Mortality in CAP Following Sepsis Clinical Criteria Update

Data published in the American Journal of Respiratory Critical Care Medicine¹ evaluating predictive tools to assess risks in community-acquired pneumonia (CAP) with life-threatening sepsis found that the quick Sepsis-Related Organ Failure Assessment (qSOFA) clinical tool was superior to systemic inflammatory response syndrome (SIRS) criteria for the evaluation of in-hospital mortality.

The joint investigation from Spain and South America retrospectively reviewed a cohort of 6874 patients with CAP from 2 university hospitals in Barcelona, Spain (n=6304; patients admitted between 199 and -2015) and Valencia, Spain (n=570; patients admitted between 2012 and 2015). Mean patient age  was 66±19; 62.2% were men. The majority of the cohort (74.9%) was admitted to the hospital ward, 13.8% were admitted to the intensive care unit (ICU)/high dependency unit (HCU), and 11.3% were discharged following a short stay. The in-hospital mortality rate was 6.4% and 30-day mortality was 7.5%.

In 2016, the Sepsis-3 Task Force developed a new definition of sepsis designed to change clinical decision-making by clarifying clinical differences between sepsis and uncomplicated infections.² The new definition required an increase in SOFA scores of ≥2 points to positively identify sepsis, and eliminated the need for SIRS criteria, which did not provide any additional benefits over clinical judgment or decision making.

The investigators evaluated the clinical utility of a proposed qSOFA tool for bedside risk stratification with values for hypotension, altered mental status, and tachypnea added to the main score, along with other predictive measurement tools. Two of these included the Confusion, Urea, Respiratory rate, Blood pressure and Age (CURB-65) score and the Pneumonia Severity Index (PSI), both of which have been previously validated to support CAP management decisions and predict outcomes.^3,4 Validated, simplified versions of the CURB-65 (CRB-65, CRB) do not require blood tests, although the investigators noted that definitions used by the CRB for hypotension and tachypnea are different than those used in the qSOFA.

Overall, SIRS was the least discriminating, while CRB was slightly superior to qSOFA in discrimination and calibration of in-hospital mortality; similar clinical usefulness was demonstrated across multiple decision-making situations. Modified SOFA (mSOFA) and PSI were most predictive and afforded the greatest benefit in comprehensive assessment of CAP. mSOFA was deemed more suitable for decisions involving admission to the ICU, while PSI had the best decision-aid tool profile.

Study Limitations

• Researchers analyzed only 1 type of infection from 2 institutions, limiting the generalizability of results.
• Misclassification and selection bias may have occurred, despite collecting data prospectively and from consecutive patients.
• SOFA score could not be fully calculated for cardiovascular and neurologic parameters, which may have limited SOFA performance.
• No differentiation was made between acute and chronic organ dysfunction.
• Clinical judgement was not incorporated into models, which may “ultimately improve the performance of the Sepsis-3 flowchart.”

References

1. Ranzani OT, Prina E, Menéndez R, et al. New sepsis definition (Sepsis-3) and community-acquired pneumonia mortality: a validation and clinical decision-making study [published online June 14, 2017]. Am J Respir Crit Care Med. doi:10.1164/rccm.201611-2262OC
2. Bauer TT, Ewig S, Marre R, Suttorp N, Welte T, Group CS. CRB-65 predicts death from community-acquired pneumonia. J Intern Med 2006;260(1):93-101. doi:10.1111/j.1365-2796.2006.01657.X
3. Raith EP, Udy AA, Bailey M, et al; for the Australian and New Zealand Intensive Care Society (ANZICS) Center for Outcomes and Resource Evaluation (CORE). Prognostic accuracy of the SOFA score, SIRS criteria, and qSOFA score for in-hospital mortality among adults with suspected infection admitted to the intensive care unit. JAMA 2017;317(3):290-300. doi:10.1001/jama.2016.20328
4. Fine MJ, Auble TE, Yealy DM, et al. A prediction rule to identify low-risk patients with community-acquired pneumonia. N Engl J Med 1997;336(4):243-250. doi:10.1056/JENM199701233360402