CANCARE RESEARCH
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Real-time feedback during bag-valve-mask ventilation for out-of-hospital cardiac arrest: a before-and-after study (VEntilation during Cardiac Arrest Resuscitation Study, VECARS-2).
Clinical takeaway Feedback was associated with better control of insufflated volume, but this did not translate into a demonstrated improvement in expiratory tidal volume. Patient-centred benefits remain unestablished.
Summary & abstract
Study summary
This before-and-after study evaluated real-time bag-valve-mask ventilation feedback during adult out-of-hospital cardiac arrest, analyzing 4,300 ventilations in 163 patients. Insufflated volume was within 400–600 mL in 68% of ventilations with feedback versus 42% without, whereas expiratory tidal volume met that range in 14% versus 15%. Median expiratory tidal volume was 235 versus 243 mL with and without feedback, respectively (p=0.84). Feedback was associated with less variable insufflated volumes (within-patient IQR ratio 0.65; 95% CI 0.53–0.77) and lower leak volume (adjusted mean ratio 0.88; 95% CI 0.77–0.99).
Study limitation: Sequential observational cohorts limit causal inference; the abstract reports ventilation measures rather than survival or neurological outcomes.
Published abstract
This study compared bag-valve-mask ventilation quality and adherence to the guideline-recommended ventilation volume range during 30:2 cardiopulmonary resuscitation for out-of-hospital cardiac arrest before and after the implementation of real-time feedback. We conducted a before-and-after observational study of two sequential adult cohorts with out-of-hospital cardiac arrest managed by basic life support teams from the Paris Fire Brigade. A bidirectional sensor measured insufflated volume (Vi) and expiratory tidal volume (Vt). The display was masked during Period-1 and provided real-time feedback during Period-2. We assessed adherence to the guideline-recommended range using mixed-effects regression; we analyzed Vt and leak volume using gamma log-link generalized linear mixed models. We analyzed 4,300 ventilations in 163 patients, 96 without feedback and 67 with feedback. Median Vi was lower with feedback (471 mL) than without (513 mL, p=0.03 for the first ventilation of each cycle) but median Vt was unchanged (235 vs. 243 mL, p=0.84). Vi dispersion was reduced by 35% (mean within-patient IQR ratio 0.65 [95%-CI, 0.53-0.77]). Vi was 400-600 mL in 68% of ventilations with feedback vs. 42% without feedback. In contrast, Vt was 400-600 mL in only 14% of ventilations with feedback vs. 15% without feedback. In multivariable analysis, leak volume was 12% lower with feedback (mean ratio, 0.88 [95%-CI, 0.77-0.99]). Real-time feedback was associated with improved adherence to the guideline-recommended range for Vi, less dispersed Vi,and lower leak volume. Causal inference, clinical significance, and generalizability warrant further evaluation.
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Association between burst-suppression with identical bursts and multimodal measures of cerebral oxygenation after cardiac arrest.
Clinical takeaway These physiological associations suggest a potentially distinct pattern of post-arrest brain injury. They do not establish a modifiable mechanism or demonstrate implications for neurological recovery.
Summary & abstract
Study summary
This single-centre retrospective study examined cerebral oxygenation across EEG patterns after cardiac arrest, including 109 patients monitored with jugular bulb oxygen saturation and 33 with brain tissue oxygen tension. Burst-suppression with identical bursts was associated with higher jugular saturation than non-malignant patterns (β=12; 95% CI, 7.0 to 16.0). Compared with malignant patterns, it was associated with lower intracranial pressure (β=-19.0; 95% CI, -32.5 to -5.6). Brain tissue oxygen tension was numerically higher than with malignant patterns, but the adjusted estimate was uncertain (β=4.0; 95% CI, -4.7 to 13.0).
Study limitation: Single-centre retrospective data from selected monitored patients, including only 33 with brain tissue oxygen monitoring, limit causal interpretation and generalisability.
