Critical Care Explorations

Abstract Background: In patients with sepsis and pre-existing hypertension, admission findings may not adequately describe the subsequent course of circulatory support and organ dysfunction. We developed and externally validated a model to reassess in-hospital mortality risk after the first 72 hours of intensive care. Methods: This retrospective study used MIMIC-IV for development and eICU-CRD for external validation. Patients had received vasoactive agents and remained in the ICU for at least 72 hours. Static variables were combined with features from six consecutive 12-hour windows. Imputation, feature selection, model fitting, and calibration were performed within training folds during five-fold cross-validation. The final XGBoost model was applied externally without refitting. Evaluation included discrimination, calibration, decision curves, and risk stratification, with an exploratory comparison of static-only and static-plus-dynamic feature sets. Results: The development and external cohorts included 1019 and 1747 patients, with 338 (33.2%) and 516 (29.5%) deaths, respectively. Internal area under the receiver operating characteristic curve (AUC) was 0.752 (95% CI 0.720-0.784). External AUC was 0.713 (95% CI 0.687-0.739), average precision was 0.536, the Brier score was 0.185, and the calibration slope was 0.744. Mortality increased across external risk tertiles from 13.7% to 47.3%. In an exploratory feature-set comparison, the static-plus-dynamic feature set showed a 0.071 higher internal AUC than the static feature set (95% CI 0.042-0.109). Conclusions: Information accumulated during the first 72 hours supported subsequent mortality risk stratification in this selected population. The model retained moderate discrimination externally, supporting further evaluation as an adjunct to clinical reassessment. Local calibration and the clinical consequences of acting on model predictions require evaluation before routine use.

Introduction Norepinephrine remains first-line vasopressor therapy for septic shock despite its association at high doses with undesirable cardiovascular, kidney, and immune effects. Angiotensin-II (Ang-II) is a non-catecholamine vasopressor of the renin-angiotensin-aldosterone system (RAAS) now approved to increase blood pressure in vasodilatory shock. RAAS dysregulation is common in septic shock and may represent a treatable trait. However, few prospective investigations evaluate the effect of early Ang-II use in septic shock on dysfunctional RAAS biology, host-response, or clinical outcomes. Therefore, we designed a mechanistic clinical trial to test the hypothesis that early Ang-II therapy in septic shock normalizes systemic RAAS abnormalities and modulates innate immune responses. Methods and Analysis The Mechanistic Assessment of Norepinephrine TheRapy vs. Angiotensin-II in Septic Shock (MANTRA) trial is an investigator-initiated, prospective, multicenter, open-label, randomized mechanistic clinical trial. Adults with septic shock by Sepsis-3 criteria receiving a norepinephrine-equivalent dose (NED) of 0.10-0.50 mcg/kg/min will be randomized 1:1 to primary Ang-II (to a maximum of 40 ng/kg/min) or norepinephrine (to a maximum 35 mcg/min) treatment strategies over a 48-hour period. The primary outcome is the between-group difference in plasma renin trajectory from baseline to 24 hours, analyzed using a linear mixed-effects model with a treatment-by-time interaction term. With n=78, the trial has 90% power (at two-sided =0.05) to detect a 25% between-group difference in 24-hour renin. Secondary clinical outcomes include longitudinal NED, hours alive and vasopressor-free at 72 hours, a 28-day composite outcome (days alive and free of vasopressors, renal replacement therapy, and mechanical ventilation), treatment failure requiring crossover or protocol discontinuation, and thrombotic and arrhythmia events through 28 days. Secondary mechanistic outcomes include serial RAAS biomarkers (prorenin, soluble prorenin receptor, angiotensinogen, ACE, ACE2, Ang-II, angiotensin-(1-7), aldosterone, and DPP3), immune measures (ex vivo monocyte function, monocyte gene expression, plasma cytokines), and organ injury biomarkers. Enrollment is planned from 5/2026-7/2030. Strengths and limitations of this study MANTRA is a randomized trial comparing angiotensin-II against an active standard-of-care norepinephrine strategy rather than placebo, enrolling patients earlier in septic shock than prior trials restricted to catecholamine-resistant shock. Serial sampling profiles RAAS peptides, innate immune function, and organ-injury biomarkers, which will generate rich mechanistic data on how vasopressor strategy shapes the host response. The sample size is adequate for the biomarker primary endpoints and will establish feasibility for a larger trial, but it does not provide sufficient power for hard clinical endpoints, which remain exploratory. MANTRA compares two open-label vasopressor strategies rather than monotherapies; clinician retain discretion over background and rescue vasopressors, steroids, and crossover, which may attenuate differences between-arms. The 48-hour intervention window limit inference about clinician-assessed outcomes and the durability of treatment effect.

