Correlation of Central Venous and Arterial Blood Gas Measurements in Mechanically Ventilated Trauma Patients

HYPOTHESIS Central venous blood gas (VBG) measurements of pH, PCO2, and base excess can be substituted for the same values obtained from an arterial blood gas (ABG) analysis in mechanically ventilated trauma patients, obviating the need for arterial puncture. DESIGN AND SETTING Prospective comparison of 99 sets of VBGs and ABGs at a level 1 academic trauma center. PATIENTS A consecutive sample of 25 trauma patients admitted to the intensive care unit who required mechanical ventilation and had both central venous and arterial catheters. MAIN OUTCOME MEASURES Pearson correlations and Bland-Altman limits of agreement (LOAs) for pH, PCO2, and base excess values from each set of VBGs and ABGs. RESULTS When VBG and ABG values were compared, pH had R = 0.92, P