Risk prediction models for out-of-hospital cardiac arrest outcomes in England.

AIMS: The out-of-hospital cardiac arrest (OHCA) outcomes project is a national research registry. One of its aims is to explore sources of variation in OHCA survival outcomes. This study reports the development and validation of risk prediction models for return of spontaneous circulation (ROSC) at hospital handover and survival to hospital discharge. METHODS AND RESULTS: The study included OHCA patients who were treated during 2014 and 2015 by emergency medical services (EMS) from seven English National Health Service ambulance services. The 2014 data were used to identify important variables and to develop the risk prediction models, which were validated using the 2015 data. Model prediction was measured by area under the curve (AUC), Hosmer-Lemeshow test, Cox calibration regression, and Brier score. All analyses were conducted using mixed-effects logistic regression models. Important factors included age, gender, witness/bystander cardiopulmonary resuscitation (CPR) combined, aetiology, and initial rhythm. Interaction effects between witness/bystander CPR with gender, aetiology and initial rhythm and between aetiology and initial rhythm were significant in both models. The survival model achieved better discrimination and overall accuracy compared with the ROSC model (AUC = 0.86 vs. 0.67, Brier score = 0.072 vs. 0.194, respectively). Calibration tests showed over- and under-estimation for the ROSC and survival models, respectively. A sensitivity analysis individually assessing Index of Multiple Deprivation scores and location in the final models substantially improved overall accuracy with inconsistent impact on discrimination. CONCLUSION: Our risk prediction models identified and quantified important pre-EMS intervention factors determining survival outcomes in England. The survival model had excellent discrimination.

Can syndromic surveillance help forecast winter hospital bed pressures in England?

BACKGROUND: Health care planners need to predict demand for hospital beds to avoid deterioration in health care. Seasonal demand can be affected by respiratory illnesses which in England are monitored using syndromic surveillance systems. Therefore, we investigated the relationship between syndromic data and daily emergency hospital admissions. METHODS: We compared the timing of peaks in syndromic respiratory indicators and emergency hospital admissions, between 2013 and 2018. Furthermore, we created forecasts for daily admissions and investigated their accuracy when real-time syndromic data were included. RESULTS: We found that syndromic indicators were sensitive to changes in the timing of peaks in seasonal disease, especially influenza. However, each year, peak demand for hospital beds occurred on either 29th or 30th December, irrespective of the timing of syndromic peaks. Most forecast models using syndromic indicators explained over 70% of the seasonal variation in admissions (adjusted R square value). Forecast errors were reduced when syndromic data were included. For example, peak admissions for December 2014 and 2017 were underestimated when syndromic data were not used in models. CONCLUSION: Due to the lack of variability in the timing of the highest seasonal peak in hospital admissions, syndromic surveillance data do not provide additional early warning of timing. However, during atypical seasons syndromic data did improve the accuracy of forecast intensity.

Characteristics of neighbourhoods with high incidence of out-of-hospital cardiac arrest and low bystander cardiopulmonary resuscitation rates in England.

Aims: The aim of the project was to identify the neighbourhood characteristics of areas in England where out-of-hospital cardiac arrest (OHCA) incidence was high and bystander cardiopulmonary resuscitation (BCPR) was low using registry data. Methods and results: Analysis was based on 67 219 cardiac arrest events between 1 April 2013 and 31 December 2015. Arrest locations were geocoded to give latitude/longitude. Postcode district was chosen as the proxy for neighbourhood. High-risk neighbourhoods, where OHCA incidence based on residential population was >127.6/100 000, or based on workday population was >130/100 000, and BCPR in bystander witnessed arrest was <60% were observed to have: a greater mean residential population density, a lower workday population density, a lower rural-urban index, a higher proportion of people in routine occupations and lower proportion in managerial occupations, a greater proportion of population from ethnic minorities, a greater proportion of people not born in UK, and greater level of deprivation. High-risk areas were observed in the North-East, Yorkshire, South-East, and Birmingham. Conclusion: The study identified neighbourhood characteristics of high-risk areas that experience a high incidence of OHCA and low bystander resuscitation rate that could be targeted for programmes of training in cardiopulmonary resuscitation and automated external defibrillator use.

Recurrent seasonal outbreak of an emerging serotype of Shiga toxin-producing Escherichia coli (STEC O55:H7 Stx2a) in the south west of England, July 2014 to September 2015.

The first documented British outbreak of Shiga toxin-producing Escherichia coli (STEC) O55:H7 began in the county of Dorset, England, in July 2014. Since then, there have been a total of 31 cases of which 13 presented with haemolytic uraemic syndrome (HUS). The outbreak strain had Shiga toxin (Stx) subtype 2a associated with an elevated risk of HUS. This strain had not previously been isolated from humans or animals in England. The only epidemiological link was living in or having close links to two areas in Dorset. Extensive investigations included testing of animals and household pets. Control measures included extended screening, iterative interviewing and exclusion of cases and high risk contacts. Whole genome sequencing (WGS) confirmed that all the cases were infected with similar strains. A specific source could not be identified. The combination of epidemiological investigation and WGS indicated, however, that this outbreak was possibly caused by recurrent introductions from a local endemic zoonotic source, that a highly similar endemic reservoir appears to exist in the Republic of Ireland but has not been identified elsewhere, and that a subset of cases was associated with human-to-human transmission in a nursery.

