Long term mortality following sepsis

Prognostic factors for late death in septic shock survivors: a multi-center, prospective, registry-based observational study

Septic shock patients who survive past the acute period are associated with an increased risk of long-term mortality. However, factors for predicting late death remain unclear. We aimed to investigate the prognostic factors associated with late mortality in septic shock patients with 28-day survival after admission. This retrospective observational study used a prospective, multi-center registry of septic shock patients between October 2015 and December 2019 involving 12 emergency departments (EDs) from the Korean Shock Society. Adult septic shock patients visiting the ED with 28-day survival after admission were included. Among 4624 septic shock patients, 3588 (77.6%) who survived past day 28 were analyzed. The 90-day mortality rate was 14.2%. Non-survivors were older (66.8 vs. 68.9 years; p = 0.032) and had higher lactate levels (3.7 vs. 4.0 mmol/L; p = 0.028) than survivors. Pulmonary and hepatobiliary infections and a history of malignancy (27.7 vs. 57.5%; p < 0.001) were more frequent in the non-survivor group than in the survivor group. Independent risk factors for late death on multivariate regression analysis were age; malignancy; and hemoglobin, blood urea nitrogen, and albumin levels. The length of intensive care unit stay and Sequential Organ Failure Assessment score were independently associated with late death. Approximately, one-seventh of septic shock patients who survived past day 28 of admission died by day 90. Physicians must pay attention to survivors with these risk factors during the post-acute period as they have an increased mortality risk.

Sepsis-Associated Mortality, Resource Use, and Healthcare Costs: A Propensity-Matched Cohort Study

OBJECTIVES

To examine long-term mortality, resource utilization, and healthcare costs in sepsis patients compared to hospitalized nonsepsis controls.

DESIGN

Propensity-matched population-based cohort study using administrative data.

SETTING

Ontario, Canada.

PATIENTS

We identified a cohort of adults (≥ 18) admitted to hospitals in Ontario between April 1, 2012, and March 31, 2016, with follow-up to March 31, 2017. Sepsis patients were flagged using a validated International Classification of Diseases, 10th Revision-coded algorithm (Sepsis-2 definition), including cases with organ dysfunction (severe sepsis) and without (nonsevere). Remaining hospitalized patients were potential controls. Cases and controls were matched 1:1 on propensity score, age, sex, admission type, and admission date.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Differences in mortality, rehospitalization, hospital length of stay, and healthcare costs were estimated, adjusting for remaining confounders using Cox regression and generalized estimating equations. Of 270,669 sepsis cases, 196,922 (73%) were successfully matched: 64,204 had severe and 132,718 nonsevere sepsis (infection without organ dysfunction). Over follow-up (median 2.0 yr), severe sepsis patients had higher mortality rates than controls (hazard ratio, 1.66; 95% CI, 1.63-1.68). Both severe and nonsevere sepsis patients had higher rehospitalization rates than controls (hazard ratio, 1.53; 95% CI, 1.50-1.55 and hazard ratio, 1.41; 95% CI, 1.40-1.43, respectively). Incremental costs (Canadian dollar 2018) in sepsis cases versus controls at 1-year were: $29,238 (95% CI, $28,568-$29,913) for severe and $9,475 (95% CI, $9,150-$9,727) for nonsevere sepsis.

CONCLUSIONS

Severe sepsis was associated with substantially higher long-term risk of death, rehospitalization, and healthcare costs, highlighting the need for effective postdischarge care for sepsis survivors.

