Critical Care

We have previously shown that fresh frozen plasma (FFP) and fibrinogen have protective effects in mice with hemorrhagic shock through restoration of endothelial syndecan-1 and reversal of endothelial injury. In the current study, we tested the hypothesis that a combined model of abdominal sepsis and hemorrhagic shock would induce endothelial syndecan-1 shedding and lung injury which could be attenuated by both FFP and fibrinogen. C57BL/6 mice underwent cecal ligation and puncture (CLP) followed by hemorrhagic shock (HS) and fluid resuscitation with lactated Ringers (LR), fibrinogen (5 mg/mouse), and FFP, all at 1X shed blood volume. After 24 hours, lung tissues and plasma were harvested for assays. CLP+HS induced an increase in alveolar thickness and decreases in lung syndecan-1 and lung neutrophil granule-enzymes (myeloperoxidase, neutrophil elastase, and MMP9), with reciprocal elevations in plasma syndecan-1 and plasma neutrophil granule-enzymes (myeloperoxidase, neutrophil elastase, and MMP9). All these alterations were significantly attenuated by FFP but not by fibrinogen. Additionally, CLP+HS-induced hypotension at 24 hours was partially reversed by FFP but not by fibrinogen. FFP administration inhibits CLP+HS-induced neutrophil degranulation to prevent syndecan-1 shedding and lung injury. The current study supports that FFP has therapeutic benefit in a combined septic and hemorrhage shock model.

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: Plasma proteomics may identify host-response signatures in sepsis, but it is unclear whether extracellular vesicle (EV)-enriched plasma provides distinct or redundant information compared with plasma. We compared paired plasma and EV-enriched plasma proteomes in critically ill patients with sepsis and critically ill non-sepsis controls (CINS). Methods: In this prospective observational study, paired plasma and EV-enriched plasma samples were analyzed from 56 critically ill adults, including 40 patients with sepsis and 16 CINS patients. Protein abundance was quantified using liquid chromatography-tandem mass spectrometry. Analyses compared proteomic depth, protein overlap, global concordance between compartments, and differential protein abundance between CINS and sepsis. Exploratory Gene Ontology enrichment was performed as a supplementary analysis. Results: EV-enriched plasma expanded proteomic detection, identifying 2,476 filtered proteins compared with 506 in plasma. Only 386 proteins were detected in both compartments, while 2,090 were unique to EV-enriched plasma and 120 were unique to plasma. Among shared proteins, plasma and EV-enriched plasma showed modest global concordance across critically ill patients (Spearman coeff = 0.322, p = 9.19 x 10^-11), with similar findings in sepsis alone. Differential abundance analysis identified 11 sepsis-associated proteins in plasma and 22 in EV-enriched plasma. Only SAA1, SAA2, and IGFBP6 were significant in both compartments. Exploratory pathway analysis supported acute-phase and inflammatory enrichment in plasma sepsis-associated proteins, while EV-enriched signals were directionally plausible but did not meet prespecified FDR thresholds. Conclusion: Plasma and EV-enriched plasma proteomics capture related but nonredundant sepsis-associated host-response information in critically ill patients.

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: 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.

Importance: Pharmacological targeting of host mechanisms that limit sepsis-induced organ dysfunction represents a new therapeutic approach. Preclinical studies showed that low-dose epirubicin enhances tissue damage control and attenuates sepsis severity independently of pathogen burden, thereby promoting disease tolerance to infection. Yet epirubicin can cause myelotoxicity when used in cancer therapy. Objective: To investigate whether low-dose epirubicin can safely be administered to patients with sepsis and septic shock. Design, Setting, and Participants: A randomized, double-blind, placebo-controlled clinical trial conducted in five German University hospitals. Patients with sepsis, defined by Sepsis-3 criteria, were eligible within 48 hours after diagnosis. The first patient was enrolled on October 19, 2022, and the last follow-up was conducted on May 21, 2025. Interventions: Eligible patients were randomized in a 4:1 ratio to receive either placebo or low-dose epirubicin in addition to standard care. There were three consecutive phases. Patients in the epirubicin group received a single dose of epirubicin (either 3.75 mg/m2, 7.5 mg/m2 or 15 mg/m2, depending on study phase). Main Outcomes and Measures: The primary endpoint of the trial was the 14-day myelotoxicity. Secondary and explorative outcomes included 90-day mortality, the degree of organ dysfunction as assessed by SOFA score, PK/PD modelling and cytokine release. Results: Of 854 patients assessed for eligibility, 32 were randomized and 31 were included in the primary analysis population. Six participants received placebo, nine participants received 3.75 mg/m2, nine received 7.5 mg/m2 and eight individuals received 15 mg/m2 epirubicin, respectively. There was no myelotoxicity in any group. Mortality at 90 days and SOFA-scores were not significantly different between groups. Two of 39 SAEs in the epirubicin group were assessed by the investigators as possibly related to epirubicin, Conclusions and Relevance Among patients with sepsis and septic shock, low dose epirubicin was not associated with increased myelotoxicity.

