United States: Institutional Review Board of the Nebraska Medical Centre. The results of this trial will inform clinical practice and guidelines worldwide.

TRIAL REGISTRATION NUMBER

NCT03374800.

Associations of anaemia with bleeding and thrombotic complications in patients with atrial fibrillation treated with warfarin: a registry-based nested case-control study

OBJECTIVES

We studied association of laboratory testing beyond the international normalised ratio (INR) with bleeding and stroke/transient ischaemic attack (TIA) outcomes in patients with atrial fibrillation treated with warfarin.

DESIGN

This was a retrospective nested case-control study from the Finnish Warfarin in Atrial Fibrillation (FinWAF) registry (n=54 568), reporting the management and outcome in warfarin-anticoagulated patients. Associations of blood count test frequency and results were assessed together with risk of bleeding or stroke/TIA during 5-year follow-up.

SETTING

National FinWAF registry, with data from all six hospital districts. Follow-up period for complications was 1 January 2007-31 December 2011.

PARTICIPANTS

A total of 54 568 warfarin-anticoagulated patients.

RESULTS

The number of patients with bleeding was 4681 (9%) and stroke/TIA episodes, 4692 (9%). In patients with bleeds, lower haemoglobin (within 3 months) preceded the event compared with the controls (median 126 vs 135 g/L; IQR 111-141 g/L vs 123-147 g/L, p<0.001), while patients with stroke/TIA had only modestly lower INR (median 2.2 vs 2.3; 1.8-2.6 vs 2.1-2.7, p<0.001). When the last measured haemoglobin was below the reference value (130 g/L for men, 120 g/L for women), the OR for a bleeding complication was 2.9 and stroke/TIA, 1.5. If the haemoglobin level was below 100 g/L, the complication risk increased further by 10-fold. If haemoglobin values were repeatedly (more than five times) low during the preceding 3 months, future OR was for bleeds 2.3 and for stroke/TIA 2.4.

CONCLUSIONS

The deeper the anaemia, the higher the risk of bleeding and stroke/TIA. However, INR remained mainly at its target and only occasionally deviated, failing to detect the complication risk. Repeated low haemoglobin results, compatible with persistent anaemia, refer to suboptimal management and increased the complication risk in anticoagulated patients.

Can we collect health-related quality of life information from anticoagulated atrial fibrillation participants who have recently experienced a bleed? An observational feasibility study in primary and secondary care in Wales and through a UK online forum

OBJECTIVE

To evaluate the feasibility of recruiting participants diagnosed with atrial fibrillation (AF) taking oral anticoagulation therapies (OATs) and recently experiencing a bleed to collect health-related quality of life (HRQoL) information.

DESIGN

Observational feasibility study. The study aimed to determine the feasibility of recruiting participants with minor and major bleeds, the most appropriate route for recruitment and the appropriateness of the patient-reported outcome measures (PROMs) selected for collecting HRQoL information in AF patients, and the preferred format of the surveys.

SETTING

Primary care, secondary care and via an online patient forum.

PARTICIPANTS

The study population was adult patients (≥18) with AF taking OATs who had experienced a recent major or minor bleed within the last 4 weeks.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcomes - PROMs: EuroQol 5 Dimensions-5 Levels, Perception of Anticoagulant Treatment Questionnaire, part 2 only (part 2), atrial fibrillation effect on quality of life. Secondary outcomes - Location of bleed, bleed severity, current treatment, patient perceptions of HRQoL in relation to bleeding events.

RESULTS

We received initial expressions of interest from 103 participants. We subsequently recruited 32 participants to the study-14 from primary care and 18 through the AF forum. No participants were recruited through secondary care. Despite 32 participants consenting, only 26 initial surveys were completed. We received follow-up surveys from 11 participants (8 primary care and 3 AF forum). COVID-19 had a major impact on the study.

CONCLUSIONS

Primary care was the most successful route for recruitment. Most participants recruited to the study experienced a minor bleed. Further ways to recruit in secondary care should be explored, especially to capture more serious bleeds.

TRIAL REGISTRATION NUMBER

The study is registered in the Clinicaltrials.gov database, NCT04921176.

