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Background: Drones are able to deliver automated external defibrillators in cases of out-of-hospital cardiac arrest (OHCA) but can be deployed for other purposes. Our aim was to evaluate the feasibility of sending live photos to dispatch centres before arrival of other units during time-critical incidents., Methods: In this retrospective observational study, the regional dispatch centre implemented a new service using five existing AED-drone systems covering an estimated 200000 inhabitants in Sweden. Drones were deployed automatically over a 4-month study period (December 2022-April 2023) in emergency calls involving suspected OHCAs, traffic accidents and fires in buildings. Upon arrival at the scene, an overhead photo was taken and transmitted to the dispatch centre. Feasibility of providing photos in real time, and time delays intervals were examined., Results: Overall, drones were deployed in 59/440 (13%) of all emergency calls: 26/59 (44%) of suspected OHCAs, 20/59 (34%) of traffic accidents, and 13/59 (22%) of fires in buildings. The main reasons for non-deployment were closed airspace and unfavourable weather conditions (68%). Drones arrived safely at the exact location in 58/59 cases (98%). Their overall median response time was 3:49 min, (IQR 3:18-4:26) vs. emergency medical services (EMS), 05:51 (IQR: 04:29-08:04) p-value for time difference between drone and EMS = 0,05. Drones arrived first on scene in 47/52 cases (90%) and the largest median time difference was found in suspected OHCAs 4:10 min, (IQR: 02:57-05:28). The time difference in the 5/52 (10%) cases when EMS arrived first the time difference was 5:18 min (IQR 2:19-7:38), p = NA. Photos were transmitted correctly in all 59 alerts. No adverse events occurred., Conclusion: In a newly implemented drone dispatch service, drones were dispatched to 13% of relevant EMS calls. When drones were dispatched, they arrived at scene earlier than EMS services in 90% of cases. Drones were able to relay photos to the dispatch centre in all cases. Although severely affected by closed airspace and weather conditions, this novel method may facilitate additional decision-making information during time-critical incidents., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Volunteer responder dispatch to nearby out-of-hospital cardiac arrests using a smartphone application can increase the proportion of patients receiving cardiopulmonary resuscitation. It is unknown how population density is related to the efficacy of a volunteer responder system. This study aimed to compare the response time of volunteer responders and EMS dispatched to suspected OHCAs in areas of different population density., Methods: A total of 2630 suspected OHCAs in Stockholm County during 2018-2020 where at least one dispatched volunteer responder reached the patient were identified through the HeartRunner™ application database. Study outcome was the proportion of cases where volunteer responders arrived at the scene before EMS, as well as the difference in time between the arrival of volunteer responders and EMS., Results: Volunteer responders arrived before EMS in 68% of examined cases (n = 1613). Higher population density was associated with a lower proportion of cases where volunteer responders arrived at the scene before EMS. Time on scene before arrival of EMS was highest in areas of low population density and averaged 4:07 (mm:ss). Response time was significantly shorter for volunteer responders compared to EMS across all population density groups at 4:47 vs 8:11 (mm:ss) (p < 0.001); the largest difference in response time was found in low population density areas., Conclusion: Volunteer responders have significantly shorter response time than EMS regardless of population density, with the greatest difference in low population density areas. Although their impact on clinical outcome remains unknown, the benefits of dispatching volunteer responders to OHCAs may be greatest in rural areas., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Oscar Lapidus, Martin Jonsson, Ellinor Berglund, Gabriel Riva, Sune Forsberg and Anette Nord declare no competing interests. Leif Svensson, Jacob Hollenberg, Andreas Claesson, Per Nordberg, Mårten Rosenqvist and Mattias Ringh are all indirect shareholders in Heartrunner Sweden AB., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Aim: To investigate the ability of Swedish Emergency Medical Dispatch Centres (EMDCs) to answer medical emergency calls and dispatch an ambulance for out-of-hospital cardiac arrest (OHCA) in accordance with the American Heart Association (AHA) performance goals in a 1-step (call connected directly to the EMDC) and a 2-step (call transferred to regional EMDC) procedure over 10 years, and to assess whether delays may be associated with 30-day survival., Method: Observational data from the Swedish Registry for Cardiopulmonary Resuscitation and EMDC., Results: A total of 9,174,940 medical calls were answered (1-step). The median answer delay was 7.3 s (interquartile range [IQR], 3.6-14.5 s). Furthermore, 594,008 calls (6.1%) were transferred in a 2-step procedure, with a median answer delay of 39 s (IQR, 30-53 s). A total of 45,367 cases (0.5%, 1-step) were registered as OHCA, with a median answer delay of 7.2 s (IQR, 3.6-14.1 s) (AHA high-performance goal, 10 s). For 1-step procedure, no difference in 30-day survival was found regarding answer delay. For OHCA (1-step), an ambulance was dispatched after a median of 111.9 s (IQR, 81.7-159.9 s). Thirty-day survival was 10.8% (n = 664) when an ambulance was dispatched within 70 s (AHA high-performance) versus 9.3% (n = 2174) > 100 s (AHA acceptable) (p = 0.0013). Outcome data in the 2-step procedure was unobtainable., Conclusion: The majority of calls were answered within the AHA performance goals. When an ambulance was dispatched within the AHA high-performance standard in response to OHCA calls, survival was higher compared with calls when dispatch was delayed., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: F. Byrsell is an employee at SOS Alarm AB. None of the other authors have any conflicts of interest to declare., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: Systems for smartphone dispatch of lay responders to perform cardio-pulmonary resuscitation (CPR) and bring automated external defibrillators to out-of-hospital cardiac arrests (OHCAs) are advocated by recent international guidelines and emerging worldwide., Objectives: This study aimed to investigate the emotional responses, posttraumatic stress reactions and levels of wellbeing among smartphone-alerted lay responders dispatched to suspected OHCAs., Methods: Lay responders were stratified by level of exposure: unexposed (Exp-0), tried to reach (Exp-1), and reached the suspected OHCA (Exp-2). Participants rated their emotional responses online, at 90 minutes and at 4-6 weeks after an incident. Level of emotional response was measured in two dimensions of core affect: "alertness" - from deactivation to activation, and "pleasantness" - from unpleasant to pleasant. At 4-6 weeks, WHO wellbeing index and level of posttraumatic stress (PTSD) were also rated., Results: Altogether, 915 (28%) unexposed and 1471 (64%) exposed responders completed the survey. Alertness was elevated in the exposed groups: Exp-0: 6.7 vs. Exp-1: 7.3 and Exp-2: 7.5, (p < 0.001) and pleasantness was highest in the unexposed group: 6.5, vs. Exp-1: 6.3, and Exp-2: 6.1, (p < 0.001). Mean scores for PTSD at follow-up was below clinical cut-off, Exp-0: 9.9, Exp-1: 8.9 and Exp-2: 8.8 (p = 0.065). Wellbeing index showed no differences, Exp-0: 78.0, Exp-1: 78.5 and Exp-2: 79.9 (p = 0.596)., Conclusion: Smartphone dispatched lay responders rated the experience as high-energy and mainly positive. No harm to the lay responders was seen. The exposed groups had low posttraumatic stress scores and high-level general wellbeing at follow-up., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Early defibrillation is essential for increasing the chance of survival in out-of-hospital-cardiac-arrest (OHCA). Automated external defibrillator (AED)-equipped drones have a substantial potential to shorten times to defibrillation in OHCA patients. However, optimal locations for drone deployment are unknown. Our aims were to find areas of high incidence of OHCA on a national level for placement of AED-drones, and to quantify the number of drones needed to reach 50, 80, 90 and 100% of the target population within eight minutes., Methods: This is a retrospective observational study of OHCAs reported to the Swedish Registry for Cardiopulmonary Resuscitation between 2010-2018. Spatial analyses of optimal drone placement were performed using geographical information system (GIS)-analyses covering high-incidence areas (>100 OHCAs in 2010-2018) and response times., Results: 39,246 OHCAs were included. To reach all OHCAs in high-incidence areas with AEDs delivered by drone or ambulance within eight minutes, 61 drone systems would be needed, resulting in overall OHCA coverage of 58.2%, and median timesaving of 05:01 (min:sec) [IQR 03:22-06:19]. To reach 50% of the historically reported OHCAs in <8 min, 21 drone systems would be needed; for 80%, 366; for 90%, 784, and for 100%, 2408., Conclusions: At a national level, GIS-analyses can identify high incidence areas of OHCA and serve as tools to quantify the need of AED-equipped drones. Use of only a small number of drone systems can increase national coverage of OHCA substantially. Prospective real-life studies are needed to evaluate theoretically optimized suggestions for drone placement., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Therapeutic cooling initiated during cardiopulmonary resuscitation (intra arrest therapeutic hypothermia, IATH) provided diverging effect on neurological outcome of out-of-hospital cardiac arrest (OHCA) patients depending on the initial cardiac rhythm and the cooling methods used., Methods: We performed a systematic search of PubMed, EMBASE and the CENTRAL databases using established Medical Subject Headings (MeSH) terms for IATH and OHCA. Only studies comparing IATH to standard in-hospital targeted temperature management (TTM) were selected. We used the revised Cochrane RoB-2 and the Newcastle-Ottawa scale tool to assess risk of bias of each study. Primary outcome was favorable neurological outcome (FO); secondary outcomes included return of spontaneous circulation (ROSC) rate and survival to hospital discharge., Results: Out of 20,950 studies, 8 studies (n = 3493 patients, including 4 randomized trials, RCTs) were included in the final analysis. Compared to controls, the use of IATH was not associated with improved FO (OR 0.96 [95% CIs 0.68-1.37]; p = 0.84), increased ROSC rate (OR 1.11 [95% CIs 0.83-1.49]; p = 0.46) or survival (OR 0.91 [95% CIs 0.73-1.14]; p = 0.43). Significant heterogeneity among studies was observed for the analysis of ROSC rate (I 2  = 69%). Trans-nasal evaporative cooling and cold fluids were explored in two RCTs each and no differences were observed on FO, event when only patients with an initial shockable rhythm were analyzed (OR 1.62 [95% CI 1.00-2.64]; p = 0.05]., Conclusions: In this meta-analysis, IATH was not associated with improved neurological outcome when compared to standard in-hospital TTM, based on very low certainty of evidence., Clinical Trial Registration: PROSPERO (CRD42019130322)., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Aim: Drowning is a global health problem and deeper knowledge about the extent and causes is of utmost importance for implementing preventative actions. The aim of this study was to describe the incidence and characteristics of drowning in Sweden over time, including both non-fatal and fatal cases., Methods: All cases identified as drowning (ICD-10 coding) at a national level in Sweden between 2003-2017 were collected. Three sources of data from the Swedish National Board of Health and Welfare were extracted via the Cause of Death Register and the National Patient Register., Results: Over 15 years, a total of 6609 cases occurred, resulting in an annual incidence of 4.66 per 100 000. The median age was 49 years (IQR 23-67) and 67% were males. Non-fatal drownings represented 51% (n = 3363), with an overall non-fatal to fatal ratio of 1:1, this being 8:1 for children (0-17 years of age). Non-fatal cases were more often female (36% vs. 30%; p < 0.001), younger 30 (IQR 10-56) vs. 60 (IQR: 45-72) (p < 0.001) and of unintentional nature (81% vs. 55%; p < 0.001). The overall incidence decreased over time from 5.6 to 4.1 per 100 000 (p < 0.001). The highest rate of 30-day survival was found in females 0-17 years (94%, 95% CI 91.1-95.5) and the lowest in males >66 years (28.7%, 95% CI 26.2-31.2). Although the incidence in children 0-4 years increased from 7.4 to 8.1 per 100 000 (p < 0.001), they demonstrated the highest non-fatal to fatal ratio (13:1)., Conclusion: Drowning is declining but remains a consistent and underestimated public-health problem. Non-fatal drowning cases represent about half of the burden and characteristics differ from fatal drowning cases, being younger, more often female and of unintentional nature., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Aim: Fast recognition of out-of-hospital cardiac arrest (OHCA) by dispatchers might increase survival. The aim of this observational study of emergency calls was to (1) examine whether a machine learning framework (ML) can increase the proportion of calls recognizing OHCA within the first minute compared with dispatchers, (2) present the performance of ML with different false positive rate (FPR) settings, (3) examine call characteristics influencing OHCA recognition., Methods: ML can be configured with different FPR settings, i.e., more or less inclined to suspect an OHCA depending on the predefined setting. ML OHCA recognition within the first minute is evaluated with a 1.5 FPR as the primary endpoint, and other FPR settings as secondary endpoints. ML was exposed to a random sample of emergency calls from 2018. Voice logs were manually audited to evaluate dispatchers time to recognition., Results: Of 851 OHCA calls, the ML recognized 36% (n = 305) within 1 min compared with 25% (n = 213) by dispatchers. The recognition rate at any time during the call was 86% for ML and 84% for dispatchers, with a median time to recognition of 72 versus 94 s. OHCA recognized by both ML and dispatcher showed a 28 s mean difference in favour of ML (P < 0.001). ML with higher FPR settings reduced recognition times., Conclusion: ML recognized a higher proportion of OHCA within the first minute compared with dispatchers and has the potential to be a supportive tool during emergency calls. The optimal FPR settings need to be evaluated in a prospective study., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Introduction: The relations between specific ECG patterns and coronary angiographic findings in cardiac arrest patients with different comorbidities are not properly assessed. More evidence is needed to identify patients with the highest risk for acute coronary artery disease as a cause of the cardiac arrest. This study aims to describe the coronary artery findings after cardiac arrest in relation to ECG and comorbidity., Method: A retrospective study of out-of-hospital cardiac arrest patients, with coronary angiography performed within 28 days. ECG on admission, comorbidity, PCI attempts and angiographic findings are described. Data were retrieved from national registries in Sweden., Results: Among 1133 patients with available ECG and angiography information the mean age was 64 years. The rate of shockable rhythm was 79%. The total incidence of any significant stenosis in cardiac arrest patients without ST-elevation who underwent coronary angiography within 28 days was 71%. The incidence of any stenosis in patients with normal ECG was 62.1% and in patients with LBBB, 59.3%. In patients with ST-depression or RBBB, PCI attempts were made in 47.1% and 42.4% respectively, compared with 33.3% in patients with normal ECG. Among patients without ST-elevation, those with diabetes mellitus and those with initial shockable rhythm respectively, 84.8% and 71.5 had at least one significant stenosis., Conclusion: Our study suggests, that evaluation of ECG patterns and comorbidities in out-of-hospital cardiac arrest patients without ST-segment elevation may be important to identify those with a high risk of coronary artery lesions that could benefit from early revascularization., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Aim: There are limited data on long-term outcome in out-of-hospital cardiac arrest patients following the treatment shift of target temperature management (TTM) from 33 °C to 36 °C outside the controlled settings of randomised trials. The aim of this study was to evaluate the adherence to TTM guidelines after the publication of the TTM trial and if the change in temperature level influence six-month survival., Methods: OHCA patients admitted to intensive care units (ICU) and recorded in the Swedish Intensive Care Registry (January 2010-March 2016) were included. Each ICU in Sweden provided information on their TTM target (i.e. 33 °C [TTM33] or 36 °C [TTM36]) used and the date of shift to 36 °C. The primary outcome was six-months survival. Multivariate logistic regression and propensity score match was used to adjust for confounders., Results: In total, 2899 OHCA patients from 69 ICUs were assessed; of those, 1038 patients were treated with TTM (TTM33, n = 755 and TTM36, n = 283). Patients receiving any TTM decreased during the study period from 70.5% to 54.5% (p for trend <0.001). There was no significant difference in six-month survival between the TTM33 (47.2%) and the TTM36 (47.3%) groups (adjusted OR 1.12 [0.80-1.56]. In the propensity score matched analysis the six-months survival was 52.7 vs 47.3 %, OR 1.29 [0.90-1.85])., Conclusions: The proportion of patients receiving therapeutic hypothermia in Sweden has decreased significantly since the publication of the TTM-trial indicating lower adherence to guidelines. This was not associated with any significant difference in long term outcome., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Introduction: We investigated the impact of gender in performance and findings of early coronary angiography (CAG) and percutaneous coronary intervention (PCI), comorbidity and outcome in a large population of out-of-hospital cardiac arrest (OHCA) patients with an initially shockable rhythm., Methods: Retrospective cohort study. Data retrieved 2008-2013 from the Swedish Register for Cardio-Pulmonary Resuscitation, Swedeheart Registry and National Patient Register., Results: We identified 1498 patients of whom 78% were men. Men and women had the same pathology on the first registered electrocardiogram (ECG): 30% vs. 29% had ST-elevation and 10% vs. 9% had left bundle branch block (LBBB) (P = 0.97). Proportions of performed CAG did not differ between genders. Among patients without ST-elevation/LBBB men more often had at least one significant stenosis, 78% vs. 54% (P = 0.001), more multi-vessel disease (P = 0.01), had normal coronary angiography less often, 22% vs. 46% and PCI more often, 59% vs. 42% (P = 0.03). Among patients without ST-elevation/LBBB on the initial ECG, more men had previously known ischaemic heart disease, 27% vs. 19% (P = 0.02) and a presumed cardiac origin of the cardiac arrest, 86% vs. 72% (P < 0.001). Multivariable analysis showed no association between gender and evaluation by early CAG. In men and women, 1-year survival was 56% vs. 50% (P = 0.22) in patients with ST-elevation/LBBB and 48% vs. 51% (P = 0.50) in patients without., Conclusion: Despite no gender differences in ECG findings indicating an early CAG, men had more severe coronary artery disease while women more frequently had normal coronary angiography. However, this did not influence 1-year survival., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: The clinical importance of immediate coronary angiography, with potentially subsequent percutaneous coronary intervention (PCI), in out-of-hospital cardiac arrest (OHCA) patients without ST-elevation on the ECG is unclear. In this study, we assessed feasibility and safety aspects of performing immediate coronary angiography in a pre-specified pilot phase of the 'DIrect or Subacute Coronary angiography in Out-of-hospital cardiac arrest' (DISCO) randomized controlled trial (ClinicalTrials.gov ID: NCT02309151)., Methods: Resuscitated bystander witnessed OHCA patients >18 years without ST-elevation on the ECG were randomized to immediate coronary angiography versus standard of care. Event times, procedure related adverse events and safety variables within 7 days were recorded., Results: In total, 79 patients were randomized to immediate angiography (n = 39) or standard of care (n = 40). No major differences in baseline characteristics between the groups were found. There were no differences in the proportion of bleedings and renal failure. Three patients randomized to immediate angiography and six patients randomized to standard care died within 24 h. The median time from EMS arrival to coronary angiography was 135 min in the immediate angiography group. In patients randomized to immediate angiography a culprit lesion was found in 14/38 (36.8%) and PCI was performed in all these patients. In 6/40 (15%) patients randomized to standard of care, coronary angiography was performed before the stipulated 3 days., Conclusion: In this out-of-hospital cardiac arrest population without ST-elevation, randomization to a strategy to perform immediate coronary angiography was feasible although the time window of 120 min from EMS arrival at the scene of the arrest to start of coronary angiography was not achieved. No significant safety issues were reported., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Early cardiopulmonary resuscitation (CPR) and defibrillation with an Automated External Defibrillator (AED) increase survival from out-of-hospital cardiac arrest (OHCA). Although international guidelines recommend the use of AED registries to increase AED use, little is known about implementation. The aim of this paper is to describe the development of a national AED registry, to analyse the coverage and barriers to register AEDs., Methods: The Swedish AED Registry (SAEDREG) was initiated in 2009 with the purpose of gathering the data of all public AEDs in Sweden. Data on all AEDs between 2013 and 2016 were included in the study. Additionally, data of non-registered AEDs was collected in one region using a survey to AED owners focusing on AED functionality., Results: The number of AEDs doubled between 2013-2016. A total of 6703 AEDs (30%) were removed due to unavailability of validation. At the end of 2016, AEDs were most frequently registered in offices and workplaces, 45% (n = 7241) followed by shops, 7% (n = 1200). In the Gotland region, 218 AEDs, 57% (n = 124) were registered in the SAEDREG. Of n = 94 Non-registered AED functionality was high, the main reason not to register was unawareness of the SAEDREG, 74.5%. Of those aware of the register but not having registered, 25% stated "hard to register" as cause., Conclusions: A national AED registry may gather information of AEDs on a national level. Although numbers have doubled between 2013-2016 in Sweden, a large proportion is still non-registered. More awareness of the registry and easier registration process is needed. General AED functionality seems high regardless of registered or non-registered AEDs. A key area for future research may be to use AED-registers to ascertain effectiveness of AED programs in terms of actual patient outcome., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Bystander cardiopulmonary resuscitation (CPR) has been proved to save lives; however, whether survival is affected by the training level of the bystander is not fully described., Aim: To describe if the training level of laymen and medically educated bystanders affect 30-day survival in out-of-hospital cardiac arrests (OHCA)., Methods: This observational study included all witnessed and treated cases of bystander CPR reported to the Swedish Registry of Cardiopulmonary Resuscitation between 2010 and 2014. Bystander CPR was divided into two categories: (a) lay-byCPR (non-medically educated) and (b) med-byCPR (off duty medically educated personnel)., Results: During 2010-2014, 24,643 patients were reported to the OHCA registry, of which 6850 received lay-byCPR and 1444 med-byCPR; 16,349 crew-witnessed and non-witnessed cases and those with missing information were excluded from the analysis. The median interval from collapse to call for emergency medical services was 2min in both groups (p=0.97) and 2min from collapse to start of CPR for lay-byCPR versus 1min for med-byCPR (p<0.0001). There were no significant differences in CPR methods used; 64.3% (lay-byCPR) and 65.7% (med-byCPR) applied compressions and ventilation, respectively (p=0.33). The 30-day survival was 14.7% for lay-byCPR and 17.2% for the med-byCPR group (p=0.02). The odds ratio adjusted for potential confounders regarding survival (med-byCPR versus lay-byCPR) was 1.34 (95% confidence interval, 1.11-1.62; p=0.002)., Conclusions: In cases of OHCA, medically educated bystanders initiated CPR earlier and an increased 30-day survival was found compared with laymen bystanders. These results support the need to improve the education programme for laypeople., (Copyright © 2017 Elsevier B.V. All rights reserved.)