Published abstract
OBJECTIVE: Burst-suppression with identical bursts (BSIB) is an electroencephalographic (EEG) pattern associated with severe post-cardiac arrest brain injury (PCABI). Whether modifiable mechanisms of brain injury underlie BSIB is unknown. We hypothesized BSIB is associated with impaired cerebral oxygen metabolism, reflected as pathologically elevated jugular bulb venous oxygen saturation (SjvO2), higher brain tissue oxygen tension (PbtO2), normal jugular bulb venous-to-arterial carbon dioxide gradient (PbCO2 gap, and lower intracranial pressure (ICP) compared to other EEG patterns. METHODS: This single-center retrospective study included patients resuscitated from cardiac arrest who underwent EEG and SjvO2 or PbtO2 monitoring. We categorized EEG patterns as BSIB, malignant without BSIB, and non-malignant. Using mixed effects linear regression, we examined associations between EEG and SjvO2, PbCO2 gap, PbtO2, and ICP. RESULTS: The SjvO2 and PbtO2 cohorts included 109 and 33 patients, respectively. SjvO2 did not differ between BSIB and malignant EEGs (β=3; 95% CI, -0.6 to 7.0), butwas higher with BSIB compared to non-malignant patterns (β=12; 95% CI, 7.0 to 16.0). BSIB was associated with lower PbCO2 gap compared to malignant (β=-1.4; 95% CI, -2.6 to -0.3) and non-malignant (β=-2.6; 95% CI, -4.1 to -1.0) patterns. PbtO2 was highest with BSIB, but not significantly higher compared to malignant patterns in our adjusted model (β=4.0; 95% CI, -4.7 to 13.0). ICP was lower in those with BSIB compared to malignant patterns (β=-19.0; 95% CI, -32.5 to -5.6). Interpretation BSIB may represent a distinct subtype of PCABI characterized by impaired oxygen metabolism with preserved oxygen delivery and diffusion.
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Regional implementation of a prehospital advanced life support program with video-assisted physician direction and outcomes after out-of-hospital cardiac arrest.
Clinical takeaway Regional implementation was associated with increased prehospital ROSC, but no demonstrated improvement in discharge survival or favorable neurological outcome. These observational findings do not establish a causal benefit.
Summary & abstract
Study summary
This South Korean retrospective cohort included 129,207 adult out-of-hospital cardiac arrests and compared regional changes after implementation of video-assisted physician-directed advanced life support using difference-in-differences analyses. Compared with nonimplementing regions, implementing regions had a greater increase in prehospital ROSC: 1.35 percentage points (95% CI, 0.56 to 2.15). There were no significant additional improvements in survival to discharge (−0.35 percentage points; 95% CI, −1.31 to 0.62) or favorable neurological outcome (−0.35 percentage points; 95% CI, −1.08 to 0.37). Prehospital time increased by an additional 4.12 minutes (95% CI, 2.91 to 5.33).
Study limitation: The observational design limits causal inference, and differential pre-intervention trends specifically weaken interpretation of the prehospital time finding.
Published abstract
BACKGROUND: The smart advanced life support (SALS) program was introduced to provide prehospital advanced life support under real-time video-assisted physician direction for out-of-hospital cardiac arrest (OHCA). This study evaluated the association between regional SALS implementation and OHCA outcomes. METHODS: This retrospective cohort study used difference-in-differences and event-study analyses with data from the OHCA surveillance system in South Korea and included adult OHCA cases (aged ≥19 years) from 2 years before through 4 years after SALS implementation in August 2015. The exposure was region-level implementation of SALS. Outcomes were the prehospital time interval, prehospital return of spontaneous circulation (ROSC), survival to discharge, and favorable neurological outcome. Pre- to post-implementation changes were compared between regions with and without SALS. RESULTS: A total of 129,207 cases were included. SALS regions had greater increases in the prehospital time interval (4.12 minutes; 95% confidence interval [CI], 2.91 to 5.33) and prehospital ROSC (1.35 percentage points; 95% CI, 0.56 to 2.15) than regions without SALS. No significant additional improvements were observed in survival to discharge (-0.35 percentage points; 95% CI, -1.31 to 0.62) or favorable neurological outcome (-0.35 percentage points; 95% CI, -1.08 to 0.37). Event-study analyses suggested differential pre-intervention trends for prehospital time, but not for the other outcomes. CONCLUSION: SALS regions showed greater increases in prehospital time and prehospital ROSC without significant improvements in survival to discharge or favorable neurological outcome, but the finding for prehospital time should be interpreted cautiously because differential pre-intervention trends were observed.
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Fatigue, Anxiety and Depression 12 Months After Out-of-Hospital Cardiac Arrest: A Population Based Cohort Study.
Clinical takeaway Persistent symptoms are an important component of cardiac-arrest survivorship beyond hospital discharge. Their association with poorer recovery highlights a patient-centred outcome domain, without establishing causality or an effective intervention.
