RESUMO
AIM: This study aimed to test delta-lactate (ΔL) as a short-term risk stratification method in critically ill children. METHODS: An exploratory study of patients admitted to paediatric intensive care unit (PICU) was conducted. ΔL was calculated as the difference between the maximum lactate concentrations on Days 1 and 2. According to the ΔL cutoff, two groups were considered: low mortality risk (LMR) - ΔL ≥ 0.05 mmol/L - and high mortality risk (HMR) - ΔL < 0.05 mmol/L. RESULTS: Mortality, both during PICU stay and at 28 days, was statistically associated with elevated serum lactate on D1 and D2, per se. For the 93 cases with elevated lactate on Day 1, and a ΔL cutoff of 0.05 mmol/L, the area under the ROC curve was 0.698 (95% confidence interval, 0.47-0.93). HMR patients scored higher PIM3, were not discharged home until 28 days, counted fewer ventilation-free days and needed renal replacement therapy more often. CONCLUSION: Elevated lactate levels at admission, as well as applying the optimal cutoff for ΔL, allowed to predict short-term mortality: if an increase or minimal decrease in lactate maximum levels occurred from D1 to D2, death was almost eight times more probable. In critically ill children, delta-lactate predicts short-term outcome.