Correlation of serum electrolyte value between point-of-care test and central laboratory test in emergency department patients
Category:
Background:
Nowadays, POCT has been used more frequently in clinical practice due to abilityto provide rapid results, meanwhile, there is no sufficient study data to support that electrolytevalues obtained from POCT can help physicians in clinical decision making.
Objective:
To find correlation between arterial electrolytes from point-of-care test and venouselectrolytes from central laboratory.
Method:
A prospective observational study including 100 patients who visited emergencyroom at Ramathibodi hospital was performed. 2 samples from arterial and venous blood weretaken from each patients. Sodium value, Potassium value, amount of arterial blood sample, siteof arterial puncture and time interval between bloods samples were recorded.
Results:
Both sodium and potassium values obtained from each methods were highlycorrelated (Pearson’s correlation 0.94, 0.94 respectively). We were able to convert arterialvalues to venous values by using equations (Venous sodium = Arterial sodium*0.96 + 8.2,Venous potassium = Arterial potassium*0.93 + 0.63).
Conclusion:
Arterial sodium and potassium values obtained from Point-of-care test were highlycorrelated with venous values from central laboratory. We were able to demonstrate theserelationship using linear equations.