Risk factors for vascular occlusive events and death due to bleeding in trauma patients; an analysis of the CRASH-2 cohort

Background Vascular occlusive events can complicate recovery following trauma. We examined risk factors for venous and arterial vascular occlusive events in trauma patients and the extent to which the risk of vascular occlusive events varies with the severity of bleeding. Methods and Findings We conducted a cohort analysis using data from a large international, double-blind, randomised, placebo-controlled trial (The CRASH-2 trial) [1]. We studied the association between patient demographic and physiological parameters at hospital admission and the risk of vascular occlusive events. To assess the extent to which risk of vascular occlusive events varies with severity of bleeding, we constructed a prognostic model for the risk of death due to bleeding and assessed the relationship between risk of death due to bleeding and risk of vascular occlusive events. There were 20,127 trauma patients with outcome data including 204 (1.01%) patients with a venous event (pulmonary embolism or deep vein thrombosis) and 200 (0.99%) with an arterial event (myocardial infarction or stroke). There were 81 deaths due to vascular occlusive events. Increasing age, decreasing systolic blood pressure, increased respiratory rates, longer central capillary refill times, higher heart rates and lower Glasgow Coma Scores (all p<0.02) were strong risk factors for venous and arterial vascular occlusive events. Patients with more severe bleeding as assessed by predicted risk of haemorrhage death had a greatly increased risk for all types of vascular occlusive event (all p<0.001). Conclusions Patients with severe traumatic bleeding are at greatly increased risk of venous and arterial vascular occlusive events. Older age and blunt trauma are also risk factors for vascular occlusive events. Effective treatment of bleeding may reduce venous and arterial vascular occlusive complications in trauma patients

Postpartum management of hypertensive disorders of pregnancy: a systematic review

OBJECTIVES: Hypertensive disorders of pregnancy (HDP) affect one in ten pregnancies and often persist postpartum when complications can occur. We aimed to determine the effectiveness and safety of pharmacological interventions, other interventions and different care models for postpartum hypertension management. DESIGN: A systematic review was undertaken. Nine electronic databases, including Medline, were searched from inception to 16 March 2017. After duplicate removal, 4561 records were screened. Two authors independently selected studies, extracted study characteristics and data, and assessed methodological quality. SETTING: Randomised controlled trials, case-control studies and cohort studies from any country and healthcare setting. PARTICIPANTS: Postnatal women with HDP. INTERVENTIONS: Therapeutic intervention for management of hypertension, compared with another intervention, placebo or no intervention. PRIMARY AND SECONDARY OUTCOME MEASURES: Outcome data were collected for maternal mortality and severe morbidity; systolic, diastolic and mean arterial blood pressure (BP) control; and safety data. Secondary outcome data collected included the length of postnatal hospital stay and laboratory values. RESULTS: 39 studies were included (n=2901). Results were heterogeneous in terms of intervention, comparison and outcome requiring a narrative approach. There were insufficient data to recommend any single pharmacological intervention. 18 studies reported calcium-channel blockers, vasodilators and beta-blockers lowered BP postpartum. 12 of these reported safety data. Limited data existed regarding management in the weeks following hospital discharge. Neither loop diuretics (three studies) nor corticosteroids (one study) produced clinical benefit. Uterine curettage significantly reduced BP over the first 48 hours postpartum (range 6-13 mm Hg) compared with standard care (eight studies), with safety data only reported by four of eight studies. CONCLUSION: There was insufficient evidence to recommend a particular BP threshold, agent or model of care, but three classes of antihypertensive appeared variably effective. Further comparative research, including robust safety data, is required. Curettage reduced BP, but without adequate reporting of harms, so it cannot currently be recommended

Tranexamic acid for the prevention of postpartum bleeding in women with anaemia: study protocol for an international, randomised, double-blind, placebo-controlled trial.

