Has mortality from sepsis improved and what to expect from new treatment modalities: review of current insights

Long-Term Survival of Young Patients Surviving ICU Admission With Severe Sepsis

OBJECTIVES

Sepsis remains a disease with a high mortality rate. The study goal was to assess long-term survival of severe sepsis in young patients.

DESIGN

Retrospective cohort study.

SETTING

Patients admitted with sepsis to ICUs in seven tertiary hospitals between 2003 and 2011.

PATIENTS

A total of 409 patients less than 45 years who survived to hospital discharge were age and sex matched with 818 patients with infectious disease without sepsis selected from internal medicine or surgical department admissions.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The median age in sepsis patients and the comparison group was 31 and 32 years, respectively. The proportions of patients surviving after hospital discharge were significantly lower in the sepsis group compared with the control group; among survivors, 6-month, 1-year, and 3-year mortality rates were 0.7% versus 0%, 4.5% versus 0.7%, 7.9% versus 1.2%, and 10.8% versus 1.8%, respectively (p < 0.001 for all). In a multivariate Cox proportional hazards regression model, sepsis was associated with an increased risk of mortality (hazard ratio, 3.79; 95% CI, 2.27-6.32), while controlling for age, Charlson Comorbidity Index, history of stroke, and congestive heart failure. Past the 24-month landmark, sepsis was not found to be an independent risk for mortality (hazard ratio, 1.79; 95% CI, 0.67-4.79). Based on cause of death analysis, chronic underlying comorbidities might explain the excess mortality in patients with sepsis.

CONCLUSIONS

Young patients experiencing an episode of severe sepsis continue to be at higher risk of long-term mortality. The highest mortality rates were observed during the first 24 months following discharge.

A novel role for coinhibitory receptors/checkpoint proteins in the immunopathology of sepsis

Coinhibitory molecules, such as PD-1, CTLA-4, 2B4, and BTLA, are an important new family of mediators in the pathophysiology of severe bacterial and/or fungal infection, as well as the combined insults of shock and sepsis. Further, the expression of these molecules may serve as indicators of the immune status of the septic individual. Using PD-1:PD-L as an example, we discuss in this review how such checkpoint molecules may affect the host response to infection by mediating the balance between effective immune defense and immune-mediated tissue injury. Additionally, we explore how the up-regulation of PD-1 and/or PD-L1 expression on not only adaptive immune cells (e.g., T cells), but also on innate immune cells (e.g., macrophages, monocytes, and neutrophils), as well as nonimmune cells during sepsis and/or shock contributes to functional alterations often with detrimental sequelae.

Checklists and crisis management in surgical emergencies

Using checklists to improve clinical outcomes

Physical therapist-established intensive care unit early mobilization program: quality improvement project for critical care at the University of California San Francisco Medical Center

BACKGROUND

Long-term weakness and disability are common after an intensive care unit (ICU) stay. Usual care in the ICU prevents most patients from receiving preventative early mobilization.

OBJECTIVE

The study objective was to describe a quality improvement project established by a physical therapist at the University of California San Francisco Medical Center from 2009 to 2011. The goal of the program was to reduce patients' ICU length of stay by increasing the number of patients in the ICU receiving physical therapy and decreasing the time from ICU admission to physical therapy initiation.

DESIGN

This study was a 9-month retrospective analysis of a quality improvement project.

METHODS

An interprofessional ICU Early Mobilization Group established and promoted guidelines for mobilizing patients in the ICU. A physical therapist was dedicated to a 16-bed medical-surgical ICU to provide physical therapy to selected patients within 48 hours of ICU admission. Patients receiving early physical therapy intervention in the ICU in 2010 were compared with patients receiving physical therapy under usual care practice in the same ICU in 2009.

RESULTS

From 2009 to 2010, the number of patients receiving physical therapy in the ICU increased from 179 to 294. The median times (interquartile ranges) from ICU admission to physical therapy evaluation were 3 days (9 days) in 2009 and 1 day (2 days) in 2010. The ICU length of stay decreased by 2 days, on average, and the percentage of ambulatory patients discharged to home increased from 55% to 77%.

LIMITATIONS

This study relied upon the retrospective analysis of data from 6 collectors, and the intervention lacked physical therapy coverage for 7 days per week.

