SEPSIS remains a leading cause of mortality in hospitals worldwide, requiring rapid diagnosis and management for improved patient outcomes. Lactate measurements have been shown to predict poor outcomes in sepsis patients. However, venous lactate (VL) is not always readily available, particularly in resource-limited settings. Capillary lactate (CL), measured with a handheld device, has emerged as a promising alternative.
A recent study investigated the correlation between CL and VL in patients with sepsis at the time of admission and after six hours, and identified CL cut-off values that can predict poor patient outcomes. The findings suggest that CL is a feasible and effective tool for sepsis prognosis.
The descriptive study was conducted between March and June 2022, involving 102 patients, who had a quick Sequential Organ Failure Assessment (qSOFA) score of ≥2, and confirmed infection. Both CL and VL were measured using the “Lactate-plus” handheld analyser at admission (t0) and at six hours (t6). The analyser’s accuracy was first tested in a pilot study with 30 patients, correlating its results with laboratory lactate values. Patient demographics, clinical data, and outcomes were assessed throughout the hospital stay and up to 28 days.
The results revealed that there was no significant difference between the median CL at t0 (3.4 mmol/L; IQR 2.5–4.2), and the median VL (3.6 mmol/L; IQR 2.6–4.6). Similar results were observed at t6 (median CL 0.85 mmol/L; IQR 0.4–1.8, median VL 0.85 mmol/L; IQR 0.6–1.8). A CL cut-off of 3.5 mmol/L at t0 predicted 28-day mortality with an area under the ROC curve (AUC) of 0.89 (95% CI: 0.82–0.95), offering 85% sensitivity and 78% specificity. Additionally, CL ≥3.5 mmol/L was associated with higher ICU admissions (p<0.01), vasopressor requirements (p<0.0001), and increased mortality. Capillary lactate clearance of 64% was a strong predictor of survival, with a sensitivity of 97% and specificity of 91%.
In conclusion, CL measured with a handheld analyser strongly correlates with VL and is a reliable prognostic tool for sepsis. The optimal CL cut-off of 3.5 mmol/L at admission is linked to higher mortality and severe disease outcomes, making it a valuable marker for early sepsis risk stratification. Although CL offers a practical and cost-effective alternative to VL, limitations such as the study’s single-centre design and small sample size must be acknowledged. Further research, especially in ICU settings, is necessary to fully validate the clinical utility of CL in critically ill patients.
Reference
Joseph PA et al. Capillary lactate as a prognostic marker in sepsis: correlation with venous lactate and prediction of outcomes. BMC Infect Dis. 2025;25(1):438
