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Background: Survival from an out-of-hospital cardiac arrest (OHCA) depends on the sequence of interventions in "the chain of survival". If OHCA is recognized in the emergency medical communication centre (EMCC), the proper emergency medical service (EMS) should be dispatched and cardiopulmonary resuscitation (CPR) instructions should be given to a bystander. The study aimed to examine the impact of OHCA recognition in the EMCC on survival rates and the main elements of the chain of survival.Methods: Data from the Helsinki University Hospital's registry of OHCA patients between 1997 and 2013 were studied. Altogether, 2054 EMCC-handled and bystander-witnessed OHCA proven events of cardiac origin were analysed.Results: In 80.5% of the victims, two EMS units were correctly dispatched and the OHCA was classified as recognized. Achieved return of spontaneous circulation (ROSC) and survival to hospital discharge were 49% and 23%, respectively, if cardiac arrest was recognized by the EMCC and 40% and 16% when it was not (P = 0.003 and 0.002). Dispatchers gave CPR instructions in 60% of the recognized OHCA cases. Bystander-performed CPR increased over time and was given in 58% of the recognized OHCAs and also in 17% of the unrecognized events. EMS delays were shorter if OHCA was recognized as opposed to unrecognized (8 min with an IQR 6.5-10 min vs. 9 min with an IQR 6.5-11 min; P = 0.001).Conclusions: Recognition of OHCA by the EMCC was significantly associated with an increased rate of bystander-performed CPR, reduced EMS response time, and increased OHCA patient ROSC and survival rates. [ABSTRACT FROM AUTHOR]

Atrial fibrillation (AF) is globally the most common arrhythmia associated with significant morbidity and mortality. It impairs the quality of the patient's life, imposing a remarkable burden on public health, and the healthcare budget. The detection of AF is important in the decision to initiate anticoagulation therapy to prevent thromboembolic events. Nonetheless, AF detection is still a major clinical challenge as AF is often paroxysmal and asymptomatic. AF screening recommendations include opportunistic or systematic screening in patients ≥65 years of age or in those individuals with other characteristics pointing to an increased risk of stroke. The popularities of well-being and taking personal responsibility for one's own health are reflected in the continuous development and growth of mobile health technologies. These novel mobile health technologies could provide a cost-effective solution for AF screening and an additional opportunity to detect AF, particularly its paroxysmal and asymptomatic forms., Competing Interests: Disclosure: O.E.S., J.A.L., T.T.R., T.J.M., H.J., J.H., E.S.V., and M.P.T. are shareholders of a company (Heart2Save) that designs electrocardiogram-based software for medical equipment. J.A.L., M.P.T., and H.J. report personal fees from Heart2Save. The other authors declare no conflict of interest., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc.)

Atrial fibrillation is the most common arrhythmia to occur after cardiac surgery, with an incidence of 10% to 50%. It is associated with postoperative complications including increased risk of stroke, prolonged hospital stays and increased costs. Despite new insights into the mechanisms of atrial fibrillation, no specific etiologic factor has been identified as the sole perpetrator of the arrhythmia. Current evidence suggests that the pathophysiology of atrial fibrillation in general, as well as after cardiac surgery, is multifactorial. Studies have also shown that new-onset postoperative atrial fibrillation following cardiac surgery is associated with a higher risk of short-term and long-term mortality. Furthermore, it has been demonstrated that prophylactic medical therapy decreases the incidence of postoperative atrial fibrillation after cardiac surgery. Of note, the incidence of postoperative atrial fibrillation has not changed during the last decades despite the numerous preventive strategies and operative techniques proposed, although the perioperative and postoperative care of cardiac patients as such has improved., Competing Interests: Disclosure: The authors declare no conflict of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Discovery of meningeal lymphatic vessels (LVs) in the dura mater, also known as dural LVs (dLVs) that depend on vascular endothelial growth factor C expression, has raised interest in their possible involvement in Alzheimer's disease (AD). Here we find that in the APdE9 and 5xFAD mouse models of AD, dural amyloid-β (Aβ) is confined to blood vessels and dLV morphology or function is not altered. The induction of sustained dLV atrophy or hyperplasia in the AD mice by blocking or overexpressing vascular endothelial growth factor C, impaired or improved, respectively, macromolecular cerebrospinal fluid (CSF) drainage to cervical lymph nodes. Yet, sustained manipulation of dLVs did not significantly alter the overall brain Aβ plaque load. Moreover, dLV atrophy did not alter the behavioral phenotypes of the AD mice, but it improved CSF-to-blood drainage. Our results indicate that sustained dLV manipulation does not affect Aβ deposition in the brain and that compensatory mechanisms promote CSF clearance., Competing Interests: Competing interests The authors declare no competing interests.

Background: Air pollution is recognized as an emerging environmental risk factor for neurological diseases. Large-scale epidemiological studies associate traffic-related particulate matter (PM) with impaired cognitive functions and increased incidence of neurodegenerative diseases such as Alzheimer's disease. Inhaled components of PM may directly invade the brain via the olfactory route, or act through peripheral system responses resulting in inflammation and oxidative stress in the brain. Microglia are the immune cells of the brain implicated in the progression of neurodegenerative diseases. However, it remains unknown how PM affects live human microglia., Results: Here we show that two different PMs derived from exhausts of cars running on EN590 diesel or compressed natural gas (CNG) alter the function of human microglia-like cells in vitro. We exposed human induced pluripotent stem cell (iPSC)-derived microglia-like cells (iMGLs) to traffic related PMs and explored their functional responses. Lower concentrations of PMs ranging between 10 and 100 µg ml -1 increased microglial survival whereas higher concentrations became toxic over time. Both tested pollutants impaired microglial phagocytosis and increased secretion of a few proinflammatory cytokines with distinct patterns, compared to lipopolysaccharide induced responses. iMGLs showed pollutant dependent responses to production of reactive oxygen species (ROS) with CNG inducing and EN590 reducing ROS production., Conclusions: Our study indicates that traffic-related air pollutants alter the function of human microglia and warrant further studies to determine whether these changes contribute to adverse effects in the brain and on cognition over time. This study demonstrates human iPSC-microglia as a valuable tool to study functional microglial responses to environmental agents., (© 2024. The Author(s).)

New in vitro models provide an exciting opportunity to study live human microglia. Previously, a major limitation in understanding human microglia in health and disease has been their limited availability. Here, we provide an overview of methods to obtain human stem cell or blood monocyte-derived microglia-like cells that provide a nearly unlimited source of live human microglia for research. We address how understanding microglial ontogeny can help modeling microglial identity and function in a dish with increased accuracy. Moreover, we categorize stem cell-derived differentiation methods into embryoid body based, growth factor driven, and coculture-driven approaches, and review novel viral approaches to reprogram stem cells directly into microglia-like cells. Furthermore, we review typical readouts used in the field to verify microglial identity and characterize functional microglial phenotypes. We provide an overview of methods used to study microglia in environments more closely resembling the (developing) human CNS, such as cocultures and brain organoid systems with incorporated or innately developing microglia. We highlight how microglia-like cells can be utilized to reveal molecular and functional mechanisms in human disease context, focusing on Alzheimer's disease and other neurodegenerative diseases as well as neurodevelopmental diseases. Finally, we provide a critical overview of challenges and future opportunities to more accurately model human microglia in a dish and conclude that novel in vitro microglia-like cells provide an exciting potential to bring preclinical research of microglia to a new era., (© 2024. The Author(s), under exclusive license to Springer Nature Switzerland AG.)

