Clinical and Therapeutic Insights into Sepsis: A Retrospective Observational Study of Inflammatory Markers, and Outcomes

Abstract

Introduction: Sepsis is a life-threatening condition caused by dysregulated host responses to infection, leading to organ failure and high mortality. Early recognition, especially in vulnerable populations, remains challenging due to variable presentations. Key biomarkers like CRP, procalcitonin, fibrinogen, and neutrophil-to-lymphocyte ratio (NLR) aid in diagnosis, monitoring, and prognosis. Rapid identification and targeted therapy are critical, particularly amid rising antimicrobial resistance. This study aims to analyze the relationship between early biomarker levels and patient outcomes, focusing on mortality risk prediction within the first week of hospitalization. Methods: A retrospective study of 198 sepsis patients hospitalized in Bucharest, Romania, between January and December 2024, analyzing inflammatory biomarkers at admission-T0, 48-72 h-T1, and one week-T2, to identify predictors of clinical outcomes. Results: In patients under 65 years old, fibrinogen, CRP, and NLR significantly decreased from T0 to T2, especially in survivors. In contrast, patients over 65 years old showed less consistent biomarker changes, with higher mortality associated, with comorbidities such as heart failure and cancer. Overall, early reductions in inflammatory markers correlated with better outcomes, highlighting their prognostic value in sepsis management. Conclusions: In sepsis patients over 65 years old, a stable or rising neutrophil-to-lymphocyte ratio (NLR) and fibrinogen levels after the first week of hospitalization may indicate a poor prognosis, whereas decreasing levels suggest a better chance of survival.

Keywords: inflammatory biomarkers; neutrophil-to-lymphocyte ratio; sepsis.

Figure 1

Dynamics of NLR T0–T2. NLR = neutrophil-to-lymphocyte ratio. T0, T1, and T2 = Time 0, 1, and 2. (*) = outliers values.

Figure 2

The dynamics of WBC were observed at T0, T1, and T2. WBC = white blood cells. T0, T1, and T2 = Time 0, 1, and 2. (*) = outliers values.

Figure 3

The dynamics of neutrophils were observed at T0, T1, and T2. NEU = Neutrophils. T0, T1, T2 = Time 0, 1, and 2. (*) = outliers values.

Figure 4

The dynamics of lymphocytes were observed at T0, T1, and T2. LYM = lymphocytes (illustrated as base10 logarithmic values). T0, T1, and T2 = Time 0, 1, and 2. (*) = outliers values.

Figure 5

Median values of NLR at T0, T1, and T2. NLR = neutrophil-to-lymphocyte ratio. T0, T1, and T2 = Time 0, 1, and 2.

Figure 6

Dynamics of the median values of inflammatory parameters and NLR at T0, T1, and T2 in patients who died. Legend: Fbg = fibrinogen, CRP = C-reactive protein, PCT = procalcitonin, NLR = neutrophil-to-lymphocytes Ratio. T0, T1, and T2 = Time 0, 1, and 2.

Figure 7

Dynamics of the median values of inflammatory parameters and NLR at T0, T1, and T2 in patients who survived. Legend: Fbg = Fibrinogen, CRP = C-reactive protein, PCT = procalcitonin, NLR = neutrophil-to-lymphocytes ratio. T0, T1, and T2 = Time 0, 1, and 2.

Figure 8

Distribution of analyzed patients according to comorbidities and mortality. DM = diabetes mellitus; CPOD = chronic obstructive pulmonary disease; CKD = chronic kidney disease; CHF = chronic heart failure; CLD = chronic liver disease; HIV = human immunodeficiency virus.

Figure 9

Evolution of NLR in patients who died, with known CHF or malignancies. CHF = cardiac heart failure. NLR = neutrophil-to-lymphocytes ratio. T0, T1, and T2 = Time 0, 1, and 2.

Figure 10

Evolution of NLR in patients who survived the sepsis episode. CHF = cardiac heart failure. NLR = neutrophil-to-lymphocytes ratio. T0, T1, and T2 = Time 0, 1, and 2.

Figure 11

Evolution of CRP in patients with comorbidities who died. CHF = cardiac heart failure. CRP = C-reactive protein. T0, T1, and T2 = Time 0, 1, and 2.

Figure 12

Evolution of CRP in patients with comorbidities who survived the sepsis episode. CHF = cardiac heart failure. CRP = C-reactive protein. T0, T1, and T2 = Time 0, 1, and 2.

Figure 13

Evolution of mean fibrinogen levels in patients who died, according to age categories (<65 years, ≥65 years). T0, T1, and T2 = Time 0, 1, and 2.

Figure 14

Evolution of mean fibrinogen levels in patients who survived the sepsis episode, according to age categories (<65 years, ≥65 years). T0, T1, and T2 = Time 0, 1, and 2.