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...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” (<2.2 mmol/L). Limits of agreement for lactate values (as measured by Lactate ProTM) were –1.46 - 0.97 mmol/L for arterial lactate levels <4.8 mmol/L and –3.21 - 0.88 mmol/L for 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.展开更多
文摘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” (<2.2 mmol/L). Limits of agreement for lactate values (as measured by Lactate ProTM) were –1.46 - 0.97 mmol/L for arterial lactate levels <4.8 mmol/L and –3.21 - 0.88 mmol/L for 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.