LRRK2-G2019S is one of the most common Parkinson's disease (PD)-associated mutations and has been shown to alter microglial functionality. However, the impact of LRRK2-G2019S on transcriptional profile of human induced pluripotent stem cell-derived microglia-like cells (iMGLs) and how it corresponds to microglia in idiopathic PD brain is not known. Here we demonstrate that LRRK2-G2019S carrying iMGL recapitulate aspects of the transcriptional signature of human idiopathic PD midbrain microglia. LRRK2-G2019S induced subtle and donor-dependent alterations in iMGL mitochondrial respiration, phagocytosis and cytokine secretion. Investigation of microglial transcriptional state in the midbrains of PD patients revealed a subset of microglia with a transcriptional overlap between the in vitro PD-iMGL and human midbrain PD microglia. We conclude that LRRK2-G2019S iMGL serve as a model to study PD-related effects in human microglia., (© 2023. The Author(s).)

Background: In the digitalized world, there is a need for developing new online teaching and learning methods. Although audio and video recordings are increasingly used in everyday learning, little scientific evidence is available on the efficacy of new online methods. This randomized trial was set out to compare the learning outcomes of online and classroom teaching methods in training healthcare students to diagnose breathing difficulties in children., Methods: In total, 301 students of medicine (N = 166) and nursing (N = 135) volunteered to participate in this total sampling study in 2021-2022. The students were randomized into four groups based on teaching methods: classroom teaching (live, N = 72), streamed classroom teaching (live-stream, N = 77), audio recording (podcast, N = 79) and video recording (vodcast, N = 73). Each 45-minute lesson was taught by the same teachers and used the same protocol. The students participated an online test with their own electronic device at three distinct time points: prior to any teaching (baseline), immediately after teaching (final test), and five weeks later (long-term memory test). The test consisted of 10 multiple-choice questions on recognizing breathing difficulties from real-life videos of breathing difficulties in pre-school age. The test results scale ranged from - 26 to 28 points. Statistical analyses were performed using ANOVA multiple comparison and multiple regression tests., Results: The mean scores (SD) of the final tests were 22.5 (5.3) in the vodcast, 22.9 (6.1) in the live, 20.0 (5.6) in the podcast (p < 0.05 vs. live) and 20.1 (6.8) in the live-stream group. The mean difference of test scores before and after the lesson improved significantly (p < 0.05) in all study groups, with 12.9 (6.5) in the vodcast, 12.6 (5.6) in the live, 10.9 (7.0) in the live-stream and 10.4 (6.9) in the podcast group. The improvement in test scores was significantly higher in the vodcast (p = 0.016) and the live (p = 0.037) groups than in the podcast group. No significant differences were found between the other groups. However, there was a nonsignificant difference towards better results in the vodcast group compared to the live-stream group., Conclusions: While the new online teaching methods produce learning, only video learning is comparable to team teaching in classrooms., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Eutrophication increases the input of labile, algae-derived, organic matter (OM) into lake sediments. This potentially increases methane (CH 4 ) emissions from sediment to water through increased methane production rates and decreased methane oxidation efficiency in sediments. However, the effect of OM lability on the structure of methane oxidizing (methanotrophic) and methane producing (methanogenic) microbial communities in lake sediments is still understudied. We studied the vertical profiles of the sediment and porewater geochemistry and the microbial communities (16S rRNA gene amplicon sequencing) at five profundal stations of an oligo-mesotrophic, boreal lake (Lake Pääjärvi, Finland), varying in surface sediment OM sources (assessed via sediment C:N ratio). Porewater profiles of methane, dissolved inorganic carbon (DIC), acetate, iron, and sulfur suggested that sites with more autochthonous OM showed higher overall OM lability, which increased remineralization rates, leading to increased electron acceptor (EA) consumption and methane emissions from sediment to water. When OM lability increased, the abundance of anaerobic nitrite-reducing methanotrophs ( Candidatus Methylomirabilis) relative to aerobic methanotrophs ( Methylococcales ) in the methane oxidation layer of sediment surface decreased, suggesting that Methylococcales were more competitive than Ca . Methylomirabilis under decreasing redox conditions and increasing methane availability due to their more diverse metabolism (fermentation and anaerobic respiration) and lower affinity for methane. Furthermore, when OM lability increased, the abundance of methanotrophic community in the sediment surface layer, especially Ca . Methylomirabilis, relative to the methanogenic community decreased. We conclude that increasing input of labile OM, subsequently affecting the redox zonation of sediments, significantly modifies the methane producing and consuming microbial community of lake sediments. IMPORTANCE Lakes are important natural emitters of the greenhouse gas methane (CH 4 ). It has been shown that eutrophication, via increasing the input of labile organic matter (OM) into lake sediments and subsequently affecting the redox conditions, increases methane emissions from lake sediments through increased sediment methane production rates and decreased methane oxidation efficiency. However, the effect of organic matter lability on the structure of the methane-related microbial communities of lake sediments is not known. In this study, we show that, besides the activity, also the structure of lake sediment methane producing and consuming microbial community is significantly affected by changes in the sediment organic matter lability.

The PSEN1 ΔE9 mutation causes a familial form of Alzheimer's disease (AD) by shifting the processing of amyloid precursor protein (APP) towards the generation of highly amyloidogenic Aβ42 peptide. We have previously shown that the PSEN1 ΔE9 mutation in human-induced pluripotent stem cell (iPSC)-derived astrocytes increases Aβ42 production and impairs cellular responses. Here, we injected PSEN1 ΔE9 mutant astrosphere-derived glial progenitors into newborn mice and investigated mouse behavior at the ages of 8, 12, and 16 months. While we did not find significant behavioral changes in younger mice, spatial learning and memory were paradoxically improved in 16-month-old PSEN1 ΔE9 glia-transplanted male mice as compared to age-matched isogenic control-transplanted animals. Memory improvement was associated with lower levels of soluble, but not insoluble, human Aβ42 in the mouse brain. We also found a decreased engraftment of PSEN1 ΔE9 mutant cells in the cingulate cortex and significant transcriptional changes in both human and mouse genes in the hippocampus, including the extracellular matrix-related genes. Overall, the presence of PSEN1 ΔE9 mutant glia exerted a more beneficial effect on aged mouse brain than the isogenic control human cells likely as a combination of several factors.

Rationale: Stable isotope approaches are increasingly applied to better understand the cycling of inorganic nitrogen (N i ) forms, key limiting nutrients in terrestrial and aquatic ecosystems. A systematic comparison of the accuracy and precision of the most commonly used methods to analyze δ 15 N in NO 3 - and NH 4 + and interlaboratory comparison tests to evaluate the comparability of isotope results between laboratories are, however, still lacking., Methods: Here, we conducted an interlaboratory comparison involving 10 European laboratories to compare different methods and laboratory performance to measure δ 15 N in NO 3 - and NH 4 + . The approaches tested were (a) microdiffusion (MD), (b) chemical conversion (CM), which transforms N i to either N 2 O (CM-N 2 O) or N 2 (CM-N 2 ), and (c) the denitrifier (DN) methods., Results: The study showed that standards in their single forms were reasonably replicated by the different methods and laboratories, with laboratories applying CM-N 2 O performing superior for both NO 3 - and NH 4 + , followed by DN. Laboratories using MD significantly underestimated the "true" values due to incomplete recovery and also those using CM-N 2 showed issues with isotope fractionation. Most methods and laboratories underestimated the at% 15 N of N i of labeled standards in their single forms, but relative errors were within maximal 6% deviation from the real value and therefore acceptable. The results showed further that MD is strongly biased by nonspecificity. The results of the environmental samples were generally highly variable, with standard deviations (SD) of up to ± 8.4‰ for NO 3 - and ± 32.9‰ for NH 4 + ; SDs within laboratories were found to be considerably lower (on average 3.1‰). The variability could not be connected to any single factor but next to errors due to blank contamination, isotope normalization, and fractionation, and also matrix effects and analytical errors have to be considered., Conclusions: The inconsistency among all methods and laboratories raises concern about reported δ 15 N values particularly from environmental samples., (© 2022 The Authors. Rapid Communications in Mass Spectrometry published by John Wiley & Sons Ltd.)

