Quality assessment of two lactate test strip methods suitable for obstetric use

Abstract

Accuracy of lactate determinations in cord blood was tested for one reflectometric (Accusport) and one amperometric (Lactate Pro) microvolume test strip lactate meter. Both meters, using a whole blood sample, measure lower levels of lactate than a reflectometric device considered as a reference method, which analyses lactate in plasma. Readings were unaffected irrespective of lactate concentrations for the Lactate Pro, whilst the Accusport overestimated low lactate concentrations and underestimated high values. Both lactate meters underestimated lactate concentrations at high hematocrits, as compared with the reference method. The Lactate Pro has a fixed sample volume of 5 microliters while the Accusport uses random blood drop as sample volume. However, in analyses with less than 20 microliters sample volume considerable underestimation was found with the Accusport. Coefficient of variation was 3.8-8.9% for the Accusport and 3.1-4.0% for the Lactate Pro within lactate concentrations between 2.1 and 5.3 mmol/l. The amperometric device, the Lactate Pro, performed best in these tests dealing with fetal blood lactate concentrations. The new technique can be a useful tool in perinatal research as well as in obstetric practice.

Comparison of methods for the rapid laboratory assessment of children with malaria.

“…18,19 Studies that have used BlandAltman analysis showed that mean differences (95% LOA) were similar to our findings, Ϫ0.2 (Ϫ1.2 to 0.8), 16 Ϫ0.3 (Ϫ1.33 to 0.69), 18 and for a study that tested 2 Accusport machines with machine A Ϫ0.4 (Ϫ1.8 to 1.1) and machine B Ϫ0.4 (Ϫ1.5 to 0.7). 19 These published limits of agreement were also similar to the values for our Accusport B, although different for those of Accusport A.…”

“…A number of other studies have examined the accuracy of the Accusport lactate analyzer in athletes, 14,15 neonates, 16,17 and critically ill patients. 18,19 Studies that have used BlandAltman analysis showed that mean differences (95% LOA) were similar to our findings, Ϫ0.2 (Ϫ1.2 to 0.8), 16 Ϫ0.3 (Ϫ1.33 to 0.69), 18 and for a study that tested 2 Accusport machines with machine A Ϫ0.4 (Ϫ1.8 to 1.1) and machine B Ϫ0.4 (Ϫ1.5 to 0.7).…”

Point‐of‐care measurement of fetal blood lactate – Time to trust a new device

“…Limitations include the use of fetal umbilical cord blood rather than scalp blood to allow sufficient volume, as others have; 16,19,20 studies using both have shown greater variation in scalp than cord samples, possibly due to mixture with tissue fluid. 13,26 Only two alternative POC meters which have undergone recent obstetric investigation 13,17,24 were included in the study, although other lactate devices are currently being studied for obstetric use, including Roche Accutrend PlusTM, 21 together with a range of devices in the sporting world.…”

Impact of Delayed Arterial Cord Blood Sampling for Lactate Assay

“…These micromethods are simple, cheap and suitable for use in the delivery room [5] . Nordström et al [7] reported several factors that may alter the reliability of lactate determination. The reflectometric method gives falsely low levels, owing to slower diffusion of plasma in samples with a high hematocrit [7] .…”

“…Nordström et al [7] reported several factors that may alter the reliability of lactate determination. The reflectometric method gives falsely low levels, owing to slower diffusion of plasma in samples with a high hematocrit [7] . Indeed, lactate concentrations are higher in plasma than in whole blood containing intact erythrocytes [1] .…”