A stabilized high drug load intravenous formulation could allow compounds with less optimal pharmacokinetic profiles to be developed. Polyethylene glycol (PEG)-ylation is a frequently used strategy for particle delivery systems to avoid the liver, thereby extending blood circulation time. The present work reports the mouse in vivo distribution after i.v. administration of a series of nanocrystals prepared with the bead milling technique and PEG-ylated with DSPE-PEG2000 and Pluronic F127, with and without polyvinylpyrrolidone K30 (PVP)/Aerosol OT (AOT) as primary stabilizers. While all formulations were cleared significantly faster than expected from nanocrystal dissolution alone, purely DSPE-PEG2000 PEG-ylated particles displayed prolonged circulation time (particles elimination half-life of 9min) compared to DSPE-PEG2000/PVP/AOT formulation (half-life of 3min). The two Pluronic F127 stabilized formulations displayed similar half-lives (9min with and without PVP/AOT, respectively). Whole tissue kinetics shows that clearance of particles could be attributed to accumulation in the liver. A separate in vivo study addressed the liver cell distribution after administration. Dissolved compound accumulated in hepatocytes only, while particles were distributed between liver sinusoidal endothelial cells and Kupffer cells. More DSPE-PEG2000/PVP/AOT stabilized particles accumulated in the liver, preferably in Kupffer cells, compared to Pluronic F127/PVP/AOT stabilized particles. The present study extends the understanding of PEG-ylation and "stealth" behaviour to also include nanocrystals., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: Drowning leading to out-of-hospital cardiac arrest (OHCA) and death is a major public health concern. Submersion with duration of less than 10min is associated with favorable neurological outcome and nearby bystanders play a considerable role in rescue and resuscitation. Drones can provide a visual overview of an accident scene, their potential as lifesaving tools in drowning has not been evaluated., Aim: The aim of this simulation study was to evaluate the efficiency of a drone for providing earlier location of a submerged possible drowning victim in comparison with standard procedure., Method: This randomized simulation study used a submerged manikin placed in a shallow (<2m) 100×100-m area at Tylösand beach, Sweden. A search party of 14 surf-lifeguards (control) was compared to a drone transmitting video to a tablet (intervention). Time from start to contact with the manikin was the primary endpoint., Results: Twenty searches were performed in total, 10 for each group. The median time from start to contact with the manikin was 4:34min (IQR 2:56-7:48) for the search party (control) and 0:47min (IQR 0:38-0:58) for the drone-system (intervention) respectively (p<0.001). The median time saved by using the drone was 3:38min (IQR 2:02-6:38)., Conclusion: A drone transmitting live video to a tablet is feasible, time saving in comparison to traditional search parties and may be used for providing earlier location of submerged victims at a beach. Drone search can possibly contribute to earlier onset of CPR in drowning victims., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Introduction: Early use of automated external defibrillators (AED) increases survival in cases of out-of-hospital cardiac arrest (OHCA). Dispatchers play important roles in identifying OHCA, dispatching ambulances and providing callers with telephone-assisted cardiopulmonary resuscitation. Guidelines recommend that AED registries be linked to dispatch centres as tools to refer callers to nearby AED., Aim: The aim of this study was to investigate to what extent dispatchers, when provided with a tool to display AED locations and accessibility, referred callers to nearby AED., Methods: An application providing real-time visualization of AED locations and accessibility was implemented at four dispatch centres in Sweden. Dispatchers were instructed to refer callers to nearby AED when OHCA was suspected. Such cases were prospectively collected, and geographic information systems were used to identify those located ≤100m from an AED. Audio recordings of emergency calls were assessed to evaluate the AED referral rate., Results: Between February and August 2014, 3009 suspected OHCA calls were received. In 6.6% of those calls (200/3009), an AED was ≤100m from the suspected OHCA. The AED was accessible and the caller was not alone on scene in 24% (47/200) of these cases. In two of those 47 cases (4.3%), the dispatcher referred the caller to the AED., Conclusion: Despite a tool for dispatchers to refer callers to a nearby AED, referral was rare. Only a minority of the suspected OHCA cases occurred ≤100m from an AED. We identified AED accessibility and callers being alone on scene as obstacles for AED referral., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Aim: To describe differences and similarities between reported and non-reported data in the Swedish Cardiac Arrest Register in selected parts in Sweden., Methods: Prospective and retrospective data for treated OHCA patients in Sweden, 2008-2010, were compared in the Swedish Cardiac Arrest Register. Data were investigated in three Swedish counties, which represented one third of the population. The recording models varied. Prospective data are those reported by the emergency medical service (EMS) crews, while retrospective data are those missed by the EMS crews but discovered afterwards by cross-checking with the local ambulance register., Result: In 2008-2010, the number of prospectively (n=2398) and retrospectively (n=800) reported OHCA cases was n=3198, which indicates a 25% missing rate. When comparing the two groups, the mean age was higher in patients who were reported retrospectively (69 years vs. 67 years; p=0.003). There was no difference between groups with regard to gender, time of day and year of OHCA, witnessed status or initial rhythm. Bystander cardiopulmonary resuscitation (CPR) was more frequent among patients who were reported prospectively (65% vs. 60%; p=0.023), whereas survival to one month was higher among patients who were reported retrospectively (9.2% vs. 11.9%; p=0.035)., Conclusion: Among 3198 cases of OHCA in three counties in Sweden, 800 (25%) were not reported prospectively by the EMS crews but were discovered retrospectively as missing cases. Patients who were reported retrospectively differed from prospectively reported cases by being older, having less frequently received bystander CPR but having a higher survival rate. Our data suggest that reports on OHCA from national quality registers which are based on prospectively recorded data may be influenced by selection bias., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Background: Among patients who survive after out-of-hospital cardiac arrest (OHCA), a large proportion are recruited from cases witnessed by the Emergency Medical Service (EMS), since the conditions for success are most optimal in this subset., Aim: To evaluate outcome after EMS-witnessed OHCA in a 20-year perspective in Sweden, with the emphasis on changes over time and factors of importance., Methods: All patients included in the Swedish Cardiac Arrest Register from 1990 to 2009 were included., Results: There were 48,349 patients and 13.5% of them were EMS witnessed. There was a successive increase in EMS-witnessed OHCA from 8.5% in 1992 to 16.9% in 2009 (p for trend<0.0001). Among EMS-witnessed OHCA, the survival to one month increased from 13.9% in 1992 to 21.8% in 2009 (p for trend<0.0001). Among EMS-witnessed OHCA, 51% were found in ventricular fibrillation, which was higher than in bystander-witnessed OHCA, despite a lower proportion with a presumed cardiac aetiology in the EMS-witnessed group. Among EMS-witnessed OHCA overall, 16.0% survived to one month, which was significantly higher than among bystander-witnessed OHCA. Independent predictors of a favourable outcome were: (1) initial rhythm ventricular fibrillation; (2) cardiac aetiology; (3) OHCA outside home and (4) decreasing age., Conclusion: In Sweden, in a 20-year perspective, there was a successive increase in the proportion of EMS-witnessed OHCA. Among these patients, survival to one month increased over time. EMS-witnessed OHCA had a higher survival than bystander-witnessed OHCA. Independent predictors of an increased chance of survival were initial rhythm, aetiology, place and age., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Aim: To describe the reported incidence of out of hospital cardiac arrest (OHCA) and the characteristics and outcome after OHCA in relation to population density in Sweden., Methods: All patients participating in the Swedish Cardiac Arrest Register between 2008 and 2009 in (a) 20 of 21 regions (n=6457) and in (b) 165 of 292 municipalities (n=3522) in Sweden, took part in the survey., Results: The regional population density varied between 3 and 310 inhabitants per km(2) in 2009. In 2008-2009, the number of reported cardiac arrests varied between 13 and 52 per 100,000 inhabitants and year. Survival to 1 month varied between 2% and 14% during the same period in different regions. With regard to population density, based on municipalities, bystander CPR (p=0.04) as well as cardiac etiology (p=0.002) were more frequent in less populated areas. Ambulance response time was longer in less populated areas (p<0.0001). There was no significant association between population density and survival to 1 month after OHCA or incidence (adjusted for age and gender) of OHCA., Conclusion: There was no significant association between population density and survival to 1 month after OHCA or incidence (adjusted for age and gender) of OHCA. However, bystander CPR, cardiac etiology and longer response times were more frequent in less populated areas., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Aim: To describe (a) changes in the organisation of training in cardiopulmonary resuscitation (CPR) and the treatment of cardiac arrest in hospital in Sweden and (b) the clinical achievement, i.e. survival and cerebral function, among survivors after in-hospital cardiac arrest (IHCA) in Sweden., Methods: Aspects of CPR training among health care providers (HCPs) and treatment of IHCA in Sweden were evaluated in 3 national surveys (1999, 2003 and 2008). Patients with IHCA are recorded in a National Register covering two thirds of Swedish hospitals., Results: The proportion of hospitals with a CPR coordinator increased from 45% in 1999 to 93% in 2008. The majority of co-ordinators are nurses. The proportions of hospitals with local guidelines for acceptable delays from cardiac arrest to the start of CPR and defibrillation increased from 48% in 1999 to 88% in 2008. The proportion of hospitals using local defibrillation outside intensive care units prior to arrival of rescue team increased from 55% in 1999 to 86% in 2008. During the past 4 years in Sweden, survival to hospital discharge has been 29%. Among survivors, 93% have a cerebral performance category (CPC) score of I or II, indicating acceptable cerebral function., Conclusion: During the last 10 years, there was a marked improvement in CPR training and treatment of IHCA in Sweden. During the past 4 years, survival after IHCA is high and the majority of survivors have acceptable cerebral function., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)