Background: Species-specific differences in astrocytes and their Alzheimer disease-associated pathology may influence cellular responses to other insults. Herein, human glial chimeric mice were generated to evaluate how Alzheimer disease predisposing genetic background in human astrocytes contributes to behavioral outcome and brain pathology after cortical photothrombotic ischemia., Methods: Neonatal (P0) immunodeficient mice of both sexes were transplanted with induced pluripotent stem cell-derived astrocyte progenitors from Alzheimer disease patients carrying PSEN1 exon 9 deletion (PSEN1 ΔE9), with isogenic controls, with cells from a healthy donor, or with mouse astrocytes or vehicle. After 14 months, a photothrombotic lesion was produced with Rose Bengal in the motor cortex. Behavior was assessed before ischemia and 1 and 4 weeks after the induction of stroke, followed by tissue perfusion for histology., Results: Open field, cylinder, and grid-walking tests showed a persistent locomotor and sensorimotor impairment after ischemia and female mice had larger infarct sizes; yet, these were not affected by astrocytes with PSEN1 ΔE9 background. Staining for human nuclear antigen confirmed that human cells successfully engrafted throughout the mouse brain. However, only a small number of human cells were positive for astrocytic marker GFAP (glial fibrillary acidic protein), mostly located in the corpus callosum and retaining complex human-specific morphology with longer processes compared with host counterparts. While host astrocytes formed the glial scar, human astrocytes were scattered in small numbers close to the lesion boundary. Aβ (beta-amyloid) deposits were not present in PSEN1 ΔE9 astrocyte-transplanted mice., Conclusions: Transplanted human cells survived and distributed widely in the host brain but had no impact on severity of ischemic damage after cortical photothrombosis in chimeric mice. Only a small number of transplanted human astrocytes acquired GFAP-positive glial phenotype or migrated toward the ischemic lesion forming glial scar. PSEN1 ΔE9 astrocytes did not impair behavioral recovery after experimental stroke.

Background: The detection of atrial fibrillation (AF) is a major clinical challenge as AF is often paroxysmal and asymptomatic. Novel mobile health (mHealth) technologies could provide a cost-effective and reliable solution for AF screening. However, many of these techniques have not been clinically validated., Objective: The purpose of this study is to evaluate the feasibility and reliability of artificial intelligence (AI) arrhythmia analysis for AF detection with an mHealth patch device designed for personal well-being., Methods: Patients (N=178) with an AF (n=79, 44%) or sinus rhythm (n=99, 56%) were recruited from the emergency care department. A single-lead, 24-hour, electrocardiogram-based heart rate variability (HRV) measurement was recorded with the mHealth patch device and analyzed with a novel AI arrhythmia analysis software. Simultaneously registered 3-lead electrocardiograms (Holter) served as the gold standard for the final rhythm diagnostics., Results: Of the HRV data produced by the single-lead mHealth patch, 81.5% (3099/3802 hours) were interpretable, and the subject-based median for interpretable HRV data was 99% (25th percentile=77% and 75th percentile=100%). The AI arrhythmia detection algorithm detected AF correctly in all patients in the AF group and suggested the presence of AF in 5 patients in the control group, resulting in a subject-based AF detection accuracy of 97.2%, a sensitivity of 100%, and a specificity of 94.9%. The time-based AF detection accuracy, sensitivity, and specificity of the AI arrhythmia detection algorithm were 98.7%, 99.6%, and 98.0%, respectively., Conclusions: The 24-hour HRV monitoring by the mHealth patch device enabled accurate automatic AF detection. Thus, the wearable mHealth patch device with AI arrhythmia analysis is a novel method for AF screening., Trial Registration: ClinicalTrials.gov NCT03507335; https://clinicaltrials.gov/ct2/show/NCT03507335., (©Onni E Santala, Jukka A Lipponen, Helena Jäntti, Tuomas T Rissanen, Mika P Tarvainen, Tomi P Laitinen, Tiina M Laitinen, Maaret Castrén, Eemu-Samuli Väliaho, Olli A Rantula, Noora S Naukkarinen, Juha E K Hartikainen, Jari Halonen, Tero J Martikainen. Originally published in JMIR Cardio (https://cardio.jmir.org), 21.06.2022.)

Background: Microglia are the endogenous immune cells of the brain and act as sensors of pathology to maintain brain homeostasis and eliminate potential threats. In Alzheimer's disease (AD), toxic amyloid beta (Aβ) accumulates in the brain and forms stiff plaques. In late-onset AD accounting for 95% of all cases, this is thought to be due to reduced clearance of Aβ. Human genome-wide association studies and animal models suggest that reduced clearance results from aberrant function of microglia. While the impact of neurochemical pathways on microglia had been broadly studied, mechanical receptors regulating microglial functions remain largely unexplored., Methods: Here we showed that a mechanotransduction ion channel, PIEZO1, is expressed and functional in human and mouse microglia. We used a small molecule agonist, Yoda1, to study how activation of PIEZO1 affects AD-related functions in human induced pluripotent stem cell (iPSC)-derived microglia-like cells (iMGL) under controlled laboratory experiments. Cell survival, metabolism, phagocytosis and lysosomal activity were assessed using real-time functional assays. To evaluate the effect of activation of PIEZO1 in vivo, 5-month-old 5xFAD male mice were infused daily with Yoda1 for two weeks through intracranial cannulas. Microglial Iba1 expression and Aβ pathology were quantified with immunohistochemistry and confocal microscopy. Published human and mouse AD datasets were used for in-depth analysis of PIEZO1 gene expression and related pathways in microglial subpopulations., Results: We show that PIEZO1 orchestrates Aβ clearance by enhancing microglial survival, phagocytosis, and lysosomal activity. Aβ inhibited PIEZO1-mediated calcium transients, whereas activation of PIEZO1 with a selective agonist, Yoda1, improved microglial phagocytosis resulting in Aβ clearance both in human and mouse models of AD. Moreover, PIEZO1 expression was associated with a unique microglial transcriptional phenotype in AD as indicated by assessment of cellular metabolism, and human and mouse single-cell datasets., Conclusion: These results indicate that the compromised function of microglia in AD could be improved by controlled activation of PIEZO1 channels resulting in alleviated Aβ burden. Pharmacological regulation of these mechanoreceptors in microglia could represent a novel therapeutic paradigm for AD., (© 2022. The Author(s).)

