Fever Is Associated with Reduced, Hypothermia with Increased Mortality in Septic Patients: A Meta-Analysis of Clinical Trials

Spontaneous and pharmacologically induced hypothermia protect mice against endotoxic shock

BACKGROUND AND PURPOSE

Despite the well-known occurrence of hypothermia during sepsis, its underlying biological nature and adaptive value remain debated.

EXPERIMENTAL APPROACH

Using indirect calorimetry, telemetry, thermal gradient studies and pharmacological studies, we examined the thermal and metabolic responses of mice treated with a shock-inducing lethal dose of lipopolysaccharide (LPS).

KEY RESULTS

We report that LPS-treated mice undergo spontaneous hypothermia, driven by hypometabolism and cold-seeking behaviours, even when animals approach the end of life. Conversely, rewarming LPS-treated mice at 30°C delayed hypothermia but worsened mortality, thus highlighting the adaptive importance of hypothermia. Additionally, we show that LPS-induced hypothermia was partly mediated by peripheral neurotensin expressed in response to vascular toll-like receptor 4 (TLR4) signalling. The administration of a neurotensin analogue (JMV449) induced pharmacological hypothermia and significantly ameliorated the clinical presentation and lethality rates in LPS-treated mice. Moreover, the therapeutic benefits of pharmacological hypothermia were prevented when LPS-treated mice were switched to 30°C. Lastly, these beneficial outcomes were attributed to a reduction in oxygen consumption, metabolic stress and cytopathic hypoxia, rather than the modulation of the cytokine storm.

CONCLUSION AND IMPLICATIONS

Collectively, our findings indicate that spontaneous and pharmacologically-induced hypothermia protect against endotoxic shock.

The Effect of Different Temperature Management Strategies in Adult Sepsis Patients: A Meta-Analysis of Randomized Controlled Trials

This investigation seeks to assess the impact of various temperature management approaches on the rates of death and organ failure among adult patients suffering from sepsis. A comprehensive search of PubMed, Embase, and CENTRAL was performed to identify randomized controlled trials (RCTs) published up to September 2024. These trials examined the impact of temperature management strategies on sepsis patients. Two independent investigators conducted literature screening, quality assessment, and data extraction. A meta-analysis was conducted using a fixed-effect model to evaluate outcome measures, including mortality and organ dysfunction. This study is registered with PROSPERO, CRD42024627677. The analysis incorporated eight RCTs, involving 1843 patients. The findings demonstrated that the management of hyperthermia markedly diminished the mortality risk among individuals suffering from sepsis (risk ratio = 0.47, 95% confidence interval [CI]: 0.37-0.59, p < 0.001), exhibiting low heterogeneity (I2 = 39%). However, the effects of hyperthermia on organ dysfunction remained unclear (Mean Difference [MD] = -0.92, 95% CI: -1.91 to 0.07, p = 0.07), exhibiting low heterogeneity (I2 = 0%). However, these effects on organ dysfunction were based on only two studies and 215 patients, which made them prone to a type II error. Hyperthermia management strategies are effective in reducing mortality among adults with sepsis. However, their impact on organ dysfunction requires further investigation through high-quality RCTs. Despite the limitations of this study, hyperthermia strategies offer a promising approach to multidimensional intervention in sepsis. Further studies should strengthen structured subgroup analyses and mechanistic studies based on RCTs to optimize treatment strategies under various clinical scenarios.

The association between body temperature and 28-day mortality in sepsis patients: A retrospective observational study

OBJECTIVE

This study explored the association between body temperature and 28-day septic ICU hospital mortality.

DESIGN

Retrospective cohort analysis.

SETTING

208 ICUs in the United States.

PATIENTS OR PARTICIPANTS

Sepsis patients from 2014-2015 eICU Collaborative Research Database.

INTERVENTIONS

Binary logistic regression models, Generalized Additive Model (GAM), Two-Piece Binary Logistic Regression Model.

MAIN VARIABLES OF INTEREST

Body temperature, 28-day inpatient mortality.

RESULTS

Nonlinear relationship observed; hypothermia (≤36.67 ℃) associated with increased mortality (adjusted OR = 0.74, 95% CI: 0.70-0.80, p < 0.0001).

CONCLUSIONS

Hypothermia in sepsis correlates with higher mortality; rewarming's potential benefit warrants further exploration.

How I diagnose and treat acute infection-associated purpura fulminans

ABSTRACT

Purpura fulminans (PF) is a rare but devastating complication of sepsis characterized by a highly thrombotic subtype of disseminated intravascular coagulation (DIC). A medical emergency, PF often requires the involvement of consultant hematologists to assist with diagnosis and management of patients who are in a highly dynamic and deteriorating clinical situation. Patients who survive past the first 24 to 72 hours often die from complications of unchecked thrombosis rather than shock, and survivors are usually left with severe scarring and tissue loss. Despite these challenging features, PF is a pathophysiologically distinct, homogeneous, and highly predictable form of sepsis-associated DIC for which poor outcomes are not a foregone conclusion. The fundamental pathologic lesion in PF is a failure of the anticoagulant protein C pathway, which leads to uncontrolled microvascular clotting and inadequate protein C-mediated cytoprotective effects, which are vital for survival in sepsis. Herein, we review the clinical features and diagnosis of PF. Drawing from existing clinical literature and recent advances in our understanding of the pathophysiology of PF, we describe rationally designed treatment approaches for this disorder, including repletion of natural circulating anticoagulants, use of therapeutic anticoagulation, and ways to optimize transfusion support, and we outline specific interventions that we would recommend avoiding.

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2024

The 2024 revised edition of the Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock (J-SSCG 2024) is published by the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine. This is the fourth revision since the first edition was published in 2012. The purpose of the guidelines is to assist healthcare providers in making appropriate decisions in the treatment of sepsis and septic shock, leading to improved patient outcomes. We aimed to create guidelines that are easy to understand and use for physicians who recognize sepsis and provide initial management, specialized physicians who take over the treatment, and multidisciplinary healthcare providers, including nurses, physical therapists, clinical engineers, and pharmacists. The J-SSCG 2024 covers the following nine areas: diagnosis of sepsis and source control, antimicrobial therapy, initial resuscitation, blood purification, disseminated intravascular coagulation, adjunctive therapy, post-intensive care syndrome, patient and family care, and pediatrics. In these areas, we extracted 78 important clinical issues. The GRADE (Grading of Recommendations Assessment, Development and Evaluation) method was adopted for making recommendations, and the modified Delphi method was used to determine recommendations by voting from all committee members. As a result, 42 GRADE-based recommendations, 7 good practice statements, and 22 information-to-background questions were created as responses to clinical questions. We also described 12 future research questions.

Interpretable machine learning-derived nomogram model for early detection of persistent diarrhea in Salmonella typhimurium enteritis: a propensity score matching based case-control study

BACKGROUND

Salmonella typhimurium infection is a considerable global health concern, particularly in children, where it often leads to persistent diarrhea. This condition can result in severe health complications including malnutrition and cognitive impairment.

METHODS

A comprehensive retrospective study was conducted involving 627 children diagnosed with Salmonella typhimurium enteritis. These children were hospitalized for Salmonella typhimurium enteritis between January 2010 and December 2022 at the Second Affiliated Hospital of Wenzhou Medical University. Propensity score matching was used to explore the potential risk factors and predictors of persistent diarrhea following S. typhimurium infection.

RESULTS

The study identified body temperature, C-reactive protein (CRP) levels, alanine aminotransferase (ALT) levels, white blood cell count, and lactose intolerance were significant predictors of persistent diarrhea. Nomogram models developed based on these predictors demonstrated robust performance in predicting persistent diarrhea risk, with an accuracy of > 90%.

CONCLUSION

The developed nomogram models provide a practical tool for the early identification of children at high risk of persistent diarrhea, facilitating intervention, potentially preventing serious sequelae, and improving the prognosis of children with S. typhimurium enteritis.

Hypothermia: Pathophysiology and the propensity for infection

Hypothermia in combination with infection presents a complex challenge in clinical and battlefield medicine. Multifaceted physiological and immunological consequences of hypothermia drastically change the risk, progression, and treatment of a concomitant infection. Managing hypothermia and infection in extreme cold settings is particularly relevant in an era with increased risk of military operations in Polar climates. Here, we discuss the elevated instance of infection during accidental and therapeutic hypothermia and speculate how a compromised immune system may contribute. We focus on skin and soft tissue infections and sepsis, which are among the serious infectious complications of hypothermia and battlefield injuries. We also present the challenges associated with treating infections under hypothermic conditions. Finally, we advocate for a renewed focus on identifying causal relationships between hypothermia and infection risk and assessing established infection treatment regiments in hypothermic patients to enhance trauma management and survival outcomes in hypothermia-related injuries.

Investigating the effectiveness of whole-virus, protein-based, and vector-based SARS-CoV-2 vaccines on the rates of COVID-19 infection, hospitalization, and mortality: a historical cohort study in Iran

BACKGROUND

Each of the Coronavirus disease 2019 (COVID-19) vaccines has its characteristics that can affect their effectiveness in preventing hospitalization and patient mortality. The present study aimed to determine the effectiveness of COVID-19 vaccines, including whole-virus, protein-based, and vector-based on COVID-19 infection, hospitalization, and mortality.

METHODS

The current cohort study was conducted using the data of all people who received at least two doses of each type of COVID-19 vaccine from March 2020 to August 2022 in Khorasan Rzavi province. Quantitative data were characterized using measures of central tendency and dispersion, while the risks of infection, hospitalization, and mortality were assessed for each type of vaccine. Logistic regression was employed to evaluate the effect of various vaccine types on infection rate, hospitalization, and mortality while adjusting for other independent variables.

