Charlotte Warren-Gash

Influenza as a trigger for acute myocardial infarction or death from cardiovascular disease: a systematic review

Cardiac complications of influenza infection, such as myocarditis, are well recognised, but the role of influenza as a trigger of acute myocardial infarction is less clear. We did a systematic review of the evidence that influenza (including influenza-like illness and acute respiratory infection) triggers acute myocardial infarction or cardiovascular death. We examined the effectiveness of influenza vaccines at protecting against cardiac events and did a meta-analysis of data from randomised controlled trials. 42 publications describing 39 studies were identified. Many observational studies in different settings with a range of methods reported consistent associations between influenza and acute myocardial infarction. There was weaker evidence of an association with cardiovascular death. Two small randomised trials assessed the protection provided by influenza vaccine against cardiac events in people with existing cardiovascular disease. Whereas one trial found that influenza vaccination gave significant protection against cardiovascular death, the other trial was inconclusive. A pooled estimate from a random-effects model suggests a protective, though non-significant, effect (relative risk 0.51, 95% CI 0.15-1.76). We believe influenza vaccination should be encouraged wherever indicated, especially in people with existing cardiovascular disease, among whom there is often suboptimum vaccine uptake. Further evidence is needed on the effectiveness of influenza vaccines to reduce the risk of cardiac events in people without established vascular disease.

Influenza Infection and Risk of Acute Myocardial Infarction in England and Wales: A CALIBER Self-Controlled Case Series Study

Background. An association between infections and vascular events has been observed, but the specific effect of influenza and influenza-like illnesses on triggering acute myocardial infarction (AMI) is unclear. Methods. Episodes of first AMI from 1 January 2003 through 31 July 2009 were identified using linked anonymized electronic medical records from the Myocardial Ischaemia National Audit Project and the General Practice Research Database. Self-controlled case series analysis was used to investigate AMI risks after consultation for acute respiratory infection. Infections were stratified by influenza virus circulation, diagnostic code, and vaccination status to assess whether influenza was more likely than other infections to trigger AMI. Results. Of 22 024 patients with acute coronary syndrome, 11 208 met the criterion of having had their first AMI at the age of ≥40 years, and 3927 had also consulted for acute respiratory infection. AMI risks were significantly raised during days 1–3 after acute respiratory infection (incidence ratio, 4.19 [95% confidence interval, 3.18–5.53], with the effect tapering over time. The effect was greatest in those aged ≥80 years (P = .023). Infections occurring when influenza was circulating and those coded as influenza-like illness were associated with consistently higher incidence ratios for AMI (P = .012). Conclusions. Influenza and other acute respiratory infections can act as a trigger for AMI. This effect may be stronger for influenza than for other infections. Clinical trials registration. NCT01106196.

Circulating Influenza Virus, Climatic Factors, and Acute Myocardial Infarction: A Time Series Study in England and Wales and Hong Kong

BACKGROUND Previous studies identifying associations between influenza and acute cardiac events may have been confounded by climatic factors. Differing seasonal patterns of influenza activity in Hong Kong and England and Wales provide a natural experiment to examine associations with myocardial infarction (MI) independent of cold weather effects. METHODS Weekly clinical and laboratory influenza surveillance data, environmental temperature and humidity data, and counts of MI-associated hospitalizations and deaths were obtained for England and Wales and for Hong Kong for the period 1998-2008. We used Poisson regression models that included environmental and seasonal variables to investigate the relationship between influenza and MI. RESULTS There were ≥1.2 million MI-associated hospitalizations and 410,204 MI-associated deaths in England and Wales, with a marked peak in the winter season. In Hong Kong, the incidence of MI, on the basis of 65,108 hospitalizations and 18,780 deaths, had a large winter and smaller summer peak, mirroring patterns of influenza activity. There was strong evidence for a link between influenza and MI both in England and Wales, where 3.1%-3.4% of MI-associated deaths (P < .001) and 0.7%-1.2% of MI-associated hospitalizations (P < .001) were attributable to influenza, and in Hong Kong, where the corresponding figures were 3.9%-5.6% (P = .018) and 3.0%-3.3% (P = .002). CONCLUSIONS Influenza was associated with an increase in MI-associated deaths and hospitalizations in 2 contrasting settings.

