TITLE:
Accuracy of a hand-held lactate meter in measuring umbilical cord blood lactate at all lactate levels
AUTHORS:
Seng C. Chua, May Y. W. Wong, Tina Y. Su, Mifanwy Reece
KEYWORDS:
Agreement; Blood Gas Analyser; Comparison; Lactate; Umbilical Cord Blood
JOURNAL NAME:
Open Journal of Obstetrics and Gynecology,
Vol.4 No.1,
January
16,
2014
ABSTRACT: Objective: Fetal scalp
lactate has largely replaced pH analysis to assess intrapartum hypoxia. Many obstetrics units use hand-held lactate meters to measure
umbilical blood because of its affordability and ease of use. We sought to investigate the agreement of
Lactate ProTM with a
reference method blood gas analyser and to determine its usefulness with
a recommended cutoff value of 4.8 mmol/L. Methods: Prospective study carried
out at a tertiary institution where 237 arterial and 233 venous samples from umbilical cords of 16 elective caesarean and 285 emergency deliveries were
measured using Lactate ProTM and ABL735 Sesries
Acid-Base analyser. Limits of
agreement were analysed using Bland-Altman plots. Results: Lactate ProTM differentiated fewer deliveries as “high
risk” (≥4.8 mmol/L) and more as “low risk” (TM) were
–1.46 - 0.97 mmol/L for arterial lactate levels arterial lactate levels ≥ 4.8 mmol/L.
Conclusion: There was a poorer agreement between the two devices at
higher lactate values. Lactate ProTM underestimates by up to 3.2 mmol/L;
a 4.8 mmol/L reading may actually signify a
lactate level of 8.0 mmol/L, indicating severe metabolic acidosis. We
caution the use of this device in assessing fetal lactate levels.