RESULTS

In this study, over 2 million vaccinated individuals had received at least two doses of the COVID-19 vaccine. Whole-virus vaccines, which had an infection rate of 3%, a hospitalization rate of 1.4%, and a mortality rate of 0.2%, were the most effective vaccines. The study also identified several factors associated with an increased risk of COVID-19 infection, hospitalization, and mortality, including kidney disease, cardiovascular disease, respiratory issues, age, sex, diabetes, olfactory dysfunction, fever, chills, body mass index (BMI), and the type of vaccine.

CONCLUSION

This study highlights the substantial impact of COVID-19 vaccination in reducing infection, hospitalization, and mortality rates in Iran. The results support the use of whole-virus and vector-based vaccines as more effective options for preventing COVID-19 outcomes. The study also emphasizes the importance of considering various factors, including medical history and side effects, when evaluating the effectiveness of different vaccine types. The findings of this study can inform public health policy and vaccination strategies in Iran and other countries.

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2024

The 2024 revised edition of the Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock (J-SSCG 2024) is published by the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine. This is the fourth revision since the first edition was published in 2012. The purpose of the guidelines is to assist healthcare providers in making appropriate decisions in the treatment of sepsis and septic shock, leading to improved patient outcomes. We aimed to create guidelines that are easy to understand and use for physicians who recognize sepsis and provide initial management, specialized physicians who take over the treatment, and multidisciplinary healthcare providers, including nurses, physical therapists, clinical engineers, and pharmacists. The J-SSCG 2024 covers the following nine areas: diagnosis of sepsis and source control, antimicrobial therapy, initial resuscitation, blood purification, disseminated intravascular coagulation, adjunctive therapy, post-intensive care syndrome, patient and family care, and pediatrics. In these areas, we extracted 78 important clinical issues. The GRADE (Grading of Recommendations Assessment, Development and Evaluation) method was adopted for making recommendations, and the modified Delphi method was used to determine recommendations by voting from all committee members. As a result, 42 GRADE-based recommendations, 7 good practice statements, and 22 information-to-background questions were created as responses to clinical questions. We also described 12 future research questions.

A pilot observational study of the association of 24-hour mortality with the subjective assessment of the forearm skin temperature and moisture compared to other bedside indicators of illness severity

Background

Although the association of peripheral skin temperature with infection, serious illness and death have been recognised for centuries, few studies have explicitly compared this finding with other bedside indicators of illness severity. This study compared subjectively assessed dorsal forearm skin temperature and moisture with other indicators of illness severity.

Methods

Non-interventional observational study of acutely ill medical patients admitted to a low-resource Ugandan hospital, which examined the association of subjectively assessed dorsal forearm skin temperature and other bedside findings with death within 24 h.

Results

While in hospital 653 patients had 2,104 observations; the dorsal forearm skin was subjectively felt to be abnormally hot or cold at 239 observations, and this finding was associated with 24-hour mortality (odds ratio 4.48, 95% CI 1.89-10.46); this increased risk of death was comparable to the increased mortality risk associated with tachypnoea, hypoxia, and a Shock Index >1.0, but considerably lower than that associated with a Kitovu Fast Triage score >0. When stratified according to both temperature and wetness, 'cold and wet' and 'hot and wet' skin were associated with higher early warning scores. Cold or hot forearm skin had a specificity for 24-hour mortality of 0.83, but a sensitivity of only 0.34; therefore, its absence does not rule-out the chance of imminent death.

Conclusion

Touching and feeling the skin temperature and moisture is a valuable clinical sign, which can be rapidly determined at the bedside. However, although it has high specificity, its sensitivity for imminent death is low.

Thermoregulation and survival during sepsis: insights from the cecal ligation and puncture experimental model

BACKGROUND

Sepsis remains a major global health concern due to its high prevalence and mortality. Changes in body temperature (Tb), such as hypothermia or fever, are diagnostic indicators and play a crucial role in the pathophysiology of sepsis. This study aims to characterize the thermoregulatory mechanisms during sepsis using the cecal ligation and puncture (CLP) model and explore how sepsis severity and ambient temperature (Ta) influence Tb regulation and mortality. Rats were subjected to mild or severe sepsis by CLP while housed at thermoneutral (28 °C) or subthermoneutral (22 °C) Ta, and their Tb was monitored for 12 h. Blood and hypothalamus were collected for cytokines and prostaglandin E2 (PGE2) analysis.

RESULTS

At 28 °C, febrile response magnitude correlated with sepsis severity and inflammatory response, with tail vasoconstriction as the primary heat retention mechanism. At 22 °C, Tb was maintained during mild sepsis but dropped during severe sepsis, linked to reduced UCP1 expression in brown adipose tissue and less effective vasoconstriction. Despite differences in thermoregulatory responses, both Ta conditions induced a persistent inflammatory response and increased hypothalamic PGE2 production. Notably, mortality in severe sepsis was significantly higher at 28 °C (80%) compared to 22 °C (0%).

CONCLUSIONS

Our findings reveal that ambient temperature and the inflammatory burden critically influence thermoregulation and survival during early sepsis. These results emphasize the importance of considering environmental factors in preclinical sepsis studies. Although rodents in experimental settings are often adapted to cold environments, these conditions may not fully translate to human sepsis, where cold adaptation is rare. Thus, researchers should carefully consider these variables when designing experiments and interpreting translational implications.

Hypothermia and Influence of Rewarming Rates on Survival Among Patients Admitted to Intensive Care with Bloodstream Infection: A Multicenter Cohort Study

Although critically ill patients with bloodstream infections (BSIs) who present with hypothermia are at the highest risk for death, it is not known how rewarming rates may influence the outcomes. The objective of this study was to identify the occurrence and determinants of hypothermia among patients admitted to intensive care units (ICUs) with BSI and assess how the rate of temperature correction may influence 90-day all-cause case-fatality. A cohort of 3951 ICU admissions associated with BSI was assembled. The lowest temperature measured within the first 24 hours of admission was identified, and among those who were hypothermic (<36°C), the rewarming rate [(time difference between lowest and subsequent first temperature ≥36°C) divided by hypothermia severity (difference between lowest measured and 36°C)] was determined. Within the first 24 hours of admission to the ICU, 329 (8.4%) and 897 (22.7%) subjects had the lowest temperature measurements ranging <34.9°C and 35-35.9°C, respectively. Patients with lower temperatures were more likely to be admitted to tertiary care ICUs, have more comorbid illnesses, have greater severity of illness, and have a higher need for organ-supportive therapies. The 90-day all-cause case-fatality rate was 22.9% overall and was 45.3%, 24.8%, and 19.6% for those with the lowest 24 hours temperatures of <35°C, 35-35.9°C, and ≥36°C, respectively (p < 0.001). Among 1133 hypothermic patients with documented temperatures corrected to the normal range while admitted to the ICU, the median rate of temperature increase was 0.24 (interquartile range, 0.13-0.45)oC/hour. After controlling for the severity of illness and comorbidity, a faster rewarming rate was associated with significantly lower 90-day case-fatality. Hypothermia is a significant risk factor associated with death among critically ill patients with BSI that faster rates of rewarming may modify.

Comprehensive risk factor-based nomogram for predicting one-year mortality in patients with sepsis-associated encephalopathy

Sepsis-associated encephalopathy (SAE) is a frequent and severe complication in septic patients, characterized by diffuse brain dysfunction resulting from systemic inflammation. Accurate prediction of long-term mortality in these patients is critical for improving clinical outcomes and guiding treatment strategies. We conducted a retrospective cohort study using the MIMIC IV database to identify adult patients diagnosed with SAE. Patients were randomly divided into a training set (70%) and a validation set (30%). Least absolute shrinkage and selection operator regression and multivariate logistic regression were employed to identify significant predictors of 1-year mortality, which were then used to develop a prognostic nomogram. The model's discrimination, calibration, and clinical utility were assessed using the area under the receiver operating characteristic curve (AUC), calibration plots, and decision curve analysis, respectively. A total of 3,882 SAE patients were included in the analysis. The nomogram demonstrated strong predictive performance with AUCs of 0.881 (95% CI: 0.865, 0.896) in the training set and 0.859 (95% CI: 0.830, 0.888) in the validation set. Calibration plots indicated good agreement between predicted and observed 1-year mortality rates. The decision curve analysis showed that the nomogram provided greater net benefit across a range of threshold probabilities compared to traditional scoring systems such as Glasgow Coma Scale and Sequential Organ Failure Assessment. Our study presents a robust and clinically applicable nomogram for predicting 1-year mortality in SAE patients. This tool offers superior predictive performance compared to existing severity scoring systems and has significant potential to enhance clinical decision-making and patient management in critical care settings.

Modern CRRT systems are associated with lower risk of hypothermia

One risk of continuous renal replacement therapy (CRRT) is inadvertent hypothermia (IH), which is defined as a non-therapeutic core temperature decrease below normal. In continuous renal replacement therapy, heat loss will always occur from blood pumped through the dialysis circuit to cooler environment, predisposing for hypothermia. Blood flow and effluent flows are the most important parameters causing heat loss. We investigated and compared the novel TherMax warmer to previous generation technologies during CRRT in a multicenter setting. This was a prospective observational multicenter study with historic single-center controls. The study group consisted of 100 patients in eight Swedish ICUs with clinical indication for CRRT, using the PrisMax platform and TherMax warmer. Both patient and set warmer temperatures were recorded hourly for the first 24 h. The presence of treatment hours in hypothermia (< 36.0 Celsius) and the difference between set warmer temperature and measured patient temperature in the multi-center study cohort were compared to a matched single-center historic control cohort treated with the old Prismaflex platform and adjacent Barkey warmer. In the TherMax group 77/100 (77.0%) of patients, and for controls 26/86 (30.2%) of patients were free of hypothermia (Chi square, p < 0.001). The mean number of hours spent in hypothermia was (mean ± SD) 0.66 ± 1.60 and 6.92 ± 7.79 h in the TherMax and control groups, respectively (Chi square p < 0.001). In the study group the patient temperature was higher than the set temperature on the warmer with a difference of Δ0.47 ± 0.80 °C (minor difference), whereas in the control group the set temperature on the warmer was higher than the patient temperature with a difference of Δ4.55 ± 1.00 °C (over-correction). The novel TherMax warmer technology protected against hypothermia and was significantly more accurate than the Barkey warmer.