Background: The outcome of out-of-hospital cardiac arrest (OHCA) with a non-shockable rhythm is poor. For patients found in asystole or pulseless electrical activity (PEA), recent guidelines or rules that may be used include "do not attempt to resuscitate" (DNAR) guidelines from Helsinki, discontinuing resuscitation in the guidelines of the European Resuscitation Council and a clinical prediction rule from Canada. We compared these guidelines and the rule using a large Scandinavian dataset., Materials and Methods: The Swedish Cardiac Arrest Registry includes prospectively collected data on 44121 OHCA patients. We identified patients with asystole or PEA as the initial rhythm and excluded cases caused by trauma or drowning. The specificities and positive predictive values (PPVs) were calculated for the guidelines, and the clinical prediction rule for comparison., Results: A total of 20484 patients with non-shockable rhythms were identified; 85% had asystole and 15% PEA. The overall survival to hospital admission was 9% (n=1.861) and 1% (n=231) were alive at 1 month from the arrest. The specificity of the Helsinki guidelines in identifying non-survivors was 71% (95% confidence interval (CI): 65-77%) and the PPV was 99.4% (95% CI: 99.3-99.5), while the corresponding values for the European Resuscitation Council (ERC) was 95% (95% CI: 91.3-97.5) and 99.9% (95% CI: 99.9-99.9) and, for the prediction rule, 99.1% (95% CI: 96.7-99.9) and 99.9% (95% CI: 99.9-100.00), respectively., Conclusion: In this comparison study, the Helsinki DNAR guidelines did not perform well enough in a general OHCA material to be widely adopted. The main reason for this was the unpredicted survival of patients with unwitnessed asystole. The clinical prediction rule and the recommendations of the ERC Guidelines worked well., (Copyright 2010 Elsevier Ireland Ltd. All rights reserved.)

