Clinical Conditions Associated With Elevated Lactate Levels in Hospitalized Children.

AIM: Lactate is included in adult septic shock criteria, but its role in paediatric sepsis is unclear. Recent guidelines propose lactate thresholds, though supporting evidence is limited. We aimed to identify conditions associated with elevated lactate in children and determine where levels are highest. METHODS: We conducted a 10-year retrospective cohort study of patients < 17 years admitted to ICU or acute paediatric wards (2013-2023). Patients with elevated lactate were included. Diagnoses were grouped into 11 categories and underlying conditions into five groups. Maximum lactate levels were compared across diagnostic categories. RESULTS: Among 3039 patients (4577 hospitalisations), 175 had lactate ≥ 5 mmol/L. Respiratory infections were most common (45.1%), while sepsis/meningitis accounted for 4%. Median lactate was highest in sepsis/meningitis, exceeding six other categories. Only five patients had lactate ≥ 11 mmol/L, mostly with sepsis/meningitis. CONCLUSIONS: Elevated lactate is common in hospitalised children and occurs across diverse conditions. Although highest in sepsis, most cases are non-septic. Lactate should be interpreted in a clinical context.