ARTERIALBLOODGAS ANALYSER ELECTROLYTES VERSUS SERUM ELECTROLYTES: A COMPARATIVE STUDY

Life Science - Biochemistry

Abstract

The importance of electrolyte balance in determining the prognosis of the patient cannot be underestimated. Electrolytes are important for optimum cellular functioning in most tissues of the body. Most of the metabolic processes depend on the electrolyte balance. Imbalance in the electrolyte concentrations can be either the cause or the consequence of many disorders, therefore such problems need to be identified promptly to ensure adequate treatment. Electrolyte imbalance can cause significant risks to life Measurement of electrolytes is of critical importance in the Intensive care units also So the electrolyte analysis by the laboratory should not only be accurate but also quick as timely corrections of the imbalance can greatly affect the patient's outcome Routinely serum electrolytes are analysed in the laboratory using Auto analysers which are very accurate but take atleast a minimum of 15 minutes to be reported. Electrolytes can also be measured in heparin blood using stand alone ABG analysers In this study we compare the measurement of electrolytes by these two methodologies Our aim was to explore the possibilities of using both interchangeably taking into account preanalytical factors also. We used Ortho Clinical Diagnostics Vitros 5600 Dry chemistry Auto analyser for serum elctrolytes and the Roche diagnostics Cobas b121: Analyser for measuring blood gases. Comparison between the two methodologies was figuratively represented in Bar diagrams and Line diagrams. Statistical analysis was done by using Passing-Bablock regression analysis in the method validator tool. The data was represented in the form of difference plots and scatter diagrams. The “t” value for Sodium. Potassium, Chlorideswere-3.0342;- 4.7271;0.3502 respectively It is observed that the correlation is not acceptable as per Kendall"s Tau Correlation (0.9724) for sodium(0.887) and potassium (0.900), though it was found acceptable for chlorides(0.981)For all the three electrolytes the two-tailed P value equals 1.0000 By conventional criteria, this difference is considered to be not statistically significant We recommend that both the methodologies cannot be used interchangeably. Even though ABG electrolytes can be relied upon in emergencies it is always advisable to confirm the results with serum electrolytes analysed in Auto analysers upon stabilisation of the patient’s condition