Background: Intracerebral hemorrhage (ICH) is associated with high early mortality. Although routine coagulation markers are clinically relevant, their incremental value for mortality prediction beyond neurologic and physiologic information is uncertain. We developed and externally validated models using first-24-hour ICU data and evaluated the added predictive value of routine coagulation measurements. Methods: We used MIMIC-IV for model development and eICU-CRD for external validation. The development cohort included 2,669 adults with non-traumatic ICH and 388 ICU deaths. Logistic regression, random forest, and XGBoost were evaluated using a patient-level 70:30 holdout split and 5-fold stratified cross-validation. External validation used a high-specificity primary eICU cohort (396 patients; 39 deaths) and a broader secondary hemorrhagic-stroke/likely-ICH cohort (1,555 patients; 168 deaths). Performance was assessed using AUROC, AUPRC, Brier score, calibration, and paired bootstrap comparisons. GCS-only and age-plus-GCS models served as clinical benchmarks. Coagulation-only, clinical-only, and combined XGBoost models were compared to assess incremental value. Results: In the internal holdout cohort, AUROCs were 0.870 for logistic regression, 0.859 for random forest, and 0.867 for XGBoost. In the primary external cohort, corresponding AUROCs were 0.804, 0.839, and 0.817; AUPRCs were 0.342, 0.419, and 0.406; and Brier scores were 0.080, 0.072, and 0.074. In the broader cohort, AUROCs were 0.826, 0.848, and 0.838. Random forest showed the numerically strongest external performance, but pairwise AUROC differences among multivariable models were not clearly supported. GCS-only achieved AUROCs of 0.780 and 0.813 in the primary and broader cohorts. Coagulation-only XGBoost showed weak discrimination (AUROC 0.598 internally, 0.598 primary external, and 0.566 broader external). Adding coagulation variables to the clinical model produced AUROC differences of 0.014 (95% CI -0.009 to 0.037) and 0.003 (95% CI -0.007 to 0.013) in the two external cohorts. Conclusions: Multivariable models based on first-24-hour ICU data retained useful discrimination across external cohorts and provided modest gains over simple GCS-based benchmarks. Routine coagulation markers alone were weak predictors and did not provide clearly supported incremental discrimination beyond broader clinical information. Cross-database transportability should be interpreted together with phenotype alignment and calibration.

Purpose To estimate the per-protocol effect of red blood cell (RBC) transfusion strategies on ICU-acquired infection in critically ill adults with sepsis using a target trial emulation framework. We evaluated whether restrictive strategy and liberal strategy, defined by hemoglobin (Hgb) thresholds, differ in their effect on ICU-acquired infection during ICU stay. Methods We conducted a target trial emulation using the MIMIC-IV database and included adults who met Sepsis criteria at ICU admission. Clones were assigned to restrictive or liberal transfusion strategies. Under the restrictive strategy, RBC transfusion was permitted only when Hgb was [≤]7.0 g/dL, whereas under the liberal strategy, transfusion was permitted when Hgb was >7.0 g/dL. The primary outcome was the first ICU-acquired infection occurring at least 72 hours after ICU admission. Per-protocol effects were estimated using a clone-censor-weight approach with a marginal structural model. A parametric g-formula was used as a complementary analysis that jointly modeled ICU discharge and ICU mortality as competing events to derive strategy-specific 28-day cumulative incidences and risk differences. Results 8 Among 4,013 eligible ICU stays, the liberal-versus-restrictive comparison provided little evidence of a difference in the risk of ICU-acquired infection (adjusted conditional OR, 0.954; 95% CI, 0.797 to 1.142). In the complementary g-formula analysis, the 28-day risk difference for the liberal versus restrictive comparison was -0.02 percentage points (95% CI, -0.15 to 0.11), consistent with the primary analysis. Findings were generally robust across prespecified subgroup and sensitivity analyses. Conclusion In this target trial emulation of adults with sepsis, we observed no clinically meaningful difference in ICU-acquired infection between RBC transfusion strategies defined by hemoglobin thresholds.

Background: Capillary refill time (CRT) is an increasingly endorsed bedside perfusion marker in septic shock.Publicly available intensive care unit (ICU) databases such as MIMIC-IV and eICU-CRD enable large-scale multi-database research, but the cross-database comparability of CRT operationalization has not been systematically examined. Methods: We conducted a retrospective, descriptive, cross-database methodological analysis of adult ICU stays in MIMIC-IV v3.1 (2008-2022) and eICU-CRD v2.0 (2014-2015). CRT availability, definitional thresholds, recording patterns and time windows, bilateral measurement consistency, and selection bias in the CRT-documented population were characterized descriptively. Results: Among 94,458 MIMIC-IV and 200,234 eICU-CRD adult ICU stays, CRT availability differed markedly:79.85% of MIMIC-IV stays had at least one CRT record within the first 24 hours, versus 6.35% of eICU-CRD stays across the entire ICU stay, a 73.5-percentage-point gap. The abnormality threshold was 3 seconds in MIMIC-IV and 2 seconds in eICU-CRD. Among CRT-available MIMIC-IV stays, the mean number of CRT records in the first 24 hours was 7.0 (median 6, interquartile range (IQR) 4-10); 99.6% had bilateral records, with 99.4% left-right agreement (Cohen's kappa 0.914). The temporal distribution of CRT records was strikingly similar between databases: only 28.7% of MIMIC-IV and 29.1% of eICU-CRD records occurred within 24 hours of ICU admission (including pre-admission records), with roughly 71% in both databases recorded later in the stay. In eICU-CRD, the CRT-documented population had higher illness severity than the undocumented population (Acute Physiology and Chronic Health Evaluation (APACHE) IV 60.0 versus 54.4; standardized mean difference 0.21), consistent with selection by indication. Structured peripheral perfusion index fields were unavailable in both databases. Conclusions: CRT operationalization differs fundamentally across MIMIC-IV and eICU-CRD in availability, definitional thresholds, recording patterns, bilateral structure, and patient selection. Cross-database CRT research should explicitly declare definitional heterogeneity, avoid pooling across thresholds, and treat sparsely documented subsets as selected populations. Selection bias was evident in both databases, in opposite directions. Severity-score-based comparison was possible only in eICU-CRD. Standardized common data elements for bedside perfusion assessment are needed to make cross-database CRT research valid by design.

