Canadian Journal of Anesthesia, Vol 15, 332-346, Copyright © 1968 by Canadian Anesthesiologists' Society

Central Venous Blood as an Index of Acid-Base and Oxygenation Status

¹ Department of Anaesthesia, University of Toronto

A statistical study has been carried out, with the object of examining the usefulness of blood drawn from a central venous pressure line as an index of arterial acid-base status and oxygenation. Good correlation was observed between arterial and central venous values for carbon dioxide tension, base excess, pH, hydrogen ion concentration, and oxygen content. However, the scatter of values was too great to recommend arterial predictions from any of the central venous values other than those for carbon dioxide tension, base excess and pH. The subtraction of 6 mm. Hg from a central venous carbon dioxide tension and the use of the actual central venous base excess value would give clinically useful indices of the true arterial levels. Arterial pH may be estimated by adding 0.04 pH units to central venous values.

Central venous oxygen levels are not considered useful indices of arterial status.