Older adults demonstrate biomarker evidence of the persistent inflammation, immunosuppression and catabolism syndrome (PICS) after sepsis

Definitions, epidemiology, and outcomes of persistent/chronic critical illness: a scoping review for translation to clinical practice

BACKGROUND

Medical advances in intensive care units (ICUs) have resulted in the emergence of a new patient population-those who survive the initial acute phase of critical illness, but require prolonged ICU stays and develop chronic critical symptoms. This condition, often termed Persistent Critical Illness (PerCI) or Chronic Critical Illness (CCI), remains poorly understood and inconsistently reported across studies, resulting in a lack of clinical practice use. This scoping review aims to systematically review and synthesize the existing literature on PerCI/CCI, with a focus on definitions, epidemiology, and outcomes for its translation to clinical practice.

METHODS

A scoping review was conducted using MEDLINE and Scopus, adhering to the PRISMA-ScR guidelines. Peer-reviewed original research articles published until May 31, 2024 that described adult PerCI/CCI in their definitions of patient populations, covariates, and outcomes were included. Data on definitions, epidemiology, and outcomes were extracted by a data charting process from eligible studies and synthesized.

RESULTS

Ninety-nine studies met the inclusion criteria. Of these studies, 64 used the term CCI, 18 used PerCI, and 17 used other terms. CCI definitions showed greater variability, while PerCI definitions remained relatively consistent, with an ICU stay ≥ 14 days for CCI and ≥ 10 days for PerCI being the most common. A meta-analysis of the prevalence of PerCI/CCI among the denominators of "all ICU patients", "sepsis", "trauma", and "COVID-19" showed 11% (95% confidence interval 10-12%), 28% (22-34%), 24% (15-33%), and 35% (20-50%), respectively. A meta-analysis of in-hospital mortality was 27% (26-29%) and that of one-year mortality was 45% (32-58%). Meta-analyses of the prevalence of CCI and PerCI showed 17% (16-18%) and 18% (16-20%), respectively, and those for in-hospital mortality were 28% (26-30%) and 26% (24-29%), respectively. Functional outcomes were generally poor, with many survivors requiring long-term care.

CONCLUSIONS

This scoping review synthesized many studies on PerCI/CCI, highlighting the serious impact of PerCI/CCI on patients' long-term outcomes. The results obtained underscore the need for consistent terminology with high-quality research for PerCI/CCI. The results obtained provide important information to be used in discussions with patients and families regarding prognosis and care options.

Host Response in Critically Ill Patients Aged 65 Years or Older: A Prospective Study

Background

The host response plays a critical role in the progression of all critical illnesses, especially in the aging population. With aging becoming a global phenomenon, understanding changes in the host response among elderly patients can provide valuable insights for diagnosis and treatment in the ICU.

Methods

This study included all patients aged 65 and older admitted to our geriatric intensive care unit (GICU). Demographic, clinical, and medication data were extracted from electronic medical records. The primary outcome was in-hospital mortality, while secondary outcomes included hospital length of stay (LOS) and ICU stay duration. We employed the generalized additive mixed model for analysis and utilized nomogram analysis to build a predictive mortality model.

Results

A total of 1204 patients, with a median age of 75 years and a maximum age of 110 years, were admitted to the GICU. Host response biomarkers were notably lower in patients over 85 years. White blood cell (WBC) count, lactate dehydrogenase (LDH), interleukin-10 (IL-10), and tumor necrosis factor-α (TNF-α) were positively associated with mortality, while a higher platelet-to-lymphocyte ratio (PLR) was inversely related to mortality. Lymphocyte count was identified as a significant risk factor for mortality (RR = 1.2181). Elevated host response biomarkers were inversely associated with both hospital and ICU LOS. The predictive model integrating these biomarkers exhibited strong predictive performance for mortality.

Conclusion

Our findings underscore the significant impact of aging on host response in critically ill patients. Older patients, particularly those over 85, exhibited lower biomarker levels and higher mortality rates. The predictive model developed from inflammatory, immune, and coagulation markers demonstrated robust prognostic utility, aiding in the evaluation of critically ill elderly patients.

Risk factors, biomarkers, and mechanisms for persistent inflammation, immunosuppression, and catabolism syndrome (PICS): a systematic review and meta-analysis

INTRODUCTION

Persistent inflammation, immunosuppression, and catabolism syndrome (PICS) has been proposed as an endotype of chronic critical illness (CCI). The aim of this systematic review is to synthesise the available evidence of risk factors, biomarkers, and biological mechanisms underlying PICS.

