The intensive care medicine research agenda on septic shock

Expert statement for the management of hypovolemia in sepsis

Hypovolemia is frequent in patients with sepsis and may contribute to worse outcome. The management of these patients is impeded by the low quality of the evidence for many of the specific components of the care. In this paper, we discuss recent advances and controversies in this field and give expert statements for the management of hypovolemia in patients with sepsis including triggers and targets for fluid therapy and volumes and types of fluid to be given. Finally, we point to unanswered questions and suggest a roadmap for future research.

Outcomes of Surgical Sepsis

BACKGROUND

Discussion of outcomes of surgical sepsis is no longer straightforward. Definitions of sepsis have changed recently and updated data are scant. Surgical patient populations are often heterogeneous; the patient population being considered must be described with precision. Traditional 30-d operative mortality may not be the most relevant outcome to consider. What should change or be the emphasis going forward?

METHODS

Review and synthesis of pertinent English-language literature.

RESULTS

Epidemiologic data are abundant for short-term outcomes of sepsis in general, but despite the fact that approximately 30% of patients with sepsis are surgical patients, sepsis outcome data for surgical patients are scant, especially for durations longer than 30 d, and essentially non-existent for patients defined under the new Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3) criteria. Interpretability of extant data is hampered by non-standard and changing definitions.

CONCLUSIONS

Sepsis and organ dysfunction may be decreasing in prevalence and magnitude among surgical patients, but terminology must be standardized to enhance the interpretability of data generated in the future. It behooves journal editors, reviewers, and authors to insist upon standardized definitions and rigorous study design and data interpretation. Longer term data (e.g., 90-d mortality as opposed to in-hospital or traditional 30-d mortality) will be needed to justify to payers the complex, expensive care that these patients require. There is an urgent need to redefine the research agenda for surgical infections.

Advances in the understanding and treatment of sepsis-induced immunosuppression

Sepsis is defined as a life-threatening organ dysfunction that is caused by a dysregulated host response to infection. Sepsis can induce acute kidney injury and multiple organ failures and represents the most common cause of death in the intensive care unit. Sepsis initiates a complex immune response that varies over time, with the concomitant occurrence of both pro-inflammatory and anti-inflammatory mechanisms. As a result, most patients with sepsis rapidly display signs of profound immunosuppression, which is associated with deleterious consequences. Scientific advances have highlighted the role of metabolic failure, epigenetic reprogramming, myeloid-derived suppressor cells, immature suppressive neutrophils and immune alterations in primary lymphoid organs (the thymus and bone marrow) in sepsis. An improved understanding of the mechanisms underlying this immunosuppression as well as of the similarities between sepsis-induced immunosuppression and immune defects in cancer or immunosenescence has led to novel therapeutic strategies aimed at stimulating immune function in patients with sepsis. Trials assessing the therapeutic benefit of IL-7, granulocyte-macrophage colony-stimulating factor (GM-CSF) and antibodies against programmed cell death protein 1 (PD1) and programmed cell death 1 ligand 1 (PDL1) for the treatment of sepsis are in progress. The reappraisal of sepsis pathophysiology has also resulted in a novel approach to the design of clinical trials evaluating sepsis treatments, based on an evaluation of the immune status and biomarker-based stratification of patients.