///2016 Abstract Details
2016 Abstract Details2019-07-15T10:10:51-05:00

Risk Factors and Systemic Inflammatory Response Syndrome (SIRS) Criteria for Severe Sepsis in Pregnant Women: A Multicenter Case-control Study

Abstract Number: O1-03
Abstract Type: Original Research

Melissa E Bauer D.O.1 ; Michelle Housey MPH2; Brian Bateman MD, MSc3

Background: Sepsis is an increasingly important source of maternal morbidity and mortality. The most recent estimates suggest that sepsis accounts for approximately 25% of all maternal deaths in the United Kingdom and 13.6% in the United States.(1,2) Early identification and prompt treatment of patients with sepsis have been shown to improve outcomes. However, diagnosing sepsis during pregnancy can be challenging as many parturients meet SIRS criteria due to physiologic changes of pregnancy alone.(3) This multicenter case-control study aims to define revised SIRS criteria for use in pregnancy and to evaluate risk factors for severe sepsis.

Methods: Validated severe maternal sepsis cases from 1995 to 2012 were retrospectively identified at seven academic medical centers in the US and Israel. Control patients were identified and matched by date of delivery with date of severe sepsis diagnosis cases in a 1:4 ratio. Data including potential risk factors, vital signs, and white blood cell (WBC) values were collected for cases and controls. Univariate analysis estimated the association between potential risk factors and severe sepsis. Additionally, the diagnostic sensitivity and specificity for identifying cases of severe sepsis using different thresholds of abnormal vital signs and laboratory values were evaluated.

Results: Eighty-two cases of severe sepsis and 328 controls were identified. Risk factors identified in the study included PROM>24 hours to labor (OR 8.9, 95% CI 2.5 to 39.4), retained products of conception (OR 12.9, 95% CI 2.4 to 128.1), preterm delivery (OR 6.1, 95% CI 2.4 to 16.8), multiple gestation (OR 5.7, 95% CI 1.8 to 19.5), BMI≥40 (OR 3.7, 95% CI 1.4 to 9.6), cesarean delivery during labor (OR 20.9, 95% CI 5.1 to 128.3), cesarean delivery not in labor (OR 15.6, 95% CI 4.2 to 87.2), nulliparity (OR 1.8, 95% CI 1.1 to 3.1), and recent smoking history (OR 2.7, 95% CI 1.2 to 5.8).

Current SIRS criteria have the following (sensitivity, specificity): heart rate (HR)>90 (0.96, 0.45), respiratory rate (RR)>20 (0.62, 0.90), WBC<4 x10^9/L or WBC>12 x10^9/L (0.75, 0.59), temperature (T) <36°C or T >38°C (0.69, 0.71). Using more extreme thresholds for defining aberrant vital signs improved specificity but decreased sensitivity: HR≥110 (0.82, 0.82), RR≥25 (0.42, 0.99), WBC<4 x10^9/L or WBC≥20 x10^9/L (0.37, 0.97), T ≤35.5°C or T ≥38.5°C (0.44, 0.91).

Conclusions: Clinicians need to be alert to the potential for severe sepsis in parturients, particularly in those having risk factors for this complication. While the specificity is improved when higher thresholds for aberrant vital signs are used, the sensitivity is decreased. The use of criteria with higher screening thresholds is therefore not recommended due to increased false negatives in parturients with sepsis.

1) Knight et al, University of Oxford 2014

2) Creanga et al, Obstet Gynecol 2015

3) Bauer et al, Obstet Gynecol 2014

SOAP 2016