Temperature trajectories and mortality in hypothermic sepsis patients

OBJECTIVES

Hypothermia is associated with poor outcomes in sepsis patients, and hypothermic sepsis patients exhibit temperature alterations during initial treatment. The objective of this study was to classify hypothermic sepsis patients based on body temperature trajectories and investigate the associations of these patients with 28-day mortality.

METHODS

This was a retrospective analysis of prospectively collected data from adult sepsis or septic shock patients who visited three emergency departments between August 2014 and December 2019. Hypothermic sepsis was defined as an initial body temperature <36 °C. delta temperature was calculated by subtracting the 0 h body temperature from the 6 h body temperature. We divided the patients into three groups according to delta temperature: Group A (delta temperature ≤ 0), Group B (0 < delta temperature ≤ 1) and Group C (delta temperature > 1). The primary outcome was 28-day mortality, and a multivariable Cox proportional hazards regression model was generated.

RESULTS

Among 7344 patients with sepsis or septic shock, 325 hypothermic patients were included in the analysis, and the overall mortality rate was 36%. While initial body temperature was not different between survivors and nonsurvivors, survivors exhibited a higher body temperature at 6 h. The 28-day mortality rates for Groups A, B and C were 53.1%, 36.0%, and 30.0%, respectively, and Group A had significantly higher mortality than Group C did (p < 0.05). Group C demonstrated a 44.2% decrease in 28-day mortality compared to Group A (adjusted hazard ratio of 0.558; 95% confidence interval of 0.330-0.941).

CONCLUSIONS

In hypothermic sepsis patients, an increase of 1 °C or more in body temperature after the initial 6 h is associated with a reduced risk of 28-day mortality.

The Nonlinear Relationship Between Temperature and Prognosis in Sepsis-induced Coagulopathy Patients: A Retrospective Cohort Study from MIMIC-IV Database

Background

The prognostic value of body temperature in sepsis-induced coagulopathy (SIC) remains unclear. In this study we aimed to investigate the association between temperature and mortality among SIC patients.

Methods

We analyzed data for 9,860 SIC patients from an intensive care database. Patients were categorized by maximum temperature in the first 24 hours into the following: ≤36.0°C; 36.0-37.0°C; 37.0-38.0°C; 38.0-39.0°C; and ≥39.0°C. The primary outcome was 28-day mortality. We used multivariate regression to analyze the temperature-mortality association.

Results

The 37.0-38.0°C, 38.0-39.0°C and ≥39.0°C groups correlated with lower 28-day mortality (adjusted HR 0.70, 0.76 and 0.72, respectively), while the <36.0°C group correlated with higher mortality compared to the 36.0-37.0°C group (adjusted HR 2.60). A nonlinear relationship was observed between temperature and mortality. Subgroup analysis found no effect modification except in cerebrovascular disease.

Conclusion

A body temperature in the range of 37.0-38.0°C was associated with a significantly lower mortality compared to the normal temperature (36.0-37.0°C) group. Additionally, a gradual but statistically insignificant increase in mortality risk was observed when body temperature exceeded 38.0°C. Further research should validate these findings and elucidate involved mechanisms, especially in cerebrovascular disease subgroups.

Accidental hypothermia in the largest emergency hospital in North-Eastern Romania

INTRODUCTION

Accidental hypothermia (AH) presents a significant mortality risk, even in individuals with good health. Early recognition of the parameters associated with negative prognosis could save more lives.

METHODS

This was a pilot, retrospective observational study, conducted in the largest Emergency Hospital in North Eastern Romania, which included all patients with AH (defined as body temperature below 35°C), hospitalized and treated in our hospital between 2019 and 2022.

RESULTS

A total of 104 patients with AH were included in our study, 90 of whom had data collected and statistically analyzed. The clinical, biological, and therapeutic parameters associated with negative outcomes were represented by a reduced GCS score (p=0.024), diminished systolic and diastolic blood pressure (p=0.007 respectively, 0.013), decreased bicarbonate (p=0.043) and hemoglobin levels (p=0.002), the presence of coagulation disorders (p=0.007), as well as the need for administration of inotropic or vasopressor medications (p=0.04).

CONCLUSION

In this pilot, retrospective, observational study, the negative outcomes observed in patients with AH hospitalized in the largest Emergency Hospital in North-Eastern Romania were associated with several clinical, biochemical, and therapeutic factors, which are easy to identify in clinical practice. Recognizing the significance of these associated factors empowers healthcare practitioners to intervene at an early stage to save more lives.

Management of spontaneous septic hypothermia in intensive care. A national survey of French intensive care units

The benefit of temperature control in sepsis or septic shock is still under debate in the literature. We developed a national survey to assess the current state of knowledge and the practical management of spontaneous septic hypothermia in French intensive care units. Out of more 764 intensivists who were contacted, 436 responded to the survey. The majority of doctors (52.4%) considered spontaneous septic hypothermia to be a frequently encountered situation in intensive care, and 62.1% were interested in this problem. Definition of spontaneous septic hypothermia among French intensivists was not consensual. More than half of the doctors questioned (57.1%) stated that they did not actively rewarm patients suffering from spontaneous septic hypothermia.

Dehydrozaluzanin C- derivative protects septic mice by alleviating over-activated inflammatory response and promoting the phagocytosis of macrophages

Host-directed therapy (HDT) is a new adjuvant strategy that interfere with host cell factors that are required by a pathogen for replication or persistence. In this study, we assessed the effect of dehydrozaluzanin C-derivative (DHZD), a modified compound from dehydrozaluzanin C (DHZC), as a potential HDT agent for severe infection. LPS-induced septic mouse model and Carbapenem resistant Klebsiella pneumoniae (CRKP) infection mouse model was used for testing in vivo. RAW264.7 cells, mouse primary macrophages, and DCs were used for in vitro experiments. Dexamethasone (DXM) was used as a positive control agent. DHZD ameliorated tissue damage (lung, kidney, and liver) and excessive inflammatory response induced by LPS or CRKP infection in mice. Also, DHZD improved the hypothermic symptoms of acute peritonitis induced by CRKP, inhibited heat-killed CRKP (HK-CRKP)-induced inflammatory response in macrophages, and upregulated the proportions of phagocytic cell types in lungs. In vitro data suggested that DHZD decreases LPS-stimulated expression of IL-6, TNF-α and MCP-1 via PI3K/Akt/p70S6K signaling pathway in macrophages. Interestingly, the combined treatment group of DXM and DHZD had a higher survival rate and lower level of IL-6 than those of the DXM-treated group; the combination of DHZD and DXM played a synergistic role in decreasing IL-6 secretion in sera. Moreover, the phagocytic receptor CD36 was increased by DHZD in macrophages, which was accompanied by increased bacterial phagocytosis in a clathrin- and actin-dependent manner. This data suggests that DHZD may be a potential drug candidate for treating bacterial infections.

Physiologic disruption and metabolic reprogramming in infection and sepsis

Effective responses against severe systemic infection require coordination between two complementary defense strategies that minimize the negative impact of infection on the host: resistance, aimed at pathogen elimination, and disease tolerance, which limits tissue damage and preserves organ function. Resistance and disease tolerance mostly rely on divergent metabolic programs that may not operate simultaneously in time and space. Due to evolutionary reasons, the host initially prioritizes the elimination of the pathogen, leading to dominant resistance mechanisms at the potential expense of disease tolerance, which can contribute to organ failure. Here, we summarize our current understanding of the role of physiological perturbations resulting from infection in immune response dynamics and the metabolic program requirements associated with resistance and disease tolerance mechanisms. We then discuss how insight into the interplay of these mechanisms could inform future research aimed at improving sepsis outcomes and the potential for therapeutic interventions.

Non-conventional immunomodulation in the management of sepsis

Sepsis remains a critical global health issue, demanding novel therapeutic strategies. Traditional immunomodulation treatments such as corticosteroids, specific modifiers of cytokines, complement or coagulation, growth factors or immunoglobulins, have so far fallen short. Meanwhile the number of studies investigating non-conventional immunomodulatory strategies is expanding. This review provides an overview of adjunctive treatments with herbal-based medicine, immunonutrition, vasopressors, sedative treatments and targeted temperature management, used to modulate the immune response in patients with sepsis. Herbal-based medicine, notably within traditional Chinese medicine, shows promise. Xuebijing injection and Shenfu injection exhibit anti-inflammatory and immune-modulatory effects, and the potential to lower 28-day mortality in sepsis. Selenium supplementation has been reported to reduce the occurrence of ventilator-associated pneumonia among sepsis patients, but study results are conflicting. Likewise, the immune-suppressive effects of omega-3 fatty acids have been associated with improved clinical outcomes in sepsis. The immunomodulating properties of supportive treatments also gain interest. Vasopressors like norepinephrine exhibit dual dosage-dependent roles, potentially promoting both pro- and anti-inflammatory effects. Dexmedetomidine, a sedative, demonstrates anti-inflammatory properties, reducing sepsis mortality rates in some studies. Temperature management, particularly maintaining higher body temperature, has also been associated with improved outcomes in small scale human trials. In conclusion, emerging non-conventional immunomodulatory approaches, including herbal medicine, immunonutrition, and targeted supportive therapies, hold potential for sepsis treatment, but their possible implementation into everyday clinical practice necessitates further research and stringent clinical validation in different settings.