Summary & abstract
Study summary
This prospective Australian cohort assessed 728 adult out-of-hospital cardiac arrest survivors at 12 months, representing 68.2% of eligible survivors. Fatigue affected 35.8% (250/699), anxiety 22.6% (162/716), and depression 18.0% (129/716). Higher symptom burden was associated with poorer quality of life, worse functional recovery and reduced return to work. Compared with population norms, fatigue was greater (standardized mean difference 0.64; 95% confidence interval 0.50–0.78), while depression was slightly greater and anxiety lower. These findings describe substantial symptom burden among survivors but do not establish that symptoms cause poorer recovery.
Study limitation: Only 68.2% of eligible 12-month survivors completed follow-up, creating potential nonresponse bias; observational associations cannot establish causality.
Published abstract
AIM: To determine the prevalence and factors associated with fatigue, anxiety, and depression 12 months after out-of-hospital cardiac arrest (OHCA); examine their associations with health-related quality of life (HRQoL) and functional recovery; and compare symptom burden with population norms. METHODS: This prospective, population-based cohort study included adults (≥18 years) who received EMS-attempted resuscitation and survived to hospital discharge following non-traumatic OHCA in Victoria, Australia, between July 2019 and June 2022. Survivors were identified from a statewide OHCA registry and completed a 12-month telephone interview. Primary outcomes were fatigue (Modified Fatigue Impact Scale), anxiety and depression (Hospital Anxiety and Depression Scale). Secondary outcomes included HRQoL (EQ-5D, SF-12), functional recovery (GOSE), living arrangement, and return to work. RESULTS: Of 1068 eligible 12-month survivors, 728 (68.2%) completed follow-up (median age 61 years; 555 [76.2%] male). Fatigue was reported by 35.8% (250/699), anxiety by 22.6% (162/716), and depression by 18.0% (129/716). Higher symptom burden was associated with lower EQ-5D and SF-12 scores, worse GOSE outcomes (all p<0.001) and reduced return-to-work rates. Compared with population norms, survivors reported greater fatigue (SMD 0.64; 95%CI, 0.50-0.78;p<0.001), and depression (SMD, 0.12; 95%CI, 0.02,0.21;p=0.02) but lower anxiety (SMD, -0.27; 95%CI, -0.35 to -0.18;p<0.001). In adjusted models, younger age, preexisting anxiety or depression, diabetes and initial non-shockable arrest were associated with higher symptom burden, whereas EMS-witnessed arrests were associated with lower symptom burden. CONCLUSIONS: Fatigue, anxiety, and depression were common at 12 months after OHCA and are associated with poorer recovery. Fatigue exceeded population norms and may be an under-recognised component of cardiac arrest survivorship.
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12,13-diHOME Is Increased During Targeted Temperature Management And Correlates With Survival After Cardiac Arrest Resuscitation.
Clinical takeaway These findings identify a survival-associated biomarker in post-arrest temperature management. They do not establish that brown adipose tissue activity mediates treatment benefit or that biomarker-guided temperature management improves outcomes.
Summary & abstract
Study summary
This observational study measured circulating 12,13-diHOME, a brown-adipose-tissue-associated lipid, in 74 patients from 6 hours through 7 days after return of spontaneous circulation. Levels were increased in patients receiving targeted temperature management at 33°C and were associated with survival. Concentrations peaked during the first 12–48 hours and fell below the initial post-resuscitation level by day 7. Higher levels were also associated with more mature and fewer immature neutrophils, while a subset of patients with higher levels showed a specific phospholipid signature.
Study limitation: The abstract provides no survival effect estimate, uncertainty interval, adjustment details, or survival assessment timepoint.