Medical and legal confusion surrounding gamma-hydroxybutyrate (GHB) and its precursors gamma-butyrolactone (GBL) and 1,4-butanediol (1,4BD)

BACKGROUND Gamma-hydroxybutyrate (GHB) is used as a recreational drug, with significant associated morbidity and mortality; it is therefore a class C drug under the Misuse of Drugs Act (1971). However, its precursors gamma-butyrolactone (GBL) and 1,4-butanediol (1,4BD) remain legally available despite having similar clinical effects. AIM The aim of this study was to determine whether the relative proportions of self-reported ingestions of GHB or its precursors GBL and 1,4BD were similar to those seen in analysis of seized drugs. DESIGN AND METHODS Retrospective review of our clinical toxicology database to identify all cases of self-reported recreational GHB, GBL and 1,4BD use associated with ED presentation in 2006. Additionally all seized substances on people attending local club venues were analysed by a Home Office approved laboratory to identify any illicit substances present. RESULTS In 2006, there were a total of 158 ED presentations, of which 150 (94.9%) and 8 (5.1%) were GHB and GBL self-reported ingestions respectively; 96.8% (153) were recreational use. Of the 418 samples seized, 225 (53.8%) were in liquid form; 85 (37.8%) contained GHB and 140 (62.2%) contained GBL. None of the seized samples contained 1,4BD and there were no self-reported 1,4BD ingestions. CONCLUSION Self-reported GHB ingestion was much more common than GBL ingestion, whereas GBL was more commonly found in the seized samples. These differences suggest that GBL use may be more common than previously thought and we suggest that there should be further debate about the legal status of the precursors of GHB.

Hand hygiene to reduce community transmission of influenza and acute respiratory tract infection: a systematic review

Please cite this paper as: Warren‐Gash et al. (2012) Hand hygiene to reduce community transmission of influenza and acute respiratory tract infection: a systematic review. Influenza and Other Respiratory Viruses DOI: 10.1111/irv.12015.

Is there anything distinctive about epileptic déjà vu

Background Déjà vu can occur as an aura of temporal lobe epilepsy and in some psychiatric conditions but is also common in the general population. It is unclear whether any clinical features distinguish pathological and physiological forms of déjà vu. Methods 50 epileptic patients with ictal déjà vu, 50 non-epileptic patients attending general neurology clinics and 50 medical students at Edinburgh University were recruited. Data were collected on demographic factors, the experience of déjà vu using a questionnaire based on Snos Inventory for Déjà Vu Experiences Assessment, symptoms of anxiety and depression using the Hospital Anxiety and Depression Scale as well as seizure characteristics, anti-epileptic medications, handedness, EEG and neuroimaging findings for epileptic patients. Results 73.5% of neurology patients, 88% of students and (by definition) all epilepsy patients had experienced déjà vu. The experience of déjà vu itself was similar in the three groups. Epileptic déjà vu occurred more frequently and lasted somewhat longer than physiological déjà vu. Epilepsy patients were more likely to report prior fatigue and concentrated activity, associated derealisation, olfactory and gustatory hallucinations, physical symptoms such as headaches, abdominal sensations and fear. After controlling for study group, anxiety and depression scores were not associated with déjà vu frequency. Conclusions Déjà vu is common and qualitatively similar whether it occurs as an epileptic aura or normal phenomenon. However ictal déjà vu occurs more frequently and is accompanied by several distinctive features. It is distinguished primarily by ‘the company it keeps’.

Improvement in the management of acutely poisoned patients using an electronic database, prospective audit and targeted educational intervention

Problem: The need to improve the clinical assessment and management of acutely poisoned patients presenting to an NHS hospital emergency department (ED). Design: Creation of an electronic clinical toxicology database to prospectively collect all aspects of clinical information on poisoned-patient presentations. Systematic analysis of collated information to identify shortfalls in patient assessment and management. Bimonthly audit meetings, and design and implementation of educational interventions to address identified shortfalls. Ongoing audit to demonstrate continued improvement in patient care. Background and setting: ED in tertiary-level inner-city London teaching hospital. Study conducted by staff from the ED and clinical toxicology service. Key measures for improvement: Demonstration of overall reduction in the incidence of predefined shortfalls in patient assessment and management during 12-month study period. Strategies for improvement: Targeted educational lectures and case-based clinical scenarios addressing identified deficiencies in the knowledge required to effectively manage poisoned patients. Weekly case-based anonymised feedback report sent electronically to staff involved in caring for poisoned patients. Effects of change: Implementation of targeted teaching of ED staff and regular electronic distribution of teaching cases. Between the first and second 6 months of the study, there was a significant increase in the proportion of presentations for which clinical management was graded as “good” (77.6% to 89.4%, p<0.0001) and a significant reduction in the proportion of “major” (9.9% to 5.8%, p = 0.012) and “minor” (12.6% to 4.8%, p<0.0001) shortfalls. Lessons learnt: Systematic collection of clinical information, using a dedicated electronic database and subsequent review and audit of collated data by interested clinicians, enabled design and implementation of targeted educational interventions to address shortfalls in patient management. This process has led to significant improvements in the clinical care of acutely poisoned patients presenting to the ED.