The Effect of Body Temperature Changes on the Course of Treatment in Patients With Pneumonia and Sepsis: Results of an Observational Study

BACKGROUND

Traditionally, patients who are critically ill with infection and fever have been treated with antipyretics or even physically cooled. Presumed benefits of the reduction of body temperature are mostly based on decreased metabolic demands. However, it has been shown that decreasing body temperature in patients who are critically ill is not associated with improvement in treatment outcomes. Additionally, there is some data to support the use of temperature modulation (therapeutic hyperthermia) as an adjuvant treatment strategy in patients with infection.

OBJECTIVE

This study aims to determine the effect of body temperature on the course of intensive care unit (ICU) treatment of patients who are mechanically ventilated with pneumonia, sepsis, and positive tracheal aspirates on admission.

METHODS

We performed a single-center retrospective study. Core body temperature was measured in all patients. We analyzed associations between average temperatures in the first 48 hours after admission to ICU and ICU treatment parameters. Additionally, patients were divided into three groups: patients with negative tracheal aspirates 1 week after ICU admission (P-N group), patients with a different pathogen in tracheal aspirates 1 week after ICU admission (P-HAP group), and patients with a persisting pathogen in tracheal aspirates 1 week after ICU admission (P-P group). Differences in body temperature and interventions aimed at temperature modulation were determined.

RESULTS

We observed a significantly higher average temperature in the first 48 hours after admission to ICU in patients who survived to hospital discharge compared to nonsurvivors (mean 37.2 °C, SD 1 °C vs mean 36.9 °C, SD 1.6 °C; P=.04). We observed no associations between average temperatures in the first 48 hours after ICU admission and days of mechanical ventilation in the first 7 days of treatment (ρ=-0.090; P=.30), the average maximum daily requirement for noradrenaline in the first 7 days of treatment (ρ=-0.029; P=.80), average maximum FiO2 in the first 7 days of ICU treatment (ρ=0.040; P=.70), and requirement for renal replacement therapy in the first 7 days of ICU treatment (mean 37.3 °C, SD 1.4 °C vs mean 37.0 °C, SD 1.3 °C; P=.23). In an additional analysis, we observed a significantly greater use of paracetamol in the P-N group (mean 1.0, SD 1.1 g vs mean 0.4, SD 0.7 g vs mean 0.4, SD 0.8 g; P=.009), a trend toward greater use of active cooling in the first 24 hours after ICU admission in the P-N group (n=11, 44% vs n=14, 33.3% vs n=16, 32%; P=.57), and no other significant differences in parameters of ICU treatment between patient groups.

CONCLUSIONS

We observed better survival in patients who developed higher body temperatures in the first 48 hours after admission to the ICU; however, we observed no changes in other treatment parameters. Similarly, we observed greater use of paracetamol in patients with negative tracheal aspirates 1 week after ICU admission. Our results support the strategy of temperature tolerance in patients who are intubated with pneumonia and sepsis.

Construction and evaluation of shortterm and longterm mortality risk prediction model for patients with sepsis based on MIMICIV database

OBJECTIVES

Given the high incidence and mortality rate of sepsis, early identification of high-risk patients and timely intervention are crucial. However, existing mortality risk prediction models still have shortcomings in terms of operation, applicability, and evaluation on long-term prognosis. This study aims to investigate the risk factors for death in patients with sepsis, and to construct the prediction model of short-term and long-term mortality risk.

METHODS

Patients meeting sepsis 3.0 diagnostic criteria were selected from the Medical Information Mart for Intensive Care-IV (MIMIC-IV) database and randomly divided into a modeling group and a validation group at a ratio of 7꞉3. Baseline data of patients were analyzed. Univariate Cox regression analysis and full subset regression were used to determine the risk factors of death in patients with sepsis and to screen out the variables to construct the prediction model. The time-dependent area under the curve (AUC), calibration curve, and decision curve were used to evaluate the differentiation, calibration, and clinical practicability of the model.

RESULTS

A total of 14 240 patients with sepsis were included in our study. The 28-day and 1-year mortality were 21.45% (3 054 cases) and 36.50% (5 198 cases), respectively. Advanced age, female, high sepsis-related organ failure assessment (SOFA) score, high simplified acute physiology score II (SAPS II), rapid heart rate, rapid respiratory rate, septic shock, congestive heart failure, chronic obstructive pulmonary disease, liver disease, kidney disease, diabetes, malignant tumor, high white blood cell count (WBC), long prothrombin time (PT), and high serum creatinine (SCr) levels were all risk factors for sepsis death (all P<0.05). Eight variables, including PT, respiratory rate, body temperature, malignant tumor, liver disease, septic shock, SAPS II, and age were used to construct the model. The AUCs for 28-day and 1-year survival were 0.717 (95% CI 0.710 to 0.724) and 0.716 (95% CI 0.707 to 0.725), respectively. The calibration curve and decision curve showed that the model had good calibration degree and clinical application value.

CONCLUSIONS

The short-term and long-term mortality risk prediction models of patients with sepsis based on the MIMIC-IV database have good recognition ability and certain clinical reference significance for prognostic risk assessment and intervention treatment of patients.

Itaconate stabilizes CPT1a to enhance lipid utilization during inflammation

One primary metabolic manifestation of inflammation is the diversion of cis-aconitate within the tricarboxylic acid (TCA) cycle to synthesize the immunometabolite itaconate. Itaconate is well established to possess immunomodulatory and metabolic effects within myeloid cells and lymphocytes, however, its effects in other organ systems during sepsis remain less clear. Utilizing Acod1 knockout mice that are deficient in synthesizing itaconate, we aimed to understand the metabolic role of itaconate in the liver and systemically during sepsis. We find itaconate aids in lipid metabolism during sepsis. Specifically, Acod1 KO mice develop a heightened level of hepatic steatosis when induced with polymicrobial sepsis. Proteomics analysis reveals enhanced expression of enzymes involved in fatty acid oxidation in following 4-octyl itaconate (4-OI) treatment in vitro. Downstream analysis reveals itaconate stabilizes the expression of the mitochondrial fatty acid uptake enzyme CPT1a, mediated by its hypoubiquitination. Chemoproteomic analysis revealed itaconate interacts with proteins involved in protein ubiquitination as a potential mechanism underlying its stabilizing effect on CPT1a. From a systemic perspective, we find itaconate deficiency triggers a hypothermic response following endotoxin stimulation, potentially mediated by brown adipose tissue (BAT) dysfunction. Finally, by use of metabolic cage studies, we demonstrate Acod1 KO mice rely more heavily on carbohydrates versus fatty acid sources for systemic fuel utilization in response to endotoxin treatment. Our data reveal a novel metabolic role of itaconate in modulating fatty acid oxidation during polymicrobial sepsis.

Association of body temperature and mortality in critically ill patients: an observational study using two large databases

BACKGROUND

Body temperature (BT) is routinely measured and can be controlled in critical care settings. BT can impact patient outcome, but the relationship between BT and mortality has not been well-established.

METHODS

A retrospective cohort study was conducted based on the MIMIC-IV (N = 43,537) and eICU (N = 75,184) datasets. The primary outcome and exposure variables were hospital mortality and first 48-h median BT, respectively. Generalized additive models were used to model the associations between exposures and outcomes, while adjusting for patient age, sex, APS-III, SOFA, and Charlson comorbidity scores, temperature gap, as well as ventilation, vasopressor, steroids, and dialysis usage. We conducted subgroup analysis according to ICU setting, diagnoses, and demographics.

RESULTS

Optimal BT was 37 °C for the general ICU and subgroup populations. A 10% increase in the proportion of time that BT was within the 36-38 °C range was associated with reduced hospital mortality risk in both MIMIC-IV (OR 0.91; 95% CI 0.90-0.93) and eICU (OR 0.86; 95% CI 0.85-0.87). On the other hand, a 10% increase in the proportion of time when BT < 36 °C was associated with increased mortality risk in both MIMIC-IV (OR 1.08; 95% CI 1.06-1.10) and eICU (OR 1.18; 95% CI 1.16-1.19). Similarly, a 10% increase in the proportion of time when BT > 38 °C was associated with increased mortality risk in both MIMIC-IV (OR 1.09; 95% CI 1.07-1.12) and eICU (OR 1.09; 95% CI 1.08-1.11). All patient subgroups tested consistently showed an optimal temperature within the 36-38 °C range.

CONCLUSIONS

A BT of 37 °C is associated with the lowest mortality risk among ICU patients. Further studies to explore the causal relationship between the optimal BT and mortality should be conducted and may help with establishing guidelines for active BT management in critical care settings.

Association between the severity of hypothermia and in-hospital mortality in patients with infectious diseases: The J-Point registry

Aim

Hypothermia is associated with poor prognosis in patients with sepsis. However, no studies have explored the correlation between the severity of hypothermia and prognosis.

Methods

Using data from the Japanese accidental hypothermia network registry (J-Point registry), we examined adult patients aged ≥18 years with infectious diseases whose initial body temperature was ≤35°C from April 1, 2011 to March 31, 2016, in 12 centers. Patients were divided into three groups according to their body temperature: Tertile 1 (T1) (32.0-35.0°C), Tertile 2 (T2) (28.0-31.9°C), and Tertile 3 (T3) (<28.0°C). In-hospital mortality was employed as a metric to assess outcomes. We conducted a multivariate logistic regression analysis to investigate the relationship between the three categories and the occurrence of in-hospital mortality.