METHODS

MEDLINE, CENTRAL, and EMBASE were searched on June 2, 2023. Our population of interest was adult intensive care unit survivors. The exposure group was patients with PICS and the comparator group was patients with no PICS, CCI, or rapid recovery. Mean differences were pooled for each biomarker using a random effects DerSimonian-Laird method. Risk of bias assessment was done using the Newcastle-Ottawa Scale.

RESULTS

Six papers were included. Five were single-centre retrospective cohort studies, and one was a prospective cohort study, with sample sizes ranging from 22 to 391 patients. Two studies showed an increased incidence of PICS with age, and two studies showed an association between PICS and Charlson Comorbidity Index scores. PICS was associated with requiring mechanical ventilation in four studies. Meta-analysis showed a 34.4 mg L-1 higher C-reactive protein (95% confidence interval [CI] 12.7-56.2 mg L-1; P<0.01), a 4.4 g L-1 lower albumin (95% CI 0.5-8.3 g L-1; P<0.01), and a 0.36×109 L-1 lower lymphocyte count (95% CI 0.25-0.47×109 L-1; P=0.01) in the PICS compared with the non-PICS group. There are a large variety of other potential biomarkers but limited validation studies. The overall quality of evidence is limited, and these results should be interpreted accordingly.

CONCLUSIONS

While older patients and those with co-morbidities could be at greater risk for PICS, acquired risk factors, such as injury severity, are potentially more predictive of PICS than intrinsic patient characteristics. There are many potential biomarkers for PICS, but limited validation studies have been conducted. Persistent myeloid-derived suppressor cell expansion, the continual release of danger-associated molecular patterns and pathogen-associated molecular patterns propagating inflammation, and bioenergetic failure are all mechanisms underlying PICS that could offer potential for novel biomarkers and therapeutic interventions.

CLINICAL TRIAL REGISTRATION

International Prospective Register of Systematic Reviews (PROSPERO; CRD42023427749).

LASSO-Based Machine Learning Algorithm for Prediction of PICS Associated with Sepsis

Introduction

This study aims to establish a comprehensive, multi-level approach for tackling tropical diseases by proactively anticipating and managing Persistent Inflammation, Immunosuppression, and Catabolism Syndrome (PICS) within the initial 14 days of Intensive Care Unit (ICU) admission. The primary objective is to amalgamate a diverse array of indicators and pathogenic microbial data to pinpoint pivotal predictive variables, enabling effective intervention specifically tailored to the context of tropical diseases.

Methods

A focused analysis was conducted on 1733 patients admitted to the ICU between December 2016 and July 2019. Utilizing the Least Absolute Shrinkage and Selection Operator (LASSO) regression, disease severity and laboratory indices were scrutinized. The identified variables served as the foundation for constructing a predictive model designed to forecast the occurrence of PICS.

Results

Among the subjects, 13.79% met the diagnostic criteria for PICS, correlating with a mortality rate of 38.08%. Key variables, including red-cell distribution width coefficient of variation (RDW-CV), hemofiltration (HF), mechanical ventilation (MV), Norepinephrine (NE), lactic acidosis, and multiple-drug resistant bacteria (MDR) infection, were identified through LASSO regression. The resulting predictive model exhibited a robust performance with an Area Under the Curve (AUC) of 0.828, an accuracy of 0.862, and a specificity of 0.977. Subsequent validation in an independent cohort yielded an AUC of 0.848.

Discussion

The acquisition of RDW-CV, HF requirement, MV requirement, NE requirement, lactic acidosis, and MDR upon ICU admission emerges as a pivotal factor for prognosticating PICS onset in the context of tropical diseases. This study highlights the potential for significant improvements in clinical outcomes through the implementation of timely and targeted interventions tailored specifically to the challenges posed by tropical diseases.

COMPREHENSIVE THERAPEUTIC EFFICACY ANALYSIS OF INTRAVENOUS IMMUNOGLOBULIN IN TREATING SEPSIS-INDUCED COAGULOPATHY: A SINGLE-CENTER, RETROSPECTIVE OBSERVATIONAL STUDY