Published abstract
CONTEXT: Trials of targeted temperature management (TTM) after cardiac arrest (CA) have had conflicting results. Brown adipose tissue (BAT) is a thermogenic organ activated by cold temperature to regulate body temperature, systemic metabolism and the immune system. Approximately 10-30% of adult patients have BAT and this heterogeneity may explain variable treatment to TTM. OBJECTIVE: This study sought to measure differences in outcome, metabolic and immune activation between patients treated with TTM following CA with varying BAT activity, measured through BAT-associated lipid 12,13-diHOME concentrations in circulation. DESIGN: BAT biomarker 12,13-diHOME was quantified using liquid chromatography-mass spectrometry (LC-MS) on plasma from 74 patients at various time points starting at 6 hours and up until 7 days after return of spontaneous circulation (ROSC). Additionally, circulating glucose, C-peptide and fatty acids were measured by glucometer, ELISA and LC-MS, respectively. Peripheral blood mononuclear cells were analyzed by flow cytometry. RESULTS: 12,13-diHOME was increased in patients treated with TTM at 33°C and positively correlated with favorable outcomes. 12,13-diHOME levels peaked in the first 12 to 48 hours and decreased below the first post-ROSC level by 7 days. Glucose homeostasis was not associated with 12,13-diHOME levels. In a subset of patients, we could detect a specific phospholipid signature in patients with higher 12,13-diHOME. Patients with higher 12,13-diHOME also had increased mature neutrophils and lower immature neutrophils. CONCLUSIONS: Circulating 12,13-diHOME levels are increased in some patients undergoing targeted temperature management after cardiac arrest, which may be indicative of increased BAT activity. 12,13-diHOME is associated with survival, alterations of phospholipid metabolism, and a profile of less activated immune system. BAT may mediate the effects of temperature management on outcome after cardiac arrest.
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Hemoglobin trends and transfusion practices after cardiac arrest: a cohort study.
Clinical takeaway Anemia and transfusion were common after cardiac arrest. The mortality association is hypothesis-generating and does not establish that a higher transfusion target improves outcomes.
Summary & abstract
Study summary
This retrospective cohort included 958 adult cardiac arrest patients at three academic hospitals who survived initial resuscitation and had hemoglobin measured. Mean initial hemoglobin was 9.75 g/dL (SD 2.60), declining progressively over the first 20 days. Within 30 days, 369 patients (38.5%) received red cell transfusions; mean pre-transfusion hemoglobin was 6.96 g/dL (SD 1.06). In exploratory analysis, initial hemoglobin ≥9 g/dL was associated with lower in-hospital mortality (adjusted OR 0.62, 95% CI 0.46–0.84), but the study did not establish whether anemia caused worse outcomes.
Study limitation: Retrospective observational data cannot disentangle anemia as a marker versus a driver of mortality or establish transfusion benefit.
Published abstract
BACKGROUND: Hemoglobin targets are absent from post-cardiac arrest guidelines. New trials suggest that patients with brain and myocardial injury, injuries common post-arrest, may benefit from higher hemoglobin targets. Trends in post-arrest hemoglobin and real-world practices remain poorly characterized. METHODS: We performed a retrospective cohort study of consecutive adult cardiac arrests at three academic hospitals. We screened in-hospital and out-of-hospital arrests with resuscitation efforts ongoing at hospital arrival for inclusion. Patients who survived the initial resuscitation and had a hemoglobin value measured were included. All post-arrest hemoglobin values and red blood cell transfusions were collected through 30 days; descriptive statistics and graphical visualization were used to present hemoglobin trends and transfusion practices. Exploratory analyses evaluated the association between hemoglobin and in-hospital mortality. RESULTS: Of 2,634 cardiac arrests, 958 met inclusion criteria, with 152 (15.9%) out-of-hospital arrests and 806 (84.1%) in-hospital. The mean initial post-arrest hemoglobin was 9.75 g/dL (SD 2.60), with hemoglobin levels declining progressively over the first 20 days post-arrest. Red cell transfusions were delivered for 369 (38.5%) patients in the 30 days post-arrest, with 1,238 total transfusions. The mean pre-transfusion hemoglobin value was 6.96 g/dL (SD 1.06). Pre-transfusion hemoglobin levels were < 7 g/dL for 762 (61.6%) of transfusions, and ≥ 7 g/dL for 476 (38.4%) of transfusions. Over 30 days, the highest proportion of patients transfused was in the first 48 h. Patients with initial post-arrest hemoglobin ≥ 9 g/dL had lower in-hospital mortality (adjusted OR 0.62, 95% CI 0.46-0.84, p<0.01). In time-varying analysis, post-arrest hemoglobin through 30 days demonstrated an L-shaped association with mortality, with 95% of the total reduction in mortality hazard captured below 9.20 g/dL. CONCLUSIONS: Anemia is common after cardiac arrest, worsening in initial survivors. There is substantial variation in pre-transfusion hemoglobin levels, reflecting clinical equipoise. Clinical trials are needed to disentangle anemia as a driver versus a marker of outcomes, and test whether the risk is modifiable.
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The Cost-Effectiveness and Health Equity of Prehospital Treatment Strategies for Out-of-Hospital Cardiac Arrest Patients: A Systematic Review.
