Introduction: ABG is a painful procedure and it requires lot of skills to master the art of obtaining ABG from sick patients specially who are in shock,thus even the most skilful of person requires quite a few attempts,so main idea of this study is to come up with something which can be an alternative to ABG.Various studies have been done where comparisons have been drawn between ABG VS VBG VS CBG but since VBG is also an invasive procedure, so less invasive procedure was obtaining a CBG and the whole idea of the study is that can CBG replace ABG? CBG only requires a finger prick or heel stick, and is much less painful than an ABG. The results, however, are not as reliable as an ABG. Aims and Objectives: To investigate the degree of corroboration between capillary blood gas (CBG) and ABG values using correlation analysis and to evaluate whether capillary blood gas can be equally reliable as arterial blood gas (ABG) to be used in clinical practice. Reliability of CBG over ABG is aimed to make blood gas analysis easier, less painful, faster and equally reliable. Also, it will be easier to assess blood gases in patients with generalized oedema, feeble pulses and in anxious and psychiatric / psychotic patients where ABG can be difficult. Materials and Methods: Blood samples were drawn simultaneously from the radial artery via an arterial puncture into a heparinised syringe and the fingertip via finger prick into a capillary tube of every patient participating in the study. Two sets of capillary samples was taken in order to assess the repeatability of capillary sampling. Immediately afterwards an arterial sample was taken from the radial artery in order to assess the agreement between the capillary and arterial samples. These samples so obtained was analyzed immediately by the blood gas analyzer (AVL Compact 3, Roche Diagnostics GmbH, Mannheim, Germany) of the Emergency Department for values of acid-base and oxygenation: pH, PO2 , PCO2 , HCO3 values will be recorded. Blood gases was obtained if the patients need blood gases analysis for clinical decisions. In addition, the measurement of oxygen saturation (SpO2) was obtained from a finger pulse oximeter (Non-invasive pulse oximeter). Results and Conclusion:Although CBG is far less invasive than ABG, but the values obtained by the T-TEST method of analysis shows disparity between the two. There is some level of similarity in the values of HCO3 and PCO2 but the values of PO2 and PH did not have any correlation. Hence, the study concludes that CBG cannot replace ABG until more studies are done with greater sample size.

Keywords: Capillary blood gas; PCO2 ; pH; Blood gas analysis.