Background: Molecular markers and mediators of adverse post-hospital outcomes following critical illness remain incompletely characterized. Anemia and red blood cell (RBC) indices integrate inflammation, nutritional status, and hematopoietic function, and may represent biological processes that influence long-term outcomes. We therefore examined whether pre-discharge anemia and hematologic clusters derived from correlated RBC indices were associated with one-year mortality among critical illness survivors. Methods: We conducted an exploratory, retrospective cohort study of adult ICU patients discharged alive using MIMICIV. Pre-hospital discharge RBC indices (hemoglobin, red cell distribution width (RDW), mean corpuscular volume (MCV), mean cell hemoglobin (MCH), mean cell hemoglobin concentration (MCHC), and RBC count) were analyzed. Hemoglobin and anemia were first evaluated, followed by Gaussian mixture modeling of standardized RBC indices to identify patient clusters in a derivation cohort (70%) and validated findings in a held-out cohort (30%). Associations with one-year mortality were assessed using multivariable-adjusted Cox models. Results: Among 20,233 ICU survivors with available pre-discharge hemoglobin (median age, 67 years), based on the WHO definition of anemia, 17,247 (85.2%) critical illness survivors were anemic at hospital discharge. Anemia was associated with higher one-year mortality (adjusted HR 1.42, p<0.001). Mortality was 20% overall and decreased across increasing hemoglobin quartiles, from 28.8% to 12.5% (log-rank P<0.005); lower hemoglobin was associated with progressively higher adjusted one-year mortality risk. Six hematologic clusters derived from RBC indices were identified with one-year mortality ranging from 10.1% to 31.4% (log-rank p<0.005). Compared with the lowest-risk group, the cluster characterized by elevated RDW and MCV had a twofold higher adjusted mortality risk (HR 2.14; 95% CI, 1.81-2.53). Conclusion: Both anemia and hematologic clusters derived from standard RBC indices at hospital discharge are associated with one-year mortality following critical illness. These hypothesis-generating findings support further investigation of RBC indices as potential biomarkers for post-discharge risk stratification and of the underlying biological pathways as possible therapeutic targets.

Background: When intravenous insulin is stopped in critically ill patients, the basal insulin dose that balances rebound hyperglycemia against hypoglycemia is uncertain, because randomized trials were small and not designed to quantify this trade-off. We examined how the first glargine dose, relative to the preceding intravenous insulin requirement, was associated with both outcomes. Methods: In this retrospective cohort study of the Medical Information Mart for Intensive Care IV database (2008-2022), we included transitions from intravenous insulin infusions of at least 6 hours to subcutaneous glargine in adults without diabetic ketoacidosis or hyperosmolar hyperglycemic state. The exposure was the ratio of the first glargine dose to 24 times the mean infusion rate over the final 6 hours. The primary outcomes, rebound hyperglycemia (glucose >180 mg/dL within 24 hours) and hypoglycemia (glucose <70 mg/dL within 48 hours) during intensive care unit follow-up, were analyzed with multivariable Cox models after multiple imputation. Results: Among 6,220 transitions in 5,924 patients (87.5% after cardiac surgery), the median ratio was 0.41 (interquartile range 0.30-0.46). Kaplan-Meier cumulative incidences were 44.4% for rebound hyperglycemia (2,109 events) and 6.4% for hypoglycemia (211 events). Each 0.1 increase in the ratio was associated with less rebound hyperglycemia (hazard ratio 0.96, 95% confidence interval 0.93-0.99) and more hypoglycemia (1.11, 1.04-1.18), consistently across 21 sensitivity analyses. Rebound within the first 6 hours (57.6% of events) was not associated with the ratio (0.99, 0.95-1.02), whereas later rebound was (0.91, 0.86-0.96). Standardized to the cohort, a ratio of 0.60 versus 0.40 corresponded to 2.7 (0.6-4.9) fewer rebound and 1.7 (-0.2 to 3.5) more hypoglycemia episodes per 100 transitions. In secondary analyses, rebound was less frequent with glargine given at least 2 hours before discontinuation (0.86, 0.77-0.96) and more frequent with an oral diet (1.49, 1.30-1.71). Conclusions: In critically ill adults, mostly after cardiac surgery, higher glargine doses relative to the preceding intravenous requirement were associated with less rebound hyperglycemia after the first 6 hours and more hypoglycemia, a gradual trade-off. Which basal fraction is preferable depends on the weight given to each outcome; a randomized trial including the guideline-implied fraction of about 0.30 is warranted.

