Clinical Criteria for Persistent Inflammation, Immunosuppression, and Catabolism Syndrome: An Exploratory Analysis of Optimal Cut-Off Values for Biomarkers

Disseminated Intravascular Coagulopathy and Persistent Inflammation, Immunosuppression, and Catabolism Syndrome: Pathophysiology, shared pathways, and clinical implications

BACKGROUND

Disseminated Intravascular Coagulopathy (DIC) and Persistent Inflammation, Immunosuppression, and Catabolism Syndrome (PICS) are critical care syndromes that frequently coexist in critically ill patients, but mechanisms underlying their shared pathways are not well understood.

OBJECTIVE

This review discusses the pathophysiology of DIC and PICS and explores the shared mechanisms behind DIC and PICS and their implications for clinical management.

FINDINGS

DIC and PICS share a common pathophysiological foundation of endothelial dysfunction, coagulation dysregulation, and inflammation, leading to a vicious cycle of microvascular injury and systemic inflammation, culminating in organ dysfunction. DIC has also been identified as an independent risk factor for PICS. Anticoagulation therapies such as antithrombin, recombinant human soluble thrombomodulin (rhTM), and heparin attenuates inflammation, a mechanism underlying both syndromes, thereby improving outcomes in PICS.

CONCLUSION

DIC and PICS share critical pathophysiological pathways that exacerbate outcomes in critically ill patients. Recognizing these interconnections is essential for developing targeted therapies. Standardizing PICS definitions and advancing research to clarify mechanisms, interplay, and causality between DIC and PICS are crucial next steps.

Intravenous immunoglobulin for mortality and inflammatory status in patients with sepsis: a retrospective database study

Background

Sepsis is a life-threatening condition caused by severe infection. The efficacy of intravenous immunoglobulin (IVIG) as adjunctive therapy on mortality remains controversial. Moreover, IVIG may favorably affect sepsis-induced immunosuppression like persistent inflammation, immunosuppression, and catabolism syndrome (PICS).

Methods

This study was a retrospective cohort study using inpatient claims database provided by Medical Data Vision, which included approximately 190,000 episodes of intensive care unit admissions in Japanese acute care hospitals between April 2008 and September 2021. We used a propensity score-matched analysis to compare outcomes between the IVIG and control groups. Primary outcomes were 28-day mortality, while secondary outcomes included in-hospital mortality, the Barthel Index at discharge, length of hospital stay and laboratory data (albumin, C-reactive protein (CRP), and lymphocyte count) on days 14 and 28.

Results

Of the 17,626 patients enrolled, 15,159 (786 in the IVIG group and 14,373 in the control group) were included in the analysis. Propensity score matching generated 758 matched pairs. Before matching, 28-day mortality and in-hospital mortality were lower in the control group; however, in the matched cohort, 28-day mortality was significantly lower in the IVIG group than in the control group (90/758 [11.9%] vs 124/758 [16.4%]; risk difference [95% confidence intervals (CI)], -4.5% [-8.0% to -1.0%]; P = 0.015). In-hospital mortality in the matched cohort was also significantly more favorable in the IVIG group (137/758 [18.1%] vs 177/758 [23.4%]; risk difference [95%CI], -5.3% [-9.3% to -1.2%]; P = 0.013). Favorable outcomes in terms of albumin on days14 and 28 and CRP levels on day 28 were observed in the IVIG group.

Conclusions

The administration of IVIG was associated with a reduction in sepsis mortality and favorable outcomes in laboratory parameters and the functional status. These results will contribute to the ongoing debate on the efficacy of IVIG for sepsis. The results obtained herein suggest the benefit of IVIG, particularly in mitigating PICS. Further research, including prospective studies, is warranted to confirm these results and examine long-term outcomes.

Recent nanoengineered therapeutic advancements in sepsis management

Sepsis (defined as sepsis 3.0) is a life-threatening organ dysfunction caused by a dysregulated host response to a variety of pathogenic microorganisms. Characterized by high morbidity and mortality, sepsis has become a global public health problem. However, there is a lack of appropriate diagnostic and therapeutic strategies for sepsis and current management rely on the limited treatment strategies. Recently, nanomedicines targeting and controlling the release of bio-active agents have shown excellent potency in sepsis management, with improved therapeutic efficacy and reduced adverse effects. In this review, we have summarized the advantages of nanomaterials. Also, the preparation and efficacy of the main categories of anti-sepsis nanomedicines applied in sepsis management are described in detail, including antibiotic-coated nanomaterials, antimicrobial peptides-coated nanomaterials, biomimetic nanomaterials, nanomaterials targeting macrophages and natural products loaded nanomaterials. These advances in nanomedicines establish the huge potential for nanomaterials-based sepsis management, especially in the improved pharmaceutical and pharmacological properties, enhanced therapeutic efficacy, controllable drug-targeting and reduced side effects. To further facilitate clinical translation of anti-sepsis nanomedicines, we propose that the issues involving safety, regulatory laws and cost-effectiveness should receive much more attention in the future.