BACKGROUND: Postpartum haemorrhage (PPH) is responsible for about 100,000 maternal deaths every year, most of which occur in low- and middle-income countries. Tranexamic acid (TXA) reduces bleeding by inhibiting the enzymatic breakdown of fibrin blood clots. TXA decreases blood loss in surgery and reduces death due to bleeding after trauma. When given within 3 h of birth, TXA reduces deaths due to bleeding in women with PPH. However, for many women, treatment of PPH is too late to prevent death. Over one third of pregnant women in the world are anaemic and many are severely anaemic. These women have an increased risk of PPH and suffer more severe outcomes if PPH occurs. There is an urgent need to identify a safe and effective way to reduce postpartum bleeding in anaemic women. METHODS/DESIGN: The WOMAN-2 trial is an international, multicentre, randomised, double-blind, placebo-controlled trial to quantify the effects of TXA on postpartum bleeding in women with moderate or severe anaemia. Ten thousand women with moderate or severe anaemia who have given birth vaginally will be randomised to receive 1 g of TXA or matching placebo by intravenous injection immediately (within 15 min) after the umbilical cord is cut or clamped. The primary outcome is the proportion of women with a clinical diagnosis of primary PPH. The cause of PPH will be described. Data on maternal health and wellbeing, maternal blood loss and its consequences, and other health outcomes will be collected as secondary outcomes. The main analyses will be on an 'intention-to-treat' basis, irrespective of whether the allocated treatment was received. Results will be presented as appropriate effect estimates with a measure of precision (95% confidence intervals). Subgroup analyses will be based on the severity of anaemia (moderate versus severe) and type of labour (induced or augmented versus spontaneous). A study with 10,000 patients will have over 90% power to detect a 25% relative reduction from 10 to 7.5% in PPH. The trial will be conducted in hospitals in Africa and Asia. DISCUSSION: The WOMAN-2 trial should provide reliable evidence for the effects of TXA for preventing postpartum bleeding in women with anaemia. TRIAL REGISTRATION: ISRCTN, ISRCTN62396133 . Registered on 7 December 2017; ClincalTrials.gov, ID: NCT03475342 . Registered on 23 March 2018

Risk of tuberculosis in patients with diabetes: population based cohort study using the UK Clinical Practice Research Datalink.

BACKGROUND: Previous cohort studies demonstrate diabetes as a risk factor for tuberculosis (TB) disease. Public Health England has identified improved TB control as a priority area and has proposed a primary care-based screening program for latent TB. We investigated the association between diabetes and risk of tuberculosis in a UK General Practice cohort in order to identify potential high-risk groups appropriate for latent TB screening. METHODS: Using data from the UK Clinical Practice Research Datalink we constructed a cohort of patients with incident diabetes. We included 222,731 patients with diabetes diagnosed from 1990-2013 and 1,218,616 controls without diabetes at index date who were matched for age, sex and general practice. The effect of diabetes was explored using a Poisson analysis adjusted for age, ethnicity, body mass index, socioeconomic status, alcohol intake and smoking. We explored the effects of age, diabetes duration and severity. The effects of diabetes on risk of incident TB were explored across strata of chronic disease care defined by cholesterol and blood pressure measurement and influenza vaccination rates. RESULTS: During just under 7 million person-years of follow-up, 969 cases of TB were identified. The incidence of TB was higher amongst patients with diabetes compared with the unexposed group: 16.2 and 13.5 cases per 100,000 person-years, respectively. After adjustment for potential confounders the association between diabetes and TB remained (adjusted RR 1.30, 95 % CI 1.01 to 1.67, P = 0.04). There was no evidence that age, time since diagnosis and severity of diabetes affected the association between diabetes and TB. Diabetes patients with the lowest and highest rates of chronic disease management had a higher risk of TB (P <0.001 for all comparisons). CONCLUSIONS: Diabetes as an independent risk factor is associated with only a modest overall increased risk of TB in our UK General Practice cohort and is unlikely to be sufficient cause to screen for latent TB. Across different consulting patterns, diabetes patients accessing the least amount of chronic disease care are at highest risk for TB.This article presents independent research supported by a National Institute for Health Research (NIHR) In Practice Fellowship to LP (grant number NIHR/IPF/11/05). DAJM received Wellcome Trust funding (grant number 092691/Z/10/Z). LS is supported by a Wellcome Trust Senior Research Fellowship in Clinical Science

A randomised controlled trial of blood pressure self-monitoring in the management of hypertensive pregnancy. OPTIMUM-BP: A feasibility trial.