Study protocol for assessment of the coagulation potential of concomitantly used factor VIII concentrates in patients with haemophilia A with emicizumab prophylaxis (CAGUYAMA Study): a multicentre open-label non-randomised clinical trial

INTRODUCTION

Emicizumab prophylaxis substantially reduces bleeding episodes in patients with haemophilia A (HA). The haemostatic efficacy of emicizumab in patients with HA is estimated as approximately 15% based on mimic activity of factor (F) VIII. Although it has been proven effective in preventing bleeding, its haemostatic effect during breakthrough bleeding or surgery is considered insufficient. Therefore, haemostatic management of emicizumab-treated patients with HA without inhibitors frequently requires FVIII replacement therapy. In haemostatic management of emicizumab-treated patients with HA, conventional FVIII dosage calculations are used in clinical practice without considering the coagulant effects of emicizumab.

METHODS AND ANALYSIS

In the CAGUYAMA study, 100 patients with HA without inhibitors will be enrolled for a maximum duration of 1 year, and samples of 30 events following the concomitant use of FVIII concentrates (30±5 U/kg) with emicizumab will be collected. An 'event' is defined as obtaining blood samples at preadministration and postadministration of FVIII concentrates during a breakthrough bleeding or a surgical procedure. Global coagulation assays will be used to measure the coagulation potential of the obtained samples. Clot waveform analysis (CWA) is used to identify the primary end-point, that is, the degree of improvement in the maximum coagulation rate at preadministration and post-administration of fixed-dose FVIII concentrations. The parameter obtained from CWA, which is triggered by an optimally diluted mixture of prothrombin time reagent and activated partial thromboplastin time reagent, is reported to be an excellent marker for assessing the degree of improvement of the coagulation potential in emicizumab-treated plasmas.

ETHICS AND DISSEMINATION

The CAGUYAMA study was approved by the Japan-Certified Review Board of Nara Medical University (Approval ID; nara0031). The study results will be communicated through publication in international scientific journals and presentations at (inter)national conferences.

TRIAL REGISTRATION NUMBER

jRCTs051210137.

Living with vaccine-induced immune thrombocytopenia and thrombosis: a qualitative study

OBJECTIVES

To explore the experiences of people up to 18 months after being diagnosed with vaccine-induced immune thrombocytopenia and thrombosis (VITT).

DESIGN

A semistructured qualitative study, conducted via Zoom, of a cohort of people with VITT.

SETTING

Participants discussed their experiences of hospitalisation and following discharge.

PARTICIPANTS

14 individuals diagnosed with VITT, recruited via a Facebook support group and advertising on Twitter.

RESULTS

Thematic analysis identified challenges of obtaining medical care and diagnosis; fear of the severity of symptoms and unclear prognosis; and lack of family support due to isolation imposed by the COVID-19 pandemic. Once home, participants experienced continued significant symptoms; fear of recurrence; inadequate medical knowledge of their condition; and difficulties coping with residual physical disabilities and psychosocial losses. Also reported were feelings of isolation and abandonment due to lack of government support.

CONCLUSIONS

This is a significantly challenged group of people, with multiple health, financial, social and psychological losses. These losses have been compounded by experiences of limited governmental and societal recognition of the problems they face.

Efficacy and safety of novel oral anticoagulants for the treatment of cancer-associated venous thromboembolism: protocol for an umbrella review of systematic reviews and meta-analyses

INTRODUCTION

Novel oral anticoagulants (NOACs) have been used in antithrombotic therapy in patients with cancer, and their efficacy and safety have been evaluated in several meta-analyses. Although a large body of findings has accumulated to support the benefit of NOACs for the treatment and prevention of cancer-associated thromboembolism, there is no convincing evidence because of inconsistent results across studies and questionable data quality. Its efficacy and safety remain controversial, especially with regard to the risk of bleeding.

METHODS AND ANALYSIS

We will search PubMed, Embase and Web of science, Cochrane Library on 19 April 2022 (searches will be updated until complete) to identify systematic reviews, meta-analyses and pooled analyses of the efficacy and safety of NOACs for the treatment of cancer-associated venous thromboembolism. The quality of eligible systematic evaluations will be measured by A Measurement Tool to Assess Systematic Reviews. For each outcome, if a random effects model is not used, we will extract the data and estimate a 95% CI using the random effects model approach. For each random effects estimate, a 95% prediction interval is calculated. Heterogeneity between studies will be quantified using the I² metric. In addition, if an assessment contains at least three articles, we will reanalyse the assessment using Egger's asymmetry test to detect and visualise possible publication bias in the articles.

