Quantification of Serial Cerebral Blood Flow in Acute Stroke Using Arterial Spin Labeling.

BACKGROUND AND PURPOSE: Perfusion-weighted imaging is used to select patients with acute ischemic stroke for intervention, but knowledge of cerebral perfusion can also inform the understanding of ischemic injury. Arterial spin labeling allows repeated measurement of absolute cerebral blood flow (CBF) without the need for exogenous contrast. The aim of this study was to explore the relationship between dynamic CBF and tissue outcome in the month after stroke onset. METHODS: Patients with nonlacunar ischemic stroke underwent ≤5 repeated magnetic resonance imaging scans at presentation, 2 hours, 1 day, 1 week, and 1 month. Imaging included vessel-encoded pseudocontinuous arterial spin labeling using multiple postlabeling delays to quantify CBF in gray matter regions of interest. Receiver-operator characteristic curves were used to predict tissue outcome using CBF. Repeatability was assessed in 6 healthy volunteers and compared with contralateral regions of patients. Diffusion-weighted and T2-weighted fluid attenuated inversion recovery imaging were used to define tissue outcome. RESULTS: Forty patients were included. In contralateral regions of patients, there was significant variation of CBF between individuals, but not between scan times (mean±SD: 53±42 mL/100 g/min). Within ischemic regions, mean CBF was lowest in ischemic core (17±23 mL/100 g/min), followed by regions of early (21±26 mL/100 g/min) and late infarct growth (25±35 mL/100 g/min; ANOVA P<0.0001). Between patients, there was marked overlap in presenting and serial CBF values. CONCLUSIONS: Knowledge of perfusion dynamics partially explained tissue fate. Factors such as metabolism and tissue susceptibility are also likely to influence tissue outcome.

Restrictive versus liberal blood transfusion for acute upper gastrointestinal bleeding (TRIGGER): a pragmatic, open-label, cluster randomised feasibility trial.

BACKGROUND: Transfusion thresholds for acute upper gastrointestinal bleeding are controversial. So far, only three small, underpowered studies and one single-centre trial have been done. Findings from the single-centre trial showed reduced mortality with restrictive red blood cell (RBC) transfusion. We aimed to assess whether a multicentre, cluster randomised trial is a feasible method to substantiate or refute this finding. METHODS: In this pragmatic, open-label, cluster randomised feasibility trial, done in six university hospitals in the UK, we enrolled all patients aged 18 years or older with new presentations of acute upper gastrointestinal bleeding, irrespective of comorbidity, except for exsanguinating haemorrhage. We randomly assigned hospitals (1:1) with a computer-generated randomisation sequence (random permuted block size of 6, without stratification or matching) to either a restrictive (transfusion when haemoglobin concentration fell below 80 g/L) or liberal (transfusion when haemoglobin concentration fell below 100 g/L) RBC transfusion policy. Neither patients nor investigators were masked to treatment allocation. Feasibility outcomes were recruitment rate, protocol adherence, haemoglobin concentration, RBC exposure, selection bias, and information to guide design and economic evaluation of the phase 3 trial. Main exploratory clinical outcomes were further bleeding and mortality at day 28. We did analyses on all enrolled patients for whom an outcome was available. This trial is registered, ISRCTN85757829 and NCT02105532. FINDINGS: Between Sept 3, 2012, and March 1, 2013, we enrolled 936 patients across six hospitals (403 patients in three hospitals with a restrictive policy and 533 patients in three hospitals with a liberal policy). Recruitment rate was significantly higher for the liberal than for the restrictive policy (62% vs 55%; p=0·04). Despite some baseline imbalances, Rockall and Blatchford risk scores were identical between policies. Protocol adherence was 96% (SD 10) in the restrictive policy vs 83% (25) in the liberal policy (difference 14%; 95% CI 7-21; p=0·005). Mean last recorded haemoglobin concentration was 116 (SD 24) g/L for patients on the restrictive policy and 118 (20) g/L for those on the liberal policy (difference -2·0 [95% CI -12·0 to 7·0]; p=0·50). Fewer patients received RBCs on the restrictive policy than on the liberal policy (restrictive policy 133 [33%] vs liberal policy 247 [46%]; difference -12% [95% CI -35 to 11]; p=0·23), with fewer RBC units transfused (mean 1·2 [SD 2·1] vs 1·9 [2·8]; difference -0·7 [-1·6 to 0·3]; p=0·12), although these differences were not significant. We noted no significant difference in clinical outcomes. INTERPRETATION: A cluster randomised design led to rapid recruitment, high protocol adherence, separation in degree of anaemia between groups, and non-significant reduction in RBC transfusion in the restrictive policy. A large cluster randomised trial to assess the effectiveness of transfusion strategies for acute upper gastrointestinal bleeding is both feasible and essential before clinical practice guidelines change to recommend restrictive transfusion for all patients with acute upper gastrointestinal bleeding. FUNDING: NHS Blood and Transplant Research and Development.

Association between self-reported signs and symptoms and SARS-CoV-2 antibody detection in UK key workers.