Relationship between very early enteral nutrition and persistent inflammation, immunosuppression, and catabolism syndrome in cardiovascular surgery patients: a propensity score-matched study

BACKGROUND

Early enteral nutrition (EN) is recommended for patients with critical illness to maintain intestinal immunity. However, the optimal timing of the commencement of EN remains unclear, particularly after cardiovascular surgery.

OBJECTIVES

We herein focused on Persistent Inflammation, Immunosuppression, and Catabolism Syndrome (PICS) as a predisposing immunodeficiency and investigated its association with very early EN (VEEN) (<24 h) in patients who underwent cardiovascular surgery.

METHODS

In this retrospective study, we used an administrative claims database with laboratory examinations between 2008 and 2021 to identify adult patients admitted to the intensive care unit after cardiovascular surgery. Patients who received EN the day after surgery were assigned to the EN <24 h group, whereas those who received EN on day 2 or day 3 were assigned to the control group. The primary outcome was a composite of the incidence of PICS and mortality on day 14 after surgery. We defined PICS as patients who were hospitalized for >14 day and meeting ≥2 of the following conditions: a lymphocyte count <800/μL, albumin <3.0 g/dL, and C-reactive protein >2.0 mg/dL. We compared the 2 groups using propensity score analysis.

RESULTS

A propensity score matching generated 2082 pairs. The primary outcome was significantly lower in the EN <24 h group than in the control group on days 14 {risk difference [95% confidence interval (CI)]: -3.1% [-5.9%, -0.3%]} and 28 (risk difference [95% CI]: -2.1% [-3.7%, -0.4%]). Mortality did not significantly differ between the 2 groups. The length of hospital stay was significantly shorter in the EN <24 h group: the difference (95% CI) was -2.2 (-3.7, -0.7) d.

CONCLUSIONS

Among patients who underwent cardiovascular surgery, VEEN provided on the day after surgery was associated with a lower incidence of PICS and a shorter length of hospital stay than EN provided 2 day or 3 day after surgery.

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.

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.

Profiling the dysregulated immune response in sepsis: overcoming challenges to achieve the goal of precision medicine

Sepsis is characterised by a dysregulated host immune response to infection. Despite recognition of its significance, immune status monitoring is not implemented in clinical practice due in part to the current absence of direct therapeutic implications. Technological advances in immunological profiling could enhance our understanding of immune dysregulation and facilitate integration into clinical practice. In this Review, we provide an overview of the current state of immune profiling in sepsis, including its use, current challenges, and opportunities for progress. We highlight the important role of immunological biomarkers in facilitating predictive enrichment in current and future treatment scenarios. We propose that multiple immune and non-immune-related parameters, including clinical and microbiological data, be integrated into diagnostic and predictive combitypes, with the aid of machine learning and artificial intelligence techniques. These combitypes could form the basis of workable algorithms to guide clinical decisions that make precision medicine in sepsis a reality and improve patient outcomes.

Dynamics of iron metabolism in patients with bloodstream infections: a time-course clinical study

The close relationship between infectious diseases and iron metabolism is well known, but a more detailed understanding based on current knowledge may provide new insights into the diagnosis and treatment of infectious diseases, considering the growing threat of antibiotic-resistant bacteria. This study investigated adult patients with bloodstream infections, temporal changes, and relationships between blood levels of iron and related markers, including hepcidin and lipocalin-2 (LCN2). We included 144 samples from 48 patients (mean age 72 years, 50% male), with 30 diagnosed with sepsis. During the acute phase of infection, blood levels of hepcidin and LCN2 increased rapidly, whereas iron levels decreased, with values in 95.8% of cases below the normal range (40-188 μg/dL). Later, hepcidin and LCN2 decreased significantly during the recovery phase, and the decreased iron concentrations were restored. In the case of persistent inflammation, iron remained decreased. Acute LCN2 levels were significantly higher in patients with sepsis (p < 0.01). Hypoferremia induced by increased hepcidin would reduce iron in the environment of extracellular pathogens, and the increased LCN2 would inhibit siderophores, resulting in the prevention of the pathogen's iron acquisition in each manner during the acute phase of bloodstream infection.

Impact of Persistent Inflammation, Immunosuppression, and Catabolism Syndrome during Intensive Care Admission on Each Post-Intensive Care Syndrome Component in a PICS Clinic

BACKGROUND

Persistent inflammation, immunosuppression, and catabolism syndrome (PIICS) is known as a prolonged immunodeficiency that occurs after severe infection. Few studies have demonstrated a direct relationship between PIICS and physical dysfunction in post-intensive care syndrome (PICS). We herein investigated how each component of PICS was affected by the diagnosis of PIICS during hospitalization and examined the relationship between PIICS and PICS using PICS assessments performed at the Hitachi General Hospital PICS Clinic.

