Fig. 1

Diagram describing the calculation of lactate load and normalized lactate load. Each “T” on the x-axis represents the timepoint of lactate measurement, and “Lac” represents the corresponding lactate value. Lactate load was calculated as: (Lac₁ + Lac₀)/2 × (T₁—T₀) + (Lac₂ + Lac₁)/2 × (T₂—T₁) + … + (Lac₂₄ + Lac_N)/2 × (T₂₄—T_N). T₀ represents the time of ICU admission, and the corresponding Lac₀ was defined as equals to Lac₁. Similarly, Lac₂₄ (lactate value at 24 h after admission) was defined as equals to the last lactate value within the 24 h (Lac_N). Normalized lactate load was calculated as lactate load divided by 24 h