Description: Ventricular fibrillation (VF) in the globally ischemic heart is characterized by a progressive electrical depression manifested as a decline in the VF excitation rate (VFR) and loss of excitability, which occur first in the subepicardium (Epi) and spread to the subendocardium (Endo). Early electrical failure is detrimental to successful defibrillation and resuscitation during cardiac arrest. Hyperkalemia and/or the activation of ATP-sensitive K + (K ATP ) channels have been implicated in electrical failure, but the role of these factors in ischemic VF is poorly understood. We determined the VFR-extracellular K + concentration ([K + ] o ) relationship in the Endo and Epi of the left ventricle during VF in globally ischemic hearts (Isch group) and normoxic hearts subjected to hyperkalemia (HighK group) or a combination of hyperkalemia and the K ATP channel opener cromakalim (HighK-Crom group). In the Isch group, Endo and Epi values of [K + ] o and VFR were compared in the early (0–6 min), middle (7–13 min), and late (14–20 min) phases of ischemic VF. A significant transmural gradient in VFR (Endo 〉 Epi) was observed in all three phases, whereas a significant transmural gradient in [K + ] o (Epi 〉 Endo) occurred only in the late phase of ischemic VF. In the Isch group, the VFR decrease and inexcitability started to occur at much lower [K + ] o than in the HighK group, especially in the Epi. Combining K ATP activation with hyperkalemia only shifted the VFR-[K + ] o curve upward (an effect opposite to real ischemia) without changing the [K + ] o threshold for asystole. We conclude that hyperkalemia and/or K ATP activation cannot adequately explain the heterogeneous electrical depression and electrical failure during ischemic VF.

Description: Objectives Social prescribing is a way of linking patients in primary care with sources of support within the community to help improve their health and well-being. Social prescribing programmes are being widely promoted and adopted in the UK National Health Service and so we conducted a systematic review to assess the evidence for their effectiveness. Setting/data sources Nine databases were searched from 2000 to January 2016 for studies conducted in the UK. Relevant reports and guidelines, websites and reference lists of retrieved articles were scanned to identify additional studies. All the searches were restricted to English language only. Participants Systematic reviews and any published evaluation of programmes where patient referral was made from a primary care setting to a link worker or facilitator of social prescribing were eligible for inclusion. Risk of bias for included studies was undertaken independently by two reviewers and a narrative synthesis was performed. Primary and secondary outcome measures Primary outcomes of interest were any measures of health and well-being and/or usage of health services. Results We included a total of 15 evaluations of social prescribing programmes. Most were small scale and limited by poor design and reporting. All were rated as a having a high risk of bias. Common design issues included a lack of comparative controls, short follow-up durations, a lack of standardised and validated measuring tools, missing data and a failure to consider potential confounding factors. Despite clear methodological shortcomings, most evaluations presented positive conclusions. Conclusions Social prescribing is being widely advocated and implemented but current evidence fails to provide sufficient detail to judge either success or value for money. If social prescribing is to realise its potential, future evaluations must be comparative by design and consider when, by whom, for whom, how well and at what cost. Trial registration number PROSPERO Registration: CRD42015023501.

Description: Objective To identify existing evidence on interagency collaboration between law enforcement, emergency services, statutory services and third sector agencies regarding people with mental ill health. Design Systematic scoping review. Scoping reviews map particular research areas to identify research gaps. Data sources and eligibility ASSIA, CENTRAL, the Cochrane Library databases, Criminal Justice Abstracts, ERIC, Embase, MEDLINE, PsycINFO, PROSPERO and Social Care Online and Social Sciences Citation Index were searched up to 2017, as were grey literature and hand searches. Eligible articles were empirical evaluations or descriptions of models of interagency collaboration between the police and other agencies. Study appraisal and synthesis Screening and data extraction were undertaken independently by two researchers. Arksey’s framework was used to collate and map included studies. Results One hundred and twenty-five studies were included. The majority of articles were of descriptions of models (28%), mixed methods evaluations of models (18%) and single service evaluations (14%). The most frequently reported outcomes (52%) were ‘organisational or service level outcomes’ (eg, arrest rates). Most articles (53%) focused on adults with mental ill health, whereas others focused on adult offenders with mental ill health (17.4%). Thirteen models of interagency collaboration were described, each involving between 2 and 13 agencies. Frequently reported models were ‘prearrest diversion’ of people with mental ill health (34%), ‘coresponse’ involving joint response by police officers paired with mental health professionals (28.6%) and ‘jail diversion’ following arrest (23.8%). Conclusions We identified 13 different interagency collaboration models catering for a range of mental health-related interactions. All but one of these models involved the police and mental health services or professionals. Several models have sufficient literature to warrant full systematic reviews of their effectiveness, whereas others need robust evaluation, by randomised controlled trial where appropriate. Future evaluations should focus on health-related outcomes and the impact on key stakeholders.

Description: Objective To identify and synthesise the evidence on the relationship between surgical volume and patient outcomes for adults and children with congenital heart disease. Design Evidence synthesis of interventional and observational studies. Data sources MEDLINE, EMBASE, CINAHL, Cochrane Library and Web of Science (2009–2014) and citation searching, reference lists and recommendations from stakeholders (2003–2014) were used to identify evidence. Study selection Quantitative observational and interventional studies with information on volume of surgical procedures and patient outcomes were included. Results 31 of the 34 papers identified (91.2%) included only paediatric patients. 25 (73.5%) investigated the relationship between volume and mortality, 7 (20.6%) mortality and other outcomes and 2 (5.9%) non-mortality outcomes only. 88.2% were from the US, 97% were multicentre studies and all were retrospective observational studies. 20 studies (58.8%) included all congenital heart disease conditions and 14 (41.2%) single conditions or procedures. No UK studies were identified. Most studies showed a relationship between volume and outcome but this relationship was not consistent. The relationship was stronger for single complex conditions or procedures. We found limited evidence about the impact of volume on non-mortality outcomes. A mixed picture emerged revealing a range of factors, in addition to volume, that influence outcome including condition severity, individual centre and surgeon effects and clinical advances over time. Conclusions The heterogeneity of findings from observational studies suggests that, while a relationship between volume and outcome exists, this is unlikely to be a simple, independent and directly causal relationship. The effect of volume on outcome relative to the effect of other, as yet undetermined, health system factors remains a complex and unresolved research question.