Clinical takeaway These findings may inform resuscitation-system economic discussions, particularly around prehospital ECPR. They do not establish a survival advantage, and heterogeneous comparisons limit confidence in applying the estimates across settings.
Summary & abstract
Study summary
This systematic review included ten economic evaluations of prehospital out-of-hospital cardiac arrest strategies, mostly cost-utility analyses, with six using Markov models. Prehospital ECPR was reported as more cost-effective than in-hospital ECPR, with incremental cost-effectiveness ratios ranging from AUD $27,323 to $44,000 per quality-adjusted life-year gained. Survival and neurological outcomes influenced cost-effectiveness estimates, while almost all studies reported fewer than 40% of assessed equity criteria. The authors concluded that many strategies enabling earlier advanced care were cost-effective, but heterogeneous comparators and sparse equity reporting limited evidence certainty.
Study limitation: The evidence primarily comprised economic evaluations, often using Markov models, with heterogeneous comparators and sparse equity reporting.
Published abstract
OBJECTIVES: Out-of-hospital cardiac arrest (OHCA) remains a major public health challenge, associated with substantial mortality and significant costs for health care system. This systematic review aimed to (i) synthesize economic evaluations of prehospital treatment strategies for OHCA from ambulance attendance through to hospital discharge; (ii) assess the methodological quality and reporting of the included studies; and (iii) evaluate the reporting of health equity-relevant data. METHODS: We searched Medline, Embase, Scopus, EconLit, and CINAHL databases for records from database inception to 12 June 2026. The QHES and CHEERS checklists were used to assess the quality and reporting standards of included studies, and the review was reported according to the PRISMA checklist. The completeness of reporting health equity outcomes was reviewed using the PROGRESS (Place of residence, Race, Occupation, Gender, Religion, Education, Socioeconomic status and Social capital) - Plus framework. RESULTS: Ten economic evaluations met eligibility criteria. Most studies were cost-utility analyses (n = 8, 80%) and used Markov models (n = 6, 60%). Most evaluations were 'very good quality' (≥80%) (n = 6, 60%). Early defibrillation and advanced life support (ALS) delivered by trained emergency medical technicians were cost-effective compared with no intervention, emergency physician-led ALS, standard emergency medical services or paramedic care (ICER range from £11,407 to USD $56,700 per QALY gained). Prehospital extracorporeal cardiopulmonary resuscitation (ECPR) was more cost-effective than in-hospital ECPR strategies (ICER range from AUD $27,323 to $44,000 per QALY gained). Termination-of-resuscitation (TOR) strategies were cost-effective compared with no TOR or other TOR strategies, including basic life support and ALS TOR, with estimates of $110,554 saved per QALY lost and USD $23,851 per QALY gained. Survival rate and neurological outcomes influenced cost-effectiveness results. Equity reporting was limited: almost all included studies addressed less than 40% of the PROGRESS-Plus equity criteria. CONCLUSIONS: Most strategies that increased prehospital treatment intensity, avoided futile transport, or enabled earlier advanced care were cost-effective; however, the certainty of evidence, particularly for sub-groups, was limited by heterogeneous comparators and sparse equity reporting.
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Influencing factors analysis and prediction model development for ROSC in adult non-traumatic OHCA: a retrospective study based on pre-hospital emergency settings.
Clinical takeaway The model showed internal discrimination for sustained ROSC, not survival or neurological recovery. Its predictive associations do not establish treatment effects or justify care-limitation decisions.
Summary & abstract
Study summary
This retrospective study included 9,386 adults with non-traumatic out-of-hospital cardiac arrest treated through Tianjin Emergency Medical Center during 2023–2024. Sustained return of spontaneous circulation through emergency department arrival and handover occurred in 678 patients (7.2%). An initially shockable rhythm was associated with higher odds of ROSC (adjusted OR 2.850, 95% CI 2.390–3.397). A prediction nomogram developed using a random 7:3 training–test split achieved a test-set AUC of 0.775 (95% CI 0.745–0.805), with an optimism-corrected C-index of 0.7679 after bootstrap internal validation.
Study limitation: Retrospective data from one emergency medical centre and internal validation alone limit confidence in transportability to other resuscitation systems.