ETHICS AND DISSEMINATION

No formal ethical approval is required since we will use publicly available data. We will disseminate the findings of the umbrella review through publication in a peer-reviewed journal and conference presentations.

PROSPERO REGISTRATION NUMBER

CRD42022342053.

Use of tranexamic acid (TXA) to reduce preterm birth and other adverse obstetrical outcomes among pregnant individuals with placenta previa: a systematic review protocol

INTRODUCTION

Placenta previa is a placental implantation pathology where the placenta overlies the internal endocervical os. Placenta previa affects approximately 4 per 1000 pregnancies and increases the risk of antepartum bleeding, emergent preterm labour and emergency caesarean sections. Currently, placenta previa is managed through expectant management. Guidelines primarily revolve around the mode and timing of delivery, in-hospital admissions and surveillance. However, the methods to prolong pregnancy have not proven to be clinically effective. Tranexamic acid (TXA), an antifibrinolytic agent, is effectively used to prevent and treat postpartum haemorrhage as well as menorrhagia, with limited adverse effect, and may prove to be an effective treatment for placenta previa. The objective of this systematic review protocol is to review and synthesise the evidence of TXA use for antepartum haemorrhage in placenta previa.

METHODS AND ANALYSIS

Preliminary searches were conducted on 12 July 2022. We will search MEDLINE, EMBASE, CINAHL, Scopus and the Cochrane Central Register of Controlled Trials. Grey literature resources such as clinical trials registries (ClinicalTrials.gov and the WHO's International Clinical Trials Registry) and preprint servers (Europe PMC and Open Science Framework) will also be searched. The search terms will comprise of index headings and keyword searches related to TXA and the placenta or antepartum bleeding. Cohort and randomised and non-randomised trials will be considered. The target population is pregnant people, of any age, with placenta previa. The intervention is TXA given in the antepartum period. The main outcome of interest is preterm birth before 37 weeks, however, all perinatal outcomes will be collected. Title and abstract will be screened by two reviewers and any conflict will be discussed and evaluated by a third reviewer. The literature will be summarised in narrative form.

ETHICS AND DISSEMINATION

No ethics approval is required for this protocol. Findings will be disseminated through peer-review publication, lay summaries and conference presentations.

PROSPERO REGISTRATION NUMBER

CRD42022363009).

Predictive value of tachycardia for mortality in trauma-related haemorrhagic shock: a systematic review and meta-regression

OBJECTIVES

Heart rate (HR) is one of the physiological variables in the early assessment of trauma-related haemorrhagic shock, according to Advanced Trauma Life Support (ATLS). However, its efficiency as predictor of mortality is contradicted by several studies. Furthermore, the linear association between HR and the severity of shock and blood loss presented by ATLS is doubtful. This systematic review aims to update current knowledge on the role of HR in the initial haemodynamic assessment of patients who had a trauma.

DESIGN

This study is a systematic review and meta-regression that follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations.

DATA SOURCES

EMBASE, MEDLINE, CENTRAL and Web of Science databases were systematically searched through on 1 September 2020.

ELIGIBILITY CRITERIA

Papers providing early HR and mortality data on bleeding patients who had a trauma were included. Patient cohorts were considered haemorrhagic if the inclusion criteria of the studies contained transfusion and/or positive focused assessment with sonography for trauma and/or postinjury haemodynamical instability and/or abdominal gunshot injury. Studies on burns, traumatic spinal or brain injuries were excluded. Papers published before January 2010 were not considered.

DATA EXTRACTION AND SYNTHESIS

Data extraction and risk of bias were assessed by two independent investigators. The association between HR and mortality of patients who had a trauma was assessed using meta-regression analysis. As subgroup analysis, meta-regression was performed on patients who received blood products.

RESULTS

From a total of 2017 papers, 19 studies met our eligibility criteria. Our primary meta-regression did not find a significant relation (p=0.847) between HR and mortality in patients who had a trauma with haemorrhage. Our subgroup analysis included 10 studies, and it could not reveal a linear association between HR and mortality rate.

CONCLUSIONS

In accordance with the literature demonstrating the multiphasic response of HR to bleeding, our study presents the lack of linear association between postinjury HR and mortality. Modifying the pattern of HR derangements in the ATLS shock classification may result in a more precise teaching tool for young clinicians.