Objectives: Prehospital critical care physicians regularly attend to patients with poor prognosis and may limit the advanced therapies. The aim of this study was to evaluate the accuracy of poor prognosis given by prehospital critical care clinicians., Design: Cohort study., Setting: We performed a retrospective cohort study using the national helicopter emergency medical services (HEMS) quality database., Participants: Patients classified by the HEMS clinician to have survived until hospital admission solely because of prehospital interventions but evaluated as having no long-term survival by prehospital clinician, were included., Primary and Secondary Outcome: The survival of the study patients was examined at 30 days, 1 year and 3 years., Results: Of 36 715 patients encountered by the HEMS during the study period, 2053 patients were classified as having no long-term survival and included. At 30 days, 713 (35%, 95% CI 33% to 37%) were still alive and 69 were lost to follow-up. Furthermore, at 1 year 524 (26%) and at 3 years 267 (13%) of the patients were still alive. The deceased patients received more often prehospital rapid sequence intubation and vasoactives, compared with patients alive at 30 days. Patients deceased at 30 days were older and had lower initial Glasgow Coma Scores. Otherwise, no clinically relevant difference was found in the prehospital vital parameters between the survivors and non-survivors., Conclusions: The prognostication of long-term survival for critically ill patients by a prehospital critical care clinician seems to fulfil only moderately. A prognosis based on clinical judgement must be handled with a great degree of caution and decision on limitation of advanced care should be made cautiously., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: Recognizing stroke and other intracranial pathologies in prehospital phase facilitates prompt recanalization and other specific care. Recognizing these can be difficult in patients with decreased level of consciousness. We previously derived a scoring system combining systolic blood pressure, age and heart rate to recognize patients with intracranial pathology. In this study we aimed to validate the score in a larger, separate population., Materials and Methods: We conducted a register based retrospective study on patients ≥16 years old and Glasgow Coma Score <15 encountered by helicopter emergency medical services. Diagnoses at the end of hospitalization were used to identify if patients had intracranial lesion or not. The performance of score was evaluated by area under the receiver operating characteristics curve (AUROC)., Results: Of 9,309 patients included, 1,925 (20.7%) had an intracranial lesion including 1,211 cases of stroke. Older age, higher blood pressure and lower heart rate were predictors for an intracranial lesion (P<0.001 for all). The score distinguished patients with intracranial lesion with AUROC of 0.749 (95% CI 0.737 to 0.761). The performance slightly improved if only patients intubated in prehospital phase were included AUROC 0.780 (95% CI 0.770 to 0.806) or convulsion related diagnosis excluded AUROC of 0.788 (95% CI 0.768 to 0.792)., Conclusions: A scoring of systolic blood pressure, heart rate and age help differentiate intracranial lesions in patients with decreased level of consciousness in prehospital care. This may facilitate direct transportation to stroke center and application of neuroprotective measures in prehospital critical care., Competing Interests: Declarations of Competing Interest None., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Pre-hospital anaesthesia is a core competency of helicopter emergency medical services (HEMS). Whether physician pre-hospital anaesthesia case volume affects outcomes is unknown in this setting. We aimed to investigate whether physician case volume was associated with differences in mortality or medical management., Methods: We conducted a registry-based cohort study of patients undergoing drug-facilitated intubation by HEMS physician from January 1, 2013 to August 31, 2019. The primary outcome was 30-day mortality, analysed using multivariate logistic regression controlling for patient-dependent variables. Case volume for each patient was determined by the number of pre-hospital anaesthetics the attending physician had managed in the previous 12 months. The explanatory variable was physician case volume grouped by low (0-12), intermediate (13-36), and high (≥37) case volume. Secondary outcomes were characteristics of medical management, including the incidence of hypoxaemia and hypotension., Results: In 4818 patients, the physician case volume was 511, 2033, and 2274 patients in low-, intermediate-, and high-case-volume groups, respectively. Higher physician case volume was associated with lower 30-day mortality (odds ratio 0.79 per logarithmic number of cases [95% confidence interval: 0.64-0.98]). High-volume physician providers had shorter on-scene times (median 28 [25th-75th percentile: 22-38], compared with intermediate 32 [23-42] and lowest 32 [23-43] case-volume groups; P<0.001) and a higher first-pass success rate for tracheal intubation (98%, compared with 93% and 90%, respectively; P<0.001). The incidence of hypoxaemia and hypotension was similar between groups., Conclusions: Mortality appears to be lower after pre-hospital anaesthesia when delivered by physician providers with higher case volumes., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Aim: Atrial fibrillation (AF) detection is challenging because it is often asymptomatic and paroxysmal. We evaluated continuous photoplethysmogram (PPG) for signal quality and detection of AF. Methods: PPGs were recorded using a wrist-band device in 173 patients (76 AF, 97 sinus rhythm, SR) for 24 h. Simultaneously recorded 3-lead ambulatory ECG served as control. The recordings were split into 10-, 20-, 30-, and 60-min time-frames. The sensitivity, specificity, and F1-score of AF detection were evaluated for each time-frame. AF alarms were generated to simulate continuous AF monitoring. Sensitivities, specificities, and positive predictive values (PPVs) of the alarms were evaluated. User experiences of PPG and ECG recordings were assessed. The study was registered in the Clinical Trials database (NCT03507335). Results: The quality of PPG signal was better during night-time than in daytime (67.3 ± 22.4% vs. 30.5 ± 19.4%, p  < 0.001). The 30-min time-frame yielded the highest F1-score (0.9536), identifying AF correctly in 72/76 AF patients (sensitivity 94.7%), only 3/97 SR patients receiving a false AF diagnosis (specificity 96.9%). The sensitivity and PPV of the simulated AF alarms were 78.2 and 97.2% at night, and 49.3 and 97.0% during the daytime. 82% of patients were willing to use the device at home. Conclusion: PPG wrist-band provided reliable AF identification both during daytime and night-time. The PPG data's quality was better at night. The positive user experience suggests that wearable PPG devices could be feasible for continuous rhythm monitoring., Competing Interests: JL, TR, TM, HJ, JH, and MT are shareholders of a company (Heart2Save) that designs ECG-based software for medical equipment. TM, PK, JL, MT, and HJ report personal fees from Heart2Save., (Copyright © 2022 Väliaho, Lipponen, Kuoppa, Martikainen, Jäntti, Rissanen, Castrén, Halonen, Tarvainen, Laitinen, Laitinen, Santala, Rantula, Naukkarinen and Hartikainen.)

Background: Earlier studies have shown variable results regarding the success of paediatric emergency endotracheal intubation between different settings and operators. We aimed to describe the paediatric population intubated by physician-staffed helicopter emergency medical service (HEMS) and evaluate the factors associated with overall and first-pass success (FPS)., Methods: We conducted a retrospective observational cohort study in Finland including all children less than 16 years old who required endotracheal intubation by a HEMS physician from January 2014 to August 2019. Utilising a national HEMS database, we analysed the incidence, indications, overall and first-pass success rates of endotracheal intubation., Results: A total of 2731 children were encountered by HEMS, and intubation was attempted in 245 (9%); of these, 22 were younger than 1 year, 103 were aged 1-5 years and 120 were aged 6-15 years. The most common indications for airway management were cardiac arrest for the youngest age group, neurological reasons (e.g., seizures) for those aged 1-5 years and trauma for those aged 6-15. The HEMS physicians had an overall success rate of 100% (95% CI: 98-100) and an FPS rate of 86% (95% CI: 82-90). The FPS rate was lower in the youngest age group (p = .002) and for patients in cardiac arrest (p < .001)., Conclusions: Emergency endotracheal intubation of children is successfully performed by a physician staffed HEMS unit even though these procedures are rare. To improve the care, emphasis should be on airway management of infants and patients in cardiac arrest., (© 2021 The Authors. Acta Anaesthesiologica Scandinavica published by John Wiley & Sons Ltd on behalf of Acta Anaesthesiologica Scandinavica Foundation.)