Published abstract
BACKGROUND: Cardiac arrest is a major global public health problem. This study aimed to explore factors influencing return of spontaneous circulation (ROSC) and develop a prediction model for out-of-hospital cardiac arrest (OHCA) patients. METHODS: We retrospectively collected electronic medical records of adult non-traumatic OHCA patients at Tianjin Emergency Medical Center from January 1, 2023 to December 31, 2024. The primary outcome was sustained ROSC up to emergency department arrival and handover to receiving-hospital staff. Multivariable mixed-effects logistic regression with clinician ID as random intercept adjusted clustering bias; predictors with p < 0.05 formed the nomogram. Patients were randomly split 7:3 for training and internal testing. Discrimination was assessed by ROC-AUC (acceptable threshold >0.7). We performed 1000 bootstrap resampling to correct C-index against overfitting. Calibration curves and decision curve analysis (DCA) further evaluated predictive consistency and net clinical benefit. RESULTS: Among 9,386 included cases, 678 (7.2%) achieved ROSC. Mixed-effects regression identified independent ROSC predictors: public location (aOR = 1.285, 95% CI:1.038-1.592), 06:00-12:00 onset (aOR = 1.308, 95% CI:1.018-1.682), prolonged emergency response time (aOR = 0.971, 95% CI:0.945-0.999), extended onset-to-ambulance intervals (5-10 min: aOR = 0.758;10-30 min: aOR = 0.578;>30 min:aOR = 0.498 vs ≤5 min), no OHCA occurred at emergency call (aOR = 1.540, 95% CI:1.048-2.262), male attending physicians (aOR = 1.255, 95% CI:1.077-1.464), longer physician practice years (aOR = 1.043, 95%CI: 1.022-1.065), intermediate physician title (aOR = 1.236, 95% CI:1.047-1.459), shockable initial rhythm (aOR = 2.850, 95% CI:2.390-3.397), endotracheal intubation (aOR = 2.294, 95% CI:1.936-2.718), epinephrine >5 mg (aOR = 0.765,95% CI:0.626-0.935). The nomogram AUC reached 0.775 (95% CI:0.756-0.794) in the training set and 0.775 (95% CI:0.745-0.805) in the test set; 1000 bootstrap internal validation gave an optimism-corrected C-index of 0.7679 with minimal optimism of 0.0071, showing negligible overfitting, good calibration and favorable net clinical benefit via DCA. CONCLUSION: This study identified multiple factors significantly associated with ROSC in OHCA patients; the constructed model showed good predictive value.
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Between patterns and predictions: Interpretable latent EEG representations for clinical insights.
Clinical takeaway This EEG representation showed potentially useful outcome discrimination after cardiac arrest. The abstract does not establish its incremental clinical value or suitability for individual prognostic decisions.
Summary & abstract
Study summary
Researchers applied a pretrained EEG embedding framework without retraining to three independent cohorts, including 575 cardiac arrest patients, 100 patients with subarachnoid hemorrhage, and 141 routine EEG recordings. EEG segments were mapped into a 128-dimensional space anchored by expert-derived reference brain states. Favorable outcomes or physiological recordings lay closer to healthy reference states, whereas poor outcomes and pathological recordings shifted toward pathological regions. Trajectory-derived geometric and temporal features discriminated outcomes after cardiac arrest with ROC-AUC 0.83 and after subarachnoid hemorrhage with ROC-AUC 0.76.
Study limitation: The abstract does not specify outcome definitions, assessment timing, or uncertainty around discrimination estimates.
Published abstract
Electroencephalography (EEG) captures rich brain dynamics, yet in clinical practice this complexity is often reduced to simplified summaries or categorical labels, limiting its interpretability for decision-making. We tested the hypothesis that a pretrained latent embedding framework, the Universal Map of EEG (UM-EEG), can preserve clinically meaningful structure across heterogeneous datasets and provide a generalizable representation of brain states. We applied UM-EEG, without retraining, to three independent cohorts spanning distinct clinical contexts: long-term EEG recordings from cardiac arrest patients (n = 575), subarachnoid hemorrhage (n = 100), and routine clinical EEG recordings containing physiological and pathological patterns (n = 141). EEG segments were projected into a 128-dimensional space anchored by expert-derived reference states, including wakefulness, sleep stages, ictal-interictal continuum activity, and burst suppression. Across datasets, favorable outcome or physiological recordings were consistently located closer to healthy reference states, whereas poor outcome and pathological recordings shifted toward pathological regions of the embedding space. Trajectory-derived geometric and temporal features discriminated outcome in cardiac arrest (ROC-AUC 0.83) and subarachnoid hemorrhage (ROC-AUC 0.76), and distinguished physiological from pathological routine EEGs (ROC-AUC 0.93). In routine EEG, similarity relationships derived from embedding trajectories correlated with those derived from structured clinical reports, indicating that the latent space recapitulates clinically relevant organization. These findings show that a fixed, semantically structured EEG embedding generalizes across etiologies and recording settings, enabling prognostic stratification and contextual interpretation while preserving the relational structure of brain states.