ABSTRACT

Objective : The aim of the study is to investigate the efficacy of intravenous immunoglobulin (IVIg) in treating sepsis-induced coagulopathy ( SIC ). Methods : A retrospective controlled analysis was conducted on 230 patients with SIC at Ganzhou People's Hospital from January 2016 to December 2022. All patients were screened using propensity score matching and treated according to the SSC2016 guidelines. Compared with the control group (n = 115), patients in the test group (n = 115) received IVIg (200 mg/kg.d) for 3 consecutive days after admission. The rating scales, coagulation function, survival, and treatment duration were evaluated. Results : On day 3 of treatment, both groups exhibited reduced platelet and thromboelastogram (TEG) maximum amplitude (MA) levels, with the control group showing a more significant decrease ( P < 0.05). By the fifth day, these levels had recovered in both groups. However, the test group experienced a significant increase by day 7 ( P < 0.05). Coagulation factors II and X began to increase on day 3, and normalization was significantly faster in the test group on day 5 ( P < 0.05). The levels of prothrombin time, international normalized ratio, activated partial thromboplastin time, d -dimer, fibrinogen, fibrin degradation products, TEG-R, and TEG-K exhibited a notable decline on day 3 and demonstrated significantly faster recovery on day 5 in the test group ( P < 0.05). In addition, both groups showed a reduction in Acute Physiology and Chronic Health Evaluation II, Sequential Organ Failure Assessment, disseminated intravascular coagulation, and lactate (LAC) levels on day 3, but the test group's scores decreased significantly more by day 7 ( P < 0.05). Within the test group, white blood cell count, C-reactive protein, procalcitonin, IL-6, and Tmax levels were lower ( P < 0.05). Furthermore, the test group demonstrated shorter duration for intensive care unit stay, mechanical ventilation, and continuous renal replacement therapy ( P < 0.05). No significant differences were observed in the duration of fever or vasoactive drug use between the groups. However, the log-rank method indicated a higher 28-day survival rate in the test group ( P < 0.05). Conclusion : IVIg can successfully increase platelet count and coagulation factors, correct coagulation disorders, enhance organ function, and reduce 28-day mortality in patients with SIC .

The Tri-Steps Model of Critical Conditions in Intensive Care: Introducing a New Paradigm for Chronic Critical Illness

Background: The prevailing model for understanding chronic critical illness is a biphasic model, suggesting phases of acute and chronic critical conditions. A major challenge within this model is the difficulty in determining the timing of the process chronicity. It is likely that the triad of symptoms (inflammation, catabolism, and immunosuppression [ICIS]) could be associated with this particular point. We aimed to explore the impact of the symptom triad (inflammation, catabolism, immunosuppression) on the outcomes of patients hospitalized in intensive care units (ICUs). Methods: The eICU-CRD database with 200,859 ICU admissions was analyzed. Adult patients with the ICIS triad, identified by elevated CRP (>20 mg/L), reduced albumin (<30 g/L), and low lymphocyte counts (<0.8 × 109/L), were included. The cumulative risk of developing ICIS was assessed using the Nelson-Aalen estimator. Results: This retrospective cohort study included 894 patients (485 males, 54%), with 60 (6.7%) developing ICIS. The cumulative risk of ICIS by day 21 was 22.5%, with incidence peaks on days 2-3 and 10-12 after ICU admission. Patients with the ICIS triad had a 2.5-fold higher mortality risk (p = 0.009) and double the likelihood of using vasopressors (p = 0.008). The triad onset day did not significantly affect mortality (p = 0.104). Patients with ICIS also experienced extended hospital (p = 0.041) and ICU stays (p < 0.001). Conclusions: The symptom triad (inflammation, catabolism, immunosuppression) during hospitalization increases mortality risk by 2.5 times (p = 0.009) and reflects the chronicity of the critical condition. Identifying two incidence peaks allows the proposal of a new Tri-steps model of chronic critical illness with acute, extended, and chronic phases.

Association Between Age and the 28-Day All-Cause Mortality in Tuberculosis Complicated by Sepsis in ICU Patients: A Retrospective Cohort Study

Purpose

Age is considered a vital factor in intensive care units (ICUs) because of its association with physiological frailty, comorbidities, and immune system function. Previous studies have examined the association between age and prognosis in patients with tuberculosis (TB) or sepsis; however, the association between age and prognosis in ICU patients with TB complicated by sepsis is rare. This study aimed to assess the association between age and the prognosis of patients in the ICU with TB complicated by sepsis.

Patients and Methods

Data from the ICU of the Public Health Clinical Center of Chengdu were analyzed using the multivariable Cox regression model, stratified analysis with interaction, restricted cubic spline (RCS), and threshold effect analysis to investigate the association between age and 28-day all-cause mortality in patients with TB complicated by sepsis.

Results

In total, 520 patients diagnosed with TB and sepsis were enrolled (120 women [23.1%]; median age, 64 years). The association between age and risk of death exhibited a J-shaped curve on the RCS (P for nonlinearity = 0.001). In the threshold analysis, the hazard ratio for the risk of death was 1.104 (95% confidence interval, 1.05-1.16) in participants aged ≥66.2 years. The risk of death increased by 10.4% with every 1-year increase in age in patients with TB complicated by sepsis. No significant association was found between age and 28-day all-cause mortality in patients aged <66.2 years.

