Title: Undisplayed Bicarbonate ion Concentration in Arterial Blood Gas Analysis
Abstract: Blood bicarbonate ion concentration (BcHCO 3 -) is a vital parameter in the management of acid base disorders.In an arterial blood gas (ABG) analyzer, the BcHCO 3 -is calculated from the values of pH and pCO 2 .We received four samples in a span of one year, from December 2011 to November 2012 for arterial blood gas analysis, in which the BcHCO 3 -was not displayed by the blood gas analyzer.Based on the information available in literature, the formula for calculating the BcHCO 3 -from pH and pCO 2 was obtained and BcHCO 3 -was calculated in all four samples mentioned above.An attempt was made to establish a clinical correlation between laboratory and clinical data of these patients.All these values of BcHCO 3 -were above the maximum display limit of our blood gas analyzer, which was 60 mmol/L and hence, they were not displayed.All four patients had chronic respiratory disease and they were taking furosemide and / or dexamethasone.High values of BcHCO 3 -, sometimes falling beyond the display range of the ABG analyzer, could be observed in patients of chronic respiratory disease, treated with drugs like furosemide and dexamethasone, that result in bicarbonate retention.