OBJECTIVE: To assess the feasibility of a blood pressure self-monitoring intervention for managing pregnancy hypertension. STUDY DESIGN: OPTIMUM-BP was an unmasked randomised controlled trial comparing a self-monitoring of blood pressure (SMBP) intervention versus usual care for the management of pregnancy hypertension. Women with chronic (CH) or gestational hypertension (GH) from 4 UK centres were randomised (2:1) intervention to control. Self-monitoring involved daily home blood pressure (BP) measurements, with recording via study diary or telemonitoring. Clinicians were invited to use the home readings in clinical and antihypertensive titration decisions. MAIN OUTCOMES: The primary outcomes were recruitment, retention, adherence and persistence with the intervention. RESULTS: Women from four UK centres were randomised: 158/222 (71%) of those approached agreed, comprising: 86 women with chronic hypertension (55 SMBP, 31 control) and 72 with gestational hypertension (49 SMBP, 23 control) of whom outcome data were available from 154 (97%) and were included in the analysis. The median (IQR) number of days with home BP readings per week were 5.5 (3.1-6.5) for those with chronic hypertension and 6.1 (4.5-6.7) with gestational hypertension. Participants persisted with the intervention for 80% or more of their time from enrolment until delivery in 86% (43/50) and 76% (38/49) of those with chronic and gestational hypertension respectively. Recorded clinic and study BPs were similar for both groups. CONCLUSIONS: This is the first randomised investigation of BP self-monitoring for the management of pregnancy hypertension and indicates that a large RCT would be feasible

Structural and mechanistic mapping of a unique fumarate reductase

The 1.8 Å resolution crystal structure of the tetraheme flavocytochrome c3, Fcc3, provides the first mechanistic insight into respiratory fumarate reductases or succinate dehydrogenases. The multi-redox center, three-domain protein shows a 40 Å long ‘molecular wire’ allowing rapid conduction of electrons through a new type of cytochrome domain onto the active site flavin, driving the reduction of fumarate to succinate. In this structure a malate-like molecule is trapped in the enzyme active site. The interactions between this molecule and the enzyme suggest a clear mechanism for fumarate reduction in which the substrate is polarized and twisted, facilitating hydride transfer from the reduced flavin and subsequent proton transfer. The enzyme active site in the oxidized form is completely buried at the interface between the flavin-binding and the clamp domains. Movement of the cytochrome and clamp domains is postulated to allow release of the product

Outcome reporting across randomised controlled trials evaluating therapeutic interventions for pre-eclampsia.