Conclusion

A nonlinear relationship was observed between age and short-term all-cause mortality in patients in the ICU with TB complicated by sepsis. Patients with a higher age at admission may have a higher risk of death and require focused attention, close monitoring, and early treatment to reduce mortality.

Prediction of Th17/Treg cell balance on length of stay in intensive care units of patients with sepsis

Background

Prolonged length of stay (LOS) of sepsis can drain a hospital's material and human resources. This study investigated the correlations between T helper type 17 (Th17) and regulatory T (Treg) balance with LOS in sepsis.

Methods

A prospective clinical observational study was designed in Changhai Hospital affiliated to Naval Medical University in Shanghai, China, from January to October 2020. The patients diagnosed with sepsis and who met the inclusion and exclusion criteria were recruited and whether the levels of cytokines, procalcitonin, subtypes, and biomarkers of T cells in the peripheral blood were detected. We analyzed the correlation between these and LOS.

Results

Sixty septic patients were classified into two groups according to whether their intensive care unit (ICU) stay exceeded 14 days. The patients with LOS ≥14 days were older ([72.6±7.5] years vs. [63.3±10.4] years, P=0.015) and had higher Sequential Organ Failure Assessment (SOFA) (median [interquartile range]: 6.5 [5.0-11.0] vs. 4.0 [3.0-6.0], P=0.001) and higher Acute Physiology and Chronic Health Evaluation (APACHE) II scores (16.0 [13.0-21.0] vs. 8.5 [7.0-14.0], P=0.001). There was no difference in other demographic characteristics and cytokines, interleukin-6, tumor necrosis factor-α, and interleukin-10 between the two groups. The Th17/Treg ratio of sepsis with LOS <14 days was considerably lower (0.48 [0.38-0.56] vs. 0.69 [0.51-0.98], P=0.001). For patients with LOS ≥14 days, the area under the receiver operating characteristic curve for the Th17/Treg ratio was 0.766. It improved to 0.840 and 0.850 when combined with the SOFA and APACHE II scores, respectively.

Conclusions

The Th17/Treg ratio was proportional to septic severity and can be used as a potential predictor of ICU stay in sepsis, presenting a new option for ICU practitioners to better care for patients with sepsis.

Immunometabolic features of natural killer cells are associated with infection outcomes in critical illness

Immunosuppression increases the risk of nosocomial infection in patients with chronic critical illness. This exploratory study aimed to determine the immunometabolic signature associated with nosocomial infection during chronic critical illness. We prospectively recruited patients who were admitted to the respiratory care center and who had received mechanical ventilator support for more than 10 days in the intensive care unit. The study subjects were followed for the occurrence of nosocomial infection until 6 weeks after admission, hospital discharge, or death. The cytokine levels in the plasma samples were measured. Single-cell immunometabolic regulome profiling by mass cytometry, which analyzed 16 metabolic regulators in 21 immune subsets, was performed to identify immunometabolic features associated with the risk of nosocomial infection. During the study period, 37 patients were enrolled, and 16 patients (43.2%) developed nosocomial infection. Unsupervised immunologic clustering using multidimensional scaling and logistic regression analyses revealed that expression of nuclear respiratory factor 1 (NRF1) and carnitine palmitoyltransferase 1a (CPT1a), key regulators of mitochondrial biogenesis and fatty acid transport, respectively, in natural killer (NK) cells was significantly associated with nosocomial infection. Downregulated NRF1 and upregulated CPT1a were found in all subsets of NK cells from patients who developed a nosocomial infection. The risk of nosocomial infection is significantly correlated with the predictive score developed by selecting NK cell-specific features using an elastic net algorithm. Findings were further examined in an independent cohort of COVID-19-infected patients, and the results confirm that COVID-19-related mortality is significantly associated with mitochondria biogenesis and fatty acid oxidation pathways in NK cells. In conclusion, this study uncovers that NK cell-specific immunometabolic features are significantly associated with the occurrence and fatal outcomes of infection in critically ill population, and provides mechanistic insights into NK cell-specific immunity against microbial invasion in critical illness.

The persistent inflammation, immunosuppression, and catabolism syndrome 10 years later

