Lactate measurement is included in adult septic shock criteria, but its role and thresholds in paediatric sepsis remain uncertain. Recent guidelines propose lactate cutoffs for children, yet evidence supporting these thresholds is limited. The study aimed to identify clinical conditions associated with elevated lactate in hospitalized children and to determine which diagnostic categories show the highest lactate levels.
The authors performed a 10-year retrospective cohort study covering 2013–2023. The population comprised patients younger than 17 years who were admitted to an intensive care unit (ICU) or acute paediatric wards. The dataset included 3,039 unique patients and a total of 4,577 hospitalisations. Patients with elevated lactate values were selected for analysis; the source reports lactate thresholds and counts as described below.
Diagnoses associated with elevated lactate were grouped into 11 diagnostic categories for comparison. Underlying conditions were additionally categorized into five groups. The investigators recorded maximum lactate levels for each included hospitalisation and compared these maxima across diagnostic categories. Elevated lactate was defined in the source as lactate ≥ 5 mmol/L for inclusion in the detailed analysis.
Out of the cohort, 175 hospitalisations had lactate ≥ 5 mmol/L. Among these elevated-lactate episodes, respiratory infections were the most common diagnostic category, accounting for 45.1% of cases. By contrast, sepsis and meningitis together represented 4% of the elevated-lactate group. The study therefore found that elevated lactate values are frequently observed in non-septic conditions in hospitalized children.
Although sepsis/meningitis constituted a small proportion of elevated-lactate episodes, median lactate concentrations were highest in this category and exceeded those in six other diagnostic categories. Extremely high lactate values (≥ 11 mmol/L) were rare: only five patients reached or exceeded this level, and these very high readings were observed mostly in children with sepsis/meningitis.
The study highlights two key points. First, elevated lactate is a common laboratory finding across a broad range of acute pediatric conditions, not only in sepsis. Second, while the highest median lactate values were seen in sepsis/meningitis, the majority of elevated-lactate cases occurred in non-septic diagnoses—most commonly respiratory infections. The authors therefore advise that lactate measurements in children should be interpreted within the full clinical context, rather than used as a sole diagnostic or triage marker for paediatric sepsis.
The abstract reports a retrospective cohort design and diagnostic grouping but does not provide full detail on some methodological elements in the abstract text available on PubMed (for example, exact laboratory methods, timing of lactate sampling relative to illness onset or interventions, or adjustment for potential confounders). Those specific details were not reported in the provided source abstract and would require review of the full text for clarification.
In this 10-year single-cohort analysis of hospitalized children, elevated lactate (≥ 5 mmol/L) occurred across a wide range of conditions, with respiratory infections being most common and sepsis/meningitis showing the highest median values. Very high lactate concentrations (≥ 11 mmol/L) were uncommon and concentrated in sepsis/meningitis cases. The authors conclude that lactate should be interpreted alongside the clinical picture when evaluating paediatric patients.
Clinicians assessing paediatric patients with elevated lactate should recognize that elevated values are not specific to sepsis and can arise in diverse acute conditions. Lactate can provide useful information but should not replace comprehensive clinical assessment and diagnostic evaluation. For full methodological details, timing of measurements, and potential adjustments, consultation of the full article is recommended.