Aim: To describe the use of cardiopulmonary resuscitation (CPR) training programmes in Sweden for 25 years and relate those to changes in the percentage of patients with out of hospital cardiac arrest (OHCA) who receive bystander CPR., Methods: Information was gathered from (a) the Swedish CPR training registry established in 1983 and includes most Swedish education programmes in CPR and (b) the Swedish Cardiac Arrest Register (SCAR) established in 1990 and currently covers about 70% of ambulance districts in Sweden., Results: CPR education in Sweden functions according to a cascade principle (instructor-trainers who train instructors who then train rescuers in CPR). Since 1989, 5000 instructor-trainers have taught more than 50,000 instructors who have taught nearly 2 million of Sweden's 9 million inhabitants adult CPR. This is equivalent to one new rescuer per 100 inhabitants every year in Sweden. In addition, since 1989, there are 51,000 new rescuers in Advanced Life Support (ALS), since 1996, 41,000 new Basic Life Support (BLS) rescuers with Automated External Defibrillation (AED) training, and since 1998, there are 93,000 new rescuers in child CPR. As a result of this CPR training the number of bystander CPR attempts for OHCA in Sweden increased from 31% in 1992 to 55% in 2007., Conclusion: By using a cascade principle for CPR education nearly 2 million rescuers were educated in Sweden (9 million inhabitants) between 1989 and 2007. This resulted in a marked increase in bystander CPR attempts., (Copyright 2009 Elsevier Ireland Ltd. All rights reserved.)