With the implementation of new intensive care unit (ICU) therapies in the 1970s, multiple organ failure (MOF) emerged as a fulminant inflammatory phenotype leading to early ICU death. Over the ensuing decades, with fundamental advances in care, this syndrome has evolved into a lingering phenotype of chronic critical illness (CCI) leading to indolent late post-hospital discharge death. In 2012, the University of Florida (UF) Sepsis Critical Illness Research Center (SCIRC) coined the term Persistent Inflammation, Immunosuppression, and Catabolism Syndrome (PICS) to provide a mechanistic framework to study CCI in surgical patients. This was followed by a decade of research into PICS-CCI in surgical ICU patients in order to define the epidemiology, dysregulated immunity, and long-term outcomes after sepsis. Other focused studies were performed in trauma ICU patients and emergency department sepsis patients. Early deaths were surprisingly low (4%); 63% experienced rapid recovery. Unfortunately, 33% progressed to CCI, of which 79% had a poor post-discharge disposition and 41% were dead within one year. These patients had biomarker evidence of PICS, and these biomarkers enhanced clinical prediction models for dismal one-year outcomes. Emergency myelopoiesis appears to play a central role in the observed persistent immune dysregulation that characterizes PICS-CCI. Older patients were especially vulnerable. Disturbingly, over half of the older CCI patients were dead within one year and older CCI survivors remained severely disabled. Although CCI is less frequent (20%) after major trauma, PICS appears to be a valid concept. This review will specifically detail the epidemiology of CCI, PICS biomarkers, effect of site of infection, acute kidney injury, effect on older patients, dysfunctional high-density lipoproteins, sarcopenia/cachexia, emergency myelopoiesis, dysregulated erythropoiesis, and potential therapeutic interventions.

A review of UF SCIRC’s research efforts characterizing CCI, PICS biomarkers, effect of site of infection, acute kidney injury, effects on older patients, dysfunctional high-density lipoproteins, sarcopenia/cachexia, emergency myelopoiesis, and dysregulated erythropoiesis.

Understanding Post-Sepsis Syndrome: How Can Clinicians Help?

Sepsis is a global health challenge, with over 49 million cases annually. Recent medical advancements have increased in-hospital survival rates to approximately 80%, but the escalating incidence of sepsis, owing to an ageing population, rise in chronic diseases, and antibiotic resistance, have also increased the number of sepsis survivors. Subsequently, there is a growing prevalence of "post-sepsis syndrome" (PSS). This syndrome includes long-term physical, medical, cognitive, and psychological issues after recovering from sepsis. PSS puts survivors at risk for hospital readmission and is associated with a reduction in health- and life span, both at short and long term, after hospital discharge. Comprehensive understanding of PSS symptoms and causative factors is vital for developing optimal care for sepsis survivors, a task of prime importance for clinicians. This review aims to elucidate our current knowledge of PSS and its relevance in enhancing post-sepsis care provided by clinicians.

Muscle stem cells contribute to long-term tissue repletion following surgical sepsis

BACKGROUND

Over the past decade, advances in sepsis identification and management have resulted in decreased sepsis mortality. This increase in survivorship has highlighted a new clinical obstacle: chronic critical illness (CCI), for which there are no effective treatment options. Up to half of sepsis survivors suffer from CCI, which can include multi-organ dysfunction, chronic inflammation, muscle wasting, physical and mental disabilities, and enhanced frailty. These symptoms prevent survivors from returning to regular day-to-day activities and are directly associated with poor quality of life.

METHODS

Mice were subjected to cecal ligation and puncture (CLP) with daily chronic stress (DCS) as an in vivo model to study sepsis late-effects/sequelae on skeletal muscle components. Longitudinal monitoring was performed via magnetic resonance imaging, skeletal muscle and/or muscle stem cell (MuSCs) assays (e.g., post-necropsy wet muscle weights, minimum Feret diameter measurements, in vitro MuSC proliferation and differentiation, number of regenerating myofibres and numbers of Pax7-positive nuclei per myofibre), post-sepsis whole muscle metabolomics and MuSC isolation and high-content transcriptional profiling.

RESULTS

We report several findings supporting the hypothesis that MuSCs/muscle regeneration are critically involved in post-sepsis muscle recovery. First, we show that genetic ablation of muscle stem cells (MuSCs) impairs post-sepsis muscle recovery (maintenance of 5-8% average lean mass loss compared with controls). Second, we observe impaired MuSCs expansion capacity and morphological defects at 26 days post-sepsis compared with control MuSCs (P < 0.001). Third, when subjected to an experimental muscle injury, sepsis-recovered mice exhibited evidence of impaired muscle regeneration compared with non-septic mice receiving the same muscle injury (CLP/DCS injured mean minimum Feret is 92.1% of control injured, P < 0.01). Fourth, we performed a longitudinal RNA sequencing study on MuSCs isolated from post-sepsis mice and found clear transcriptional differences in all post-sepsis samples compared with controls. At Day 28, CLP/DCS mice satellite cells have multiple altered metabolic pathways, such as oxidative phosphorylation, mitochondrial dysfunction, sirtuin signalling and oestrogen receptor signalling, compared with controls (P < 0.001).