Background: Atrial fibrillation (AF) is the most common tachyarrhythmia and associated with a risk of stroke. The detection and diagnosis of AF represent a major clinical challenge due to AF's asymptomatic and intermittent nature. Novel consumer-grade mobile health (mHealth) products with automatic arrhythmia detection could be an option for long-term electrocardiogram (ECG)-based rhythm monitoring and AF detection., Objective: We evaluated the feasibility and accuracy of a wearable automated mHealth arrhythmia monitoring system, including a consumer-grade, single-lead heart rate belt ECG device (heart belt), a mobile phone application, and a cloud service with an artificial intelligence (AI) arrhythmia detection algorithm for AF detection. The specific aim of this proof-of-concept study was to test the feasibility of the entire sequence of operations from ECG recording to AI arrhythmia analysis and ultimately to final AF detection., Methods: Patients (n=159) with an AF (n=73) or sinus rhythm (n=86) were recruited from the emergency department. A single-lead heart belt ECG was recorded for 24 hours. Simultaneously registered 3-lead ECGs (Holter) served as the gold standard for the final rhythm diagnostics and as a reference device in a user experience survey with patients over 65 years of age (high-risk group)., Results: The heart belt provided a high-quality ECG recording for visual interpretation resulting in 100% accuracy, sensitivity, and specificity of AF detection. The accuracy of AF detection with the automatic AI arrhythmia detection from the heart belt ECG recording was also high (97.5%), and the sensitivity and specificity were 100% and 95.4%, respectively. The correlation between the automatic estimated AF burden and the true AF burden from Holter recording was >0.99 with a mean burden error of 0.05 (SD 0.26) hours. The heart belt demonstrated good user experience and did not significantly interfere with the patient's daily activities. The patients preferred the heart belt over Holter ECG for rhythm monitoring (85/110, 77% heart belt vs 77/109, 71% Holter, P=.049)., Conclusions: A consumer-grade, single-lead ECG heart belt provided good-quality ECG for rhythm diagnosis. The mHealth arrhythmia monitoring system, consisting of heart-belt ECG, a mobile phone application, and an automated AF detection achieved AF detection with high accuracy, sensitivity, and specificity. In addition, the mHealth arrhythmia monitoring system showed good user experience., Trial Registration: ClinicalTrials.gov NCT03507335; https://clinicaltrials.gov/ct2/show/NCT03507335., (©Onni E Santala, Jari Halonen, Susanna Martikainen, Helena Jäntti, Tuomas T Rissanen, Mika P Tarvainen, Tomi P Laitinen, Tiina M Laitinen, Eemu-Samuli Väliaho, Juha E K Hartikainen, Tero J Martikainen, Jukka A Lipponen. Originally published in JMIR mHealth and uHealth (https://mhealth.jmir.org), 22.10.2021.)

Background: It is largely unknown how often physicians in emergency helicopter medical services (HEMS) encounter various critical care events and if HEMS exposure is associated with particular practice patterns or outcomes., Objectives: This study aimed: to describe the frequency and distribution of critical care events; to investigate whether HEMS exposure is associated with differences in practice patterns and determine if HEMS exposure factors are associated with mortality., Design: A retrospective registry-based study., Setting: Physician-staffed HEMS in Finland between January 2012 and August 2019., Participants: Ninety-four physicians who worked at least 6 months in the HEMS during the study period. Physicians with undeterminable HEMS exposure were excluded from practice pattern comparisons and mortality analysis, leaving 80 physicians., Main Outcome Measures: The primary outcome measure was a physician's average annual frequencies for operational events and clinical interventions. Our secondary outcomes were the proportion of missions cancelled or denied, time onsite (OST) and proportion of unconscious patients intubated. Our tertiary outcome was adjusted 30-day mortality of patients., Results: The physicians encountered 62 [33 to 98], escorted 31 [17 to 41] and transported by helicopter 2.1 [1.3 to 3.5] patients annually, given as median [interquartile range; IQR]. Rapid sequence intubation was performed 11 [6.2 to 16] times per year. Physicians were involved in out-of-hospital cardiac arrest (OHCA) 10 [5.9 to 14] and postresuscitation care 5.5 [3.1 to 8.1] times per year. Physicians with longer patient intervals had shorter times onsite. Proportionally, they cancelled more missions and intubated fewer unconscious patients. A short patient interval [odds ratio (OR); 95% confidence interval (CI)] was associated with decreased mortality (0.87; 95% CI, 0.76 to1.00), whereas no association was observed between mortality and HEMS career length., Conclusion: Prehospital exposure is distributed unevenly, and some physicians receive limited exposure to prehospital critical care. This seems to be associated with differences in practice patterns. Rare HEMS patient contacts may be associated with increased mortality., (Copyright © 2021 European Society of Anaesthesiology and Intensive Care. Unauthorized reproduction of this article is prohibited.)

Aims of the Study: Helicopter Emergency Medical Services (HEMS) often provide post-resuscitation care. Our aims were to investigate whether physicians' frequent exposure to prehospital post-resuscitation care is associated with differences in (1) medical management, (2) achieving treatment targets recommended by resuscitation guidelines, (3) survival., Methods: We conducted a retrospective cohort study using data from a national HEMS quality register. We included patients between January 1st, 2012 and September 9th, 2019 who received post-resuscitation care by a HEMS physician. We excluded patients <16 years old. For each patient we determined the number of post-resuscitation cases the physician had attended in the previous 12 months. Patients were divided in to three groups: low (0-5), intermediate (6-11) and high exposure (≥12 cases). Medical management and proportions within treatment targets were compared. Survival at 30-days and 1-year was analysed by multivariate logistic regression analysis, controlling for known prognostic factors., Results: 2272 patients were analysed. Patients in the high exposure group had mechanical ventilation and vasoactive medications initiated more often (P < 0.001 and P = 0.008, respectively) and on-scene times were longer (P < 0.001). The target for blood pressure was achieved more often in this group (P = 0.026), but targets for oxygenation and ventilation were not. We did not see an association between survival and physicians' exposure to post-resuscitation care (odds ratio 0.96, 95% confidence interval 0.70-1.33 for low and 0.78, 0.56-1.08 for intermediate, compared to high exposure)., Conclusions: Physicians with more, frequent exposure take a more active approach to post-resuscitation care, but this does not seem to improve survival., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Atrial fibrillation is often asymptomatic and intermittent making its detection challenging. A photoplethysmography (PPG) provides a promising option for atrial fibrillation detection. However, the shapes of pulse waves vary in atrial fibrillation decreasing pulse and atrial fibrillation detection accuracy. This study evaluated ten robust photoplethysmography features for detection of atrial fibrillation. The study was a national multi-center clinical study in Finland and the data were combined from two broader research projects (NCT03721601, URL: https://clinicaltrials.gov/ct2/show/NCT03721601 and NCT03753139, URL: https://clinicaltrials.gov/ct2/show/NCT03753139). A photoplethysmography signal was recorded with a wrist band. Five pulse interval variability, four amplitude features and a novel autocorrelation-based morphology feature were calculated and evaluated independently as predictors of atrial fibrillation. A multivariate predictor model including only the most significant features was established. The models were 10-fold cross-validated. 359 patients were included in the study (atrial fibrillation n = 169, sinus rhythm n = 190). The autocorrelation univariate predictor model detected atrial fibrillation with the highest area under receiver operating characteristic curve (AUC) value of 0.982 (sensitivity 95.1%, specificity 93.7%). Autocorrelation was also the most significant individual feature ( p < 0.00001) in the multivariate predictor model, detecting atrial fibrillation with AUC of 0.993 (sensitivity 96.4%, specificity 96.3%). Our results demonstrated that the autocorrelation independently detects atrial fibrillation reliably without the need of pulse detection. Combining pulse wave morphology-based features such as autocorrelation with information from pulse-interval variability it is possible to detect atrial fibrillation with high accuracy with a commercial wrist band. Photoplethysmography wrist bands accompanied with atrial fibrillation detection algorithms utilizing autocorrelation could provide a computationally very effective and reliable wearable monitoring method in screening of atrial fibrillation., Competing Interests: JL, TR, TM, HJ, JH, and MT are shareholders of Heart2Save company that designs ECG-based software for medical equipment. JL, MT, and HJ have a patent pending. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Väliaho, Kuoppa, Lipponen, Hartikainen, Jäntti, Rissanen, Kolk, Pohjantähti-Maaroos, Castrén, Halonen, Tarvainen, Santala and Martikainen.)