METHODS

The 273 patients who visited the PICS clinic at one month after discharge from the ICU at Hitachi General Hospital were included in the study. We used the diagnostic criteria for PIICS described in previous studies. At least two of the following blood test values on day 14 of hospitalization had to be met for a diagnosis of PIICS: C-reactive protein (CRP) > 2.0 mg/dL, albumin (Alb) < 3.0 g/dL, and lymphocytes (Lym) < 800/μL. Blood test values closest to day 14 out of 11-17 days of hospitalization were used. The primary outcome was a Barthel Index (BI) < 90, while secondary outcomes were the results of various PICS assessments, including mental and cognitive impairments, performed at the PICS clinic. We supplemented missing data with multiple imputations by chained equations. We performed a nominal logistic regression analysis with age, sex, BMI, SOFA, and the presence of PIICS as variables for BI < 90.

RESULTS

Forty-three out of two hundred seventy-three PICS outpatients met the diagnostic criteria for PIICS during hospitalization. In comparisons with non-PIICS patients, significantly higher severity scores for APACHE II and SOFA and a longer hospital stay were observed in PIICS patients, suggesting a higher clinical severity. The primary outcome, BI, was lower in the PIICS group (97.5 (58.5, 100) vs. 100 (95, 100), p = 0.008), as were the secondary outcomes (FSS-ICU: 35 (31, 35) vs. 35 (35, 35), MRC score: 55 (50.25, 58) vs. 58 (53, 60), grip strength: 16.45 (9.2, 25.47) vs. 20.4 (15.3, 27.7)). No significant differences were noted in mental or cognitive function assessments, such as HADS, IES-R, and SMQ. A multivariable analysis supplemented with missing data revealed that PIICS (odds ratio: 1.23 (1.08-1.40 p = 0.001) and age (odds ratio: 1.007 (1.004-1.01), p < 0.001) correlated with BI < 90, independent of clinical severity such as sequential organ failure assessment (SOFA). Similar results were obtained in the sensitivity analysis excluding missing data.

CONCLUSIONS

The present study revealed a strong relationship between PIICS and post-discharge PICS physical dysfunction in patients requiring intensive care.

Nanotechnology Applications in Sepsis: Essential Knowledge for Clinicians

Sepsis is a life-threatening condition caused by a dysregulated host response to an invading pathogen such as multidrug-resistant bacteria. Despite recent advancements, sepsis is a leading cause of morbidity and mortality, resulting in a significant global impact and burden. This condition affects all age groups, with clinical outcomes mainly depending on a timely diagnosis and appropriate early therapeutic intervention. Because of the unique features of nanosized systems, there is a growing interest in developing and designing novel solutions. Nanoscale-engineered materials allow a targeted and controlled release of bioactive agents, resulting in improved efficacy with minimal side effects. Additionally, nanoparticle-based sensors provide a quicker and more reliable alternative to conventional diagnostic methods for identifying infection and organ dysfunction. Despite recent advancements, fundamental nanotechnology principles are often presented in technical formats that presuppose advanced chemistry, physics, and engineering knowledge. Consequently, clinicians may not grasp the underlying science, hindering interdisciplinary collaborations and successful translation from bench to bedside. In this review, we abridge some of the most recent and most promising nanotechnology-based solutions for sepsis diagnosis and management using an intelligible format to stimulate a seamless collaboration between engineers, scientists, and clinicians.

Effects of Antithrombin on Persistent Inflammation, Immunosuppression, and Catabolism Syndrome among Patients with Sepsis-Induced Disseminated Intravascular Coagulation

Persistent inflammation, immunosuppression, and catabolism syndrome (PICS) is a serious condition after critical care. We examined the efficacy of antithrombin, which may attenuate coagulopathy with the control of inflammation, for PICS among patients with sepsis-induced disseminated intravascular coagulation (DIC). The present study used the inpatient claims database with laboratory findings to identify patients admitted to intensive care units and diagnosed with sepsis and DIC. A composite of the incidence of PICS on day 14 or 14-day mortality as the primary outcome was compared between the antithrombin and control groups using a propensity-score-matched analysis. Secondary outcomes were the incidence of PICS on day 28, 28-day mortality, and in-hospital mortality. A total of 324 well-balanced matched pairs were generated from 1622 patients. The primary outcome did not differ between the antithrombin and control groups (63.9% vs. 68.2%, respectively, p = 0.245). However, the incidences of 28-day and in-hospital mortality were significantly lower in the antithrombin group (16.0% vs. 23.5% and 24.4% vs. 35.8%, respectively). Similar results were obtained in a sensitivity analysis using overlap weighting. Antithrombin did not reduce the occurrence of PICS on day 14 in patients with sepsis-induced DIC; however, it was associated with a better mid-term (day 28) prognosis.