Red Ginseng Reduces Inflammatory Response via Suppression MAPK/P38 Signaling and p65 Nuclear Proteins Translocation in Rats and Raw 264.7 Macrophage

Lipopolysaccharides (LPS) cause systemic inflammatory responses, which are characterized by high mortality and multiple signs, including metabolic disturbances, respiratory acidosis, hypotension, and vital organs disorder. Cytokines secretion and oxidative stress are the main features of the disease. Diagnosis and treatment of systemic inflammation (SI) remain a challenge. Korean Red Ginseng (RG) is one of medicinal herbs that showed a potent anti-oxidant effect. We aimed to study the protective effects of RG on systemic inflammatory response in rats and RAW 264.7 macrophage cells induced by LPS. The rats were treated with water and alcohol extracts of RG for four weeks to prevent the inflammatory response. The result showed that LPS toxin increased morbidity and mortality, and induced liver, kidney, and lung injuries manifested by deteriorated biomarkers. Hypotension, hypomagnesemia, acidosis, and oxidative stress were observed in septic rats. However, RG extracts attenuated liver, kidney, and lung enzymes and metabolites in treated groups via its anti-inflammatory and anti-oxidant properties. Furthermore, RG improved magnesium and blood pressure in the treated groups. RAW 264.7 macrophage cells exposed to LPS disturbance in translocation of p65 and MAPK/p38. Nevertheless, RG-pretreated cells did not significantly alter. In conclusion, RG reduced the rates of mortality and morbidity of treated rats - liver, kidney, and lung injuries were protected in the treated groups through the potentiation of anti-oxidant defense. RG was able to conserve mitochondrial function, inhibiting the activation of MAPK/p38 signaling and suppressing NF-κB p65 cytoplasm-nucleus transport. Further studies are needed to examine the effects on chronic conditions in animal models and human.

Sepsis-Induced State of Immunoparalysis Is Defined by Diminished CD8 T Cell-Mediated Antitumor Immunity

Patients who survive sepsis experience long-term immunoparalysis characterized by numerical and/or functional lesions in innate and adaptive immunity that increase the host's susceptibility to secondary complications. The extent to which tumor development/growth is affected in sepsis survivors remains unknown. In this study, we show cecal ligation and puncture (CLP) surgery renders mice permissive to increased B16 melanoma growth weeks/months after sepsis induction. CD8 T cells provide partial protection in this model, and tumors from sepsis survivors had a reduced frequency of CD8 tumor-infiltrating lymphocytes (TILs) concomitant with an increased tumor burden. Interestingly, the postseptic environment reduced the number of CD8 TILs with high expression of activating/inhibitory receptors PD-1 and LAG-3 (denoted PD-1^hi) that define a tumor-specific CD8 T cell subset that retain some functional capacity. Direct ex vivo analysis of CD8 TILs from CLP hosts showed decreased proliferation, IFN-γ production, and survival compared with sham counterparts. To increase the frequency and/or functional capacity of PD-1^hi CD8 TILs in tumor-bearing sepsis survivors, checkpoint blockade therapy using anti-PD-L1/anti-LAG-3 mAb was administered before or after the development of sepsis-induced lesions in CD8 TILs. Checkpoint blockade did not reduce tumor growth in CLP hosts when therapy was administered after PD-1^hi CD8 TILs had become reduced in frequency and/or function. However, early therapeutic intervention before lesions were observed significantly reduced tumor growth to levels seen in nonseptic hosts receiving therapy. Thus, sepsis-induced immunoparalysis is defined by diminished CD8 T cell-mediated antitumor immunity that can respond to timely checkpoint blockade, further emphasizing the importance of early cancer detection in hosts that survive sepsis.