CONCLUSIONS

The improvements in outcomes demonstrated the value and feasibility of a physical therapist-led early mobilization program.

Altered Immune Responses during Septicaemia in Patients Suffering from Haematological Malignancies

Septicaemia is a frequent complication in patients with haematological malignancies. In this study we analysed markers of inflammation/immune activation (C- reactive protein, interleukin-6, neopterin), tryptophan metabolites and mannose binding lectin (MBL) levels consecutively in 36 septic patients with haematological malignancies (HM) and “non-haematological” diseases [intensive care unit (ICU) patients]. During septicaemia different chronological sequences for inflammation markers CRP, IL-6 and neopterin were seen in HM and ICU patients. Septic ICU-patients presented with significantly increased tryptophan degradation and higher neopterin and CRP levels at baseline, while MBL levels were lower in this group compared to subjects with HM. Concentrations of inflammation markers Were linked to each other and associated with enhanced tryptophan degradation. Patients who died during follow-up of 28 days tended to have lower baseline MBL concentrations than survivors. Septic patients with HM showed an impaired pro-inflammatory immune response compared to patients with non-haematological diseases.

T-cell activation differentially mediates the host response to sepsis

Survival during sepsis requires both swift control of infectious organisms and tight regulation of the associated inflammatory response. As the role of T cells in sepsis is somewhat controversial, we examined the impact of increasing antigen-dependent activation of CD4 T cells in a murine model of cecal ligation and puncture using T-cell receptor transgenic II (OT-II) mice that are specific for chicken ovalbumin (OVA) in the context of major histocompatibility complex II. Here, we injected OT-II mice with 0, 1, or 100 μg of OVA and demonstrate that increased antigen treatment resulted in increased numbers of activated splenic CD4 T cells. Vehicle-treated, septic OT-II mice had decreased survival, increased bacterial load, and increased levels of IL-6. Interestingly, this decrease in survival was abrogated when OT-II mice were injected with 1 μg OVA, which was correlated with normalized bacterial load and levels of IL-6. However, when OT-II mice were injected with 100 μg OVA, decreased survival was restored but, in contrast to vehicle-treated OT-II mice, had decreased bacterial load and enhanced IL-6 levels. We also observed that neutrophil oxidative burst and phagocytosis were dependent on CD4 T-cell activation. Further, at extreme levels of T-cell activation, intestinal permeability was significantly increased. Altogether, we conclude that too little CD4 T-cell activation produces dysfunctional neutrophils leading to decreased bacteria clearance and survival, whereas too much CD4 T-cell activation produces a neutrophil phenotype that leads to efficient bacterial clearance but with increased tissue damage and mortality.

The protein C pathway in tissue inflammation and injury: pathogenic role and therapeutic implications

Inflammation and coagulation are closely linked interdependent processes. Under physiologic conditions, the tissue microcirculation functions in anticoagulant and anti-inflammatory fashions. However, when inflammation occurs, coagulation is also set in motion and actively participates in enhancing inflammation. Recently, novel and unexpected roles of hemostasis in the humoral and cellular components of innate immunity have been described. In particular, the protein C system, besides its well-recognized role in anticoagulation, plays a crucial role in inflammation. Indeed, the protein C system is now emerging as a novel participant in the pathogenesis of acute and chronic inflammatory diseases, such as sepsis, asthma, inflammatory bowel disease, atherosclerosis, and lung and heart inflammation, and may emerge as unexpected therapeutic targets for intervention.

The protein C pathway in tissue inflammation and injury: pathogenic role and therapeutic implications

Inflammation and coagulation are closely linked interdependent processes. Under physiologic conditions, the tissue microcirculation functions in anticoagulant and anti-inflammatory fashions. However, when inflammation occurs, coagulation is also set in motion and actively participates in enhancing inflammation. Recently, novel and unexpected roles of hemostasis in the humoral and cellular components of innate immunity have been described. In particular, the protein C system, besides its well-recognized role in anticoagulation, plays a crucial role in inflammation. Indeed, the protein C system is now emerging as a novel participant in the pathogenesis of acute and chronic inflammatory diseases, such as sepsis, asthma, inflammatory bowel disease, atherosclerosis, and lung and heart inflammation, and may emerge as unexpected therapeutic targets for intervention.