CONCLUSIONS

Our data show that MuSCs and muscle regeneration are required for effective post-sepsis muscle recovery and that sepsis triggers morphological, functional, and transcriptional changes in MuSCs. Moving forward, we strive to leverage a more complete understanding of post-sepsis MuSC/regenerative defects to identify and test novel therapies that promote muscle recovery and improve quality of life in sepsis survivors.

Biomarkers of neuropsychiatric dysfunction in intensive care unit survivors: a prospective cohort study

OBJECTIVE

To assess factors associated with long-term neuropsychiatric outcomes, including biomarkers measured after discharge from the intensive care unit.

METHODS

A prospective cohort study was performed with 65 intensive care unit survivors. The cognitive evaluation was performed through the Mini-Mental State Examination, the symptoms of anxiety and depression were evaluated using the Hospital Anxiety and Depression Scale, and posttraumatic stress disorder was evaluated using the Impact of Event Scale-6. Plasma levels of amyloid-beta (1-42) [Aβ (1-42)], Aβ (1-40), interleukin (IL)-10, IL-6, IL-33, IL-4, IL-5, tumor necrosis factor alpha, C-reactive protein, and brain-derived neurotrophic factor were measured at intensive care unit discharge.

RESULTS

Of the variables associated with intensive care, only delirium was independently related to the occurrence of long-term cognitive impairment. In addition, higher levels of IL-10 and IL-6 were associated with cognitive dysfunction. Only IL-6 was independently associated with depression. Mechanical ventilation, IL-33 levels, and C-reactive protein levels were independently associated with anxiety. No variables were independently associated with posttraumatic stress disorder.

CONCLUSION

Cognitive dysfunction, as well as symptoms of depression, anxiety, and posttraumatic stress disorder, are present in patients who survive a critical illness, and some of these outcomes are associated with the levels of inflammatory biomarkers measured at discharge from the intensive care unit.

CLINICAL AND PROGNOSTIC FEATURES OF CHRONIC CRITICAL ILLNESS/PERSISTENT INFLAMMATION IMMUNOSUPPRESSION AND CATABOLISM PATIENTS: A PROSPECTIVE OBSERVATIONAL CLINICAL STUDY

ABSTRACT

Objective: The aims of this study were to investigate and compare the clinical features and prognosis of chronic critical illness (CCI)/persistent inflammation immunosuppression and catabolism (PICS). Methods: This is a prospective observational clinical study. During this study period, we collect intensive care unit patients' data from Suzhou Municipal Hospital and Suzhou Ninth People's Hospital. All patients older than 18 years were included, and according to the corresponding exclusion and diagnostic criteria, they were divided into four groups: PICS group, CCI group, CCI and PICS group (CCI + PICS), and neither CCI nor PICS group (NCCI + NPICS) and collected and recorded age, sex, hospital time, hospital diagnosis, Acute Physiology and Chronic Health Evaluation II score, Sequential Organ Failure Assessment score, C-reactive protein, absolute value lymphocyte count, serum albumin, white blood cell count, absolute value neutrophil count, secondary infection, and 28-day case fatality rate separately. Results: A total of 687 patients were admitted to the intensive care unit during the study period. The hospitalization time less than 14 days were excluded, and 168 patients were eventually included. There are 17 in the PICS group, 71 in the CCI group, 50 in the CCI + PICS group, and 30 in the NCCI + NPICS group. Baseline characteristics showed statistically significant differences in Sequential Organ Failure Assessment, length of hospital stay, and 28-day mortality among four groups. Baseline main indicator and multiple comparisons showed that the CCI + PICS group had longer hospital stay, worse prognosis, and more adverse outcomes. Multivariate analysis showed that final age, C-reactive protein on days 14 and 21, and serum albumin on days 1 and 21 had an impact on the prognosis ( P < 0.05). Conclusion: The clinical prognosis of the four groups decreased in order of NCCI + NPICS, CCI, PICS, and CCI + PICS. Our finding of clinically isolated PICS may indicate that PICS acts as an inducement or independent factor to worsen the prognosis of CCI.

Identification of biomarkers and the mechanisms of multiple trauma complicated with sepsis using metabolomics

Sepsis after trauma increases the risk of mortality rate for patients in intensive care unit (ICUs). Currently, it is difficult to predict outcomes in individual patients with sepsis due to the complexity of causative pathogens and the lack of specific treatment. This study aimed to identify metabolomic biomarkers in patients with multiple trauma and those with multiple trauma accompanied with sepsis. Therefore, the metabolic profiles of healthy persons designated as normal controls (NC), multiple trauma patients (MT), and multiple trauma complicated with sepsis (MTS) (30 cases in each group) were analyzed with ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF/MS)-based untargeted plasma metabolomics using collected plasma samples. The differential metabolites were enriched in amino acid metabolism, lipid metabolism, glycometabolism and nucleotide metabolism. Then, nine potential biomarkers, namely, acrylic acid, 5-amino-3-oxohexanoate, 3b-hydroxy-5-cholenoic acid, cytidine, succinic acid semialdehyde, PE [P-18:1(9Z)/16:1(9Z)], sphinganine, uracil, and uridine, were found to be correlated with clinical variables and validated using receiver operating characteristic (ROC) curves. Finally, the three potential biomarkers succinic acid semialdehyde, uracil and uridine were validated and can be applied in the clinical diagnosis of multiple traumas complicated with sepsis.

