Open AccessAgreement of 2 electrolyte analyzers for identifying electrolyte and acid‐base disorders in sick horses
Author(s) -
Gomez Diego E.,
Buczinski Sébastien,
Darby Shan,
Palmisano Megan,
Beatty Sarah S. K.,
Mackay Robert J.
Publication year - 2020
Publication title -
journal of veterinary internal medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.356
H-Index - 103
eISSN - 1939-1676
pISSN - 0891-6640
DOI - 10.1111/jvim.15889
Subject(s) - electrolyte , intraclass correlation , spectrum analyzer , medicine , limits of agreement , analytical chemistry (journal) , chromatography , chemistry , nuclear medicine , reproducibility , electrode , electrical engineering , engineering
Background Use of different analyzers to measure electrolytes in the same horse can lead to different interpretation of acid‐base balance when using the simplified strong ion difference ( s SID) approach. Objective Investigate the level of agreement between 2 analyzers in determining electrolytes concentrations, s SID variables, and acid‐base disorders in sick horses. Animals One hundred twenty‐four hospitalized horses. Methods Retrospective study using paired samples. Electrolytes were measured using a Beckman Coulter AU480 Chemistry analyzer (PBMA) and a Nova Biomedical Stat Profile (WBGA), respectively. Calculated s SID variables included strong ion difference, SID 4 ; unmeasured strong ions, USI; and total nonvolatile buffer ion concentration in plasma (A tot ). Agreement between analyzers was explored using Passing‐Bablok regression and Bland‐Altman analysis. Kappa (κ) test evaluated the level of agreement between analyzers in detecting acid‐base disorders. Results Methodologic differences were identified in measured Na + and Cl − and calculated values of SID 4 and USI. Mean bias (95% limits of agreement) for Na + , Cl − , SID 4 , and USI were: −1.2 mmol/L (−9.2 to 6.8), 4.4 mmol/L (−4.4 to 13), −5.4 mmol/L (−13 to 2), and −6.2 mmol/L (−14 to 1.7), respectively. The intraclass correlation coefficient for SID 4 and USI was .55 (95%CI: −0.2 to 0.8) and .2 (95%CI: −0.15 to 0.48), respectively. There was a poor agreement between analyzers for detection of SID 4 (κ = 0.20, 95%CI, 0.1 to 0.31) or USI abnormalities (κ = −0.04, 95%CI, −0.11 to 0.02). Conclusions and Clinical Importance Differences between analyzer methodology in measuring electrolytes led to a poor agreement between the diagnosis of acid‐base disorders in sick horses when using the s SID approach.