Background: Stratification of the severity of infection is currently based on the Sequential Organ Failure Assessment (SOFA) score, which is difficult to calculate outside the ICU. Biomarkers could help to stratify the severity of infection in surgical patients.Methods: Levels of ten biomarkers indicating endothelial dysfunction, 22 indicating emergency granulopoiesis, and six denoting neutrophil degranulation were compared in three groups of patients in the first 12 h after diagnosis at three Spanish hospitals.Results: There were 100 patients with infection, 95 with sepsis and 57 with septic shock. Seven biomarkers indicating endothelial dysfunction (mid-regional proadrenomedullin (MR-ProADM), syndecan 1, thrombomodulin, angiopoietin 2, endothelial cell-specific molecule 1, vascular cell adhesion molecule 1 and E-selectin) had stronger associations with sepsis than infection alone. MR-ProADM had the highest odds ratio (OR) in multivariable analysis (OR 11⋅53, 95 per cent c.i. 4⋅15 to 32⋅08; P = 0⋅006) and the best area under the curve (AUC) for detecting sepsis (0⋅86, 95 per cent c.i. 0⋅80 to 0⋅91; P < 0⋅001). In a comparison of sepsis with septic shock, two biomarkers of neutrophil degranulation, proteinase 3 (OR 8⋅09, 1⋅34 to 48⋅91; P = 0⋅028) and lipocalin 2 (OR 6⋅62, 2⋅47 to 17⋅77; P = 0⋅002), had the strongest association with septic shock, but lipocalin 2 exhibited the highest AUC (0⋅81, 0⋅73 to 0⋅90; P < 0⋅001).
Conclusion: MR-ProADM and lipocalin 2 could be alternatives to the SOFA score in the detection of sepsis and septic shock respectively in surgical patients with infection.
Healthy control Infection Sepsis Septic shockBiomarkers of a,b emergency granulopoiesis and c acute-phase response. Levels of C-reactive protein (CRP) are in mg/l, those of procalcitonin (PCT) are in ng/ml, and those of the remaining biomarkers are copies of cDNA per ng mRNA. MMP, matrix metalloproteinase; LTF, lactoferrin; PRTN, proteinase; LCN, lipocalin, OLFM, olfactomedin; ELANE, elastase, neutrophil expressed; MPO, myeloperoxidase; CTSG, cathepsin G; AZU, azurocidin; BPI, bactericidal/permeability-increasing protein; DEFA, defensin α; CEACAM, carcinoembryonic antigen-related cell adhesion molecule; CD, cluster of differentiation; TCN, transcobalamin; STOM, stomatin; IL1R2, interleukin-1 receptor type 2; CHIT, chitinase. *P ≤ 0⋅050 versus healthy control;†P ≤ 0⋅050 (Kruskal-Wallis test).