Background: Risk adjustment for disease severity in pediatric intensive care research commonly relies on clinical organ dysfunction scores requiring detailed clinical and laboratory information, which is often unavailable in administrative healthcare datasets. We therefore evaluated the feasibility of a coding-based Pediatric Organ Dysfunction Index (PODI) derived from International Classification of Diseases (ICD-10) and Operation and Procedure System (OPS) codes, for approximating sepsis-related organ dysfunction and adjusting for disease severity, using the pediatric Sequential Organ Failure Assessment (pSOFA) score as a reference standard. Methods: In this retrospective single-center cohort study, pediatric sepsis episodes treated between November 2011 and November 2021 were identified. Discrimination for in-hospital mortality and calibration were assessed. Agreement between PODI and pSOFA was quantified using Spearman's rank correlation, and organ-specific agreement using sensitivity, specificity, and predictive values. An expanded PODI incorporating additional ICD-10 and OPS codes was evaluated in sensitivity analyses. Results: A total of 488 pediatric sepsis episodes were included, with an in-hospital mortality of 14.1%. The PODI showed good discrimination for in-hospital mortality (AUC 0.85, 95% CI 0.80-0.89), comparable to the maximum pSOFA (pSOFAmax) (AUC 0.78, 95% CI 0.72-0.83) and superior to pSOFA at sepsis onset (pSOFAonset) (AUC 0.73, 95% CI 0.67-0.80). Agreement between PODI and pSOFA organ-specific components varied considerably across organ systems, with the highest sensitivity to detect pulmonary dysfunction. Correlation between both scores was moderate (0.54 for pSOFAonset and 0.60 for pSOFAmax), indicating that comparable predictive performance does not render the scores interchangeable. The expanded PODI improved organ-level sensitivity for selected components but did not meaningfully improve mortality discrimination. Conclusions: The standard PODI may represent a practical approach to adjust for organ dysfunction and therapy intensity in administrative datasets with ICD-10 coding where clinical and laboratory information is unavailable. Given only moderate agreement with the pSOFA, the PODI should be understood as a covariate for risk adjustment at the group level rather than as a substitute for clinical organ dysfunction scores in individual patients. Further validation and refinement in non-sepsis cohorts are required before broader implementation in large-scale administrative research can be recommended.

Background Despite numerous randomized controlled trials (RCTs) and systematic reviews (SRs), current sepsis guidelines continue to issue only weak recommendations for corticosteroids. We examined the clinical scope, underlying study pools, and mortality conclusions of SRs evaluating corticosteroids for sepsis. Methods We conducted a meta-research study of SRs on corticosteroids in sepsis (2015 to 2025), extracting SR characteristics, mortality results, and included RCTs. Study-pool overlap was assessed using an SRxRCT inclusion matrix, Jaccard similarity (J), and hierarchical clustering. SRs and RCTs were classified according to standardized Population, Intervention, Comparison, Outcome (PICO) profiles. We explored discordance in short-term mortality conclusions among clinically comparable SRs and potential associations with study-pool composition, target populations, and methodological characteristics. Results Forty-two SRs including 121 unique RCTs were identified. More than half of pairwise SR comparisons shared no RCTs, and only three pairs showed high overlap (J>0.8). SRs addressing similar intervention and target population profiles frequently relied on different study pools. Among 38 SRs with short-term mortality meta-analyses, 15 (39%) reported benefit and 23 (61%) no evidence of effect. Discordance occurred exclusively among SRs evaluating broad, non-specific corticosteroid strategies; conclusions were consistent for hydrocortisone plus fludrocortisone (benefit) and hydrocortisone, ascorbic acid, and thiamine (no evidence of effect). SRs including sepsis +/- shock populations more frequently reported benefit than those restricted to septic shock (62% vs 22%), although estimates were imprecise. No single methodological or clinical factor consistently explained discordance. Conclusions SRs addressing apparently similar clinical questions frequently synthesized different underlying evidence bases and reported discordant conclusions. Guideline developers should therefore consider not only methodological quality and reported PICO, but also whether the RCTs included in an SR adequately represent the intended clinical question. Clinically coherent evidence syntheses may improve the interpretability of pooled treatment effects and support more targeted corticosteroid therapy in sepsis.