Objectives: Bystanders cardiopulmonary resuscitation (CPR) increases survival in out-of-hospital cardiac arrest (OHCA). Emergency medical dispatchers (EMDs) can provide even totally inexperienced bystanders with instructions by telephone on how to resuscitate victims (T-CPR) until the emergency medical services (EMS) arrive. Agonal respiration makes it difficult for EMDs to identify cardiac arrests (CAs) which will prevent or delay initiation of T-CPR. The aim of this investigation was to study if tuition of EMDs can improve their ability to identify agonal respiration in OHCA to allow for more frequent offers of T-CPR., Methods: An observational study was made in 2004 and subsequently, a repeat study was made in 2006. All OHCA (n=315 in 2004, n=255 in 2006) in the Stockholm region reported to the Swedish Cardiac Arrest Register were included and all corresponding EMS reports were reviewed. Emergency calls were recorded during the event. Witnessed cases of OHCA (n=76 in both 2004 and 2006) were analyzed using a structured data collection tool., Results: The frequency of offered T-CPR to all bystanders of OHCA in 2004 was 47%. After special tuition on agonal respiration in OHCA it rose to 68% in 2006 (p=0.01). An even more marked rise was observed in OHCA cases with agonal respiration. In 2004 T-CPR was offered in 23% of these situations whereas the corresponding figures in 2006 had risen to 56% (p=0.006)., Conclusions: Teaching EMDs to understand and recognize bystander descriptions of agonal respiration in patients with OHCA has resulted in a significant increase in offers of T-CPR in these situations.

Aim: To describe changes in the proportion of bystanders performing cardiopulmonary resuscitation (CPR) in out of hospital cardiac arrest (OHCA) in Sweden and to study the impact of bystander CPR on ventricular fibrillation and on survival during various times., Patients and Methods: All patients who suffered from OHCA in Sweden in whom CPR was attempted and who were included in the Swedish cardiac arrest register (SCAR) between 1992 and 2005. Crew witnessed cases were excluded., Results: In all 34,125 patients were included in the survey. Among witnessed OHCA the proportion of patients receiving bystander CPR increased from 40% in 1992 to 55% in 2005 (p<0.0001). In non-witnessed OHCA the corresponding proportion increased from 22% to 44% (p<0.0001). There was a significant increase in bystander CPR regardless of age, sex and place. The increase was only found when CPR was performed by lay persons (21% in 1992 to 40% in 2005; p<0.0001). Bystander CPR was associated with an increased proportion of patients found in a shockable rhythm and a lower number of shocks to receive return of spontaneous circulation. Bystander CPR was associated with a similar increase in survival early and late in the evaluation., Conclusion: There was a marked increase in bystander CPR in OHCA, when performed by lay persons, during the last 14 years in Sweden. Bystander CPR was associated with positive effects both on ventricular fibrillation and survival.

The caudate nucleus is a structure implicated in the neural circuitry of psychological responses to trauma. This study aimed to quantify the volume of the caudate in persons exposed to trauma. Thirty-six subjects under 65 were recruited from transport workers in Stockholm who reported having been unintentionally responsible for a person-under-the-train accident or among employees having experienced an assault in their work (1999-2001) between 3 months and 6 years before MRI scanning. In those exposed to the trauma, a DSM-IV diagnosis of post-traumatic stress disorder (PTSD) was made by an independent psychiatrist, with subjects being classified as PTSD or no PTSD. MRI data were analyzed blindly to all clinical information by an experienced rater using a standardized manual tracing protocol to quantify the volume of the caudate. Within-group comparisons of PTSD (n=19) and no PTSD (n=17) found the right caudate nucleus to be significantly (9%) larger than the left: a right hemisphere baseline asymmetry. A multivariate analysis of covariance (MANCOVA) was conducted to assess the volume of the caudate nucleus (right and left) in relation to the diagnosis of no PTSD (n=17) or PTSD (n=19). After adjustment for the covariates (age, sex, intracranial volume, years since trauma, and number of trauma episodes), there was a significant difference in raw right caudate nucleus volume between subjects with PTSD compared with those without PTSD. Volume of the left caudate nucleus was not significantly different between the PTSD and no PTSD groups. The right caudate volume in the PTSD group was 9% greater compared with the no PTSD group. There is a larger right hemisphere volume of the caudate within those exposed to trauma with active PTSD compared with those without PTSD, superimposed upon a baseline caudate asymmetry.

Our aim was to develop a reliable and valid manual segmentation protocol for tracing the caudate nucleus in MRI for volumetric and, potentially, shape analysis of the caudate. Using the protocol, two inter- and intra-rater reliability studies were conducted using five different raters on two different image analysis platforms (ANALYZE, Mayo Biomedical Imaging Resource, Rochester MN, USA, and HERMES, Nuclear Diagnostics AB, Stockholm, Sweden). Reference images for the detailed protocol are described. Two studies were performed. In study 1, the intra-rater class correlation ICC(1,1) for an experienced rater (JCLL) using this protocol for caudate nucleus volumes was evaluated by repeating right and left caudate measurements on 10 scans (20 comparisons) and was 0.972. The inter-rater class correlation ICC(1,k) with OL was 0.922 on 5 scans (10 comparisons) and with BL was 0.960 on 5 scans (10 comparisons). In study 2, VT obtained an intra-rater class correlation of 0.9 on 5 scans (involving 10 comparisons, e.g. right and left caudate). The inter-rater class correlation ICC(1,k) was 0.988 on 5 scans (again involving 10 comparisons) with EM. We therefore developed a novel, reliable and reference image-based, method of outlining the caudate nucleus on axial MRI scans, usable in two different image analysis laboratories, across two different sets number of tracers reliably, and across software platforms. This method is therefore potentially usable for any image analysis package capable of displaying and measuring outlined voxels from MRI brain scans.

A novel PCR method was developed to discriminate amongst genotypes A-C of the rotavirus non-structural protein 4 (NSP4). Genotype-specific primers were designed that correctly identified the NSP4 genotype when evaluated as a multiplex PCR with cell culture adapted rotavirus strains. Rotavirus strains B223 SGIG6P6[1], NCDV SGIG6P6[1] and SA11 SGIG3P5B[2] were used as control for NSP4 genotype A; A34 SGIG5P14[23], Gottfried SGIIG4P2B[6] and Wa SGIIG1P1A[8] for NSP4 genotype B; RRV SGIG3P5B[3] for NSP4 genotype C. Subsequently, the same set of specific primers was used to genotype a set of 77 Swedish clinical samples. The results showed that all human clinical samples analyzed belong to the NSP4 genotype B and the VP6 subgroup II.

Aim: To describe the characteristics and outcome among patients with out-of-hospital cardiac arrest (OHCA) caused by drowning as compared with OHCA caused by a cardiac etiology (outside home)., Patients and Methods: All the patients included in the Swedish OHCA Registry between 1990 and 2005 which were not crew witnessed, in whom cardio-pulmonary resuscitation (CPR) was attempted, were evaluated for inclusion. Those caused by drowning were compared with those with a cardiac etiology (outside home)., Results: Patients with OHCA due to drowning (n=255) differed from patients with OHCA with a cardiac etiology (n=7494) as they were younger, less frequently suffered a witnessed OHCA, more frequently received bystander CPR and less frequently were found in a shockable rhythm. Patients with OHCA due to drowning had a prolonged ambulance response time as compared with patients with OHCA with a cardiac etiology. Patients with OHCA due to drowning had a survival rate to 1 month of 11.5% as compared with 8.8% among patients with OHCA due to a cardiac etiology (NS). Among patients with OHCA due to drowning, only one independent predictor of survival was defined, i.e. time from calling for an ambulance until the arrival of the rescue team, with a much higher survival among patients with a shorter ambulance response time., Conclusion: Among patients with OHCA 0.9% were caused by drowning. They had a similar survival rate to 1 month as compared with OHCA outside home with a cardiac etiology. The factor associated with survival was the ambulance response time; a higher survival with a shorter response time.