Results

A total of 572 patients were registered, and 170 eligible patients were identified. Of these patients, 55 were in T1 (32.0-35.0°C), 76 in T2 (28.0-31.9°C), and 39 in T3 (<28.0°C) groups. The overall in-hospital mortality rate in accidental hypothermia (AH) patients with infectious diseases was 34.1%. The in-hospital mortality rates in the T1, T2, and T3 groups were 34.5%, 36.8%, and 28.2%, respectively. The multivariable analysis demonstrated no significant differences regarding in-hospital mortality among the three groups (T2 vs. T1, adjusted odds ratio [OR]: 1.29; 95% confidence interval [CI]: 0.58-2.89 and T3 vs. T1, adjusted OR: 0.83; 95% CI: 0.30-2.31).

Conclusion

In this multicenter retrospective observational study, hypothermia severity was not associated with in-hospital mortality in AH patients with infectious diseases.

Core Warming of Coronavirus Disease 2019 Patients Undergoing Mechanical Ventilation: A Pilot Study

Fever is a recognized protective factor in patients with sepsis, and growing data suggest beneficial effects on outcomes in sepsis with elevated temperature, with a recent pilot randomized controlled trial (RCT) showing lower mortality by warming afebrile sepsis patients in the intensive care unit (ICU). The objective of this prospective single-site RCT was to determine if core warming improves respiratory physiology of mechanically ventilated patients with coronavirus disease 2019 (COVID-19), allowing earlier weaning from ventilation, and greater overall survival. A total of 19 patients with mean age of 60.5 (±12.5) years, 37% female, mean weight 95.1 (±18.6) kg, and mean body mass index 34.5 (±5.9) kg/m2 with COVID-19 requiring mechanical ventilation were enrolled from September 2020 to February 2022. Patients were randomized 1:1 to standard of care or to receive core warming for 72 hours through an esophageal heat exchanger commonly utilized in critical care and surgical patients. The maximum target temperature was 39.8°C. A total of 10 patients received usual care and 9 patients received esophageal core warming. After 72 hours of warming, the ratio of arterial oxygen partial pressure to fractional inspired oxygen (PaO2/FiO2) ratios were 197 (±32) and 134 (±13.4), cycle thresholds were 30.8 (±6.4) and 31.4 (±3.2), ICU mortalities were 40% and 44%, 30-day mortalities were 30% and 22%, and mean 30-day ventilator-free days were 11.9 (±12.6) and 6.8 (±10.2) for standard of care and warmed patients, respectively (p = NS). This pilot study suggests that core warming of patients with COVID-19 undergoing mechanical ventilation is feasible and appears safe. Optimizing time to achieve febrile-range temperature may require a multimodal temperature management strategy to further evaluate effects on outcome. ClinicalTrials.gov Identifier: NCT04494867.

Temperature control in sepsis

Fever can be viewed as an adaptive response to infection. Temperature control in sepsis is aimed at preventing potential harms associated with high temperature (tachycardia, vasodilation, electrolyte and water loss) and therapeutic hypothermia may be aimed at slowing metabolic activities and protecting organs from inflammation. Although high fever (>39.5°C) control is usually performed in critically ill patients, available cohorts and randomized controlled trials do not support its use to improve sepsis prognosis. Finally, both spontaneous and therapeutic hypothermia are associated with poor outcomes in sepsis.

Neutrophil extracellular traps formation and clearance is enhanced in fever and attenuated in hypothermia

Fever and hypothermia represent two opposite strategies for fighting systemic inflammation. Fever results in immune activation; hypothermia is associated with energy conservation. Systemic Inflammatory Response Syndrome (SIRS) remains a significant cause of mortality worldwide. SIRS can lead to a broad spectrum of clinical symptoms but importantly, patients can develop fever or hypothermia. During infection, polymorphonuclear cells (PMNs) such as neutrophils prevent pathogen dissemination through the formation of neutrophil extracellular traps (NETs) that ensnare and kill bacteria. However, when dysregulated, NETs also promote host tissue damage. Herein, we tested the hypothesis that temperature modulates NETs homeostasis in response to infection and inflammation. NETs formation was studied in response to infectious (Escherichia coli, Staphylococcus aureus) and sterile (mitochondria) agents. When compared to body temperature (37°C), NETs formation increased at 40°C; interestingly, the response was stunted at 35°C and 42°C. While CD16+ CD49d+ PMNs represent a small proportion of the neutrophil population, they formed ~45-85% of NETs irrespective of temperature. Temperature increased formyl peptide receptor 1 (FPR1) expression to a differential extent in CD16+ CD49d- vs. CD49d+ PMNSs, suggesting further complexity to neutrophil function in hypo/hyperthermic conditions. The capacity of NETs to induce Toll-like receptor 9 (TLR9)-mediated NF-κB activation was found to be temperature independent. Interestingly, NET degradation was enhanced at higher temperatures, which corresponded with greater plasma DNase activity in response to temperature increase. Collectively, our observations indicate that NETs formation and clearance are enhanced at 40°C whilst temperatures of 35°C and 42°C attenuate this response. Targeting PMN-driven immunity may represent new venues for intervention in pathological inflammation.

Clinical Sepsis Phenotypes in Critically Ill Patients

Sepsis, defined as the life-threatening dysregulated host response to an infection leading to organ dysfunction, is considered as one of the leading causes of mortality worldwide, especially in intensive care units (ICU). Moreover, sepsis remains an enigmatic clinical syndrome, with complex pathophysiology incompletely understood and a great heterogeneity both in terms of clinical expression, patient response to currently available therapeutic interventions and outcomes. This heterogeneity proves to be a major obstacle in our quest to deliver improved treatment in septic critical care patients; thus, identification of clinical phenotypes is absolutely necessary. Although this might be seen as an extremely difficult task, nowadays, artificial intelligence and machine learning techniques can be recruited to quantify similarities between individuals within sepsis population and differentiate them into distinct phenotypes regarding not only temperature, hemodynamics or type of organ dysfunction, but also fluid status/responsiveness, trajectories in ICU and outcome. Hopefully, we will eventually manage to determine both the subgroup of septic patients that will benefit from a therapeutic intervention and the correct timing of applying the intervention during the disease process.

Body temperature as a predictor of mortality in COVID-19

It remains uncertain if body temperature (BT) is a useful prognostic indicator in coronavirus disease 2019 (COVID-19). We investigated the relationship between BT and mortality in COVID-19 patients. We used a de-identified database that prospectively collected information from patients screened for COVID-19 at the Mount Sinai facilities from February 28, 2020 to July 28, 2021. All patients diagnosed with COVID-19 that had BT data were included. BT at initial presentation, maximum BT during hospitalization, comorbidity, and vaccination status data were extracted. Mortality rate was assessed as a primary outcome. Among 24,293 cases, patients with initial BT below 36 °C had higher mortality than those with BT of 36-37 °C (p < 0.001, odds ratio 2.82). Initial BT > 38 °C was associated with high mortality with an incremental trend at higher BT. In 10,503 in-patient cases, a positive association was observed between mortality and maximum BT except in patients with BT < 36 °C. Multiple logistic regression analyses including the comorbidities revealed that maximum BT was an independent predictor of mortality. While vaccination did not change the distribution of maximum BT, mortality was decreased in vaccinated patients. Our retrospective cohort study suggests that high maximum BT is an independent predictor of higher mortality in COVID-19 patients.

Prediction of 30-Day Mortality Using the Quick Pitt Bacteremia Score in Hospitalized Patients with Klebsiella pneumoniae Infection

Purpose

Klebsiella pneumoniae is an important causative pathogen of nosocomial infections, resulting in poor prognosis owing to its hypervirulence and antibiotic resistance. A simplified quicker version of the Pitt bacteremia score (PBS) (qPitt) for acute illness severity measurement was developed recently. The goal of this study was to explore the prognostic value of qPitt in patients with K. pneumoniae infection.

Patients and Methods

Demographic information and management strategies were retrospectively collected from the records of all adult patients who visited the emergency department between January 1, 2021, and December 31, 2021, with culture-positive K. pneumoniae. The qPitt score was calculated based on: temperature <36°C, systolic blood pressure ≤90 mmHg or vasopressor administration, respiratory rate ≥25 times/min or need of mechanical ventilation, altered mental status, and cardiac arrest event. The 30-day mortality prediction abilities of the qPitt were compared with the PBS, the sequential organ failure assessment (SOFA), and the quick sequential organ failure assessment (qSOFA) using receiver operating characteristic curves.

Results

Data from 867 patients (57.8% men) with a mean age of 66.9 were compiled. The 30-day mortality rate of the enrolled patients was 13.4%, and the area under the curve (AUC) of the scoring systems were as follows: SOFA, 0.91 (95% confidence interval [CI]=0.89-0.93), qPitt, 0.87 (95% CI=0.84-0.89), PBS, 0.87 (95% CI=0.85-0.89), and qSOFA, 0.73 (95% CI=0.70-0.76). The AUC of qPitt was significantly higher than that of qSOFA (p<0.01) and similar to that of PBS (p=0.65).The qPitt also demonstrated excellent mortality discrimination ability in non-bacteremic patients, AUC= 0.85 (95% CI=0.82-0.88).

Conclusion

The qPitt revealed excellent 30-day mortality prediction ability and also predicted mortality in non-bacteremic patients with K. pneumoniae infection. Clinicians can use this simplified scoring system to stratify patients earlier and initiate prompt treatment in high-risk patients.

