Agreement between capillary and venous POCT lactate in emergency department patients
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AbstractIntroduction: Increase in lactate levels (hyperlactatemia) is a sensitive marker in early identification of patients who are critically ill. Capillary lactate measurement by handheld lactate devices may allow for rapid determination of test results and extend the possible use in the pre-hospital arena. Thus, the aim of this paper is to study the agreement of handheld lactate analyzers for the measurement of capillary lactate as compared with reference venous blood lactate level assessed using a blood gas analyzer in the Emergency Department (ED).

Methods: Two hundred and forty patients triaged as ‘urgent’ (Category 3 of the five category triage scale), aged 18 or above, who presented to the ED in 2016 were recruited. Venous and capillary blood samples were collected for lactate analysis. Venous lactate levels were measured by blood gas analyzer were used as reference (VL-Ref). Capillary lactate level were measured using two handheld analyzers (Nova StatStrip Xpress Lactate Meter and Lactate Scout + Analyzer) (CL-Nova and CL-Scout+). Venous lactate measurements were also performed using two handheld analyzer (VL-Nova and VL-Scout+). Agreement of handheld lactate analyzers with blood gas analyzer will be determined by using Bland-Altman agreement analysis.

Results: Two hundred and forty patients (mean age 69.9 years; 54.2% males) were recruited. Of 240 patients, The result of VL-Ref ranged from 0.70–5.38 mmol/L, with a mean of 1.96 mmol/L. 63.75% and 36.25% showed lactate level (VL-Ref) <2 mmol/L and > = 2 mmol/L respectively. Regarding capillary lactate measurements, Bland-Altman agreement method showed bias values of −0.22 mmol/L and 0.46 mmol/L between VL-Ref and CL-Scout + and CL-Nova, with 95% limits of agreement were being −2.17 to 1.73 mmol/L and −1.08 to 2.00 mmol/L respectively. Regarding venous blood lactate level, the results showed bias values of 0.22 mmol/L and 0.83 mmol/L between VL-Ref and VL-Scout + and VL-Nova, with 95% limits of agreement being −0.46 to 0.90 mmol/L and −0.01 to 1.66 mmol/L respectively.

Conclusions: Capillary lactate POCT appears to be a promising tool for screening for hyperlactatemia. An overall low systemic bias were observed in CL-Scout + (bias: −0.22 mmol/L) and VL-Scout + (bias: 0.22 mmol/L), suggesting a potential clinical utility of Scout + handheld analyzer. However the wide range of limit of agreement suggests poor precision, and caution the interpretation of results outside of the normal values. Thus, further studies are required to improve the precision of the handheld analyzers.
All Author(s) ListGraham CA, Hung KKC, Lo RSL, Leung LY, Lee KH, Yeung CY Chan SY.
Journal nameCritical Care
Volume Number21 Suppl 1
Issue Number57
PagesP122 - P122
LanguagesEnglish-United Kingdom

Last updated on 2018-20-01 at 18:56