The central venous catheter in the assay of acid base status.

There is no claim of precedence in these underrecognized observations. There are risks accepted in the name of precision to obtain arterial blood gases when central venous determinations would be available, safe and more than adequately describe the acid base status of the patient. By subtracting 4.10 torr from the mixed venous carbon dioxide tension and adding 0.06 to the venous pH, the arterial values are quite accurately approximated. A central venous catheter is a safe, convenient, reliable access for the administration of intercardiac medications.