Prognostic Value of Hyperlactatemia and Lactate Clearance in Septic Patients With Hematological Malignancies

Abstract Background: The coexistence of sepsis and hematological malignancies increases patient vulnerability, revealing the need for precise prognostic markers. This study explores the prognostic significance of lactate levels and clearance in septic patients with hematological malignancies. Material and Methods: A retrospective cohort study conducted from January 2016 to December 2019 in a tertiary hematological intensive care unit (ICU) included 167 adults with hematological malignancies and sepsis. The relationship between lactate levels, hyperlactatemia, lactate clearance, and ICU outcomes was investigated. ICU survivors and non-survivors were compared to identify the factors affecting ICU mortality. Results: Patients were primarily with lymphoma and acute leukemia (66%) and had frequent hyperlactatemia (64%) on ICU admission. ICU non-survivors demonstrated higher lactate levels and hyperlactatemia frequency at various time points (0, 6, and 12 hours) than survivors. Lactate clearance, however, did not differ significantly between the two groups. Invasive mechanical ventilation OR (95% confidence interval-CI): 20.4 (2.4–79.8), p < 0.01, requirement of vasopressors OR (95% CI): 5.6 (1.3–24.5), p < 0.01, Lactate level at the 6th hour OR (95% CI): 1.51 (1.1–2.07), p = 0.01, and APACHE II score (OR (95% CI): 1.16 (1.01–1.34), p = 0.05) were independent risk factors for ICU mortality. The Area Under the Curve for APACHE II score and lactate level at the 6th hour were 0.774 (95% CI: 0.682–0.866) and 0.703 (95% CI: 0.602–0.804), respectively. Conclusion: While elevated lactate levels correlated with mortality rate and Lactate level at the 6th hour is an independent risk factor for mortality, the absence of a significant difference in lactate clearance challenges traditional assumptions. These results question the commonly accepted perspective regarding lactate dynamics in sepsis among individuals with hematological malignancies.