Background: Atrial fibrillation (AF) is the major cause of stroke since approximately 25% of all strokes are of cardioembolic-origin. The detection and diagnosis of AF are often challenging due to the asymptomatic and intermittent nature of AF., Hypothesis: A wearable electrocardiogram (ECG)-device could increase the likelihood of AF detection. The aim of this study was to evaluate the feasibility and reliability of a novel, consumer-grade, single-lead ECG recording device (Necklace-ECG) for screening, identifying and diagnosing of AF both by a cardiologist and automated AF-detection algorithms., Methods: A thirty-second ECG was recorded with the Necklace-ECG device from two positions; between the palms (palm) and between the palm and the chest (chest). Simultaneously registered 3-lead ECGs (Holter) served as a golden standard for the final rhythm diagnosis. Two cardiologists interpreted independently in a blinded fashion the Necklace-ECG recordings from 145 patients (66 AF and 79 sinus rhythm, SR). In addition, the Necklace-ECG recordings were analyzed with an automatic AF detection algorithm., Results: Two cardiologists diagnosed the correct rhythm of the interpretable Necklace-ECG with a mean sensitivity of 97.2% and 99.1% (palm and chest, respectively) and specificity of 100% and 98.5%. The automatic arrhythmia algorithm detected the correct rhythm with a sensitivity of 94.7% and 98.3% (palm and chest) and specificity of 100% of the interpretable measurements., Conclusions: The novel Necklace-ECG device is able to detect AF with high sensitivity and specificity as evaluated both by cardiologists and an automated AF-detection algorithm. Thus, the wearable Necklace-ECG is a new, promising method for AF screening., Clinical Trial Registration: Study was registered in the ClinicalTrials.gov database (NCT03753139)., (© 2021 The Authors. Clinical Cardiology published by Wiley Periodicals LLC.)

The vertical structuring of methanotrophic communities and its genetic controllers remain understudied in the water columns of oxygen-stratified lakes. Therefore, we used 16S rRNA gene sequencing to study the vertical stratification patterns of methanotrophs in two boreal lakes, Lake Kuivajärvi and Lake Lovojärvi. Furthermore, metagenomic analyses were performed to assess the genomic characteristics of methanotrophs in Lovojärvi and the previously studied Lake Alinen Mustajärvi. The methanotroph communities were vertically structured along the oxygen gradient. Alphaproteobacterial methanotrophs preferred oxic water layers, while Methylococcales methanotrophs, consisting of putative novel genera and species, thrived, especially at and below the oxic-anoxic interface and showed distinct depth variation patterns, which were not completely predictable by their taxonomic classification. Instead, genomic differences among Methylococcales methanotrophs explained their variable vertical depth patterns. Genes in clusters of orthologous groups (COG) categories L (replication, recombination and repair) and S (function unknown) were relatively high in metagenome-assembled genomes representing Methylococcales clearly thriving below the oxic-anoxic interface, suggesting genetic adaptations for increased stress tolerance enabling living in the hypoxic/anoxic conditions. By contrast, genes in COG category N (cell motility) were relatively high in metagenome-assembled genomes of Methylococcales thriving at the oxic-anoxic interface, which suggests genetic adaptations for increased motility at the vertically fluctuating oxic-anoxic interface., (© The Author(s) 2020. Published by Oxford University Press on behalf of FEMS.)

Background: Helicopter Emergency Medical Services (HEMS) play an important role in prehospital care of the critically ill. Differences in funding, crew composition, dispatch criteria and mission profile make comparison between systems challenging. Several systems incorporate databases for quality control, performance evaluation and scientific purposes. FinnHEMS database was incorporated for such purposes following the national organization of HEMS in Finland 2012. The aims of this study are to describe information recorded in the database, data collection, and operational characteristics of Finnish HEMS during 2012-2018., Methods: All dispatches of the six Finnish HEMS units recorded in the national database from 2012 to 2018 were included in this observational registry study. Five of the units are physician staffed, and all are on call 24/7. The database follows a template for uniform reporting in physician staffed pre-hospital services, exceeding the recommended variables of relevant guidelines., Results: The study included 100,482 dispatches, resulting in 33,844 (34%) patient contacts. Variables were recorded with little or no missing data. A total of 16,045 patients (16%) were escorted by HEMS to hospital, of which 2239 (2%) by helicopter. Of encountered patients 4195 (4%) were declared deceased on scene. The number of denied or cancelled dispatches was 66,638 (66%). The majority of patients were male (21,185, 63%), and the median age was 57.7 years. The median American Society of Anesthesiologists Physical Scale classification was 2 and Eastern Cooperative Oncology Group performance class 0. The most common reason for response was trauma representing 26% (8897) of the patients, followed by out-of-hospital cardiac arrest 20% (6900), acute neurological reason excluding stroke 13% (4366) and intoxication and related psychiatric conditions 10% (3318). Blunt trauma (86%, 7653) predominated in the trauma classification., Conclusions: Gathering detailed and comprehensive data nationally on all HEMS missions is feasible. A national database provides valuable insights into where the operation of HEMS could be improved. We observed a high number of cancelled or denied missions and a low percentage of patients transported by helicopter. The medical problem of encountered patients also differs from comparable systems.

Background: Identifying stroke and other intracranial lesions in patients with a decreased level of consciousness may be challenging in prehospital settings. Our objective was to investigate whether the combination of systolic blood pressure, heart rate and age could be used to identify intracranial lesions., Methods: We conducted a retrospective case-control study including patients with a decreased level of consciousness who had their airway secured during prehospital care. Patients with intracranial lesions were identified based on the final diagnoses at the end of hospitalization. We investigated the ability of systolic blood pressure, heart rate and age to identify intracranial lesions and derived a decision instrument., Results: Of 425 patients, 127 had an intracranial lesion. Patients with a lesion were characterized by higher systolic blood pressure, lower heart rate and higher age (P < 0.0001 for all). A systolic blood pressure ≥ 140 mmHg had an odds ratio (OR) of 3.5 (95% confidence interval [CI] 1.7 to 7.0), and > 170 mmHg had an OR of 8.2 (95% CI 4.5-15.32) for an intracranial lesion (reference: < 140 mmHg). A heart rate < 100 beats/min had an OR of 3.4 (95% CI 2.0 to 6.0, reference: ≥100). Age 50-70 had an OR of 4.1 (95% CI 2.0 to 9.0), and > 70 years had an OR of 10.2 (95% CI 4.8 to 23.2), reference: < 50. Logarithms of ORs were rounded to the nearest integer to create a score with 0-2 points for age and blood pressure and 0-1 for heart rate, with an increasing risk for an intracranial lesion with higher scores. The area under the receiver operating characteristics curve for the instrument was 0.810 (95% CI 0.850-0.890)., Conclusions: An instrument combining systolic blood pressure, heart rate and age may help identify stroke and other intracranial lesions in patients with a decreased level of consciousness in prehospital settings., Trial Registration: Not applicable.