Clinical impact of multidisciplinary carbapenem stewardship interventions: a retrospective cohort study

BACKGROUND

Antimicrobial stewardship (AMS) program aims to optimise antimicrobial utilisation and curb antimicrobial resistance. We investigated the clinical impact of AMS among patients with carbapenem in medical wards of a tertiary hospital.

METHODS

A retrospective cohort study was conducted on hospitalised adult patients treated with carbapenem and reviewed by a multidisciplinary AMS team. We compared the clinical outcomes of accepted (n = 103) and not-accepted AMS intervention cases (n = 37). The outcomes evaluated include trends of total white blood cells (TWBC), C-reactive protein (CRP), body temperature at day-7, and clinical status at day-30 post-AMS intervention.

RESULTS

The interventions included discontinuation (50%), de-escalation (47.9%) and escalation (2.1%) of antibiotics, where the acceptance rate was 67.1%, 80.6% and 66.7%, respectively. Overall, we found no significant difference in clinical outcomes between accepted and not-accepted AMS interventions at day-7 and day-30 post-interventions. On day-7, 62.0% of patients in the accepted group showed decreased or normalised TWBC and CRP levels compared to 47.4% of the not-accepted group (p = 0.271). The mortality at day-30 (32% versus 35%, p = 0.73), discharge rate (53.4% versus 45.9%, p = 0.437), and median length of hospital stay (36.0 versus 30.0 days, p = 0.526) between the groups were comparable. The predictors of 30-day mortality in the study subjects were Charlson Comorbidity Index > 3 (OR: 2.84, 95% CI 1.28-6.29, p = 0.010) and being febrile at day-7 (OR: 4.58, 95% CI 1.83-11.5, p = 0.001).

CONCLUSION

AMS interventions do not result in significant adverse clinical impact and mortality risk.

Protective effect of the novel cyclic peptide ASK0912 on mice with sepsis induced by Acinetobacter baumannii

BACKGROUND

Sepsis has become a global health concern owing to its increasing incidence and high mortality rate. In the present study, we investigated a novel drug candidate ASK0912 on its protective effects in mice with Acinetobacter baumannii 20-1-induced sepsis, and studied the related mechanisms.

MATERIAL AND METHODS

To analyze the protective effect of ASK0912 on septic mice, survival rates, body temperature, organ and blood bacterial loads, white blood cell and platelet counts, organ damage, and cytokine levels were determined.

RESULTS

ASK0912 remarkably increased the survival rate of mice with sepsis induced by A. baumannii 20-1 at a low dose of 0.6 mg/kg. Rectal temperature measurements showed that ASK0912 treatment prevented the body temperature decrease of septic mice to some extent. Treatment with ASK0912 can notably reduce the organ and blood bacterial loads and alleviate platelet count reduction due to sepsis. ASK0912 attenuated organ damage, including reduced levels of total bile acids, urea, and creatinine, aggregation of inflammatory cells, and mitigation of structural changes in septic mice, as demonstrated by biochemical analysis and hematoxylin & eosin staining. Additionally, multiplex assay showed that abnormally increased cytokine levels (IL-1β, IL-3, IL-5, IL-6, IL-10, IL-13, MCP-1, RANTES, KC, MIP-1α, MIP-1β, and G-CSF) in septic mice decreased after ASK0912 treatment.

CONCLUSIONS

ASK0912 can not only improve the survival rate, hypothermia, lower the bacterial loads in the organs and blood, but also alleviate the pathophysiological manifestations such as intravascular coagulation abnormalities, organ damages, and immune system disorder of sepsis mice induced by A. baumannii 20-1.

Outcomes and Predictors of Severe Community-acquired Pneumonia Among Adults Admitted to the University of Gondar Comprehensive Specialized Hospital: A Prospective Follow-up Study

Background

Severe community-acquired pneumonia is a common life-threatening infection with a high rate of unfavorable outcome. This study aimed to assess the outcomes and predictors of hospitalized severe community-acquired pneumonia patients at University of Gondar comprehensive specialized hospital.

Methods

A prospective follow-up study was conducted at University of Gondar comprehensive specialized hospital from May 1 to September 31, 2021. The data was collected by reviewing patients' charts and interviewing the patients themselves. Descriptive statistics, binary and multivariable logistic regression analysis were performed accordingly. Variables with p-value <0.2 on binary logistic regression were analyzed using multivariable logistic regression and variables with p<0.05 were considered to have significant association.

Results

A total of 239 admitted patients with severe community-acquired pneumonia were enrolled in the study. An unfavorable outcome was observed in 105 (44%) patients; 24.27% was in-hospital all-cause mortality, 12.5% was nonresolution, 5.8% was complicated cases, and 1.26% were gone against medical care for poor prognosis. After analyzing multivariable logistic regression, confusion (OR= 4.84; 95%CI: 1.47-15.88), anemia (OR= 2.36; 95%CI: 1.01-5.52), leukopenia (OR=4.38; 95%CI: 1.26-15.25), leukocytosis (OR=3.15; 95%CI: 1.23-7.96), elevated creatinine (OR=5.67; 95%CI: 1.72-18.65), intubation (OR=7.27; 95%CI: 1.58-33.37) and antibiotic revision during treatment for a different reason (OR=0.02; 95%CI: 0.01-0.07) were variables significantly associated with unfavorable outcome.

Conclusion

Unfavorable outcome was high among hospitalized severe community acquired pneumonia patients, and confusion, elevated creatinine, anemia, leukopenia, leukocytosis, intubation during admission, and antibiotic revision during the course were independent predictors associated significantly with the unfavorable outcome. It is important to consider the development of a treatment protocol for the hospital and to further research incorporating the microbiologic profile of the patients.

Screening auf Sepsis in der Notfallmedizin – qSOFA ist uns nicht genug

Hintergrund

Die Sepsis ist eine häufige und lebensbedrohliche Komplikation einer akuten Infektion. In der Notfallmedizin hat sich zum Screening auf Sepsis der Quick Sequential-Organ-Failure-Assessment(qSOFA)-Score etabliert. Bereits mit der Einführung des Scores wurde dessen schwache Sensitivität kritisiert. Nun fordern aktuelle Leitlinien, den qSOFA-Score nicht mehr zum Screening auf Sepsis einzusetzen. Als eine Alternative wird der National Early Warning Score 2 (NEWS2) vorgeschlagen.

Ziel der Arbeit

In einer Subanalyse einer Kohorte von notfallmedizinischen Patient*innen soll die diagnostische Aussagekraft des qSOFA-Scores und des NEWS2 zur Erkennung einer Sepsis verglichen werden. Zusätzlich soll gezeigt werden, inwieweit mithilfe von abweichenden Vitalparametern bereits eine Risikoerhöhung für eine Sepsis ableitbar ist.

Methodik

Mittels AUROC (Area Under Receiver Operating Characteristics) und Odds Ratios wurden die Scores bzw. die Vitalparameter auf ihre Fähigkeit untersucht, septische Patient*innen zu erkennen.

Ergebnisse

Von 312 eingeschlossenen Patient*innen wurde bei 17,9 % eine Sepsis diagnostiziert. Der qSOFA-Score erkannte eine Sepsis mit einer AUROC von 0,77 (NEWS2 0,81). Für qSOFA fand sich eine Sensitivität von 57 % (Spezifität 83 %), für NEWS2 96 % (Spezifität 45 %). Die Analyse der einzelnen Vitalparameter zeigte, dass unter Patient*innen mit einer akuten Infektion eine Vigilanzminderung als deutliches Warnsignal für eine Sepsis zu werten ist.

Diskussion

In der Notfallmedizin sollte qSOFA nicht als alleiniges Tool für das Screening auf Sepsis verwendet werden. Bei Verdacht auf eine akute Infektion sollten grundsätzlich sämtliche Vitalparameter erfasst werden, um das Vorliegen einer akuten Organschädigung und somit einen septischen Krankheitsverlauf frühzeitig zu erkennen.

Graphic abstract

An investigation of temperature and fever burdens in patients with sepsis admitted from the emergency department to the hospital

Aim

We sought to collect granular data on temperature burden to further explore existing conflicting information on the relationship between temperature alterations and outcomes in patients with sepsis requiring hospital admission.

Methods

This was a prospective cohort study that enrolled a convenience sample of patients with sepsis or septic shock admitted to the hospital from the emergency department (ED). A "unit of temperature burden (UTB)" was defined as >1°C (1.8°F) above or below 37°C (98.6°F) for 1 min. Fever burden was defined as the number of UTBs >38°C (100.4°F). The primary objective was to calculate the fever burden in patients with sepsis during their ED stay. This was analyzed for patients who present to triage febrile or hypothermic and also for those who developed temperature abnormalities during their ED stay. The secondary objectives were correlating fever and hypothermia burden with in-hospital mortality, Systemic Inflammatory Response Syndrome (SIRS) criteria, and the quick Sequential (Sepsis-Associated) Organ Failure Assessment (qSOFA) score and identification of patients who may benefit from early implementation of targeted temperature management.

Results

A total of 256 patients met the inclusion criteria. The mean age of patients was 60.1 ± 18.4 years; 46% were female and 29.6% were black. The median (interquartile range [IQR]) fever burden for the fever in triage cohort (n = 99) was 364.6 (174.3-716.8) UTB and for the no fever in triage cohort (n = 157) was 179.3 (80.9-374.0) UTB (p = 0.005). The two groups had similar in-hospital mortality (6.1 vs 8.3%; p = 0.5). The median fever burden for the fever anytime cohort was 303.8 (IQR 138.8-607.9) UTB and they had lower mortality than the no fever anytime cohort (4.7% vs 11.2%; p = 0.052). Patients with fever at triage had higher mean SIRS criteria than those without (2.8 vs 2.0; p < 0.001) while qSOFA points were similar (p = 0.199). A total of 27 patients had hypothermia during their ED stay and these patients were older with higher mean SIRS criteria.

