AT THE CRITICAL CARE CONGRESS
ORLANDO (FRONTLINE MEDICAL NEWS) – New consensus definitions for sepsis and septic shock focus on host dysregulation in the face of infection, propose a three-item quick-scoring option for bedside assessment, and introduce serum lactate as an important marker of cellular metabolic stress in identifying septic shock.
Sepsis is now defined as “life-threatening organ dysfunction caused by a dysregulated host response to infection,” according to a 19-member task force convened jointly by the U.S. Society for Critical Care Medicine (SCCM) and the European Society of Intensive Care Medicine (ESICM) (JAMA. 2016;315:801-10. doi: 10.1001/jama.2016.0287 ).
Since sepsis itself is inherently a life-threatening diagnosis, the term “severe sepsis” is redundant and should be eliminated, according to Dr. Mervyn Singer and his fellow task force members and coauthors. Together with his coauthors, Dr. Singer, professor of intensive care medicine at University College London, also recommended moving away from an “excessive focus on inflammation” and “the misleading model that sepsis follows a continuum through severe sepsis to shock.”
Systemic inflammatory response syndrome (SIRS) is a serious manifestation of an appropriate host response to infection, rather than the dysregulated host response that characterizes sepsis. So although it’s no longer included in sepsis criteria. “We are not discounting SIRS,” Dr. Singer said in a presentation at the Critical Care Congress, sponsored by the Society for Critical Care Medicine. The consensus statement was released and the presentation was made simultaneously.
Organ dysfunction, for the purposes of the revised definition, is defined as a 2 or more point increase in the Sequential [Sepsis-related] Organ Failure Assessment (SOFA) score. This increase is associated with a 10% or more rise in mortality while in hospital. Task force members, after review, recommended standardizing sepsis assessment with the SOFA score.
The criteria require an increase of 2 or more points on the SOFA score because many patients suspected of sepsis will have comorbidities that will “earn” them SOFA points at baseline, said Dr. Singer.
Operationalizing the sepsis definition through SOFA made sense, said Dr. Singer, because the set of five laboratory measures and one clinician-administered scale – the Glasgow Coma Scale (GCS) – are already likely to be part of daily assessments for a seriously ill hospitalized adult.
Septic shock, as defined by the task force, is associated with in-hospital mortality of over 40%. Septic shock is now defined as “a subset of sepsis in which particularly profound circulatory, cellular, and metabolic abnormalities are associated with a greater risk of mortality than with sepsis alone.” Clinically, patients have septic shock if they require a vasopressor to maintain a mean arterial pressure of 65 mm Hg or greater, and have a serum lactate level greater than 18 mg/dL (2 mmol/L) without hypovolemia.
The definitions introduce an abbreviated bedside sepsis identification tool termed quickSOFA (qSOFA). For adults suspected of infection, qSOFA requires two of the three clinical criteria of respiratory rate of 22 breaths/min or greater, altered mentation, or systolic blood pressure of 100 mm Hg or less. “This model was robust to multiple sensitivity analyses,” wrote Dr. Singer and his coauthors, and worked well in out-of-hospital, emergency department, and ward settings both within and outside of the United States. “We are encouraging prospective validation in different health care settings,” for example, in resource-poor environments, said Dr. Singer.
The extensive review process included a large meta-analysis and systematic review of observational studies of adults with sepsis to evaluate diagnostic systems and criteria currently in use. The results of the review were used to inform the task force’s Delphi study, which then led to cohort studies to test the proposed variables, through the Surviving Sepsis Campaign. A comprehensive description of the work of the task force was published concurrently with the new sepsis and septic shock definitions (JAMA. 2016;315:775-87. doi: 10.1001/jama.2016.0289 ).
“We had what I call a soft launch” of the new definitions, said Dr. Singer. The definitions and criteria have been available for review and discussion for about a year, and discussions in the public forum are already shaping thoughts about the way forward. “We expect lots and lots of discussion,” said Dr. Singer.
Limitations of the new definitions were enumerated by Dr. Singer and his coauthors, and also brought forward in an accompanying editorial by Dr. Edward Abraham, dean of the Wake Forest School of Medicine, Winston-Salem, N.C. These include that sepsis is not defined for children, that the reliance on serum lactate levels may not be feasible in resource-poor environments, and that there are limitations to the datasets used to generate the new guidelines.
The guidelines also offer suggested International Classification of Diseases-9 (ICD-9) and ICD-10 codes for sepsis and septic shock, in the hope that “greater clarity and consistency will also facilitate research and more accurate coding,” wrote Dr. Singer and his coauthors.
Multiple task force members reported relationships with pharmaceutical companies. The work of the task force was supported in part by grants from SCCM and ESICM.
The guidelines and accompanying information are available at www.sccm.org/sepsisredefined .
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