Freshwater ecosystems represent a significant natural source of methane (CH 4 ). CH 4 produced through anaerobic decomposition of organic matter (OM) in lake sediment and water column can be either oxidized to carbon dioxide (CO 2 ) by methanotrophic microbes or emitted to the atmosphere. While the role of CH 4 oxidation as a CH 4 sink is widely accepted, neither the magnitude nor the drivers behind CH 4 oxidation are well constrained. In this study, we aimed to gain more specific insight into CH 4 oxidation in the water column of a seasonally stratified, typical boreal lake, particularly under hypoxic conditions. We used 13 CH 4 incubations to determine the active CH 4 oxidation sites and the potential CH 4 oxidation rates in the water column, and we measured environmental variables that could explain CH 4 oxidation in the water column. During hypolimnetic hypoxia, 91% of available CH 4 was oxidized in the active CH 4 oxidation zone, where the potential CH 4 oxidation rates gradually increased from the oxycline to the hypolimnion. Our results showed that in warm springs, which become more frequent, early thermal stratification with cold well-oxygenated hypolimnion delays the period of hypolimnetic hypoxia and limits CH 4 production. Thus, the delayed development of hypolimnetic hypoxia may partially counteract the expected increase in the lacustrine CH 4 emissions caused by the increasing organic carbon load from forested catchments., (© The Author(s) 2020.)

Aims: Atrial fibrillation (AF) is the most common tachyarrhythmia and a significant cause of cardioembolic strokes. Atrial fibrillation is often intermittent and asymptomatic making detection a major clinical challenge. We evaluated a photoplethysmography (PPG) wrist band in individual pulse detection in patients with AF and tested the reliability of two commonly used algorithms for AF detection., Methods and Results: A 5-min PPG was recorded from patients with AF or sinus rhythm (SR) with a wrist band and analysed with two AF detection algorithms; AFEvidence and COSEn. Simultaneously registered electrocardiogram served as the golden standard for rhythm analysis and was interpreted by two cardiologists. The study population consisted of 213 (106 AF, 107 SR) patients. The wrist band PPG achieved individual pulse detection with a sensitivity of 91.7 ± 11.2% and a positive predictive value (PPV) of 97.5 ± 4.6% for AF, with a sensitivity of 99.4 ± 1.5% [7.7% (95% confidence interval, 95% CI 5.5% to 9.9%); P < 0.001] and PPV of 98.1 ± 4.1% [0.6% (95% CI -0.6% to 1.7%); P = 0.350] for SR. The pulse detection sensitivity was lower 86.7 ± 13.9% with recent-onset AF (AF duration <48 h, n = 43, 40.6%) as compared to late AF (≥48 h, n = 63, 59.4%) with 95.1 ± 7.2% [-8.3% (95% CI -12.9% to -3.7%); P = 0.001]. For the detection of AF from the wrist band PPG, the sensitivities were 96.2%/95.3% and specificity 98.1% with two algorithms., Conclusion: The wrist band PPG enabled accurate algorithm-based detection of AF with two AF detection algorithms and high individual pulse detection. Algorithms allowed accurate detection of AF from the PPG. A PPG wrist band provides an easy solution for AF screening., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)

Atrial fibrillation (AF) is a significant cause of cardioembolic strokes. AF is often symptomless and intermittent, making its detection challenging. The aim of this study was to assess the possibility to use a chest strap (Suunto Movesense) to detect AF both by cardiologists and automated algorithms. A single channel electrocardiogram (ECG) from a chest strap of 220 patients (107 AF and 111 sinus rhythm SR with 2 inconclusive rhythms) were analyzed by 2 cardiologists (Doc1 and Doc2) and 2 different algorithms (COSEn and AFEvidence). A 3-lead Holter served as the gold standard ECG for rhythm analysis. Both cardiologists evaluated the quality of the chest strap ECG to be superior to the quality of the Holter ECG; p <0.05/p <0.001 (Doc1/Doc 2). Accurate automated algorithm-based AF detection was achieved with sensitivity of 95.3%/96.3% and specificity of 95.5/98.2% with 2 AF detection algorithms from chest strap and 93.5%/97.2% and 98.2%/95.5% from Holter, respectively. P waves were detectable in 93.7% (Doc1) and 94.6% (Doc2) of the cases from the chest strap ECG with sinus rhythm and 98.2% (Doc1) and 95.5% (Doc2) from the Holter (p = n.s). In conclusion, the ECGs from both methods enabled AF detection by a cardiologist and by automated algorithms. Both methods studied enabled P-wave detection in sinus rhythm., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Recognition of out-of-hospital-cardiac arrests (OHCAs) at emergency medical communication centres is based on questions of OHCA symptoms, resulting in 50-80% accuracy rates. However, OHCAs might be recognized more promptly using 'rhythm-based' recognition, whereby a victim's cardiac rhythm is recorded with mobile phone technology that analyses and transmits recordings to emergency medical communication centres for further interpretation., Objective: To examine whether the quality of normal cardiac rhythm and the rhythm with the best prognosis in OHCA, ventricular fibrillation (VF), is sufficient for 'rhythm-based' OHCA recognition when recorded within a mobile phone-sized device., Patients and Methods: mid-sternum within an area the size of a mobile phone and analysed by automated external defibrillator (AED) software and two cardiologists. The rhythms were categorized as shockable or nonshockable. The cardiologists assessed the quality of the recordings., Results: The AED software correctly analysed all normal rhythms and 15 of 22 VF rhythms. The VF duration was too short for automatic detection in seven cases. The cardiologists analysed all the normal rhythms and VF sequences correctly and graded them as high quality., Conclusion: The recordings of normal ECG rhythm and VF within an area the size of a mobile phone are of sufficient quality and could be used in 'rhythm-based' OHCA recognition. The VF period was too short for an accurate analysis by the AED software in some cases.