Aim: To define factors associated with an improved outcome among patients suffering out-of-hospital cardiac arrest (OHCA) who were found in a non-shockable rhythm., Patients: All the patients included in the Swedish OHCA registry between 1990 and 2005 in whom resuscitation was attempted, who were found in a non-shockable rhythm and where either the OHCA was witnessed by a bystander or was not witnessed., Results: In all, 22,465 patients fulfilled the inclusion criteria. Their mean age was 67 years, 32% were women, 57% were witnessed, 64% had a cardiac aetiology, 71% occurred at home and 34% received bystander cardiopulmonary resuscitation (CPR). Survival to 1 month was 1.3%. The following were independently associated with an increased chance of survival: 1/Decreasing age, 2/Witnessed arrest, 3/Bystander CPR, 4/Cardiac arrest outside home, 5/Shorter ambulance response time and 6/Need for defibrillatory shock. If these six criteria were fulfilled (age and ambulance response time below the median), survival to 1 month increased to 12.6%. If no criteria were fulfilled, survival was 0.15%., Conclusion: The overall survival among patients with an OHCA found in a non-shockable rhythm is very low (1.3%). Six factors associated with survival can be defined. When they are taken into account, survival varies between 12.6 and 0.15%.

Aim: To describe the association between a history of diabetes and outcome among patients suffering an in-hospital cardiac arrest., Method: All patients suffering an in-hospital cardiac arrest in whom cardiopulmonary resuscitation (CPR) was attempted at Sahlgrenska University Hospital in Göteborg between 1994 and 2006 and at nine further hospitals in Sweden between 2005 and 2006., Results: In all, 1810 patients were included in the survey, 395 (22%) of whom had a previous history of diabetes. Patients with a history of diabetes differed from those without such a history by having a higher prevalence of previous myocardial infarction, stroke, heart failure and renal disease. They were more frequently treated with anti-arrhythmic drugs during resuscitation. Whereas immediate survival did not differ between groups (51.7% and 53.1%, respectively), patients with diabetes were discharged alive from hospital (29.3%) less frequently compared with those without diabetes (37.6%). When correcting for dissimilarities at baseline, the adjusted odds ratio for being discharged alive (diabetes/no diabetes) was 0.57 (95% CL 0.40-0.79)., Conclusion: Among patients suffering an in-hospital cardiac arrest in Sweden in whom CPR was attempted, 22% had a history of diabetes. These patients had a lower survival rate, which cannot simply be explained by different co-morbidity.

Aim: To describe all patients treated for out-of-hospital cardiac arrest (OHCA) according to the Utstein criteria and their characteristics and outcome with emphasis on whether they were available for early intervention trials., Design: Retrospective analysis of a study where data were collected prospectively., Setting: The Municipality of Göteborg/Mölndal in Sweden., Patients: All patients suffering from out-of-hospital cardiac arrest in the Municipality of Göteborg/Mölndal in whom cardiopulmonary resuscitation (CPR) was attempted between May 2003 and May 2005., Interventions: Part of the study cohort, i.e. patients with a witnessed, non-traumatic, out-of-hospital cardiac arrest were distributed (cluster) to mechanical (LUCAS) or manual chest compression., Results: The overall survival to discharge from hospital among the 508 patients was 8.5%. The corresponding value for non-cardiac cases was 5.1% and for cardiac cases if crew witnessed 16.1%, bystander witnessed 12.7% and non-witnessed 1.4%. Fifty-nine percent of the patients fulfilled the inclusion criteria for the trial and had no exclusion criteria and 9.7% of these survived to discharge. Ten percent of patients fulfilled the inclusion criteria but were excluded and 20.4% survived to discharge. Thirty-one percent of patients did not fulfil the inclusion criteria and 2.5% survived. Among patients included in the LUCAS group, many of the survivors, 10/13 (77%), experienced a rapid return of spontaneous circulation (ROSC) before the application of the device., Conclusion: Among patients with OHCA in whom CPR was started 8.5% survived to hospital discharge and 59% were theoretically available for an early intervention trial. These patients have a different outcome compared with patients not available. However, among those available, the majority of survivors had a rapid ROSC before the application of the intervention (LUCAS). This raises concerns about the potential for early intervention trials to improve outcome after OHCA.

Background: A recently published study has shown that survival after out-of-hospital cardiac arrest (OHCA) in Göteborg is almost three times higher than in Stockholm. The aim of this study was to investigate whether in-hospital factors were associated with outcome in terms of survival., Methods: All patients suffering from OHCA in Stockholm and Göteborg between January 1, 2000 and June 30, 2002 were included. The two groups were compared with reference to patient characteristics, medical history, pre-hospital and hospital course (including in-hospital investigations and interventions) and mortality. All medical charts from patients admitted alive to the different hospitals were studied. Data from the Swedish National Register of Deaths regarding long-term survival were analysed. Pre-hospital data were collected from the Swedish Ambulance Cardiac Arrest Register., Results: In all, 1542 OHCA in Stockholm and 546 in Göteborg were registered during the 30-month study period. In Göteborg, 28% (153 patients) were admitted alive to the two major hospitals whereas in Stockholm 16% (253 patients) were admitted alive to the seven major hospitals (p<0.0001). On admission to the emergency rooms, a larger proportion of patients in Stockholm was unconscious (p=0.006), received assisted breathing (p=0.008) and ongoing CPR (p=0.0002). Patient demography, medical history, in-hospital investigations and interventions and in-hospital mortality (78% in Göteborg, 80% in Stockholm) did not differ between the two groups. Various pre-hospital time intervals were significantly longer in Stockholm than in Göteborg. Total survival to discharge after OHCA was 3.3% in Stockholm and 6.1% in Göteborg (p=0.01)., Conclusion: An almost 2-fold difference in survival after OHCA between Stockholm and Göteborg appears to be associated with pre-hospital factors only (predominantly in form of prolonged intervals in Stockholm), rather than with in-hospital factors or patient characteristics.

Aims: To compare quality of CPR during out-of-hospital cardiac arrest with and without automated feedback., Materials and Methods: Consecutive adult, out-of-hospital cardiac arrests of all causes were studied. One hundred and seventy-six episodes (March 2002-October 2003) without feedback were compared to 108 episodes (October 2003-September 2004) where automatic feedback on CPR was given. Automated verbal and visual feedback was based on measured quality with a prototype defibrillator. Quality of CPR was the main outcome measure and survival was reported as specified in the protocol., Results: Average compression depth increased from (mean +/- S.D.) 34 +/- 9 to 38 +/- 6 mm (mean difference (95% CI) 4 (2, 6), P < 0.001), and median percentage of compressions with adequate depth (38-51 mm) increased from 24% to 53% (P < 0.001, Mann-Whitney U-test) with feedback. Mean compression rate decreased from 121 +/- 18 to 109 +/- 12 min(-1) (difference -12 (-16, -9), P = 0.001). There were no changes in the mean number of ventilations per minute; 11 +/- 5 min(-1) versus 11 +/- 4 min(-1) (difference 0 (-1, 1), P = 0.8) or the fraction of time without chest compressions; 0.48 +/- 0.18 versus 0.45 +/- 0.17 (difference -0.03 (-0.08, 0.01), P = 0.08). With intention to treat analysis 7/241 control patients were discharged alive (2.9%) versus 5/117 with feedback (4.3%) (OR 1.5 (95% CI; 0.8, 3), P = 0.2). In a logistic regression analysis of all cases, witnessed arrest (OR 4.2 (95% CI; 1.6, 11), P = 0.004) and average compression depth (per mm increase) (OR 1.05 (95% CI; 1.01, 1.09), P = 0.02) were associated with rate of hospital admission., Conclusions: Automatic feedback improved CPR quality in this prospective non-randomised study of out-of-hospital cardiac arrest. Increased compression depth was associated with increased short-term survival., Trial Registration: ClinicalTrials.gov (NCT00138996), http://www.clinicaltrials.gov/.

Phencyclidine (PCP), a non-competitive NMDA receptor antagonist, was used to model schizophrenia-like cognitive dysfunctions of learning and memory in rats using the Morris water maze model for spatial memory. A protocol introduced by Baldi and co-workers was used to distinguish working memory from reference memory. Male Sprague-Dawley rats were administered PCP (2.0 mg/kg) before the first swimming trial on each of five spatial memory acquisition days, either alone or after pre-treatment with the nitric oxide synthase inhibitor, L-NAME (10 mg/kg). Probe tests for memory were conducted before and after each acquisition session. The results showed that PCP disrupted the acquisition of both working and reference memory. Pre-treatment with L-NAME reversed both these effects of PCP. L-NAME treatment by itself did not significantly alter either acquisition or retention of spatial memory.