Objectives. Perinatal illness and preterm birth carry lifelong multiorgan complications and are associated with hematologic derangements during neonatal intensive care unit (NICU) admission. Despite this, long term hematologic morbidities following neonatal critical illness remain undefined. Our objective was to identify associations between prematurity, perinatal critical illness, and later hematologic dysfunction. Study design. Single neonatal care network retrospective cohort study with cohorts divided by gestational age and the presence of critical illness markers. The association between hematologic dysfunction, critical illness, and prematurity was investigated using multivariate logistic regression. Results. Among 13073 infants, critical illness or prematurity was found to increase the odds of developing pancytopenia post-NICU discharge. Subsequent analyses stratified on prematurity demonstrate that a diagnosis of shock or sepsis was associated with pancytopenia. Conclusions. Our findings suggest that perinatal insults are associated with hematopoietic system dysfunction and long term morbidity. Importantly, critical illness, not prematurity itself, may drive this association in preterm infants.

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: This study aims to identify which markers of tissue hypoperfusion - specifically lactate levels, central venous oxygen saturation (ScvO2), and venous arterial carbon dioxide gradient (CO2 gradient) - have the highest sensitivity and specificity in predicting the discharge of postoperative cardiac surgical patients from the ICU within 48 hours. This is an exploratory, hypothesis-generating investigation. Methods: Prospective observational study involving 100 patients in the Surgical ICU at InCor-HCFMUSP undergoing cardiac surgery with cardiopulmonary bypass. Perfusion markers were assessed at ICU admission and 24 hours post-admission. Results: ScvO2 at 24 hours was the only marker significantly associated with ICU discharge (OR=1.096; 95% CI=1.020-1.180; p=0.012). Formal DeLong's test confirmed ScvO2 had significantly superior discriminatory performance compared to lactate (AUC 0.661 vs. 0.428; p=0.004). Lactato and CO2 gap showed no significant associations. Conclusions: In this exploratory cohort, ScvO2 at 24 hours post-admission showed a statistically significant association with early ICU discharge and superior discriminatory performance compared to lactate. These findings are hypothesis-generating and require prospective validation before clinical recommendations can be made.

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: Sepsis-associated liver injury (SALI) is commonly assessed using static laboratory values, although liver dysfunction during sepsis is dynamic.Methods: This retrospective cohort study included 162 ICU patients with SALI. Early trajectories of alanine aminotransferase, total bilirubin, and albumin during the first 7 days after ICU admission were identified using group-based multi-trajectory modeling. Landmark analysis and Cox regression were used to evaluate 60-day mortality.Results: Twenty-five patients died within 60 days. Four trajectory classes were identified. Between-class separation was driven mainly by alanine aminotransferase and total bilirubin, whereas albumin showed limited short-term variation. After the landmark time point, Class 3 (HR, 4.374; 95% CI, 1.960-9.759; P <0 .001) and Class 4 (HR, 7.451; 95% CI, 3.649-15.212; P <0 .001) had higher mortality risk than Class 1.Conclusions: Early joint trajectories of liver-related laboratory biomarkers may identify clinically meaningful SALI subphenotypes and support risk stratification in critically ill patients.

