POC Assessment of Combined Umbilical Arterial and Venous Lactate: A Potential Screening Test for Neonatal Acidosis [OP04-7D]

INTRODUCTION: Umbilical artery (UA) lactate and pH aid the diagnosis of neonatal acidosis. This study examines the relationship between point-of-care (POC) measurement of combined umbilical arterial and venous (CUAV) lactate and UA lactate and pH to determine whether this POC assessment could serve as an alternative screening modality for neonatal acidosis. METHODS: In this prospective cohort study, UA and CUAV cord blood samples were collected from vaginal and cesarean deliveries occurring between June and August 2019 at a tertiary care center. UA samples were analyzed for pH and lactate using a standard laboratory blood gas analyzer (GEM 4000). CUAV lactate was analyzed at the POC (StatStrip Xpress Lactate Meter, off-label indication, IRB-approved) as well as on the blood gas analyzer. Short-term neonatal outcomes, including 1- and 5- minute APGAR scores and NICU admission rates were also assessed. RESULTS: N=190. There was a statistically significant correlation between POC CUAV lactate concentrations and UA lactate concentrations (R2=0.806 P=2.2 x 10-16). Additionally, there was a statistically significant correlation between the CUAV lactate concentrations obtained using the POC device and the GEM analyzer (R2=0.934 P=2.2 x 10-16). R2=0.95 for technical replicates of POC CUAV lactate concentration measurements. There was no statistically significant association between POC CUAV lactate and UA pH (R2=0.223 P=2.4 x 10-6). CONCLUSION: POC testing of CUAV lactate is reliable and closely correlated with UA lactate concentrations, making POCT CUAV lactate a feasible screening test for neonatal acidosis. More data is needed to establish the sensitivity and specificity of this test and its association with clinical neonatal outcomes.