Serum Levels of Acylcarnitines and Amino Acids Are Associated with Liberation from Organ Support in Patients with Septic Shock

Sepsis-induced metabolic dysfunction is associated with mortality, but the signatures that differentiate variable clinical outcomes among survivors are unknown. Our aim was to determine the relationship between host metabolism and chronic critical illness (CCI) in patients with septic shock. We analyzed metabolomics data from mechanically ventilated patients with vasopressor-dependent septic shock from the placebo arm of a recently completed clinical trial. Baseline serum metabolites were measured by liquid chromatography-mass spectrometry and ¹H-nuclear magnetic resonance. We conducted a time-to-event analysis censored at 28 days. Specifically, we determined the relationship between metabolites and time to extubation and freedom from vasopressors using a competing risk survival model, with death as a competing risk. We also compared metabolite concentrations between CCI patients, defined as intensive care unit level of care ≥ 14 days, and those with rapid recovery. Elevations in two acylcarnitines and four amino acids were related to the freedom from organ support (subdistributional hazard ratio < 1 and false discovery rate < 0.05). Proline, glycine, glutamine, and methionine were also elevated in patients who developed CCI. Our work highlights the need for further testing of metabolomics to identify patients at risk of CCI and to elucidate potential mechanisms that contribute to its etiology.

A Nomogram to Better Predict the In-Hospital Mortality of Trauma Patients with Sepsis in the Intensive Care Unit

BACKGROUND

Trauma has a high incidence and mortality worldwide, and sepsis is one of the main causes of mortality in trauma patients. Therefore, it is essential to identify the risk factors of in-hospital mortality for trauma patients with sepsis.

METHODS

Data were extracted from the Medical Information Mart for Intensive Care III database and divided into a training set and internal validation set, and another Chinese dataset was used as external validation set. Then, risk factors were estimated using univariate and multivariate logistic regression analyses in the training set. Finally, a nomogram was created to predict the probability of in-hospital mortality for trauma patients with sepsis.

RESULTS

A total of 503 patients were enrolled in our study (335 in the training set and 168 in the validation set). Multivariate logistic regression analysis revealed that age (1.047 [1.025-1.071]), respiratory rate (1.258 [1.135-1.394]), PTT (1.026 [1.008-1.044]), ventilation (6.703 [1.528-29.408]), and vasopressor use (3.682 [1.502-9.025]) were independent factors associated with in-hospital mortality. The nomogram for trauma-related sepsis predicted in-hospital mortality with AUC values of 0.8939 in the training set, 0.8200 in the internal validation set, and 0.7779 in the external validation set.

CONCLUSIONS

The new nomogram has a well predicted value for in-hospital mortality for patients with trauma and sepsis in intensive care units.

Biomarker Evidence of the Persistent Inflammation, Immunosuppression and Catabolism Syndrome (PICS) in Chronic Critical Illness (CCI) After Surgical Sepsis

OBJECTIVE

To analyze serial biomarkers of the persistent inflammation, immunosuppression, and catabolism syndrome (PICS) to gain insight into the pathobiology of chronic critical illness (CCI) after surgical sepsis.

BACKGROUND

Although early deaths after surgical intensive care unit sepsis have decreased and most survivors rapidly recover (RAP), one third develop the adverse clinical trajectory of CCI. However, the underlying pathobiology of its dismal long-term outcomes remains unclear.

METHODS

PICS biomarkers over 14 days from 124 CCI and 225 RAP sepsis survivors were analyzed to determine associations and prediction models for (1) CCI (≥14 intensive care unit days with organ dysfunction) and (2) dismal 1-year outcomes (Zubrod 4/5 performance scores). Clinical prediction models were created using PIRO variables (predisposition, insult, response, and organ dysfunction). Biomarkers were then added to determine if they strengthened predictions.