Outcomes of domestic violence screening at an acute London trust: are there missed opportunities for intervention?

Objectives Domestic violence screening is advocated in some healthcare settings. Evidence that it increases referral to support agencies or improves health outcomes is limited. This study aimed to (1) investigate the proportion of hospital patients reporting domestic violence, (2) describe characteristics and previous hospital attendances of affected patients and (3) assess referrals to an in-house domestic violence advisor from Camden Safety Net. Design A series of observational studies. Setting Three outpatient clinics at the Royal Free London NHS Foundation Trust. Participants 10 158 patients screened for domestic violence in community gynaecology, genitourinary medicine (GUM) and HIV medicine clinics between 1 October 2013 and 30 June 2014. Also 2253 Camden Safety Net referrals over the same period. Main outcome measures (1) Percentage reporting domestic violence by age group gender, ethnicity and clinic. (2) Rates of hospital attendances in the past 3 years for those screening positive and negative. (3) Characteristics, uptake and risk assessment results for hospital in-house domestic violence referrals compared with Camden Safety Net referrals from other sources. Results Of the 10 158 patients screened, 57.4% were female with a median age of 30 years. Overall, 7.1% reported ever-experiencing domestic violence, ranging from 5.7% in GUM to 29.4% in HIV services. People screening positive for domestic violence had higher rates of previous emergency department attendances (rate ratio (RR) 1.63, 95% CI 1.09 to 2.48), emergency inpatient admissions (RR 2.27, 95% CI 1.37 to 3.84) and day-case admissions (RR 2.03, 95% CI 1.23 to 3.43) than those screening negative. The 77 hospital referrals to the hospital-based domestic violence advisor during the study period were more likely to be taken up and to be classified as high risk than referrals from elsewhere. Conclusions Selective screening for domestic violence in high-risk hospital clinic populations has the potential to identify affected patients and promote good uptake of referrals for in-house domestic violence support.

Determining the volume of toxic liquid ingestions in adults: accuracy of estimates by healthcare professionals and members of the public.

Abstract Context. Ingestion of toxic liquids is common, and the volume ingested is often important for clinical decision-making. However, the accuracy and interpretation of volume estimates in the context of toxicological exposures is poorly characterised in adult practice. Objective. To inform the interpretation of volume estimates when expressed in forms commonly encountered in toxicological practice: (1) semi-quantitative volume descriptors, such as ‘mouthfuls’; (2) quantitative self-estimates of ingestion volume, for example, millilitres; and (3) estimates of residual volume in containers. Methods. In the first part of the study, 50 members of the public ingested water in response to requests to take a ‘small mouthful’, ‘large gulp’ and ‘five mouthfuls’. They estimated the amount ingested, and actual volumes were measured. In part 2, 15 members of the public and 15 healthcare professionals estimated the volumes contained in 12 opaque and transparent bottles. Results. The mean age of participants in part 1 was 37 years, and in part 2 it was 34 years. The mean volume (95% prediction interval) of a ‘small mouthful’ was 43 (3–137) mL; ‘large gulp’, 77 (20–168) mL; and ‘five mouthfuls’, 157 (25–375) mL. The mean error (95% limits of agreement) for self-estimates of ingestion volume was an underestimate of − 52% (− 90% to + 124%). Volume contained in bottles was underestimated by − 5% (− 38% to + 27%). This varied according to the container type (mean difference: opaque, − 10%; transparent, − 1%; P < 0.01) and participant type (members of the public, − 8%; healthcare professionals, − 3%; P = 0.02). Conclusions. Volume estimates derived from semi-quantitative descriptors are not a reliable basis for clinical decision-making. Self-estimates provided in a quantitative form are inaccurate and prone to underestimation. Estimates of residual volume in containers should be regarded as suspect if the container is opaque. Where clinical decisions hinge on the volume ingested, efforts should be made to quantify this using measurement.

Cohort Profile: The Flu Watch Study

Influenza is a common, highly contagious respiratory virus which infects all age groups, causing a range of outcomes from asymptomatic infection and mild respiratory disease to severe respiratory disease and death.1 If infected, the adaptive immune system produces a humoral (antibody) and cell-mediated (T cell) immune response to fight the infection.2 Influenza viruses continually evolve through antigenic drift, resulting in slightly different ‘seasonal’ influenza strains circulating each year. Population-level antibody immunity to these seasonal viruses builds up over time, so in any given season only a proportion of the population is susceptible to the circulating strains. Occasionally, influenza A viruses evolve rapidly through antigenic shift by swapping genes with influenza viruses usually circulating in animals. This process creates an immunologically distinct virus to which the population may have little to no antibody immunity. The virus can result in a pandemic if a large portion of the population is susceptible and the virus is easily spread.