Conclusions

Patients with sepsis and septic shock have a significant temperature burden in the ED. When comparing patients who had fever at any time during their ED stay with those who never had a fever, a trend toward an inverse relationship between fever burden and mortality was found.

Association between first 24-h mean body temperature and mortality in patients with diastolic heart failure in intensive care unit: A retrospective cohort study

Background

Body temperature (BT) has been used to evaluate the outcomes of patients with various diseases. In this study, patients with diastolic heart failure (DHF) in the intensive care unit (ICU) were examined for a correlation between BT and mortality.

Methods

This was a retrospective cohort study of the Medical Information Mart for Intensive Care (MIMIC)-IV dataset. A total of 4,153 patients with DHF were included. The primary outcomes were 28-day ICU and higher in-hospital mortality rates. BT was used in the analyses both as a continuous variable and as a categorical variable. According to the distribution of BT, the patients were categorized into three groups (hypothermia BT <36.5°C, normal 36.5°C ≤ BT <37.5°C, and hyperthermia BT ≥37.5°C). Multivariate logistic regression analysis was performed to explore the association between BT and patient outcomes.

Results

The proportions of the groups were 23.6, 69.2, and 7.2%, respectively. As a continuous variable, every 1°C increase in BT was associated with a 21% decrease in 28-day ICU mortality (OR: 0.79, 95% CI: 0.66-0.96, and p = 0.019) and a 23% decrease in in-hospital mortality (OR: 0.77, 95% CI: 0.66-0.91; and p = 0.002). When BT was used as a categorical variable, hypothermia was significantly associated with both 28-day ICU mortality (OR: 1.3, 95% CI: 1.03-1.65; and p = 0.026) and in-hospital mortality (OR: 1.31, 95% CI: 1.07-1.59; and p = 0.008). No statistical differences were observed between 28-day ICU mortality and in-hospital mortality with hyperthermia after adjustment.

Conclusion

The first 24-h mean BT after ICU admission was associated with 28-day ICU and in-hospital mortality in patients with DHF. Hypothermia significantly increased mortality, whereas hyperthermia did not.

Association between low body temperature on admission and in-hospital mortality according to body mass index categories of patients with sepsis

Hypothermia has been shown to be associated with a high mortality rate among patients with sepsis. However, the relationship between hypothermia and body mass index (BMI) with respect to mortality remains to be elucidated. We conducted this study to assess the association between hypothermia and survival outcomes of patients with sepsis according to BMI categories. This secondary analysis of a prospective cohort study enrolled 1184 patients (aged ≥ 16 years) with sepsis hospitalized in 59 intensive care units in Japan. Patients were divided into 3 BMI categories (<18.5 [low], 18.5-24.9 [normal], >24.9 [high] kg/m2) and 2 body temperature (36 °C and ≥ 36 °C) groups. The primary outcome was in-hospital mortality rate. Associations between hypothermia and BMI categories with respect to in-hospital mortality were evaluated using multivariate logistic regression analysis. Of the 1089 patients, 223, 612, and 254 had low, normal, and high BMI values, respectively. Patients with body temperature < 36 °C (hypothermia) had a higher in-hospital mortality rate than that had by those without hypothermia in the normal BMI group (25/63, 39.7% vs. 107/549, 19.5%); however, this was not true for patients in the low or high BMI groups. A significant interaction was observed between hypothermia and normal BMI for in-hospital mortality (odds ratio, 1.56; 95% confidence interval, 1.00-3.41; P value for interaction = .04); however, such an interaction was not found between hypothermia and low or high BMIs. Patients with sepsis and hypothermia in the normal BMI subgroup may have a higher mortality risk than that of those in the low or high BMI subgroups and, therefore, require more attention.

Browning of the white adipose tissue regulation: new insights into nutritional and metabolic relevance in health and diseases

Adipose tissues are dynamic tissues that play crucial physiological roles in maintaining health and homeostasis. Although white adipose tissue and brown adipose tissue are currently considered key endocrine organs, they differ functionally and morphologically. The existence of the beige or brite adipocytes, cells displaying intermediary characteristics between white and brown adipocytes, illustrates the plastic nature of the adipose tissue. These cells are generated through white adipose tissue browning, a process associated with augmented non-shivering thermogenesis and metabolic capacity. This process involves the upregulation of the uncoupling protein 1, a molecule that uncouples the respiratory chain from Adenosine triphosphate synthesis, producing heat. β-3 adrenergic receptor system is one important mediator of white adipose tissue browning, during cold exposure. Surprisingly, hyperthermia may also induce beige activation and white adipose tissue beiging. Physical exercising copes with increased levels of specific molecules, including Beta-Aminoisobutyric acid, irisin, and Fibroblast growth factor 21 (FGF21), which induce adipose tissue browning. FGF21 is a stress-responsive hormone that interacts with beta-klotho. The central roles played by hormones in the browning process highlight the relevance of the individual lifestyle, including circadian rhythm and diet. Circadian rhythm involves the sleep-wake cycle and is regulated by melatonin, a hormone associated with UCP1 level upregulation. In contrast to the pro-inflammatory and adipose tissue disrupting effects of the western diet, specific food items, including capsaicin and n-3 polyunsaturated fatty acids, and dietary interventions such as calorie restriction and intermittent fasting, favor white adipose tissue browning and metabolic efficiency. The intestinal microbiome has also been pictured as a key factor in regulating white tissue browning, as it modulates bile acid levels, important molecules for the thermogenic program activation. During embryogenesis, in which adipose tissue formation is affected by Bone morphogenetic proteins that regulate gene expression, the stimuli herein discussed influence an orchestra of gene expression regulators, including a plethora of transcription factors, and chromatin remodeling enzymes, and non-coding RNAs. Considering the detrimental effects of adipose tissue browning and the disparities between adipose tissue characteristics in mice and humans, further efforts will benefit a better understanding of adipose tissue plasticity biology and its applicability to managing the overwhelming burden of several chronic diseases.

Early prediction of hypothermia in pediatric intensive care units using machine learning

Hypothermia is a life-threatening condition where the temperature of the body drops below 35°C and is a key source of concern in Intensive Care Units (ICUs). Early identification can help to nudge clinical management to initiate early interventions. Despite its importance, very few studies have focused on the early prediction of hypothermia. In this study, we aim to monitor and predict Hypothermia (30 min-4 h) ahead of its onset using machine learning (ML) models developed on physiological vitals and to prospectively validate the best performing model in the pediatric ICU. We developed and evaluated ML algorithms for the early prediction of hypothermia in a pediatric ICU. Sepsis advanced forecasting engine ICU Database (SafeICU) data resource is an in-house ICU source of data built in the Pediatric ICU at the All-India Institute of Medical Science (AIIMS), New Delhi. Each time-stamp at 1-min resolution was labeled for the presence of hypothermia to construct a retrospective cohort of pediatric patients in the SafeICU data resource. The training set consisted of windows of the length of 4.2 h with a lead time of 30 min-4 h from the onset of hypothermia. A set of 3,835 hand-engineered time-series features were calculated to capture physiological features from the time series. Features selection using the Boruta algorithm was performed to select the most important predictors of hypothermia. A battery of models such as gradient boosting machine, random forest, AdaBoost, and support vector machine (SVM) was evaluated utilizing five-fold test sets. The best-performing model was prospectively validated. A total of 148 patients with 193 ICU stays were eligible for the model development cohort. Of 3,939 features, 726 were statistically significant in the Boruta analysis for the prediction of Hypothermia. The gradient boosting model performed best with an Area Under the Receiver Operating Characteristic curve (AUROC) of 85% (SD = 1.6) and a precision of 59.2% (SD = 8.8) for a 30-min lead time before the onset of Hypothermia onset. As expected, the model showed a decline in model performance at higher lead times, such as AUROC of 77.2% (SD = 2.3) and precision of 41.34% (SD = 4.8) for 4 h ahead of Hypothermia onset. Our GBM(gradient boosting machine) model produced equal and superior results for the prospective validation, where an AUROC of 79.8% and a precision of 53% for a 30-min lead time before the onset of Hypothermia whereas an AUROC of 69.6% and a precision of 38.52% for a (30 min-4 h) lead time prospective validation of Hypothermia. Therefore, this work establishes a pipeline termed ThermoGnose for predicting hypothermia, a major complication in pediatric ICUs.

Low body temperature and mortality in older patients with frailty in the emergency department

PURPOSE

The aim of this study was to assess the association between low body temperature and mortality in frail older adults in the emergency department (ED).

METHODS

Inclusion criteria were: ≥ 75 years of age, Clinical Frailty Scale (CFS) score of 4-8, and temperature documented at ED admission. Patients were allocated to three groups by body temperature: low ≤ 36.0 °C, normal 36.1-38.0 and high ≥ 38.1. Odds ratios (OR) for 30-day and 90-day mortality were analysed.

RESULTS

1577 patients, 61.2% female, were included. Overall mortalities were 85/1577 (5.4%) and 144/1557 (9.2%) in the 30-day and 90-day follow-ups, respectively. The ORs for low body temperature were 3.03 (1.72-5.35; P < 0.001) and 2.71 (1.68-4.38; P < 0.001) for 30-day and 90-day mortality, respectively. This association remained when adjusted for age, CFS score and gender. Mortality of the high-temperature group did not differ significantly when compared to the normal-temperature group.

CONCLUSIONS

Low body temperature in frail older ED patients was associated with significantly higher 30- and 90-day mortality.