RESULTS

CCI (vs RAP) and Zubrod 4/5 (vs Zubrod 0-3) cohorts had greater elevations in biomarkers of inflammation (interleukin [IL]-6, IL-8, interferon gamma-induced protein [IP-10], monocyte chemoattractant protein 1), immunosuppression (IL-10, soluble programmed death ligand-1), stress metabolism (C-reactive protein, glucagon-like peptide 1), and angiogenesis (angiopoietin-2, vascular endothelial growth factor, vascular endothelial growth factor receptor-1, stromal cell-derived factor) at most time-points. Clinical models predicted CCI on day 4 (area under the receiver operating characteristics curve [AUC] = 0.89) and 1 year Zubrod 4/5 on day 7 (AUC = 0.80). IL-10 and IP-10 on day 4 minimally improved prediction of CCI (AUC = 0.90). However, IL-10, IL-6, IL-8, monocyte chemoattractant protein 1, IP-10, angiopoietin-2, glucagon-like peptide 1, soluble programmed death ligand-1, and stromal cell-derived factor on day 7 considerably improved the prediction of Zubrod 4/5 status (AUC = 0.88).

CONCLUSIONS

Persistent elevations of PICS biomarkers in the CCI and Zubrod 4/5 cohorts and their improved prediction of Zubrod 4/5 validate that PICS plays a role in CCI pathobiology.

Chronic Critical Illness Elicits a Unique Circulating Leukocyte Transcriptome in Sepsis Survivors

Surgical sepsis has evolved into two major subpopulations: patients who rapidly recover, and those who develop chronic critical illness (CCI). Our primary aim was to determine whether CCI sepsis survivors manifest unique blood leukocyte transcriptomes in late sepsis that differ from transcriptomes among sepsis survivors with rapid recovery. In a prospective cohort study of surgical ICU patients, genome-wide expression analysis was conducted on total leukocytes in human whole blood collected on days 1 and 14 from sepsis survivors who rapidly recovered or developed CCI, defined as ICU length of stay ≥ 14 days with persistent organ dysfunction. Both sepsis patients who developed CCI and those who rapidly recovered exhibited marked changes in genome-wide expression at day 1 which remained abnormal through day 14. Although summary changes in gene expression were similar between CCI patients and subjects who rapidly recovered, CCI patients exhibited differential expression of 185 unique genes compared with rapid recovery patients at day 14 (p < 0.001). The transcriptomic patterns in sepsis survivors reveal an ongoing immune dyscrasia at the level of the blood leukocyte transcriptome, consistent with persistent inflammation and immune suppression. Furthermore, the findings highlight important genes that could compose a prognostic transcriptomic metric or serve as therapeutic targets among sepsis patients that develop CCI.

Pathophysiology and Treatment Strategies of Acute Myopathy and Muscle Wasting after Sepsis

Sepsis survivors experience a persistent myopathy characterized by skeletal muscle weakness, atrophy, and an inability to repair/regenerate damaged or dysfunctional myofibers. The origins and mechanisms of this persistent sepsis-induced myopathy are likely complex and multifactorial. Nevertheless, the pathobiology is thought to be triggered by the interaction between circulating pathogens and impaired muscle metabolic status. In addition, while in the hospital, septic patients often experience prolonged periods of physical inactivity due to bed rest, which may exacerbate the myopathy. Physical rehabilitation emerges as a potential tool to prevent the decline in physical function in septic patients. Currently, there is no consensus regarding effective rehabilitation strategies for sepsis-induced myopathy. The optimal timing to initiate the rehabilitation intervention currently lacks consensus as well. In this review, we summarize the evidence on the fundamental pathobiological mechanisms of sepsis-induced myopathy and discuss the recent evidence on in-hospital and post-discharge rehabilitation as well as other potential interventions that may prevent physical disability and death of sepsis survivors.

Increased Brain Age Gap Estimate (BrainAGE) in Young Adults After Premature Birth

Recent evidence suggests increased metabolic and physiologic aging rates in premature-born adults. While the lasting consequences of premature birth on human brain development are known, its impact on brain aging remains unclear. We addressed the question of whether premature birth impacts brain age gap estimates (BrainAGE) using an accurate and robust machine-learning framework based on structural MRI in a large cohort of young premature-born adults (n = 101) and full-term (FT) controls (n = 111). Study participants are part of a geographically defined population study of premature-born individuals, which have been followed longitudinally from birth until young adulthood. We investigated the association between BrainAGE scores and perinatal variables as well as with outcomes of physical (total intracranial volume, TIV) and cognitive development (full-scale IQ, FS-IQ). We found increased BrainAGE in premature-born adults [median (interquartile range) = 1.4 (-1.3-4.7 years)] compared to full-term controls (p = 0.002, Cohen's d = 0.443), which was associated with low Gestational age (GA), low birth weight (BW), and increased neonatal treatment intensity but not with TIV or FS-IQ. In conclusion, results demonstrate elevated BrainAGE in premature-born adults, suggesting an increased risk for accelerated brain aging in human prematurity.