Objective We aimed to evaluate the performance of the recently updated Sequential Organ Failure Assessment Score-2 (SOFA-2) on organ dysfunction classification and prognostication compared to SOFA-1 in critically injured trauma patients. Methods Adult trauma patients admitted to critical care at four urban Major Trauma Centres between 2011 and 2024 were included. Daily organ dysfunction scoring was performed using SOFA-1 and SOFA-2 until death or discharge. The primary outcome was MODS, defined as SOFA score [&ge;]6. Results In 2162 severely injured patients (median Injury Severity Score 25 [IQR, 17-34]), SOFA-2 reduced the proportion of patients classified as having MODS compared with SOFA-1 (61.6% vs 68.5%, p<0.001). SOFA-2 scores on the first day after admission were lower than SOFA-1 (median 6 [IQR, 3-8] vs 7 [IQR, 4-10], p<0.001), driven predominantly by lower respiratory and cardiovascular scoring. Critical care mortality in trauma patients was increased in respiratory, cardiovascular and renal components of SOFA-2 at the higher ends of the scores, consistent with the aims of the SOFA-2 reclassification. A group of 159 severely injured patients (7.3%) classified as MODS by SOFA-1 were reclassified to no-MODS by SOFA-2. Despite this reclassification, these patients had substantially higher ICU mortality (7.5% vs 0.7%, p<0.01), greater ventilator and vasopressor requirements, and longer hospital stays than patients classified as no-MODS by both systems. Conclusions SOFA-2 reduces MODS prevalence in severely injured patients and changes organ dysfunction classification, with lower rates of severe respiratory and cardiovascular dysfunction. This represents an important update in trauma MODS measurement and has implications for future trauma trial design. However SOFA-2 reclassification generates a small cohort a small but clinically significant group with occult MODS that warrants further evaluation in severely injured trauma patients.

BACKGROUND: Liberation from invasive mechanical ventilation (IMV) is a central therapeutic objective in acute respiratory failure (ARF). While lung-protective ventilation strategies and diaphragm function have received considerable attention as determinants of liberation success, the prognostic role of extrapulmonary thoracic tissue composition remains poorly defined. We examined whether chest computed tomography (CT)-derived thoracic skeletal muscle mass (TMM), subcutaneous fat mass (SFM), and their ratio (muscle-fat ratio: MFR) are associated with IMV outcomes in ARF. METHODS: This secondary analysis of a prospective observational ARF cohort includes patients with a chest CT obtained within 7 days before or 3 days after intubation. TMM, SFM and MFR were derived using validated three-dimensional convolutional neural network-based volumetric segmentation spanning the lung apices to bases. Co-primary outcomes were time to successful ventilator liberation within 60 days and 60-day all-cause mortality. Multivariable Cox and logistic regression models with restricted cubic splines assessed linear and non-linear associations, adjusted for age, sex, and key comorbidities. We performed prespecified BMI-stratified and ARDS subgroup analyses. RESULTS: Among 826 patients with ARF requiring IMV, 238 patients with CT imaging were included for analysis (median age 59.5 years, median BMI 28.7 kg/m^2). A higher MFR was independently associated with faster ventilator liberation (hazard ratio 1.16, 95% confidence interval [CI] 1.02 to 1.32, p=0.023). TMM demonstrated a significant J-shaped non-linear relationship with time to liberation (p for non-linearity=0.019), with delayed liberation at both low and high extremes of TMM. Higher SFM was independently associated with increased 60-day mortality (odds ratio 1.09, 95% CI 1.00 to 1.18, p=0.049). In 81 patients with ARDS, TMM also demonstrated a significant J-shaped non-linear relationship with 60-day mortality (p for non-linearity=0.037). BMI was not significantly associated with either outcome. CONCLUSIONS: Volumetric CT-derived thoracic body composition metrics, particularly MFR and TMM, are independently associated with ventilator liberation and 60-day mortality in ARF, capturing prognostic information not reflected by BMI alone. These findings support the incorporation of automated thoracic body composition analysis into early risk stratification frameworks for mechanically ventilated patients and highlight extrapulmonary tissue composition as an underexplored determinant of IMV outcomes.

Background: Optimal arterial oxygen targets after return of spontaneous circulation (ROSC) in pediatric out-of-hospital cardiac arrest (OHCA) remain uncertain. We examined whether arterial oxygen tension on the first arterial blood gas after ROSC is associated with neurological or survival outcomes. Methods: Using the Japanese Association for Acute Medicine OHCA Registry, we retrospectively studied pediatric patients (<18 years) with OHCA in whom ROSC was confirmed at or after hospital arrival. Patients were categorized by PaO? on the first arterial blood gas after ROSC as normoxemia (60?200 mmHg) or hyperoxemia (>200 mmHg). Missing covariate data were handled using multiple imputation, and associations were estimated using inverse probability-weighted logistic regression. Outcomes were favorable neurological status at 30 days, defined as a Pediatric Cerebral Performance Category score of 1?3, and 30-day survival. Multiple sensitivity analyses were performed, including analyses using an alternative PaO? threshold, restricting the timing of PaO? measurement, and excluding extracorporeal cardiopulmonary resuscitation cases. Results: A total of 189 patients were included (95 normoxemia, 94 hyperoxemia). A favorable neurological outcome occurred in 21 of 95 (22.1%) normoxemia and 13 of 94 (13.8%) hyperoxemia patients, and 30-day survival in 40 of 95 (42.1%) and 42 of 94 (44.7%), respectively. After weighting, covariate balance was achieved with standardized mean differences below 0.1. Hyperoxemia was not significantly associated with favorable neurological outcome (adjusted odds ratio [aOR] 0.94, 95% confidence interval [CI] 0.49?1.77) or 30-day survival (aOR 1.49, 95% CI 0.88?2.54). Sensitivity analyses yielded consistent results. Conclusions: Early hyperoxemia after ROSC was not significantly associated with neurological or survival outcomes in pediatric out-of-hospital cardiac arrest. These findings suggest that a single early PaO? measurement may be insufficient to characterize the clinical impact of oxygen exposure after resuscitation. Future research should focus on phase-specific and individualized oxygen management incorporating serial physiological assessment.

