The association of umbilical hyperlactatemia with short- and tong-term outcomes in extremely low birth weight neonates: a matched cohort study.

UNLABELLED

The objective of this study is to quantify the impact of umbilical arterial isolated hyperlactataemia and lactic acidosis on mortality, morbidity, and neurodevelopmental outcomes at 24 months corrected age in extremely low birth weight (ELBW) infants. The study population consisted of ELBW patients born between January 1, 2015, and December 31, 2023, at the Klinikum Kassel, receiving umbilical arterial blood analysis immediately after birth. Isolated hyperlactataemia was defined as a lactate concentration > 7.00 mmol/L, lactic acidosis as a pH < 7.10 and a lactate > 7.00 mmol/L, controls as pH ≥ 7.10 and lactate ≤ 7 mmol/L. Outcomes were analysed utilising a 1:2 case-control matched approach. Using the hospital data management system, 241 patients were eligible, 150 controls, 47 with isolated hyperlactataemia and 26 with lactic acidosis. Increased 28-day mortality was observed in both isolated hyperlactataemia patients (continuity corrected aOR 29.60 [1.63, 537.76], p = 0.022), and lactic acidosis patients (aOR 27.00 [3.18, 228.96], p = 0.003). Isolated hyperlactataemia was also associated with an increased risk for NEC stage ≥ 2 (aOR 10.00 [1.17, 85.59]), BPD ≥ moderate (aOR 2.68 [1.08, 6.65]), ROP grade ≥ 2 (aOR 13.77 [4.12, 46.02]), IVH grade ≥ 2 (aOR 2.91 [1.04, 8.13]), and septicaemia (aHR 16.76 [7.97, 35.22]). Lactic acidosis patients showed a more pronounced risk for adverse short-term outcomes (ROP grade ≥ 2 (aOR 29.33 [3.23, 266.23]), IVH grade ≥ 2 (aOR 6.31 [1.29, 30.74]), and septicaemia (aOR 1.97 [0.86, 4.54])). Neurodevelopmental outcomes did not differ between groups.

CONCLUSION

Isolated hyperlactataemia and lactic acidosis significantly increased the risk of adverse short-term outcomes; however, neither had a significant effect on long-term developmental outcomes.

WHAT IS KNOWN

• ELBW neonates face high risks of adverse outcomes, particularly with cord hyperlactatemia or lactic acidosis at birth. The long-term neurodevelopmental impact of these markers is unclear.

WHAT IS NEW

• Lactic acidosis predicts worse short-term outcomes than hyperlactatemia. However, survivors to 24 months corrected age show comparable developmental outcomes.