BACKGROUND: Standardising outcome collection and reporting in pre-eclampsia trials requires an appraisal of current outcome reporting. OBJECTIVES: To map maternal and offspring outcome reporting across randomised trials evaluating therapeutic interventions for pre-eclampsia. SEARCH STRATEGY: Randomised trials were identified by searching bibliographical databases from inception to January 2016. SELECTION CRITERIA: Randomised controlled trials. DATA COLLECTION AND ANALYSIS: We systematically extracted and categorised outcome reporting. MAIN RESULTS: Seventy-nine randomised trials, reporting data from 31 615 maternal participants and 28 172 of their offspring, were included. Fifty-five different interventions were evaluated. Included trials reported 119 different outcomes, including 72 maternal outcomes and 47 offspring outcomes. Maternal outcomes were inconsistently reported across included trials; for example, 11 trials (14%) reported maternal mortality, reporting data from 12 422 participants, and 16 trials (20%) reported cardiovascular morbidity, reporting data from 14 963 maternal participants. Forty-three trials (54%) reported fetal outcomes and 23 trials (29%) reported neonatal outcomes. Twenty-eight trials (35%) reported offspring mortality. There was poor reporting of childhood outcomes: six trials (8%) reported neurodevelopmental outcomes. Less than half of included trials reported any relevant information regarding harms for maternal participants and their offspring. CONCLUSIONS: Most randomised trials evaluating interventions for pre-eclampsia are missing information on clinically important outcomes, and in particular have neglected to evaluate efficacy and safety in the offspring of participants. Developing and implementing a minimum data set, known as a core outcome set, in future pre-eclampsia trials could help to address these issues

A systematic review of primary outcomes and outcome measure reporting in randomized trials evaluating treatments for pre-eclampsia

Background: An evaluation of outcome reporting is required to develop a core outcome set. Objectives: To assess primary outcomes and outcome measure reporting in pre-eclampsia trials. Search strategy: Five online databases were searched from inception to January 2016 using terms including “preeclampsia” and “randomized controlled trial”. Selection criteria: Randomized controlled trials evaluating treatments for pre-eclampsia published in any language were included. Data collection and analysis: Primary outcomes and data on outcome measure reporting were systematically extracted and categorized. Main results: Overall, 79 randomized trials including data from 31 615 women were included. Of those, 38 (48%) reported 35 different primary outcomes; 28 were maternal outcomes and seven were fetal/neonatal outcomes. Three randomized trials reported composite outcomes, incorporating between six and nine outcome components. The method of definition or measurement was infrequently or poorly reported. Even when outcomes were consistent across trials, different methods of definition or measurement were frequently described. Conclusions: In randomized trials evaluating interventions for pre-eclampsia, critical information related to the primary outcome, including definition and measurement, is regularly omitted. Developing a core outcome set for pre-eclampsia trials would help to inform primary outcome selection and outcome measure reporting

Towards Electrosynthesis in Shewanella: Energetics of Reversing the Mtr Pathway for Reductive Metabolism

Bioelectrochemical systems rely on microorganisms to link complex oxidation/reduction reactions to electrodes. For example, in Shewanella oneidensis strain MR-1, an electron transfer conduit consisting of cytochromes and structural proteins, known as the Mtr respiratory pathway, catalyzes electron flow from cytoplasmic oxidative reactions to electrodes. Reversing this electron flow to drive microbial reductive metabolism offers a possible route for electrosynthesis of high value fuels and chemicals. We examined electron flow from electrodes into Shewanella to determine the feasibility of this process, the molecular components of reductive electron flow, and what driving forces were required. Addition of fumarate to a film of S. oneidensis adhering to a graphite electrode poised at −0.36 V versus standard hydrogen electrode (SHE) immediately led to electron uptake, while a mutant lacking the periplasmic fumarate reductase FccA was unable to utilize electrodes for fumarate reduction. Deletion of the gene encoding the outer membrane cytochrome-anchoring protein MtrB eliminated 88% of fumarate reduction. A mutant lacking the periplasmic cytochrome MtrA demonstrated more severe defects. Surprisingly, disruption of menC, which prevents menaquinone biosynthesis, eliminated 85% of electron flux. Deletion of the gene encoding the quinone-linked cytochrome CymA had a similar negative effect, which showed that electrons primarily flowed from outer membrane cytochromes into the quinone pool, and back to periplasmic FccA. Soluble redox mediators only partially restored electron transfer in mutants, suggesting that soluble shuttles could not replace periplasmic protein-protein interactions. This work demonstrates that the Mtr pathway can power reductive reactions, shows this conduit is functionally reversible, and provides new evidence for distinct CymA:MtrA and CymA:FccA respiratory units