TY - JOUR
T1 - Serum anion gap predicts lactate poorly, but may be used to identify sepsis patients at risk for death
T2 - A cohort study
AU - Mohr, Nicholas M.
AU - Vakkalanka, J. Priyanka
AU - Faine, Brett A.
AU - Skow, Brian
AU - Harland, Karisa K.
AU - Dick-Perez, Ryan
AU - Fuller, Brian M.
AU - Ahmed, Azeemuddin
AU - Simson, Steven Q.
N1 - Funding Information:
This study was funded by the Rural Telehealth Research Center , funded by the Federal Office of Rural Health Policy, Health Resources and Services Administration , and the U.S. Department of Health and Human Services (cooperative agreement 6 U1CRH29074-01 ).
Publisher Copyright:
© 2017 Elsevier Inc.
PY - 2018/4
Y1 - 2018/4
N2 - Purpose: (1) To test whether serum bicarbonate or anion gap can be used to predict elevated lactate or mortality in emergency department (ED) patients with sepsis, and (2) to define thresholds that may predict elevated lactate and mortality. Methods: Retrospective diagnostic-validation study of adults with sepsis treated in a 60,000-visit Midwestern university ED (2010–2015). In the derivation sample, 8 experts selected thresholds based on objective measures to optimize clinical utility. Test performance was reported using likelihood ratios (LR +/−) in the validation cohort. Results: We included 4159 patients. Anion gap predicted lactate > 2 better than bicarbonate [ROC AUC 0.680 vs. 0.609], and anion gap predicted lactate > 4 better than lactate > 2 [ROC AUC 0.816 vs. 0.680]. In the validation cohort, anion gap ≥ 20 mEq/L had LR + for lactate > 2 of 3.670 (2.630–5.122), lactate > 4 of 7.019 (5.310–9.278), and mortality of 2.768 (1.922–3.986). Anion gap predicted mortality similar to lactate > 2 [LR + 2.768 vs. LR + 2.09; LR − 0.823 vs. 0.447]. Conclusions: Anion gap and serum bicarbonate poorly predict changes in lactate and mortality. In resource-limited settings where lactate is unavailable, anion gap ≥ 20 mEq/L may be used to further risk-stratify patients for ongoing sepsis care, but lactate remains a preferred biomarker.
AB - Purpose: (1) To test whether serum bicarbonate or anion gap can be used to predict elevated lactate or mortality in emergency department (ED) patients with sepsis, and (2) to define thresholds that may predict elevated lactate and mortality. Methods: Retrospective diagnostic-validation study of adults with sepsis treated in a 60,000-visit Midwestern university ED (2010–2015). In the derivation sample, 8 experts selected thresholds based on objective measures to optimize clinical utility. Test performance was reported using likelihood ratios (LR +/−) in the validation cohort. Results: We included 4159 patients. Anion gap predicted lactate > 2 better than bicarbonate [ROC AUC 0.680 vs. 0.609], and anion gap predicted lactate > 4 better than lactate > 2 [ROC AUC 0.816 vs. 0.680]. In the validation cohort, anion gap ≥ 20 mEq/L had LR + for lactate > 2 of 3.670 (2.630–5.122), lactate > 4 of 7.019 (5.310–9.278), and mortality of 2.768 (1.922–3.986). Anion gap predicted mortality similar to lactate > 2 [LR + 2.768 vs. LR + 2.09; LR − 0.823 vs. 0.447]. Conclusions: Anion gap and serum bicarbonate poorly predict changes in lactate and mortality. In resource-limited settings where lactate is unavailable, anion gap ≥ 20 mEq/L may be used to further risk-stratify patients for ongoing sepsis care, but lactate remains a preferred biomarker.
KW - Diagnostic tests, routine
KW - Emergency Department
KW - Hospitals, rural
KW - Lactic acid
KW - Sepsis
UR - http://www.scopus.com/inward/record.url?scp=85042486834&partnerID=8YFLogxK
U2 - 10.1016/j.jcrc.2017.10.043
DO - 10.1016/j.jcrc.2017.10.043
M3 - Article
C2 - 29175046
AN - SCOPUS:85042486834
SN - 0883-9441
VL - 44
SP - 223
EP - 228
JO - Journal of Critical Care
JF - Journal of Critical Care
ER -