title: Validation of Method Performance of pH, PCO2, PO2, Na(+), K(+) of Cobas b121 ABG Analyser.
abstract: BACKGROUND
  The introduction of a new method or new analyser is a common occurrence in clinical biochemistry laboratory. Blood gas measurements and electrolytes are often performed in Point-of-Care (POC) settings. When a new POC analyser is obtained, the performance of the analyser should be evaluated by comparison to the measurements with the reference analyser in the laboratory.
  
  
  OBJECTIVE
  Evaluation of method performance of pH, PCO2, PO2, Na(+), K(+) of cobas b121 ABG analyser.
  
  
  METHODS
  The evaluation of method performance of pH, PO2, PCO2, Na(+), K(+) of cobas b121 ABG analyser was done by comparing the results of 50 patient samples run on cobas b121 with the results obtained from Rapid lab values (reference analyser). Correlation coefficient was calculated from the results obtained from both the analysers. Precision was calculated by running biorad ABG control samples.
  
  
  RESULTS
  The correlation coefficient values obtained for parameters were close to 1.0 indicating good correlation. The CV obtained for all the parameters were less than 5 indicating good precision.
  
  
  CONCLUSIONS
  The new ABG analyser, Cobas b121 correlated well with the reference ABG analyser (Rapid Lab) and could be used to run on patient samples.
authors.affiliation: Associate Professor, Department of Biochemistry, Pondicherry Institute of Medical Sciences, Affiliated to Pondicherry University , Ganapathichettikulam, Kalapet, Pondicherry, India .
authors.forename: Sunil Kumar
authors.initials: SK
authors.lastname: Nanda
authors.affiliation: Assistant Professor, Department of Biochemistry, Pondicherry Institute of Medical Sciences, Affiliated to Pondicherry University , Ganapathichettikulam, Kalapet, Pondicherry, India .
authors.forename: Lopamudra
authors.initials: L
authors.lastname: Ray
authors.affiliation: Tutor, Department of Biochemistry, Pondicherry Institute of Medical Sciences, Affiliated to Pondicherry University , Ganapathichettikulam, Kalapet, Pondicherry, India .
authors.forename: Asha
authors.initials: A
authors.lastname: Dinakaran
keywords: Blood gas; Electrolytes; Point of care