Serum lactate monitoring may help to predict neurological function impairment caused by acute metabolism crisis

To investigate the predictive value of serum lactate on neurological function impairment and the possible etiology. In this retrospective study, all the adult patients admitted to ICU more than 24 h after general anesthesia elective neurosurgery from January 2018 to January 2019 were recruited. The data of the serum lactate every 8 h during the 24 h of ICU admission were acquired and analyzed. 169 patients were included in the outcomes analysis. The average serum lactate after ICU admission was 3.7(3.4–4.1) mmol/L, higher than normal, and serum lactate elevated commonly after neurosurgery. The serum lactate at ICU admission (lactate(serum)0h) was not correlated with the outcomes, whereas the predictive value increased as the monitoring time was extended. The result indicated that lactate(serum)8h, the lactate(serum)16h, and the lactate(serum)24h were correlated with the primary outcome (difference of GCS scores before the surgery and after 24 h of ICU admission (ΔGCS(24h)) (p < 0.05). The lactate(serum)16h and the lactate(serum) 24 h were correlated with all the outcomes except for the hospital LOS. The ROC curve suggested that the lactate(serum)24h achieved the best predictive value. Patients with serum lactate non-recovered trend after 24 h of ICU stay had decreased GCS scores and vice versa, as indicated by the graph of the dynamic changes in the serum lactate. The predictive value of the serum glucose/serum lactate ratio at ICU admission (G/L(serum)) was analyzed, and the result indicated that it was correlated with the ΔGCS(24h) (p < 0.05), the G/L(serum) can predict neurological impairment earlier. Dynamic serum lactate monitoring and the G/L(serum) at ICU admission have predict value on neurological function impairment after neurosurgery which might be attributed to ACMC.