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Bystander AED Effectiveness Despite Low Utilisation in OHCA.
Clinical takeaway Bystander AED application was associated with better survival and neurological outcomes, but estimates depended on the comparator definition. These observational findings also identify substantial underutilization in nonpublic settings.
Summary & abstract
Study summary
A retrospective Korean registry analysis included 23,918 adults with out-of-hospital cardiac arrest of presumed medical etiology, including 383 with bystander AED application. Compared with no prehospital defibrillation, bystander AED application was associated with higher survival to discharge (adjusted odds ratio 1.60, 95% CI 1.19–2.14) and good neurological outcome (2.31, 1.65–3.23). Pooling EMS-shocked and non-defibrillated patients as controls attenuated both associations to non-significance. AED application occurred in 8.5% of public-area versus 1.9% of nonpublic AED-opportunity cases, highlighting a utilization gap.
Study limitation: Nonrandomized comparisons remain vulnerable to residual confounding; changing the reference group materially altered the estimated associations.
Published abstract
OBJECTIVES: Observational estimates of bystander automated external defibrillator (AED) effectiveness are inconsistent in settings with mature public-access defibrillation infrastructure but low utilization, partly because the conventional reference group pools emergency medical services (EMS)-shocked with non-defibrillated patients. We estimated bystander AED effectiveness against a partitioned no-defibrillation reference, tested effect modification by location, and quantified the deployment-utilization gap. METHODS: Retrospective analysis of a prospectively collected multicenter out-of-hospital cardiac arrest (OHCA) registry (Korea, October 2015-June 2025; 23,918 adults of presumed medical etiology). A three-tier prehospital defibrillation-provider variable was defined: bystander AED applied (n = 383); EMS-delivered shock without preceding bystander AED (n = 5,975); and no prehospital defibrillation (reference; n = 17,560). Primary outcomes were survival to discharge and good neurological outcome (Cerebral Performance Category 1-2), analyzed by multivariable logistic regression with propensity-score, inverse-probability-weighting and location-stratified secondary analyses. RESULTS: Bystander AED application was associated with improved survival (adjusted odds ratio [aOR] 1.60; 95% CI 1.19-2.14) and good neurological outcome (2.31; 1.65-3.23), comparable to that of EMS-delivered shock; the pooled-control specification attenuated estimates to non-significance (survival 1.09; neurological 1.14). Shock-delivered applications significantly exceeded EMS-delivered shock for neurological outcome (aOR 1.43; p = 0.03). Effectiveness did not differ by location (interaction p ≥ 0.15). Bystander AED was applied in 8.5% of Public-area versus 1.9% of Nonpublic AED-opportunity cases-a 4.5-fold gap. CONCLUSIONS: Bystander AED was associated with improved outcomes when applied, comparable to or exceeding EMS-delivered shock; the dominant constraint was the deployment-utilization gap, greatest in residential settings. Residential rapid-activation infrastructure warrants policy priority alongside, not instead of, continued device placement.
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Mechanical versus manual bag-valve ventilation during cardiopulmonary resuscitation in adults with cardiac arrest: A systematic review and Bayesian meta-analysis.
Clinical takeaway Mechanical ventilation during CPR was associated with higher ROSC, but a survival or neurological benefit remains uncertain. These findings do not establish superiority for patient-centred outcomes.
Summary & abstract
Study summary
This Bayesian meta-analysis included eight studies involving 6,847 adults with cardiac arrest, comparing mechanical ventilation during CPR with manual bag-valve ventilation alone. Mechanical ventilation was associated with more ROSC (pooled RR 1.20; 95% credible interval 1.04–1.42), with a 99% posterior probability of benefit. Posterior probabilities favoring mechanical ventilation were 92.3% for survival to admission, 93.6% for survival to discharge, and 92.2% for favorable neurological outcome. Despite these directional signals, evidence for improved survival and neurological outcomes remained imprecise and inconclusive.
Study limitation: Classification as mechanical ventilation required any use during CPR, so this group could also have received manual ventilation.