Background: The effective treatment of airway compromise in trauma and non-trauma patients is important. Hypoxia and hypotension are predictors of negative patient outcomes and increased mortality, and may be important quality indicators of care provided by emergency medical services. Excluding cardiac arrests, critical trauma and non-trauma patients remain the two major groups to which helicopter emergency medical services (HEMS) are dispatched. Several studies describe the impact of pre-hospital hypoxia or hypotension on trauma patients, but few studies compare this in trauma and non-trauma patients. The primary aim was to describe the incidence of pre-hospital hypoxia and hypotension in the two groups receiving pre-hospital tracheal intubation (TI) by physician-staffed HEMS., Methods: Data were collected prospectively over a 12-month period, using a uniform Utstein-style airway template. Twenty-one physician-staffed HEMS in Europe and Australia participated. We compared peripheral oxygen saturation and systolic blood pressure before and after definitive airway management. Data were analysed using Cochran-Mantel-Haenszel methods and mixed-effects models., Results: Eight hundred forty three trauma patients and 422 non-trauma patients receiving pre-hospital TI were included. Non-trauma patients had significantly lower predicted mean pre-intervention SpO 2 compared to trauma patients. Post-intervention and admission SpO 2 for the two groups were comparable. However, 3% in both groups were still hypoxic at admission. For hypotension, the differences between the groups were less prominent. However, 9% of trauma and 10% of non-trauma patients were still hypotensive at admission. There was no difference in short-term survival between trauma (97%) and non-trauma patients (95%). Decreased level of consciousness was the most frequent indication for TI, and was associated with increased survival to hospital (cOR 2.8; 95% CI: 1.4-5.4)., Conclusions: Our results showed that non-trauma patients had a higher incidence of hypoxia before TI than trauma patients, but few were hypoxic at admission. The difference for hypotension was less prominent, but one in ten patients were still hypotensive at admission. Further investigations are needed to identify reversible causes that may be corrected to improve haemodynamics in the pre-hospital setting. We found high survival rates to hospital in both groups, suggesting that physician-staffed HEMS provide high-quality emergency airway management in trauma and non-trauma patients., Trial Registration: Clinicaltrials.gov Identifier: NCT01502111 . Registered 22 Desember 2011.

Background: Though airway management methods during out-of-hospital cardiac arrest (OHCA) remain controversial, no studies on the topic from Finland have examined adherence to OHCA recommendations in real life. In response, the aim of this study was to document the interventions, success rates, and adverse events in airway management processes in OHCA, as well as to analyse survival at hospital discharge and at follow-up a year later., Methods: During a 6-month study period in 2010, data regarding all patients with OHCA and attempted resuscitation in southern and eastern Finland were prospectively collected. Emergency medical services (EMS) documented the airway techniques used and all adverse events related to the process. Study endpoints included the frequency of different techniques used, their success rates, methods used to verify the correct placement of the endotracheal tube, overall adverse events, and survival at hospital discharge and at follow-up a year later., Results: A total of 614 patients were included in the study. The incidence of EMS-attempted resuscitation was determined to be 51/100,000 inhabitants per year. The final airway technique was endotracheal intubation (ETI) in 413 patients (67.3%) and supraglottic airway device (SAD) in 188 patients (30.2%). The overall success rate of ETI was 92.5%, whereas that of SAD was 85.0%. Adverse events were reported in 167 of the patients (27.2%). Having a prehospital EMS physician on the scene (p < .001, OR 5.05, 95% CI 2.94-8.68), having a primary shockable rhythm (p < .001, OR 5.23, 95% CI 3.05-8.98), and being male (p = .049, OR 1.80, 95% CI 1.00-3.22) were predictors for survival at hospital discharge., Conclusions: This study showed acceptable ETI and SAD success rates among Finnish patients with OHCA. Adverse events related to airway management were observed in more than 25% of patients, and overall survival was 17.8% at hospital discharge and 14.0% after 1 year.

Objective: Recognition of cardiac arrest (CA) during an emergency call leans on questions concerning CA symptoms and is correct in 50-83% of cases. If the heart rhythm could be recorded and analysed over a mobile phone or transmitted during the emergency call to the dispatch centre and analysed there, using software identical to one in an automated external defibrillator (AED), CA recognition could be more prompt. We investigated whether an AED can correctly analyse normal heart rhythms recorded within an area the size of a mobile phone., Methods: Bipolar ECG signal was recorded using an AED in 20 healthy volunteers in four different positions during rest and muscle tension with small pads in an area the size of a mobile phone. Recordings obtained with standard pads in standard positions served as the reference. The recorded ECGs were analysed with an AED and by two cardiologists and categorized as shockable or nonshockable., Results: All analyses were correct when the recordings were performed vertically at the midsternum level. Horizontally at this level, the AED made correct analyses in 95 and 65% of cases and the cardiologists in 100 and 88% of cases at rest and during muscle tension, respectively. In the lateral positions only the analyses by cardiologists partly reached 100% sensitivity. The analysis time of the AED was 7 s in all positions., Conclusion: ECGs can be analysed promptly with an AED within an area the size of a mobile phone. The most reliable recording position was vertical at the midsternum level.

Background: Despite numerous studies on prehospital airway management, results are difficult to compare due to inconsistent or heterogeneous data. The objective of this study was to assess advanced airway management from international physician-staffed helicopter emergency medical services., Methods: We collected airway data from 21 helicopter emergency medical services in Australia, England, Finland, Hungary, Norway and Switzerland over a 12-month period. A uniform Utstein-style airway template was used for collecting data., Results: The participating services attended 14,703 patients on primary missions during the study period, and 2,327 (16 %) required advanced prehospital airway interventions. Of these, tracheal intubation was attempted in 92 % of the cases. The rest were managed with supraglottic airway devices (5 %), bag-valve-mask ventilation (2 %) or continuous positive airway pressure (0.2 %). Intubation failure rates were 14.5 % (first-attempt) and 1.2 % (overall). Cardiac arrest patients showed significantly higher first-attempt intubation failure rates (odds ratio: 2.0; 95 % CI: 1.5-2.6; p < 0.001) compared to non-cardiac arrest patients. Complications were recorded in 13 %, with recognised oesophageal intubation being the most frequent (25 % of all patients with complications). For non-cardiac arrest patients, important risk predictors for first-attempt failure were patient age (a non-linear association) and administration of sedatives (reduced failure risk). The patient's sex, provider's intubation experience, trauma type (patient category), indication for airway intervention and use of neuromuscular blocking agents were not risk factors for first-attempt intubation failure., Conclusions: Advanced airway management in physician-staffed prehospital services was performed frequently, with high intubation success rates and low complication rates overall. However, cardiac arrest patients showed significantly higher first-attempt failure rates compared to non-cardiac arrest patients. All failed intubations were handled successfully with a rescue device or surgical airway., Study Registration: www.clinicaltrials.gov NCT01502111 . Registered 22 December 2011.

Nitrification is a crucial process in sediment nitrogen cycling. We compared two (15)N tracer-based nitrification measurement techniques (isotope pairing technique (IPT) combined with (15)N nitrate pool dilution and (15)N ammonium oxidation) and three different (15)N analyses from bottom water nitrate (ammonia diffusion, denitrifier and SPINMAS) in a sediment mesocosm. The (15)N nitrate pool dilution technique combined with IPT can be used to quantify the in situ nitrification, but the minimum detection limit for the total nitrification is higher than that in the (15)N ammonium oxidation technique. The (15)N ammonium oxidation technique, however, is not applicable for sediments that have high ammonium content. If nitrate concentration and the amount of (15)N label in the sample are low, the (15)N nitrate analysis should be done with the denitrifier method. In higher (15)N concentrations, the less sensitive SPINMAS method can also be applied. The ammonia diffusion method is not suitable for bottom water (15)N nitrate analyses.

Primary production in the eutrophic Baltic Sea is limited by nitrogen availability; hence denitrification (natural transformation of nitrate to gaseous N(2)) in the sediments is crucial in mitigating the effects of eutrophication. This study shows that dissimilatory nitrate reduction to ammonium (DNRA) process, where nitrogen is not removed but instead recycled in the system, dominates nitrate reduction in low oxygen conditions (O(2) <110 μM), which have been persistent in the central Gulf of Finland during the past decade. The nitrogen removal rates measured in this study show that nitrogen removal has decreased in the Gulf of Finland compared to rates measured in mid-1990s and the decrease is most likely caused by the increased bottom water hypoxia.