Umbilical cord blood lactate in normal infants: comparison between two methods of measurement.
OBJECTIVE
Firstly, to determine the accuracy of the Radiometer ABL 625 lactate electrode (Radiometer Medical Pty Ltd, Nunawading, Victoria, Australia) by comparing the lactate values obtained by this method to those obtained with the Hitachi 917 lactate analyser (Boehringer Mannheim Corporation, Charlottetown, Prince Edward Island, Canada). Secondly, to determine the effect of delay in measurement on blood lactate levels.


METHODS
Umbilical venous (UCV) blood samples were obtained from healthy term infants delivered vaginally. Lactate levels were measured with the Radiometer ABL 625 lactate electrode in the Neonatal Intensive Care Unit, Westmead Hospital and with the Hitachi 917 lactate analyser in 49 paired samples. In addition 26 UCV blood samples were placed in ice slurry and a further 26 samples at room temperature and blood lactate was measured at 5-min intervals for 30 min to determine the change of lactate levels with time.


RESULTS
The lactate levels obtained from the Radiometer ABL 625 lactate electrode were consistently lower than the levels obtained from the Hitachi 917 lactate analyser (mean difference - 0.24), but the correlation was high (r = 0.97). The blood lactate levels increased at the rate of 0.012 mmol/L per min if the blood was left at room temperature. The lactate levels remained stable for 20 min if the blood was placed in ice slurry.


CONCLUSIONS
The Radiometer ABL 625 lactate electrode was easy to use and there was high correlation with the values obtained by the standard laboratory method. The blood specimen must be place in an ice slurry if a delay in analysis is anticipated.
Sinn
J K
JK
Department of Women's Health and Newborn Care, Westmead Hospital, New South Wales, Australia. johnsinn@westgate.wh.usyd.edu.au
Lloyd
J
J
Todd
D A
DA
Lazarus
R
R
Maesel
A
A
John
E
E
D000704:Analysis of Variance; D001774:Blood Chemical Analysis / Q000295:instrumentation; D001800:Blood Specimen Collection; D004566:Electrodes; D005312:Fetal Blood / Q000737:chemistry*; D006801:Humans; D007231:Infant, Newborn; D019344:Lactic Acid / Q000097:blood*; D016014:Linear Models; D011237:Predictive Value of Tests; D013997:Time Factors
D019344:Lactic Acid