Background: The 2026 American Heart Association/American College of Cardiology (AHA/ACC) guidelines replaced the 2019 European Society of Cardiology (ESC) four-tier pulmonary embolism (PE) risk scheme with five clinical categories (A-E) and subcategories. These categories were set by expert consensus and have not been validated against outcomes. How patients are reclassified relative to ESC, or how the two systems compare prognostically, is unknown. Methods: We utilized three cohorts of patients with confirmed PE using structured electronic health record data, laboratory biomarkers, and large-language-model abstraction of radiology reports: Duke University Health System (n=12,992, drawn from 95,760 consecutive inpatient CT pulmonary angiography studies, 2014-2025, with no referral or registry enrollment step between imaging and cohort entry), INSPECT (Stanford; n=3,870), and MIMIC-IV (Beth Israel Deaconess; n=361). Patients were assigned AHA/ACC categories B through E, subcategorized where data allowed, and mapped to 2019 ESC risk strata. The primary outcome was 30-day mortality; discrimination was assessed with Harrell C-index. Results: Among 17,223 patients with confirmed PE, pooled 30-day mortality rose monotonically across categories: 1.5% (B), 8.9% (C), 15.5% (D), and 31.9% (E), with the ordering preserved in all three cohorts despite differing baseline mortality. Subcategory-level discrimination was reliable only at the high-acuity extreme (D2-E2); across subcategories C1 through D1, mortality did not order monotonically (9.2%, 10.8%, 8.1%, 10.9%), and adding subcategories to category C did not improve discrimination at Duke (C-index 0.699 vs 0.699). Category C patients lacking both echocardiography and biomarker testing (12.7% of category C) had mortality (10.4%) equal to or exceeding classified peers. Relative to ESC, the frameworks were concordant at the extremes, but 5.7%of ESC intermediate-risk patients were reclassified to category D, with modestly higher but non-significant 30-day mortality than those remaining in category C (10.8% versus 8.9%). Conclusions: Across a three-health-system cohort, the 2026 AHA/ACC framework produced a reproducible mortality gradient at the category level, with added subcategory granularity refining risk chiefly at the highest-acuity tiers. Discrimination across the broad intermediate band was limited, and reclassification from ESC fell almost entirely within this range.

OBJECTIVE: Sepsis-associated encephalopathy (SAE) and sepsis-associated delirium (SAD) lack confirmatory laboratory tests or biomarkers. We evaluated whether the Th17/interleukin (IL)-17 axis or neuroglial-injury biomarkers reflect acute brain dysfunction beyond systemic inflammation and whether biomarker profiles differ between these phenotypes. DATA SOURCES: EMBASE, MEDLINE/PubMed, and the Cochrane Library from inception to August 1, 2026, supplemented by backward and forward citation searching, following PRISMA 2020. STUDY SELECTION: Observational studies of adults with sepsis classified by SAE or SAD status and reporting circulating biomarker concentrations by neurological group or biomarker-outcome associations. Eighteen studies (2,388 participants; 1,863 with sepsis) were included. DATA EXTRACTION: Two reviewers independently extracted study, phenotype, assay, and outcome data. Risk of bias was assessed with the Newcastle-Ottawa Scale and certainty with GRADE. DATA SYNTHESIS: Random-effects models pooled standardized mean differences (SMDs) separately against non-septic and septic controls and odds ratios (ORs) for biomarker-outcome associations. IL-6 was the only mediator elevated in both comparative frameworks and associated with outcomes (non-septic controls: SMD, 0.54 [0.25-0.82]; septic controls: SMD, 1.05 [0.51-1.59]; OR, 1.85 [1.50-2.29]). S100B, neuron-specific enolase, IL-10, tumor necrosis factor; and interferon-gamma; were elevated versus septic controls, whereas IL-17 was modestly elevated only versus non-septic controls (SMD, 0.37 [0.01-0.73]). The IL-6 septic-control effect was concentrated in SAE (p<0.0001) and remained robust in leave-one-out and risk-of-bias sensitivity analyses. Certainty was low to very low, and all 14 computable prediction intervals included the null. CONCLUSIONS: IL-6 emerges as the leading circulating candidate biomarker of sepsis-associated brain dysfunction, while S100B and NSE capture neuroglial injury beyond sepsis. Current evidence does not establish a discriminating role for the Th17 axis. Future studies require standardized neurological phenotyping and appropriately matched septic controls to establish diagnostic value.

