Evaluation of urine output, lactate levels and lactate clearance in the transitional period in very low birth weight preterm infants.

Objective: To assess the association between urine output (UO), arterial lactate levels (LL) and lactate clearance with haemodynamic instability and death in very low birth weight (VLBW) preterm in the transitional period.

Study Design: Retrospective cohort study with VLBW newborns born in 2016 and 2017, excluding those with malformations and without data. We evaluated 254 preterm infants with a total of 482 lactate levels measured in the first 72 h.