Ghrelin regulates sepsis‑induced rat acute gastric injury

Ghrelin, a peptide expressed in the gastric mucosa, has an essential role in sustaining the normal function of the digestive system. Sepsis is one of the primary causes of mortality in intensive care units and can lead to multiple organ dysfunction, especially in the gastrointestinal system. The aim of the present study was to explore the effect of ghrelin on gastric blood flow in a rat model of sepsis, as well as the effect of ghrelin on the expression of the apoptotic markers, B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X (Bax), in gastric tissues. The sepsis model was established using cecal ligation and puncture (CLP). The expression levels of apoptosis-related factors in gastric epithelial cell were determined by immunohistochemistry, reverse transcription quantitative-PCR and western blotting. Collectively, the present results suggested that ghrelin administration attenuated sepsis symptoms induced by CLP. Blood flow in the stomach greater curvature was significantly higher in the CLP-induced sepsis group rats (284.3±95.7 perfusion units) compared with the sham operation group (317.8±5.2 perfusion units; P<0.05), whereas there was no difference between the CLP group treated with ghrelin (377.8±99.0 perfusion units) and the sham rats. Ghrelin administration also reduced the secretion of pro-inflammatory cytokines compared with the CLP-induced sepsis group rats. In addition, CLP significantly reduced the expression of Bcl-2 and enhanced the expression of the pro-apoptotic proteins, Bax and cleaved caspase-3; whereas, ghrelin application reversed the effects of CLP on these apoptosis-associated proteins. In conclusion, the present study revealed that ghrelin has the ability to increase blood flow in the gastrointestinal tract in a sepsis model and can also regulate the expressions of apoptosis-associated factors in gastric tissues. These results suggest that ghrelin could be a novel treatment for sepsis-induced gastric injury.

How Clinical Flow Cytometry Rebooted Sepsis Immunology

On May 2017, the World Health Organization (WHO) recognized sepsis as a global health priority by adopting a resolution to improve the prevention, diagnosis, and management of this deadly disease. While it has long been known that sepsis deeply perturbs immune homeostasis by inducing a tremendous systemic inflammatory response, pivotal observations based on clinical flow cytometry indicate that sepsis indeed initiates a more complex immune response that varies over time, with the concomitant occurrence of both pro- and anti-inflammatory mechanisms. As a resultant, some septic patients enter a stage of protracted immunosuppression. This paved the way for immunostimulation approaches in sepsis. Clinical flow cytometry permitted this evolution by drawing a new picture of pathophysiology and reshaping immune trajectories in patients. Additional information from cytometry by time of flight mass cytometry and other high-dimensional flow cytometry platform should rapidly enrich our understanding of this complex disease. This review reports on landmarks of clinical flow cytometry in sepsis and how this single-cell analysis technique permitted to breach the wall of decades of unfruitful anti-inflammatory-based clinical trials in sepsis. © 2019 International Society for Advancement of Cytometry.

Constitutive Vagus Nerve Activation Modulates Immune Suppression in Sepsis Survivors

Patients surviving a septic episode exhibit persistent immune impairment and increased mortality due to enhanced vulnerability to infections. In the present study, using the cecal ligation and puncture (CLP) model of polymicrobial sepsis, we addressed the hypothesis that altered vagus nerve activity contributes to immune impairment in sepsis survivors. CLP-surviving mice exhibited less TNFα in serum following administration of LPS, a surrogate for an infectious challenge, than control-operated (control) mice. To evaluate the role of the vagus nerve in the diminished response to LPS, mice were subjected to bilateral subdiaphragmatic vagotomy at 2 weeks post-CLP. CLP-surviving vagotomized mice exhibited increased serum and tissue TNFα levels in response to LPS-challenge compared to CLP-surviving, non-vagotomized mice. Moreover, vagus nerve stimulation in control mice diminished the LPS-induced TNFα responses while having no effect in CLP mice, suggesting constitutive activation of vagus nerve signaling in CLP-survivors. The percentage of splenic CD4⁺ ChAT-EGFP⁺ T cells that relay vagus signals to macrophages was increased in CLP-survivors compared to control mice, and vagotomy in CLP-survivors resulted in a reduced percentage of ChAT-EGFP⁺ cells. Moreover, CD4 knockout CLP-surviving mice exhibited an enhanced LPS-induced TNFα response compared to wild-type mice, supporting a functional role for CD4⁺ ChAT⁺ T cells in mediating inhibition of LPS-induced TNFα responses in CLP-survivors. Blockade of the cholinergic anti-inflammatory pathway with methyllcaconitine, an α7 nicotinic acetylcholine receptor antagonist, restored LPS-induced TNFα responses in CLP-survivors. Our study demonstrates that the vagus nerve is constitutively active in CLP-survivors and contributes to the immune impairment.