Therapeutic Hyperthermia Is Associated With Improved Survival in Afebrile Critically Ill Patients With Sepsis: A Pilot Randomized Trial

OBJECTIVES

To test the hypothesis that forced-air warming of critically ill afebrile sepsis patients improves immune function compared to standard temperature management.

DESIGN

Single-center, prospective, open-label, randomized controlled trial.

SETTING

One thousand two hundred-bed academic medical center.

PATIENTS

Eligible patients were mechanically ventilated septic adults with: 1) a diagnosis of sepsis within 48 hours of enrollment; 2) anticipated need for mechanical ventilation of greater than 48 hours; and 3) a maximum temperature less than 38.3°C within the 24 hours prior to enrollment. Primary exclusion criteria included: immunologic diseases, immune-suppressing medications, and any existing condition sensitive to therapeutic hyperthermia (e.g., brain injury). The primary outcome was monocyte human leukocyte antigen (HLA)-DR expression, with secondary outcomes of CD3/CD28-induced interferon gamma (IFN-γ) production, mortality, and 28-day hospital-free days.

INTERVENTIONS

External warming using a forced-air warming blanket for 48 hours, with a goal temperature 1.5°C above the lowest temperature documented in the previous 24 hours.

MEASUREMENTS AND MAIN RESULTS

We enrolled 56 participants in the study. No differences were observed between the groups in HLA-DR expression (692 vs 2,002; p = 0.396) or IFN-γ production (31 vs 69; p = 0.678). Participants allocated to external warming had lower 28-day mortality (18% vs 43%; absolute risk reduction, 25%; 95% CI, 2-48%) and more 28-day hospital-free days (difference, 2.6 d; 95% CI, 0-11.6).

CONCLUSIONS

Participants randomized to external forced-air warming did not have a difference in HLA-DR expression or IFN-γ production. In this pilot study, however, 28-day mortality was lower in the intervention group. Future research should seek to better elucidate the impact of temperature modulation on immune and nonimmune organ failure pathways in sepsis.

Temperature Management in the ICU

OBJECTIVE

Temperature abnormalities are recognized as a marker of human disease, and the therapeutic value of temperature is an attractive treatment target. The objective of this synthetic review is to summarize and critically appraise evidence for active temperature management in critically ill patients.

DATA SOURCES

We searched MEDLINE for publications relevant to body temperature management (including targeted temperature management and antipyretic therapy) in cardiac arrest, acute ischemic and hemorrhagic stroke, traumatic brain injury, and sepsis. Bibliographies of included articles were also searched to identify additional relevant studies.

STUDY SELECTION

English-language systematic reviews, meta-analyses, randomized trials, observational studies, and nonhuman data were reviewed, with a focus on the most recent randomized control trial evidence.

DATA EXTRACTION

Data regarding study methodology, patient population, temperature management strategy, and clinical outcomes were qualitatively assessed.

DATA SYNTHESIS

Temperature management is common in critically ill patients, and multiple large trials have been conducted to elucidate temperature targets, management strategies, and timing. The strongest data concerning the use of therapeutic hypothermia exist in comatose survivors of cardiac arrest, and recent trials suggest that appropriate postarrest temperature targets between 33°C and 37.5°C are reasonable. Targeted temperature management in other critical illnesses, including acute stroke, traumatic brain injury, and sepsis, has not shown benefit in large clinical trials. Likewise, trials of pharmacologic antipyretic therapy have not demonstrated improved outcomes, although national guidelines do recommend treatment of fever in patients with stroke and traumatic brain injury based on observational evidence associating fever with worse outcomes.

CONCLUSIONS

Body temperature management in critically ill patients remains an appealing therapy for several illnesses, and additional studies are needed to clarify management strategies and therapeutic pathways.

An Evaluation of the Predictive Value of Sepsis Patient Evaluation in the Emergency Department (SPEED) Score in Estimating 28-Day Mortality Among Patients With Sepsis Presenting to the Emergency Department: A Prospective Observational Study

Background and objective

Sepsis is a life-threatening medical emergency and a significant cause of mortality. Risk stratification scores for sepsis can be unsuitable for use in the emergency department (ED) due to their complexity, and an appropriate solution has yet to be found. In this study, the predictive value of the Sepsis Patient Evaluation in the Emergency Department (SPEED) score in estimating 28-day mortality was assessed among patients with sepsis presenting to the ED, in order to determine its suitability as an efficient risk stratification system.

Materials and methods

This was a single-center, prospective observational study conducted at an urban tertiary care center. We included patients presenting to the ED with suspected or confirmed sepsis who met the inclusion and exclusion criteria of our study. The patients were evaluated with the following scoring systems on arrival: the SPEED score; Predisposition, Infection, Response, and Organ dysfunction (PIRO) score; and Mortality in Emergency Department Sepsis (MEDS) score; the patients were subsequently followed up on the 28th day to record the final outcomes with regard to mortality and discharge rates.

Results

This study included 127 patients in total. The median age of the study population was 49 years, and the 28-day mortality rate was 50.4%. The area under the receiver operating characteristic (AUROC) curve for the SPEED score for predicting mortality was 0.899 (95% CI: 0.847-0.951). In comparison, the AUROC for MEDS and PIRO scores was 0.857 (95% CI: 0.793-0.92) and 0.895 (95% CI: 0.838-0.951), respectively. Based on the DeLong test, no significant difference was found in the diagnostic performances with respect to these scores.

Conclusion

The SPEED score is a simple and handy parameter that can be used for the early and appropriate risk stratification of patients with sepsis in the ED.

Cost-effectiveness of the TherMax blood warmer during continuous renal replacement therapy

Hypothermia is a common adverse event during continuous renal replacement therapy (CRRT), affecting multiple organ systems and increasing risk of poor health outcomes among patients with acute kidney injury (AKI) undergoing CRRT. TheraMax blood warmers are the next generation of extracorporeal blood warmers which reduce risk of hypothermia during CRRT. The purpose of this study is to elucidate the potential health economic impacts of avoiding CRRT-induced hypothermia by using the novel TherMax blood warming device. This study compares health care costs associated with use of the new TherMax blood warmer unit integrated with the PrisMax system compared to CRRT with a standalone blood warming device to avoid hypothermia in continuous renal replacement therapy (CRRT). An economic model was developed in which relevant health states for each intervention were normothermia, hypothermia, discharge, and death. Clinical inputs and costs were obtained from a combination of retrospective chart review and publicly available summary estimates. The proportion of AKI patients treated with CRRT who became hypothermic (<36°C) during CRRT treatment was 34.5% in the TherMax group compared to 71.9% in the ‘standalone warmer’ group. Given the 78.7-year average life expectancy in the US and the assumed average patient age at discharge/death of 65.4 years, the total life-years gained by avoiding mortality related to hypothermia was 9.0 in the TherMax group compared to 8.0 in the ‘standalone warmer’ group. Cost per life-year gained was $8,615 in the TherMax group versus $10,115 in the ‘standalone warmer’ group for a difference of -$1,501 favoring TherMax. The incremental cost-effectiveness ratio was negative, indicating superior cost-effectiveness for TherMax versus ‘standalone warmer’. The TherMax blood warming device used with the PrisMax system is associated with lower risk of hypothermia, which our model indicates leads to lower costs, lower risk of mortality due to hypothermia, and superior cost-effectiveness.

Improving sepsis recognition through use of the Sepsis Trust's community screening tool

Sepsis is associated with high levels of morbidity and mortality. All healthcare professionals have a responsibility to ensure they have sufficient knowledge to effectively screen patients for signs and symptoms of sepsis. In the community setting, screening for sepsis can be challenging, due to the complexity within the patient population and difficulties associated with observation for changes in the patient's condition. The Sepsis Trust community nursing sepsis screening tool provides decision-making support to community healthcare professionals, enabling them to make a rapid assessment for risk factors for sepsis, ensuring a proportionate, consistent and appropriate response. Through implementation of a decision-support tool within the clinical setting, it is likely that patients at risk of sepsis will be identified earlier, and patients will be escalated in a more consistent manner. This process of improving consistency in practice can improve patient outcomes, including mortality, morbidity and overall patient experience.

LPS induces rapid increase in GDF15 levels in mice, rats, and humans but is not required for anorexia in mice

Growth differentiation factor 15 (GDF15), a TGFβ superfamily cytokine, acts through its receptor, cell line-derived neurotrophic factorfamily receptor α-like (GFRAL), to suppress food intake and promote nausea. GDF15 is broadly expressed at low levels but increases in states of disease such as cancer, cachexia, and sepsis. Whether GDF15 is necessary for inducing sepsis-associated anorexia and body weight loss is currently unclear. To test this we used a model of moderate systemic infection in GDF15KO and GFRALKO mice with lipopolysaccharide (LPS) treatment to define the role of GDF15 signaling in infection-mediated physiologic responses. Since physiological responses to LPS depend on housing temperature, we tested the effects of subthermoneutral and thermoneutral conditions on eliciting anorexia and inducing GDF15. Our data demonstrate a conserved LPS-mediated increase in circulating GDF15 levels in mouse, rat, and human. However, we did not detect differences in LPS-induced anorexia between WT and GDF15KO or GFRALKO mice. Furthermore, there were no differences in anorexia or circulating GDF15 levels at either thermoneutral or subthermoneutral housing conditions in LPS-treated mice. These data demonstrate that GDF15 is not necessary to drive food intake suppression in response to moderate doses of LPS.NEW & NOTEWORTHY Although many responses to LPS depend on housing temperature, the anorexic response to LPS does not. LPS results in a potent and rapid increase in circulating levels of GDF15 in mice, rats, and humans. Nevertheless, GDF15 and its receptor (GFRAL) are not required for the anorexic response to systemic LPS administration. The anorexic response to LPS likely involves a myriad of complex physiological alterations.