Perioperative management with ferric carboxymaltose and tranexamic acid to reduce transfusion rate in gynaecological carcinoma surgery (TRANAFER-Study): study protocol for a single-blind, monocentre, randomised trial

INTRODUCTION

Radical abdominal surgery is part of the standard treatment for women with advanced gynaecological carcinoma. The surgery often leads to intraoperative blood loss frequently exceeding 1000 mL. Approximately 50% of women undergoing radical surgery require blood transfusions. Perioperative blood transfusions have been shown to increase the risk of postoperative complications, delayed wound healing, increased length of stay, increased postoperative morbidity and mortality. Previous studies have demonstrated an association between perioperative anaemia and surgical morbidity and mortality. By reducing transfusions and improving recovery from surgery, preoperative diagnostic and management of perioperative anaemia is a great opportunity to optimise postoperative patient outcome.

METHODS AND ANALYSIS

This is a single-blind, monocentre, randomised trial with four parallel groups (three therapeutic groups and one control group without treatment according to current standards of care) conducted in women undergoing radical gynaecological surgery. The primary study objective is to determine the effect of perioperative treatment with either intravenous iron, tranexamic acid or with a combination of both medicines on the reduction of intraoperative and postoperative red blood cell transfusions in gynaecological carcinoma patients. A total of N=126 women with gynaecological carcinoma will be recruited at the University Hospital Basel, Department of Gynaecology. Blood parameters will be measured at the recruitment, prior to surgery, 2 days after surgery and on the 21st-28th day after surgery. Recruitment started in August 2021.

ETHICS AND DISSEMINATION

The study will be performed according to the guidelines of the Declaration of Helsinki and is approved by the Ethics Committee for Northwest and Central Switzerland in Basel (EKNZ Protocol ID 2020-01194). The results of this study will be published and presented in various scientific forums.

TRIAL REGISTRATION NUMBER

NCT03792464.

Exploring the epidemiology of disseminated intravascular coagulation: protocol for the DANish Disseminated Intravascular Coagulation (DANDIC) Cohort Study

INTRODUCTION

Since disseminated intravascular coagulation (DIC) was first described, it has been considered a serious disease of the coagulation system and a major challenge to clinicians. Currently, several important knowledge gaps remain. The DANish Disseminated Intravascular Coagulation (DANDIC) Cohort Study will aim to answer questions regarding the incidence and mortality of patients with DIC including time trends. The study will also identify prognostic factors that may guide personalised prevention and treatment. Furthermore, the study will describe treatment patterns and the safety and effectiveness of various treatment modalities.

METHODS AND ANALYSIS

We will establish the DANDIC Cohort using data collected in daily clinical practice from the Central Denmark Region, which covers approximately 1.3 million residents. The study period will encompass 1 January 2011 through 1 July 2021. Potential DIC cases will be identified from the hospital laboratory database, based on coagulation biomarkers, and diagnoses will be adjudicated by medical experts. The dataset will be enriched with detailed clinical data from electronic medical charts on aetiologies, bleeding, microthrombus formation, organ failure, thrombosis, treatments and comorbidities. The dataset will also take advantage of in-hospital data with longitudinal information on laboratory records, transfusions, microbiology and treatments. It will be possible to merge this dataset with other unique Danish health registries with more than 10 years of virtually complete follow-up. The project will use state-of-the-art epidemiological and biostatistical methods.

ETHICS AND DISSEMINATION

The project has been approved by the Danish Patient Safety Authority (31-1521-452), the Central Denmark Region (1-45-70-83-21), the Danish Data Protection Agency (1-16-02-258-21) and all the hospital chairs. Register-based studies require no ethical approval in Denmark. The results will be disseminated in international peer-reviewed journals.

Detection of exhaled methane levels for monitoring trauma-related haemorrhage following blunt trauma: study protocol for a prospective observational study

INTRODUCTION

Early recognition and effective treatment of internal bleeding impose a cardinal challenge for trauma teams. The reduction of the superior mesenteric artery (SMA) blood flow is among the first compensatory responses to blood loss, thus being a promising candidate as a diagnostic tool for occult haemorrhage. Unfortunately, methods for monitoring the SMA flow have not been elaborated to date. Nevertheless, animal experiments suggest that exhaled methane (CH₄) levels correspond to the SMA perfusion. We hypothesise that real-time detection of CH₄ concentrations in the exhaled air is an applicable technique for the early recognition of haemorrhage in severely injured patients. We also hypothesise that exhaled CH₄ levels reflect the volume of blood loss more accurately than conventional markers of blood loss and shock such as shock index, haemoglobin, base deficit, lactate, end-tidal carbon dioxide and sublingual microcirculatory indices.