Epidemiology and outcomes from out-of-hospital cardiac arrests in England.

INTRODUCTION: This study reports the epidemiology and outcomes from out-of-hospital cardiac arrest (OHCA) in England during 2014. METHODS: Prospective observational study from the national OHCA registry. The incidence, demographic and outcomes of patients who were treated for an OHCA between 1st January 2014 and 31st December 2014 in 10 English ambulance service (EMS) regions, serving a population of almost 54 million, are reported in accordance with Utstein recommendations. RESULTS: 28,729 OHCA cases of EMS treated cardiac arrests were reported (53 per 100,000 of resident population). The mean age was 68.6 (SD=19.6) years and 41.3% were female. Most (83%) occurred in a place of residence, 52.7% were witnessed by either the EMS or a bystander. In non-EMS witnessed cases, 55.2% received bystander CPR whilst public access defibrillation was used rarely (2.3%). Cardiac aetiology was the leading cause of cardiac arrest (60.9%). The initial rhythm was asystole in 42.4% of all cases and was shockable (VF or pVT) in 20.6%. Return of spontaneous circulation at hospital transfer was evident in 25.8% (n=6302) and survival to hospital discharge was 7.9%. CONCLUSION: Cardiac arrest is an important cause of death in England. With less than one in ten patients surviving, there is scope to improve outcomes. Survival rates were highest amongst those who received bystander CPR and public access defibrillation.

High-frequency ventilation versus conventional ventilation for the treatment of acute lung injury and acute respiratory distress syndrome: a systematic review and cochrane analysis.

In this review, we examine outcomes from using high-frequency ventilation compared with conventional ventilation as therapy for acute lung injury and acute respiratory distress syndrome in children and adults. We conducted a systematic search of the literature based on the guidelines of the Cochrane Collaboration. Two trials met the inclusion criteria; one recruited children (n = 58), and the other recruited adults (n = 148). Both trials used a high-frequency oscillatory ventilator as the intervention and included variable use of lung-volume recruitment strategies. The intervention groups showed a trend toward less 30-day mortality (children: relative risk [RR], 0.83; 95% confidence interval [CI], 0.43-1.62; adults: RR, 0.72; 95% CI, 0.50-1.03), although neither study showed a statistically significant difference. Similarly, there was no statistically significant difference between the intervention and control groups for "total length of ventilator days." There was a statistically significant reduction in the risk of requiring supplemental oxygen among survivors at 30 days in the pediatric study (RR, 0.36; 95% CI, 0.14-0.93). Overall there is not enough evidence to conclude that high-frequency ventilation reduces mortality or long-term morbidity in patients with acute lung injury or acute respiratory distress syndrome. (This review is published as a Cochrane Review in The Cochrane Library 2004, Issue 3. Cochrane Reviews are regularly updated as new evidence emerges and in response to comments and criticisms, and The Cochrane Library should be consulted for the most recent version of the Review.).

Visibility aids for pedestrians and cyclists: a systematic review of randomised controlled trials.

This study aims to quantify the effect of visibility aids on the occurrence of pedestrian and cyclist-motor vehicle collisions and injuries, and drivers' responses in detection and recognition. Trial reports were systematically reviewed according to predefined eligibility criteria, including randomised controlled trials or controlled before-and-after trials comparing visibility aids and no visibility aids, and of different visibility aids on pedestrian and cyclist safety, and drivers' responses in detection and recognition. This included trials in which the order of interventions was randomised, or balanced using a Latin square design. Two reviewers independently assessed validity of trials and abstracted data. The main outcome measures were pedestrian and cyclist-motor vehicle collisions and injuries, and drivers'/observers' responses in the detection and recognition time, distance and frequency. No trials which assessed the effect of visibility aids on pedestrian and cyclist-motor vehicle collisions and injuries were identified. Twelve trials examined the effectiveness of daytime visibility aids and 25 trials on night time visibility aids, including 882 participants. Drivers' and observers' detection and recognition improved with visibility aids. For daytime, fluorescent materials in yellow, red and orange colours enhanced detection and recognition. "Biomotion" markings enhanced recognition. Substantial heterogeneity between the trials limits the possibility for meta-analysis. Visibility aids have the potential to improve detection and recognition and would merit further development to gain public acceptance. However, the impact of visibility aids on pedestrian and cyclist safety is unknown and needs to be determined.

Hospital mortality associated with day and time of admission to intensive care units.