Aim: To evaluate the outcome among patients suffering from out-of-hospital cardiac arrest (OHCA) after the introduction of mechanical chest compression (MCC) compared with standard cardiopulmonary resuscitation (SCPR) in two emergency medical service (EMS) systems., Methods: The inclusion criterion was witnessed OHCA. The exclusion criteria were age < 18 years, the following judged etiologies behind OHCA: trauma, pregnancy, hypothermia, intoxication, hanging and drowning or return of spontaneous circulation (ROSC) prior to the arrival of the advanced life support (ALS) unit. Two MCC devices were allocated during six-month periods between four ALS units for a period of two years (cluster randomisation)., Results: In all, 328 patients fulfilled the criteria for participation and 159 were allocated to the MCC tier (the device was used in 66% of cases) and 169 to the SCPR tier. In the MCC tier, 51% had ROSC (primary end-point) versus 51% in the SCPR tier. The corresponding values for hospital admission alive (secondary end-point) were 38% and 37% (NS). In the subset of patients in whom the device was used, the percentage who had ROSC was 49% versus 50% in a control group matched for age, initial rhythm, aetiology, bystander-/crew-witnessed status and delay to CPR. The percentage of patients discharged alive from hospital after OHCA was 8% versus 10% (NS) for all patients and 2% versus 4%, respectively (NS) for the patients in the subset (where the device was used and the matched control population)., Conclusion: In this pilot study, the results did not support the hypothesis that the introduction of mechanical chest compression in OHCA improves outcome. However, there is room for further improvement in the use of the device. The hypothesis that this will improve outcome needs to be tested in further prospective trials.

Aim: To describe the association between the interval between the call for ambulance and return of spontaneous circulation (ROSC) and survival in out-of-hospital cardiac arrest., Patients: All patients suffering an out-of-hospital cardiac arrest in whom cardiopulmonary resuscitation (CPR) was started, included in the Swedish Cardiac Arrest Registry (SCAR) for whom information about the time of calling for an ambulance and the time of ROSC was available., Results: Among 26,192 patients who were included in SCAR and were not witnessed by the ambulance crew, information about the time of call for an ambulance and the time of ROSC was available in 4847 patients (19%). There was a very strong relationship between the interval between call for an ambulance and ROSC and survival to one month. If the interval was less than or equal to 5 min, 47% survived to one month. If the interval exceeded 30 min, only 5% (n = 35) survived to one month. The vast majority of the latter survivors had a shockable rhythm either on admission of the rescue team or at some time during resuscitation., Conclusion: Among patients who have ROSC after an out-of-hospital cardiac arrest, there is a very strong association between the interval between the call for ambulance and ROSC and survival to one month. However, even if this delay is very long (> 30 min after calling for an ambulance), a small percentage will ultimately survive; they are mainly patients who at some time during resuscitation have a shockable rhythm. The overall percentage of patients for whom CPR continued for more than 30 min who are alive one month later can be assumed to be extremely low.

Aim: To explore the rate of survival to hospital discharge among patients who were brought to hospital alive after an out-of-hospital cardiac arrest in different hospitals in Sweden., Patients and Methods: All patients who had suffered an out-of-hospital cardiac arrest which was not witnessed by the ambulance crew, in whom cardiopulmonary resuscitation (CPR) was started and who had a palpable pulse on admission to hospital were evaluated for inclusion. Each participating ambulance organisation and its corresponding hospital(s) required at least 50 patients fulfilling these criteria., Results: Three thousand eight hundred and fifty three patients who were brought to hospital by 21 different ambulance organisations fulfilled the inclusion criteria. The number of patients rescued by each ambulance organisation varied between 55 and 900. The survival rate, defined as alive 1 month after cardiac arrest, varied from 14% to 42%. When correcting for dissimilarities in characteristics and factors of the resuscitation, the adjusted odds ratio for survival to 1 month among patients brought to hospital alive in the three ambulance organisations with the highest survival versus the three with the lowest survival was 2.63 (95% CI: 1.77-3.88)., Conclusion: There is a marked variability between hospitals in the rate of 1-month survival among patients who were alive on hospital admission after an out-of-hospital cardiac arrest. One possible contributory factor is the standard of post-resuscitation care.

Cognitive deficits of schizophrenia constitute a disabling part of the disease predicting treatment success as well as functional outcome. Phencyclidine (PCP), a non-competitive NMDA receptor antagonist was used to model schizophrenic cognitive dysfunctions of learning and memory using the Morris water maze paradigm for reference memory. In experiment 1 male Sprauge-Dawley rats were acutely administered PCP (0.5, 1.0 and 2.0 mg/kg s.c.) before the first swim session on each of the four acquisition days. Probe test for reference memory was performed 2 days after the last acquisition day; the first probe without drug treatment to assess reference memory and a second probe with prior drug treatment to control for state dependency effects of PCP. In experiment 2 the effects of pre-treatment (10 min before PCP) with the nitric oxide synthase inhibitor, L-NAME (10 mg/kg s.c.), on the PCP (2 mg/kg)-induced spatial memory deficit was evaluated in the Morris water maze paradigm for reference memory. The results showed that PCP in a dose of 2 mg/kg disrupts spatial learning as estimated by prolonged search time to find platform during acquisition as well as the reference memory test as measured by less time spent in target quadrant during probe trial. No state dependency effects of PCP were found. Pre-treatment with L-NAME completely reversed the PCP-induced disruption of acquisition learning. The reference memory disruption was, however, not completely restored as measured by probe trial.

Background: Early cardiopulmonary resuscitation (CPR) by bystanders prior to the arrival of the rescue team has been shown to be associated with increased survival after out-of-hospital cardiac arrest. The aim of this survey was to evaluate the impact on survival of no bystander CPR, lay bystander CPR and professional bystander CPR., Methods: Patients suffering an out-of-hospital cardiac arrest in Sweden between 1990 and 2002 who were given CPR and were not witnessed by the ambulance crew were included., Results: In all, 29,711 patients were included, 36% of whom received bystander CPR prior to the arrival of the rescue team. Among the latter, 72% received CPR from lay people and 28% from professionals. Survival to 1 month was 2.2% among those who received no bystander CPR, 4.9% among those who received bystander CPR from lay people (p<0.0001) and 9.2% among those who received bystander CPR from professionals (p<0.0001 compared with bystander CPR by lay people). In a multivariate analysis, lay bystander CPR was associated with improved survival compared to no bystander CPR (OR: 2.04; 95% CI: 1.72-2.42), and professional bystander CPR was associated with improved survival compared to lay bystander CPR (OR: 1.37; 95% CI: 1.12-1.67)., Conclusion: Among patients suffering an out-of-hospital cardiac arrest, bystander CPR by lay persons (excluding health care professionals) is associated with an increased chance of survival. Furthermore, there is a distinction between lay persons and health care providers; survival is higher when the latter perform bystander CPR. However, these results may not be explained by differences in the quality of CPR.

Latent inhibition (LI) is a behavioural procedure used to evaluate the potential propsychotic and antipsychotic properties of psychoactive drugs. In the present study, a conditioned taste aversion (CTA) procedure was used to investigate the effects of the nitric oxide (NO) synthase inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME), and the psychotomimetic drugs, phencyclidine (PCP) and d-amphetamine (d-AMP) on LI. PCP (2 mg/kg) and d-AMP (0.5 mg/kg) were both found to enhance LI in this procedure. The effect of d-AMP on LI was less pronounced and this drug also caused a weak disruption of taste aversion conditioning. Pretreatment with L-NAME (10 mg/kg) blocked the LI enhancing effect of PCP on LI but not that of d-AMP. L-NAME by itself caused an attenuation of LI. L-NAME has been shown to block also other behavioural and biochemical effects of PCP in previous studies and these results and the present findings suggest that at least some of the effects PCP are dependent on NO and possibly also that some NOS inhibitors may exert antipsychotic properties.