METHODS AND ANALYSIS

One hundred and eleven severely injured (Injury Severity Score ≥16), intubated, bleeding patients sustaining blunt trauma will be included in this prospective observational study. Blood loss will be detected with CT and estimated with CT-linked radiologic software. Exhaled CH₄ concentrations will be monitored by attaching a near-infrared laser technique-based photoacoustic spectroscopy apparatus to the exhalation outlet of the ventilator on patient arrival. The primary outcome is the volume of blood loss. Need for massive transfusion and 24-hour mortality will constitute secondary outcomes. The relation of exhaled CH₄ to study outcomes and its performance in predicting blood loss in comparison with conventional shock markers and microcirculatory indices will be tested.

ETHICS AND DISSEMINATION

Our protocol (ID: 5400/2021-SZTE) has been registered on ClinicalTrials.gov (NCT04987411) and complies with the Declaration of Helsinki and has been approved by the medical ethics committee at the University of Szeged (Ref.nr.:121/2021-SZTE RKEB). It is in data collection phase, theresults will be shared with the scientific community through publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT04987411; ClinicalTrials.gov, registered on 27 July 2021.

Association of direct oral anticoagulant-proton pump inhibitor cotherapy with adverse outcomes: protocol for a population-based cohort study

INTRODUCTION

Proton pump inhibitors (PPIs) are widely used for primary and secondary prevention of upper gastrointestinal bleeding. However, there remains controversy about the overall net clinical benefit of PPIs (omeprazole, rabeprazole, pantoprazole, lansoprazole) when coprescribed with direct oral anticoagulants (DOACs; dabigatran, rivaroxaban, apixaban, edoxaban). Our objective is to explore the risk of clinically relevant events, including bleeding, thromboembolic events and death, in patients prescribed DOACs while taking PPIs versus no PPI.

METHODS AND ANALYSIS

The protocol describes a retrospective cohort study of all Ontario residents aged 66 years or older with atrial fibrillation and at least one pharmacy dispensation for a DOAC identified using linked administrative healthcare databases covering 2009-2020. Ontario drug benefit dispensation records will be used to ascertain PPI exposure during DOAC therapy. The primary outcome is a composite of clinically relevant bleeding, thrombotic events or all-cause death. A minimum of 520 patients in total with at least one of the components of the composite outcome are needed. Poisson regression with a generalised estimating equation model will be used to calculate the adjusted incidence rate difference, incidence rate ratios 95% CI, adjusting for propensity for PPI use using inverse probability of treatment weights.

ETHICS AND DISSEMINATION

This research is exempt from REB review under section 45 of Ontario's Personal Health Information Protection Act. We will report our findings in a peer-reviewed biomedical journal and present them at conferences. The study will provide useful evidence to optimise the coprescription of DOACs and PPIs in practice.

Safety and effectiveness of appropriately and inappropriately dosed rivaroxaban or apixaban versus warfarin in patients with atrial fibrillation: a cohort study with nested case-control analyses from UK primary care

OBJECTIVES

To investigate effects of appropriately and inappropriately dosed apixaban/rivaroxaban versus warfarin on effectiveness and safety outcomes in patients with non-valvular atrial fibrillation (NVAF).

DESIGN

Cohort study with nested case-control analyses using primary care electronic health records (IQVIA Medical Research Data UK database).

SETTING

UK primary care.

PARTICIPANTS

Patients aged ≥18 years with NVAF newly prescribed apixaban (N=14 701), rivaroxaban (N=14 288) or warfarin (N=16 175) between 1 January 2012 and 30 June 2018, and followed up to 31 December 2018.

PRIMARY AND SECONDARY OUTCOME MEASURES

Incident cases of ischaemic stroke/systemic embolism (IS/SE) and intracranial bleeding (ICB). Cases were matched to controls on age, sex and OAC naïve status. Using logistic regression, adjusted ORs with 95% CIs were calculated for the outcomes comparing apixaban/rivaroxaban use (appropriate or inappropriate dosing based on the product label criteria) and warfarin.