OBJECTIVE: To investigate whether hospital mortality of patients was associated with the day of the week or time of admission to intensive care units (ICUs). DESIGN: Cohort study. SETTING: One hundred two adult, general (mixed medical/surgical) ICUs in England, Wales and Northern Ireland. PATIENTS AND PARTICIPANTS: A total of 56,250 admissions from 1995 to 2000 that fit the inclusion criteria for calculation of the APACHE II probability of hospital mortality. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Crude and case mix adjusted hospital mortality were examined by day of the week and time of day of admission to ICU. Patients admitted on Saturday and Sunday had higher crude hospital mortality compared with admissions on Wednesday [Saturday crude odds ratio (OR) 1.41, 95% CI 1.32-1.52; Sunday OR 1.56, 1.45-1.68]. The association was still significant after adjustment using the UK APACHE II model (Saturday OR 1.16, 1.1.07-1.26; Sunday OR 1.24, 1.14-1.35) but not after adjustment using individual components of the APACHE II model (Saturday OR 1.03, 0.95-1.12; Sunday OR 1.09, 1.00-1.19). Night admissions were also associated with higher mortality compared with day both before and after adjustment for case mix using the UK APACHE II model (crude OR 1.43, 1.37-1.51; adjusted OR 1.16, 1.10-1.23) but not after adjustment using components of the APACHE II model (OR 1.02, 95% CI 0.96-1.09). CONCLUSIONS: After appropriate adjustment for case mix, day of the week and time of day of admission of patients to ICU were not associated with significant differences in hospital mortality.

Fluid resuscitation strategies: a systematic review of animal trials.

OBJECTIVES: Our objective was to systematically review randomized, controlled trials of fluid resuscitation in animal models of uncontrolled hemorrhage and to explore potential sources of heterogeneity. METHODS: We conducted an electronic bibliographic search of published research, reviewed reference lists of included trials, and contacted authors about unpublished studies. We included all unconfounded, randomized, controlled trials of fluid resuscitation (timing, volume, or resuscitation targets) in animal models of uncontrolled hemorrhage. The outcome measure was mortality at the end of the scheduled follow-up period of the trial. Two reviewers independently applied the selection criteria to the trial reports. A third reviewer resolved disagreements. RESULTS: Forty-four trials compared fluid versus no fluid resuscitation. There was marked heterogeneity in the effect of fluid resuscitation on the risk of death, much of which was explained by the hemorrhage model used. In aortic injury models, the adjusted relative risk of death with fluid resuscitation was 0.48 (95% confidence interval [CI], 0.33-0.71). In organ incision models, the adjusted relative risk of death was 0.76 (95% CI, 0.49-1.18). In tail resection models, the adjusted relative risk of death was 0.69 (95% CI, 0.38-1.25) if 50% or more was removed and 1.86 (95% CI, 1.13-3.07) if less than 50% was removed. In other vascular injury models, the adjusted relative risk of death with fluid resuscitation was 1.70 (95% CI, 1.01-2.85), respectively. Nine trials compared hypotensive versus normotensive resuscitation. The relative risk of death with hypotensive resuscitation was 0.37 (95% CI, 0.27-0.50). CONCLUSION: Fluid resuscitation appears to reduce the risk of death in animal models of severe hemorrhage but increases the risk of death in those with less severe hemorrhage. Excessive fluid resuscitation could therefore be harmful in some situations. Hypotensive resuscitation reduced the risk of death in all the trials investigating it. An evaluation of the potential impact of hypotensive resuscitation in humans could now be warranted.

Developmental regulation of hepatic and renal gluconeogenic enzymes by thyroid hormones in fetal sheep during late gestation.

Tissue glucose-6-phosphatase (G6P) and phosphoenolpyruvate carboxykinase (PEPCK) activities were investigated in sheep fetuses after experimental manipulation of thyroid hormone status. Increments in hepatic and renal G6P and PEPCK activities seen between 127-130 and 140-145 days of gestation (term, 145 +/- 2 days) were abolished when the normal prepartum rise in plasma triiodothyronine (T3), but not cortisol, was prevented by fetal thyroidectomy (TX). At 127-130 days, hepatic and renal G6P, and renal PEPCK, activities were similar in intact and TX fetuses; however, hepatic PEPCK was increased by TX. At 140-145 days, tissue G6P and PEPCK activities in TX fetuses were lower than in intact fetuses. In immature fetuses infused with cortisol (2-3 mg (kg body wt)-1 day-1) for five days, hepatic and renal enzyme activities were increased to those seen in mature fetuses near term. After five days of T3 infusion (8-12 microg (kg body wt)-1 day-1), G6P and PEPCK activities in the liver and kidney were greater than in saline-infused fetuses, but only renal G6P and PEPCK increased to the level seen close to term. Therefore, in fetal sheep, thyroid hormones are important for the prepartum rises in G6P and PEPCK activities in the liver and kidney and may mediate, in part, the maturational effects of cortisol.