Background: The condition of a patient with acute stroke often changes within hours of ICU admission. Prognostic work here targets fixed endpoints predicted from admission data, and trajectory phenotyping assigns one label per patient. We used longitudinal ICU data to identify interpretable dynamic clinical states, characterize transitions between them, and relate the current state to later events. Methods: Retrospective cohort study of 6368 adults with acute stroke in MIMIC IV v3.1. The first 72 h were divided into twelve 6-hour windows, and a hidden Markov model was fitted to 21 neurological, physiological and organ support variables. State number was chosen against criteria fixed before fitting: statistical fit, restart stability, state occupancy and clinical interpretability. Generalized estimating equations related the current state to new mechanical ventilation and vasopressor use within 12 h, and to ICU death within 72 h. Eleven sensitivity analyses assessed the robustness of the state solution. Results: Four states were selected: neurologically preserved-low support, neurological impairment low support, impairment renal dysfunction and impairment-respiratory support (63.3%, 7.8%, 11.8% and 17.1% of windows). Within 72 h, 40.3% of patients changed state at least once, and transitions ran in both directions rather than along a single severity gradient. States were identified without outcome data, yet ICU mortality by last state ranged from 2.9% to 43.9%. Adjusted for age, sex, subtype and Charlson index, the current state remained associated with organ-support escalation and death. State prevalence differed by at most 1.1 percentage points between training and test sets, and 10 of 11 sensitivity analyses gave a stable four-state solution (ARI 0.754 0.955). Conclusions: The early ICU course of acute stroke can be represented as movement among a small number of clinically interpretable states. The representation was reproducible in a held out set and across admission eras, but requires validation in an independent database before any clinical use.

Aim: General ICU severity scores predict hospital mortality across heterogeneous populations, not recovery within one diagnosis. We described favourable discharge across the range of APACHE IVa-predicted hospital mortality after cardiac arrest, and tested whether any bedside subgroup fell below a pre-specified benchmark. Methods: Observational cohort of 3,641 first ICU admissions in 161 eICU hospitals with a cardiac-arrest diagnosis documented within 24 hours. The exposure was APACHE IVa-predicted hospital mortality; the outcome was favourable discharge (home or rehabilitation), a functional-outcome proxy. Fourteen bedside subgroups were pre-specified; the benchmark required an upper 95% bound below 5%. Results: Favourable discharge occurred in 1,039 (28.5%), falling from 78.9% in the lowest predicted-mortality decile to 4.1% in the highest (trend z, -27.2; P < 0.001). Among 2,139 patients with predicted mortality at or above 50%, 301 (14.1%; 95% CI, 12.6 to 15.6) had a favourable discharge; among 281 at or above 90%, 9 (3.2%) did. No subgroup had an upper 95% bound below 5%; the lowest was 8 of 264 (3.0%; 95% CI, 1.3 to 5.9). At a more permissive 10% benchmark, two qualified. Among 1,961 not obeying commands, 263 (13.4%) had a favourable discharge. Discrimination did not differ detectably between unfavourable functional outcome (AUROC 0.789) and in-hospital death (0.774; P = 0.078). Conclusion: Favourable discharge declined as predicted mortality rose but remained observable at the highest risk levels, and no pre-specified subgroup was bounded below 5%. A general ICU mortality estimate is not on its own evidence that a favourable outcome is absent.

Objective: To test the hypothesis that selected SIRS and SOFA criteria measured at ICU admission have divergent associations with (1) the development of new culture-confirmed infections and (2) early empiric broad-spectrum antibiotic receipt in critically ill patients with cirrhosis. Design: Retrospective, observational study using electronic health record (EHR) data. Setting: Both community and academic ICUs within a five-hospital health system between July 2017 and December 2025. Subjects: Adult patients >18 years of age diagnosed with cirrhosis admitted to the ICU within 96 hours of hospital admission. Patients transferred from outside facilities and those with positive cultures collected >24 hours before ICU admission were excluded. Interventions: None. Measurements: Multivariable logistic regression tested the association of the most aberrant values in nine SIRS/SOFA vital sign and laboratory parameters measured during the 24 hours prior to ICU admission with (1) the development a newly positive culture collected during the 24 hours before through the 96 hours after ICU admission and (2) receipt of broad-spectrum antibiotics during the 24 hours before through the 24 hours after ICU admission. Main Results: The presence of hyperthermia, hypothermia, hypoxia, or hypotension at ICU admission was associated with both culture positivity and antibiotic receipt. The presence of leukocytosis was associated with antibiotic receipt but not culture positivity. Among patients in the 21.6% of encounters with newly positive cultures, normothermia and normal WBC were common (respectively present in 97.2% and 77.5% of encounters) and associated with antibiotic omission at ICU admission despite the subsequent development culture positivity. Conclusions: Traditional physiologic markers of infection are often absent in critically ill patients with cirrhosis who develop new culture-confirmed infections at ICU admission, possibly contributing to delayed antibiotics. There may be opportunities to improve antibiotic delivery and stewardship at ICU admission in this high-risk population.