Published abstract
BACKGROUND/OBJECTIVE: Optimal ventilation delivery during cardiopulmonary resuscitation (CPR) remains uncertain. Current resuscitation guidelines do not recommend mechanical ventilation (MV) over manual bag-valve ventilation (BV). We evaluated the association between MV use during CPR and clinical outcomes in adults with cardiac arrest compared with manual BV. METHODS: We searched 6 bibliographic databases from inception through May 31, 2026. Included studies compared MV and BV ventilation CPR in adult cardiac arrest patients. Patients receiving MV at any moment during CPR were classified as the MV group; those receiving only BV comprised the BV group. Primary outcomes included return of spontaneous circulation (ROSC), survival to hospital admission, survival to hospital discharge, and good neurological outcome. Secondary outcomes included physiologic variables and pneumothorax. We calculated pooled risk ratios (RRs) and mean differences with 95% credible intervals (CrIs) using Bayesian random-effects meta-analyses. RESULTS: Eight studies involving 6,847 patients were included. For the primary outcome, MV use during CPR was associated with a higher rate of ROSC than BV use (pooled RR, 1.20; 95% CrI, 1.04 to 1.42), with a 99% posterior probability of benefit. Posterior probabilities favoring MV for survival to admission, survival to discharge, and favorable neurological outcome were 92.3%, 93.6%, and 92.2%, respectively. Pneumothorax incidence was similar between groups. CONCLUSION: In adult cardiac arrest, MV use during CPR was associated with higher ROSC compared with manual BV. Evidence for improved survival and neurological outcomes remains imprecise and inconclusive.
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Intraprocedural Cardiac Arrest in Patients Undergoing Percutaneous Coronary Interventions in the United States: An Analysis of the NCDR CathPCI Registry.
Clinical takeaway Intraprocedural cardiac arrest was uncommon but associated with substantial in-hospital mortality. Rising risk-adjusted arrest incidence alongside slightly declining mortality provides a contemporary benchmark, not evidence for any particular prevention or resuscitation strategy.
Summary & abstract
Study summary
This CathPCI registry study examined intraprocedural cardiac arrest and in-hospital mortality during PCI from 2018 to 2023. Arrest occurred during 36,755 of 3,956,840 procedures (0.93%), including 0.24% of elective procedures and 1.28% of acute coronary syndrome interventions. In-hospital mortality among patients with arrest was 40.5%; among those who died, 45.4% died in the catheterization laboratory. Over time, risk-adjusted arrest incidence increased from 0.79% to 0.95% (P = 0.042), while risk-adjusted mortality declined slightly from 45.1% to 43.6% (P = 0.027).
Study limitation: The observational registry design cannot establish causality or explain the divergent trends in arrest incidence and mortality.
Published abstract
BACKGROUND: Cardiac arrest (CA) during percutaneous coronary interventions (PCI) is a catastrophic procedural complication. Contemporary rates of CA during PCI are unknown. OBJECTIVES: This study sought to understand contemporary rates of CA, associated mortality, and identify predictors of CA during PCI. METHODS: Patients with CA during PCI from 2018 to 2023 were identified from the National Cardiovascular Data Registry CathPCI Registry. Trends in intraprocedural CA (IPCA) incidence and in-hospital death were evaluated. Predictors of IPCA and risk-adjusted mortality were identified. RESULTS: A total of 36,755 IPCA occurred during 3,956,840 PCIs (0.93%), including in 0.24% of elective PCIs, 0.32% of PCIs for stable coronary artery disease, and 1.28% of acute coronary syndrome interventions. The incidence of IPCA increased over time (0.62% in 2018 to 1.07% in 2023; P < 0.0001). In-hospital death occurred in 40.5% of patients with IPCA, 45.4% of whom died in the cardiac catheterization laboratory. Notably, although risk-adjusted IPCA increased (0.79% to 0.95%; P = 0.042), slight declines in risk-adjusted mortality (45.1% to 43.6%; P = 0.027) were observed over time. PCI for ST-segment elevation myocardial infarction, non-ST-segment acute coronary syndromes, increasing age, ventricular arrhythmias, severe aortic stenosis, vasopressors or inotrope use, mechanical circulatory support, coronary perforation, coronary dissection, cardiac tamponade, intraprocedural heart failure or myocardial infarction, and temporary cardiac pacemaker implantation were associated with increased adjusted odds of IPCA. CONCLUSIONS: IPCA complicates 0.93% of contemporary PCI. Despite an increasing incidence of risk-adjusted IPCA, there were slight declines in risk-adjusted in-hospital mortality in the study period. Several patient and procedural characteristics were independently associated with intraprocedural CA.
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