Comparison of i-STAT® with Traditional Laboratory Analysers in the Measurement of Blood Analytes from Field Captured Dugongs (Dugong dugon)

Abstract

Point-of-care (POC) testing is useful in field health assessments of wildlife when the condition of the captured animal must be immediately assessed and/or the location is remote from analytical laboratories. However, prior to their incorporation into clinical health assessment, POC devices must be assessed for potential measurement biases. In this study, the i-STAT (R) portable blood analyser was used to evaluate electrolytes (Na, K, and Cl), glucose, creatinine, lactate, urea, and haematocrit (Hct) of 85 apparently healthy dugongs (Dugong dugon) during field health assessments off the coast of southern Queensland, Australia. Blood levels of analytes measured by i-STAT (R) were compared to values reported by the Beckman Coulter AU400 (R) and AU680 (R) automated chemistry analysers, and the Sysmex XT-2000i (TM) (for Het). Lactate and urea values were outside i-STAT (R)'s detectable limits. Bland-Altman plots identified constant biases for all measurable analytes except Het. For most analytes, i-STAT (R) measurements did not show strong agreement with laboratory analysers; differences between paired measurements fell within calculated precision-based acceptance limits less than 75% of the time. Reference intervals for electrolytes, glucose, creatinine, and haematocrit as measured by i-STAT (R) are reported; however, these must be interpreted in light of measurement biases detected when compared with reference analysers.