Introduction Hospitalised community-acquired pneumonia (CAP) is heterogeneous in aetiology, severity, and outcome. Phenotyping and endotyping approaches offer potential to stratify patients biologically and guide targeted therapy, but require well-characterised cohorts with linked biosamples. We describe the PARIS (Pneumonia: Acute Respiratory Infection +/- Sepsis) study: a prospective observational cohort of hospitalised patients with pneumonia, designed to characterise functional outcomes and to provide a biobank for translational immunological research. Methods Adults admitted with CAP to a single NHS district general hospital were enrolled within 24 hours of admission between December 2020 and March 2022. Clinical, functional, and physiological data were collected at enrolment, hospital discharge, and 6-8 week follow-up. Serial blood samples were collected for flow cytometry, transcriptomics, pathogen DNA detection, and plasma biobanking. Results Forty-seven patients were enrolled (15 without and 32 with sepsis [SOFA >=2] at enrolment); 87% met sepsis criteria by 24 hours post enrolment. Most patients (30/47, 64%) were managed as COVID-19, microbiologically confirmed in 27. Mean age was 57 years (SD 16), 70% were male, and baseline comorbidity burden was low. Severity was moderate (median NEWS2 4 at enrolment, rising to 6 by 24 hours post enrolment; p<0.001). Mortality was 4/47 (8.5%), with 44/47 (94%) alive at hospital discharge. Median length of stay was 8 days (IQR 5.5-11). Translational samples were collected from the majority: fresh flow cytometry (44/47, 94%), transcriptomics from the sepsis subgroup (31/32, 97%), pathogen DNA sampling (35 samples received across study timepoints; see Table 5), and stored plasma (29/47, 62%). The primary outcome of functional decline (Barthel score decrease >=1.85) occurred in only 1/29 patients with paired assessments (3.4%). Persistent CRP elevation (>3 mg/L) at 6-8 week follow-up was present in 16/31 (52%) survivors with available data. Conclusions The PARIS cohort provides a well-characterised clinical platform and linked biobank to support translational studies of pneumonia and sepsis. The low rate of functional decline reflects the younger, lower-comorbidity, COVID-predominant population recruited. Primary protocol endpoints were not achieved owing to pandemic-related disruption. Data and samples underpin a programme of linked translational studies.

The acute respiratory distress syndrome is a heterogenous syndrome characterized by the rapid development of respiratory failure. Nearly 40% of patients who develop ARDS will die, and there is growing interest in identification of biomarkers to identify patients at risk of death and/or inform treatment decisions. Most prior work on biomarkers in ARDS has focused on the plasma compartment, but there is concern that circulating biomarkers may not reflect alveolar pathobiology. The anti-inflammatory microRNA-146a has been shown to be upregulated in inflammatory cells in human bronchoalveolar lavage fluid, but it is not known if these levels correspond with outcomes. We measured miR-146a expression by digital droplet PCR in human biospecimens from four different cohorts of patients with respiratory failure requiring mechanical ventilation - two plasma cohorts, one bronchoalveolar lavage cohort, and one heat moisture exchange (HME) filter fluid cohort. We found that miR-146a was detectible in plasma, bronchoalveolar lavage fluid, and HME fluid. However, only when measured in the alveolar space, was miR-146a expression significantly lower in older adults and those who died. It did not correlate with outcomes when measured in plasma. To our knowledge, this is the first report that nucleotides can be measured in HME fluid and builds upon expanding literature that circulating biomarkers may not reflect complex biology of the alveolar microenvironment during ARDS.

BACKGROUND: Cerebral ischemia following subarachnoid hemorrhage (SAH) has traditionally been considered transient because functional alterations of the cerebral microcirculation are thought to be self-limiting. However, we identified a previously unrecognized vasculopathy, perivascular fibrosis of the cerebral microcirculation (PFCM), characterized by excessive type I collagen deposition after SAH. This study investigated the mechanisms underlying PFCM and its subsequent effects on cerebral hemodynamics. METHODS: In vivo SAH was modeled in mice by autologous blood injection, whereas oxygenated hemoglobin (OxyHb) exposure was used to mimic SAH in vitro. Pericyte-deficient mice (Pdgfr{beta}+/-) and pericyte-specific vestigial-like family member 3 (VGLL3) conditional knockout mice (Vgll3{Delta}PC) were generated. Pericyte contractility was measured by nanoindentation and traction force microscopy. Molecular mechanisms were examined using Western blotting, immunofluorescence, CUT&Tag, RNA-seq, transmission electron microscopy, and molecular docking. PFCM, impaired dilation of the cerebral microcirculation, and cerebral autoregulation were assessed by two-photon imaging, transcranial Doppler with continuous blood pressure monitoring, super-resolution ultrasound imaging, and photoacoustic imaging. RESULTS: After SAH, mice developed long-term cerebral autoregulation dysfunction marked by impaired dilation of the cerebral microcirculation, with the abnormality being most evident within the relatively lower blood pressure range. The marked reduction in PFCM in Pdgfr{beta}+/- mice indicated that pericytes were the principal cellular contributors. Mechanistically, OxyHb-induced cytoskeletal remodeling in vitro increased pericyte contractility and promoted nuclear translocation of SAH-upregulated VGLL3. This was followed by increased genomic occupancy, Col1a1 transcriptional activation, and type I collagen deposition. Pericyte-specific VGLL3 knockout abolished PFCM and, consequently, significantly alleviated long-term cerebral autoregulation dysfunction. CONCLUSIONS: Our findings identify PFCM mediated by pericytic VGLL3 as a novel vasculopathy leading to long-term cerebral autoregulation dysfunction after SAH.