The psychotomimetic drugs, phencyclidine (PCP) and MK-801, are non-competitive antagonists of the N-methyl-d-aspartate (NMDA) receptor and used as pharmacological tools to mimic a possible NMDA receptor hypofunction in schizophrenia. These drugs were tested in two behavioural paradigms in the present study: prepulse inhibition (PPI) of acoustic startle and locomotor activity (LMA) in an open field. Recent studies show that several behavioural and biochemical effects of PCP are blocked by nitric oxide synthase (NOS) inhibition. Hence, it is likely that some effects of PCP are mediated via an increase in NO production, an assumption not in accordance with the NMDA receptor antagonistic effect of PCP. Experiments were conducted in rats to further elucidate the involvement of NO-dependent mechanisms in the effects of PCP and MK-801, and how these effects may involve the NMDA receptor. The NOS inhibitor N(G)-nitro-l-arginine methyl ester (L-NAME) (10 mg/kg) normalised the disruptive effect of PCP (2 mg/kg) on PPI and the stimulatory effect of PCP (4 mg/kg) on LMA. In contrast to these observations, the deficit in PPI induced by MK-801 (0.1 mg/kg) was not affected by L-NAME (10, 20 or 40 mg/kg). MK-801 (0.15 mg/kg)-induced hyperlocomotion was not affected by L-NAME (10 mg/kg), but attenuated by L-NAME (40 mg/kg). Furthermore, receptor binding studies aimed at investigating the influence of L-NAME on the binding of PCP to the MK-801-sensitive NMDA receptor binding site failed to show such an influence. These results suggest that the NO-sensitive effects of PCP are not sufficiently explained by its antagonistic effect at the NMDA receptor channel complex.

Latent inhibition (LI) is a behavioural procedure in which preexposure to a stimulus not followed by reinforcement retards subsequent conditioning to this stimulus when it is paired with reinforcement. Changes in LI thus reflect greater or lesser retardation of learning which essentially implies a potentiation or an attenuation of the LI effect. LI has proved sensitive to psychotomimetic and antipsychotic treatment, which has encouraged its use to model learning and attention deficits in schizophrenia. In the present study, experiments were conducted to evaluate the effects of the psychotomimetic drug, phencyclidine (PCP, 2 mg/kg), and compare it with D-amphetamine (D-AMP, 0.33 and 1 mg/kg), on LI using a conditioned taste aversion procedure. PCP was found to potentiate LI when administered acutely prior to the conditioning trails, while no such effect was observed when administered prior to the preexposure trials. D-AMP, on the other hand, disrupted LI possibly due to a failure to induce a persistent taste aversion conditioning.

Aim: To evaluate the characteristics, outcome and prognostic factors among children suffering from out of hospital cardiac arrest in Sweden., Methods: Patients aged below 18 years suffering from out of hospital cardiac arrest which were not crew witnessed and included in the Swedish cardiac arrest registry were included in the survey. This survey included the period 1990-2001 and 60 ambulance organisations covering 85% of the Swedish population (8 million inhabitants)., Results: In all 457 children participated in the survey of which 32% were bystander witnessed and 68% received bystander CPR. Ventricular fibrillation was found in 6% of the cases. The overall survival to 1 month was 4%. The aetiology was sudden infant death syndrome in 34% and cardiac in 11%. When in a multivariate analysis considering age, sex, witnessed status, bystander CPR, initial rhythm, aetiology and the interval between call for, and arrival of, the ambulance and place of arrest only one appeared as an independent predictor of an increased chance of surviving cardiac arrest occurring outside home (adjusted odds ratio 8.7; 95% CL 2.2-58.1)., Conclusion: Among children suffering from out of hospital cardiac arrest in Sweden that were not crew witnessed, the overall survival is low (4%). The chance of survival appears to be markedly increased if the arrest occurs outside the patients home compared with at home. No other strong predictors for an increased chance of survival could be demonstrated.

Aim: To describe the change in the occurrence of ventricular fibrillation as initially observed arrhythmia among patients suffering from out-of-hospital cardiac arrest in Sweden., Patients: All patients included in the Swedish cardiac arrest registry between 1991 until 2001. The registry covers 85% of the population in Sweden., Methods: All patients with bystander witnessed out-of-hospital cardiac arrest included in the Swedish Cardiac Arrest Registry between 1991 and 2001 from the same ambulance organisation each year were included in the survey., Results: Over 11 years, among patients in Sweden with a bystander witnessed out-of-hospital cardiac arrest in whom cardiopulmonary resuscitation (CPR) was attempted (n = 9666), the occurrence of ventricular fibrillation as the initially obseved arrhythmia decreased from 45% in 1991 to 28% in 2001 (P < 0.0001) if the arrest occurred at home, and from 57% to 41% if the arrest occurred outside home (P < 0.0001). This was found despite the fact that the proportion who received bystander CPR increased from 29% in 1991 to 39% in 2001 if the arrest occurred at home (P < 0.0001) and from 54% to 60% if the arrest occurred outside home (NS). There was a significant increase in age among patients with out-of-hospital cardiac arrest at home, no change in the estimated interval between collapse and call but an increase in the interval between call and arrival of the ambulance among patients with out-of-hospital cardiac arrest outside home., Conclusion: During 11 years in Sweden, there was a marked decrease in the proportion of patients found in ventricular fibrillation among patients with a bystander witnessed cardiac arrest regardless whether the arrest occurred at home or outside home. A modest increase in age and interval between call for, and arrival of, the ambulance was associated with these findings.

Aim: To evaluate survival after out-of-hospital cardiac arrest in relation to sex., Methods: All patients with out-of-hospital cardiac arrest included in the Swedish Cardiac Arrest Registry between 1990 and 2000 in whom cardiopulmonary resuscitation (CPR) was attempted and who did not have a crew witnessed arrest were included. The registry covers 85% of the inhabitants of Sweden (approximately 8 million inhabitants). P-values were adjusted to differences in age. Survival was defined as patients being hospitalised alive and being alive one month after cardiac arrest. In all, 23,797 patients participated in the survey of which 27.9% were women., Results: Among women 16.4% were hospitalised alive versus 13.2% among men ( P<0.001). After one month 3.0% among women were alive versus 3.4% among men (NS). In a multivariate analysis considering differences in age and various factors at resuscitation female sex was an independent predictor for patients being hospitalised alive (odds ratio 1.66; 95% confidence limits 1.49-1.84) and for being alive after one month (odds ratio 1.27; 95% confidence limits 1.03-1.56). Women differed from men as they were older ( P<0.001 ), had a lower prevalence of witnessed cardiac arrest ( P=0.01), a lower occurrence of bystander CPR (P<0.001), a lower occurrence of ventricular fibrillation as initial arrhythmia (P<0.001) and a lower occurrence of cardiac disease judged to be the cause of cardiac arrest ( P<0.0001 ). On the other hand they had a cardiac arrest at home more frequently ( P<0.001 )., Conclusion: Among patients suffering out-of-hospital cardiac arrest in Sweden which was not crew witnessed and in whom resuscitation efforts were attempted, female sex was associated with an increased survival.

The physiological protection from fetal rejection is believed to be dependent on a Th2 type of inflammatory response at the maternal-fetal interface and the cytokines IL-4 and IL-10 have been suggested to play a critical role. We here present data from breeding experiments with IL-10 and IL-4 double-deficient mice indicating that neither maternal nor feto-placental deficiency of these cytokines are crucial for fetal or neonatal survival. The present study does not analyse possible developmental effects of maternal or fetal IL-10 and IL-4 double-deficiency in detail, but shows that an apparently normal breeding can be achieved in different crossings, providing that the mice are kept under very clean conditions.

The effect of neonatal brain infection of herpes simplex virus type 1 (HSV-1) on the development of sensorimotor function in the rat was investigated using an acoustic startle paradigm. Intracerebral inoculation of HSV-1 at day 2 after birth, but not at day 4, caused a significant delay in the development of prepulse inhibition of acoustic startle. A decrease in prepulse inhibition was shown at 37, 46 and 58 days of age in these rats compared to control rats. No evidence was obtained for other behavioural dysfunctions such as differences in sensorimotor reactivity, sensorimotor response habituation, spontaneous locomotor activity, rearing activity or stereotyped behaviour. Prepulse inhibition of acoustic startle is an accepted model of sensorimotor gating in the CNS, a function which has been shown diminished in schizophrenic persons. The present results suggest that early viral infections during a neurone-susceptible period may contribute to the development of this deficit.

Some cell lines are difficult to grow in confluent monolayers and, therefore, the plaque assay cannot be applied since plaques may be hard to distinguish from other blank areas of the cell monolayers. To avoid this problem a rapid and sensitive immuno dot blot TCID50 method was developed using antibodies against virus antigens to detect infection and virus production. An alternative statistical method was developed to treat the scoring data and thereby obtained a coefficient of variation of 10%. To speed up the total procedure and to increase the proliferation rate of cells grown in 96-well cell culture plates, the plates were pretreated for 4 h at 4 degrees C with growth medium obtained from cell culturing flasks containing confluent cell monolayers. This immuno dot blot TCID50 method was applied for a study of the infectivity maintenance upon storage of infectious pancreatic necrosis virus (IPNV). Storage of IPNV at -70 degrees C with a cryoprotective agent (10% glycerol) preserved the TCID50 level even after as many as ten cycles of freezings and thawings, whereas the infectivity decreased by four orders of magnitude after storage at 4-8 degrees C for 2 months in the salt buffer used commonly.