Abstract
Arterial blood gas (ABG) analysis is the gold standard method for assessment of oxygenation and acid base analysis, yielding valuable information about a variety of disease process. This study is aimed to determine the extent of correlation between arterial and peripheral venous samples for blood gases and acid base status in critically ill and emergency department patients and to evaluate if venous sample may be a better alternative for initial assessment and resuscitation. The prospective study was conducted on 45 patients of either sex in the age group of 15-80 years of intensive care unit and emergency ward. Relevant history, presenting complaints, vital signs, and indication for testing were recorded. Arterial and peripheral venous samples were drawn simultaneously in a pre-heparinized syringe and analyzed immediately for blood gases and acid base status. Mean difference and Pearson's product moment correlation coefficient was used to compare the result. After statistical evaluation, the present study shows minimal mean difference and good correlation (r > 0.9) between arterial and peripheral venous sample for blood gases and acid base status. Correlation in PO2 measurement was poor (r < 0.3). Thus, venous blood may be a useful alternative to arterial blood during blood gas analysis obviating the need for arterial puncture in difficult clinical situation especially trauma patients, for initial emergency department assessment and early stages of resuscitation.