BACKGROUND: Screening for SARS-CoV-2 antibodies is under way in some key worker groups; how this adds to self-reported COVID-19 illness is unclear. In this study, we investigate the association between self-reported belief of COVID-19 illness and seropositivity. METHODS: Cross-sectional study of three key worker streams comprising (A) Police and Fire & Rescue (2 sites) (B) healthcare workers (1 site) and (C) healthcare workers with previously positive PCR result (5 sites). We collected self-reported signs and symptoms of COVID-19 and compared this with serology results from two SARS-CoV-2 immunoassays (Roche Elecsys® and EUROIMMUN). RESULTS: Between 01 and 26 June, we recruited 2847 individuals (Stream A: 1,247, Stream B: 1,546 and Stream C: 154). Amongst those without previous positive PCR tests, 687/2,579 (26%) reported belief they had COVID-19, having experienced compatible symptoms; however, only 208 (30.3%) of these were seropositive on both immunoassays. Both immunoassays had high sensitivities relative to previous PCR positivity (>93%); there was also limited decline in antibody titres up to 110 days post symptom onset. Symptomatic but seronegative individuals had differing symptom profiles and shorter illnesses than seropositive individuals. CONCLUSION: Non-COVID-19 respiratory illness may have been mistaken for COVID-19 during the outbreak; laboratory testing is more specific than self-reported key worker beliefs in ascertaining past COVID-19 disease.

Patients and doctors: rights and responsibilities in the NHS.

Whilst patients and doctors each bring a collection of rights and responsibilities with them into the consulting room, these parties must not be seen in isolation. The government of the day and its representatives have an absolute right to influence the future direction of the health service but they also have very grave responsibilities.

Restrictive vs liberal blood transfusion for acute upper gastrointestinal bleeding: rationale and protocol for a cluster randomized feasibility trial.

Acute upper gastrointestinal bleeding (AUGIB) is the commonest reason for hospitalization with hemorrhage in the UK and the leading indication for transfusion of red blood cells (RBCs). Observational studies suggest an association between more liberal RBC transfusion and adverse patient outcomes, and a recent randomised trial reported increased further bleeding and mortality with a liberal transfusion policy. TRIGGER (Transfusion in Gastrointestinal Bleeding) is a pragmatic, cluster randomized trial which aims to evaluate the feasibility and safety of implementing a restrictive versus liberal RBC transfusion policy in adult patients admitted with AUGIB. The trial will take place in 6 UK hospitals, and each centre will be randomly allocated to a transfusion policy. Clinicians throughout each hospital will manage all eligible patients according to the transfusion policy for the 6-month trial recruitment period. In the restrictive centers, patients become eligible for RBC transfusion when their hemoglobin is <8 g/dL. In the liberal centers patients become eligible for transfusion once their hemoglobin is <10 g/dL. All clinicians will have the discretion to transfuse outside of the policy but will be asked to document the reasons for doing so. Feasibility outcome measures include protocol adherence, recruitment rate, and evidence of selection bias. Clinical outcome measures include further bleeding, mortality, thromboembolic events, and infections. Quality of life will be measured using the EuroQol EQ-5D at day 28, and the costs associated with hospitalization for AUGIB in the UK will be estimated. Consent will be sought from participants or their representatives according to patient capacity for use of routine hospital data and day 28 follow up. The study has ethical approval for conduct in England and Scotland. Results will be analysed according to a pre-defined statistical analysis plan and disseminated in peer reviewed publications to relevant stakeholders. The results of this study will inform the feasibility and design of a phase III randomized trial.

Secondary spontaneous pneumothorax: a rare complication of pulmonary embolism.

An 85-year-old lady presented with a left middle cerebral artery territory infarct. Several days into her admission she became hypoxic and haemodynamically unstable. A CT pulmonary angiogram showed bilateral pulmonary emboli, right-sided parenchymal cavitation due to infarction and an associated large pneumothorax. She was treated successfully with an intercostal drain and anticoagulation. This case describes the rare phenomenon of secondary spontaneous pneumothorax due to pulmonary infarction from pulmonary embolism. The factors associated with the development of infarcts from pulmonary thromboemboli are poorly understood although a number of predisposing conditions and pathological features have been suggested. Pulmonary infarction occurs in around 10% of cases of pulmonary emboli but the complication of secondary spontaneous pneumothorax would appear to be much less common. One should consider pulmonary embolism as the cause of pneumothorax where there is significant clinical suspicion.

"Stroke Nav": a wireless data collection and review system to support stroke care delivery.

"Stroke Nav" is a novel system to support the care of stroke patients. The system contains purpose-built web-based software to facilitate accurate near-real time data collection by clinicians throughout the complex care settings traversed by patients. Tools are included to facilitate pre-defined and bespoke data review with graphical dashboards showing performance metrics and other aggregate data. The software was designed collaboratively by health care professionals and engineers, and is accessible via the hospital intranet using desktop or laptop computers and wireless mobile devices. Stroke Nav is being routinely used in two hospitals, with over 1400 patients registered, and is now being introduced in other hospitals. The system is delivering benefits in relation to multidisciplinary communication, knowledge management, patient safety, clinical audit and service performance.

Setting up an acute stroke service.

The administration of intravenous thrombolytic therapy to appropriate patients and the provision of care in a dedicated stroke unit setting form the pillars of evidence-based acute stroke care. Yet, the availability of these interventions remains variable around the world. Many challenges exist for physicians attempting to set up an acute stroke service for the first time. Based upon their experience in three countries, the authors propose 12 key steps in setting up a successful acute stroke service: *identify the building blocks *understand local funding mechanisms *forge partnerships *engage senior managers *obtain training *be inclusive *adapt to local surroundings *maintain a clinical focus *be incremental *capitalise on the enthusiasm of others *lead from the front; and *provide feedback. The authors then examine some of the specific barriers that may be encountered and offer three historical examples of evidence-based interventions that were slow to be adopted. An acute stroke service is evidence-based and cost effective, yet the ability of patients to access such a service is variable, even in the developed world. By considering 12 common sense steps, physicians and managers can maximise their chances of setting up a sustainable and successful acute stroke service.