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 [&le;]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.

ABSTRACT Background: Corticosteroids reduce mortality in severe COVID-19 requiring oxygen or invasive mechanical ventilation, yet emerging data suggest that SARS-CoV-2-associated acute lung injury is biologically heterogeneous and that treatment response may vary across molecularly defined disease states. Lung-derived molecular endotypes of severe COVID-19-associated acute lung injury have been described, but direct molecular profiling is not routinely available at the bedside. We evaluated whether a clinical predictor of previously defined lung molecular endotype identifies heterogeneity in corticosteroid treatment effect among mechanically ventilated patients with COVID-19. Methods: We utilized a single-center cohort of 5,000 patients with COVID-19 treated at the University of North Carolina Hospital between January 1, 2020, and December 31, 2022, to emulate a target trial assessing the effect of corticosteroid receipt on mortality, length of stay, and incident organ support. Confounding was addressed through inverse probability of treatment weighting (IPTW). Outcomes for severely ill patients requiring mechanical ventilation were compared to the RECOVERY trial results, with subsequent moderation analysis and stratified analysis by clinically predicted lung molecular endotype and vaccination status. The primary outcome was 28-day mortality. Secondary Outcomes were time to discharge alive and progression to additional organ support. Results: This emulated target trial showed a directionally favorable but non-statistically significant association between corticosteroid treatment and reduced 28-day mortality in patients requiring mechanical ventilation for SARS-CoV-2 infection. A clinical predictor of lung molecular endotype moderated the effect of corticosteroids on 28-day mortality (p-value for interaction 0.038) and identified distinct predicted endotype-specific treatment effect. Corticosteroid treatment was associated with lower 28-day mortality in the predicted Hyper-Inflammatory endotype (OR 0.62, 95% CI 0.39, 0.99) but not in the predicted Metabolic Dysregulation endotype (OR 1.15, 95% CI 0.82, 1.61). We did not detect significant effect modification by vaccination status (p-value for interaction 0.65), although inference was limited by the small, vaccinated subgroup (28-mortality OR 0.78, 95% CI 0.37, 1.65 in vaccinated vs 0.94, 95% CI 0.70, 1.26 in unvaccinated). Conclusions: In this target trial emulation of mechanically ventilated patients with severe COVID-19, corticosteroid treatment showed a directionally favorable but non-statistically significant association with reduced 28-day mortality in the overall cohort. However, a clinical predictor of lung molecular endotype identified significant heterogeneity in treatment effect, with benefit concentrated in the predicted Hyper-Inflammatory endotype and no apparent benefit in the predicted Metabolic Dysregulation endotype. These findings support prospective validation of clinically deployable endotype-guided corticosteroid treatment strategies in acute lung injury and ARDS.