RESULTS

For IS/SE, ORs (95% CIs) for apixaban versus warfarin were 1.19 (0.92-1.52) for appropriate dose and 1.01 (0.67-1.51) for inappropriate dose; for rivaroxaban versus warfarin, estimates were 1.07 (0.83-1.37) for appropriate dose and 1.21 (0.78-1.88) for inappropriate dose. For ICB, ORs (95% CIs) for apixaban versus warfarin were 0.67 (0.44-1.00) for appropriate dose and 0.45 (0.21-0.95) for inappropriate dose; for rivaroxaban versus warfarin, estimates were 0.81 (0.55-1.20) for appropriate dose and 1.14 (0.56-2.31) for inappropriate dose.

CONCLUSIONS

Dosing appropriateness in NVAF was not associated with a significant difference in IS/SE risk or increase in ICB risk versus warfarin. These findings may reflect residual confounding and biases that were difficult to control, as also seen in other observational studies. They should, therefore, be interpreted with caution, and prescribers should adhere to the dosing instructions in the respective Summary of Product Characteristics. Further studies on this topic from real-world populations are needed.

Fibrinogen Early In Severe paediatric Trauma studY (FEISTY junior): protocol for a randomised controlled trial

INTRODUCTION

Trauma causes 40% of child deaths in high-income countries, with haemorrhage being a leading contributor to death in this population. There is a growing recognition that fibrinogen and platelets play a major role in trauma-induced coagulopathy (TIC) but the exact physiological mechanisms are poorly understood.

METHODS AND ANALYSIS

This is a prospective multicentre, open-label, randomised, two-arm parallel feasibility study conducted in the emergency departments, intensive care units and operating theatres of participating hospitals. Severely injured children, aged between 3 months and 18 years, presenting with traumatic haemorrhage requiring transfusion of blood products will be screened for inclusion.Sixty-eight patients will be recruited and will be allocated to fibrinogen replacement using fibrinogen concentrate (FC) or cryoprecipitate in a 1:1 ratio. Fibrinogen replacement will be administered to patients with a FIBTEM A5 of ≤10. All other aspects of the currently used rotational thromboelastometry-guided treatment algorithm and damage-control approach to trauma remain the same in both groups.The primary outcome is time to administration of fibrinogen replacement from time of identification of hypofibrinogenaemia. Clinical secondary outcomes and feasibility outcomes will also be analysed.

ETHICS AND DISSEMINATION

This study has received ethical clearance from the Children's Health Queensland Human Research Ethics Committee (HREC/17/QRCH/78). Equipment and consumables for sample testing have been provided to the study by Haemoview Diagnostics, Werfen Australia and Haemonetics Australia. FC has been provided by CSL Behring, Australia. The funding bodies and industry partners have had no input into the design of the study, and will not be involved in the preparation or submission of the manuscript for publication.The use of viscoelastic haemostatic assays and early fibrinogen replacement has the potential to improve outcomes in paediatric trauma through earlier recognition of TIC. This in turn may reduce transfusion volumes and downstream complications and reduce the reliance on donor blood products such as cryoprecipitate.The use of FC has implications for regional and remote centres who would not routinely have access to cryoprecipitate but could store FC easily. Access to early fibrinogen replacement in these centres could make a significant impact and assist in closing the gap in trauma care available to residents of these communities.Outcomes of this study will be submitted for publication in peer-reviewed journals and submitted for presentation at national and international scientific fora.

TRIAL REGISTRATION NUMBER

NCT03508141.

Prolonged argatroban clearance in a critically ill patient with heparin-induced thrombocytopaenia

This is a case of argatroban use in a critically ill patient with heparin-induced thrombocytopaenia (HIT), presenting with unexpectedly prolonged drug clearance possibly secondary to hepatic congestion due to reduced cardiac contractility. A 63-year-old woman from Asia with end-stage renal failure was hospitalised in the critical care unit with non-ST elevation myocardial infarction with underlying triple vessel disease. She was subsequently started on intravenous unfractionated heparin infusion after an intra-aortic balloon pump was inserted. Six days after the initiation of heparin, she developed HIT and argatroban was started for treatment of HIT. Despite starting on the recommended dose of 2µg/kg/min, she developed significantly prolonged activated partial thromboplastin time (aPTT) with delayed clearance. Argatroban was stopped 14 hours after time of initiation in view of the markedly prolonged aPTT (in the range of 145 s), and levels only normalised at approximately 60 hours after argatroban was stopped.