Introduction and objectives Hydrocephalus is a common complication of aneurysmal subarachnoid haemorrhage. This is one of several standard indications for the insertion of an external ventricular drain, but there are no standard guidelines for timing of extraventricular drain discontinuation in this population. Therefore, the study aims were to examine the 1) factors associated with extraventricular drain duration in aneurysmal subarachnoid haemorrhage and 2) association between extraventricular drain duration and clinical and resource-based outcomes. Methods In this single centre retrospective cohort study, data for adult patients treated in the ICU between 2015-2023 with aneurysmal subarachnoid haemorrhage and requiring an extraventricular drain were analysed. Data were extracted from both a prospective patient registry and the electronic medical record. Linear regression modelling was used to identify the factors associated with extraventricular drain duration. Measures used to examine the association between extraventricular drain duration, and the outcomes of interest included hazard ratio, relative risk, and mean differences as appropriate for a specific outcome. Results Of the participants (n=205), 68% (n = 140) were female, mean age was 60.7 (SD 13.3) years and 71% (n = 145) had a modified Fisher score of 4. Mean extraventricular drain duration was 15.3 (SD 8.6) days. The number of days mechanically ventilated and extraventricular drain challenge by clamp trial were associated with an increased duration of extraventricular drain treatment. Increased extraventricular drain duration was associated with an increased incidence of ventriculoperitoneal shunt insertion, and an increase in ICU and hospital length of stay when extraventricular drain duration exceeded 20 days. Conclusion The factors associated with an increased duration of extraventricular drain treatment were a longer duration of mechanical ventilation. The outcomes associated with an increased duration of extraventricular drain treatment were an increased incidence of ventriculoperitoneal shunt insertion, an increased incidence of ventriculitis when extraventricular drain duration exceeded 20 days, and an increase in ICU length of stay. These study findings may inform the conduct of a larger multi-centre study to examine the factors associated with duration of treatment with extraventricular drain, and outcomes associated with extraventricular drain duration.

Background Spontaneous intracerebral hemorrhage (ICH) is the most devastating type of stroke but lacks the established time-critical treatment guidelines available for acute ischemic stroke. This study investigated the impact of Code Stroke activation and warfarin use on anticoagulation reversal times to identify opportunities for quality improvement. Methods We retrospectively assessed patients with anticoagulation-associated ICH admitted to our medical center between January 1, 2020, and December 31, 2025. Patients with warfarin- or direct oral anticoagulant (DOAC)-associated ICH were identified from our ICH clinical trial screening log, Vizient, and AHA's Get With The Guidelines-Stroke registry. Code Stroke activation, warfarin or DOAC use, anticoagulation reversal times, causes of delay, and clinical outcomes at hospital discharge were analyzed. Results Of 892 ICH admissions, 50 patients had confirmed anticoagulation-associated ICH. Among those who underwent reversed at our center (n=34), Code Stroke activation (n=24) significantly reduced door-to-CT time (16.5 [12.8-22.0] vs 172.5 [49.0-261.5] minutes, p <0.001), reversal agent order-to-needle time (37.5 [24.7-56.9] vs 57.0 [39.0-85.0] minutes, p <0.001), and door-to-treatment (DTT) time (64 [48-98] vs 277 [159-305] minutes, p <0.001) compared to non-activation (n=10). Conversely, warfarin use was associated with higher international normalized ratios (INR) (2.7 [2.2-3.6] vs 1.3 [1.2-1.9], p =0.003) and significantly longer DTT time (95 [51-108] vs 64 [48-77] minutes, p =0.007). Primary DTT delays stemmed from the absence of a time-critical treatment protocol, weight-based dosing for 4F-PCC, waiting for INR results, and a lack of Code Stroke activation for patients with mild symptoms, trauma or unexplained unresponsiveness. Conclusions Our findings suggest that Code Stroke activation for all suspected cases of ICH, a time-critical emergency department algorithm targeting a DTT time of less than 60 minutes, and immediate anticoagulation reversal with fixed-dose 4F-PCC without waiting for INR results may optimize the acute management of anticoagulation-associated ICH.

BACKGROUND Children receiving extracorporeal membrane oxygenation (ECMO) are at high risk for focal cerebral injury (FCI). There is emerging evidence that electroencephalography (EEG) may aid FCI detection. The EEG Correlate of Injury to the Nervous System (COIN) index quantifies and displays focal background asymmetries. We evaluated whether COIN is associated with FCI in pediatric ECMO. METHODS Retrospective, cross-sectional study of patients age 28 days to 21 years, on venoarterial ECMO at a tertiary children's hospital, who received EEG monitoring and neuroimaging during ECMO. COIN was calculated from all available EEG data. COIN of 0 implies a symmetric EEG and negative COIN values are observed with FCI. Median COIN values near FCI recognition time were compared to median COIN values from randomly selected control EEG batches using logistic regression. A receiver operator characteristic curve was used to identify multilevel FCI test ranges. Likelihood ratios were calculated to estimate the posttest FCI probability for each COIN range. RESULTS During the 8-year study period (2015-2023), 33 of 142 ECMO runs met study criteria for COIN analysis. Twelve patients (36%) had FCI. The COIN cutoff of -13.3 had 92% sensitivity and 67% specificity for FCI. The COIN cutoff of -27.7 had 67% sensitivity and 90% specificity. Likelihood ratios were 0.13 for COIN (0 to -13.3), 1.1 for COIN (-13.3 to -27.7), and 7.0 for COIN (< -27.7). Posttest probability was 0.02, 0.13, 0.49 in each respective range. CONCLUSION FCI on ECMO is associated with COIN-measured EEG asymmetry. COIN may support FCI risk-stratification during ECMO.