BACKGROUND: Subarachnoid hemorrhage (SAH) induces inflammatory responses and subsequent immune cell activation, which may contribute in cerebral vasospasm, microcirculatory impairment and poor neurological outcomes. Although cerebral vasospasm has traditionally been considered a major cause of delayed cerebral ischemia after SAH, therapies targeting angiographic vasospasm have not consistently improved functional outcomes. Early inflammatory responses may contribute to microcirculatory impairment, cerebral vasospasm, and subsequent neurological injury. Herein, we investigated whether interleukin-10 (IL-10), an anti-inflammatory cytokine, improves these outcomes in an experimental SAH model. METHODS: Mice received intramuscular injections of either an adeno-associated virus encoding IL-10 (AAV/IL-10) vector or an AAV expressing green fluorescent protein (AAV/GFP) vector (control). India ink angiography was performed to assess the diameter of the sphenoidal segment of the middle cerebral artery (MCA), the total length of the visible cortical arteries, and cortical staining intensity, as indices of cerebral vasospasm, microcirculatory impairment, and cerebral perfusion, respectively. Perivascular inflammatory cell infiltration and cytokine levels were assessed using immunohistochemistry and ELISA. We also evaluated the therapeutic efficacy of the AAV/IL-10 vector when administered immediately after SAH induction. RESULTS: IL-10 overexpression significantly improved neurological outcomes after SAH and was associated with attenuated cerebral vasospasm and microcirculatory impairment, as well as preservation of cerebral perfusion. It also significantly reduced neutrophil and macrophage infiltration around the internal carotid artery and attenuated SAH-induced elevations in IL-6 and matrix metalloproteinase-3 levels. Mice treated with the AAV/IL-10 vector immediately after SAH induction showed significant improvements in neurological scores and cerebral perfusion. CONCLUSIONS: AAV-mediated IL-10 overexpression improves neurological outcomes after SAH, likely by attenuating inflammatory responses, cerebral vasospasm, and microcirculatory impairment. These findings suggest that IL-10-based anti-inflammatory therapy is a promising therapeutic strategy for SAH.

Background: The hydrodynamic model of hydrocephalus proposes that ventriculomegaly is driven by exaggerated intraventricular pulsations rather than impaired CSF circulation alone. Under this model, endoscopic third ventriculostomy with choroid plexus cauterization (ETV/CPC) treats hydrocephalus by creating a pulsation absorber and by reducing a primary source of intraventricular pulsation. However, direct intraoperative human evidence supporting this two-step mechanism is lacking. This study aimed to test the hypothesis that ETV followed by CPC would produce measurable, stepwise decreases in mean intraventricular pressure (ICP) and pulsation amplitude in infants with hydrocephalus. Methods: This single-institution proof-of-concept study included infants with symptomatic hydrocephalus undergoing ETV/CPC as the first definitive treatment. A fiber-optic ICP sensor was attached to the operative ventriculoscope and passively recorded mean and pulsatile ICP (pulsation amplitude) throughout the procedure. Longitudinal brain parenchymal volume (BPV) and cerebrospinal fluid volume (CSFV) were obtained through segmentation of clinically acquired T2-weighted MRI and converted to age- and sex-matched z-scores. All patients were followed for a minimum of 6 months postoperatively. Results: Five infants (median corrected age at ETV/CPC 8 months) were included. No surgical complications occurred, and no ETV/CPC failures were observed during follow-up. Overall, mean ICP decreased by 56-97% after the combined procedure in four patients. In three patients (Patients 1, 3, and 5), both mean ICP and pulsation amplitude decreased stepwise following ETV and then CPC, consistent with the hypothesized therapeutic mechanism. Patient 4 demonstrated a large reduction in mean ICP after ETV with minimal additional effect from CPC and no significant change in pulsation amplitude. Patient 2 demonstrated neither a reduction in mean ICP nor a meaningful change in pulsation amplitude after either procedure; this patient also had a delayed and atypical clinical response. Intracranial segmentation demonstrated BPV z-score stabilization within normal range and CSFV plateau in all patients after surgery. Conclusions: This proof-of-concept study provides the first direct intraoperative human evidence supporting the hydrodynamic mechanism of ETV/CPC in a subset of infant with hydrocephalus. Our findings suggest that determination of intraoperative ICP parameters is feasible, safe and might ultimately prove helpful in improving patient selection for ETV/CPC, warranting further investigation in larger cohorts.

Severe dengue can damage the liver through unestablished mechanisms. We investigated the role of myeloperoxidase (MPO), a neutrophil enzyme, in dengue through patients, fatal liver samples, and mouse infection models. Observations from two independent clinical cohorts revealed elevated plasma MPO levels in dengue and, in one cohort, MPO was further linked to liver injury markers during the critical phase of disease, whereas livers from dengue fatal cases revealed MPO build-up in the vicinity of CD177+ activated neutrophils. In mice, dengue led to MPO overexpression, oxidative damage, and broad activation of innate and systemic inflammatory pathways in livers. Blocking MPO activity alleviated these and improved survival in one model and delayed disease progression without preventing death in another. These findings establish MPO as a functional mediator of severe dengue-associated liver injury and inflammation, which warrants further preclinical investigation into its hepatic pathogenic mechanism and its validity as target for therapeutic intervention.