A comparison of venous blood gas analysis with paired specimens collected in syringes and evacuated blood collection tubes.

Background: Venous blood samples collected in evacuated blood collection tubes are generally not considered suitable for measurement of oxygenation status. However, whether pH, pCO and HCO results from venous blood samples collected in evacuated tubes are reliable remains unclear.

Methods: Paired samples were collected from 38 healthy volunteers using two collection methods: (1) collection of blood directly into a blood gas syringe and (2) collection of blood into an evacuated tube with subsequent anaerobic transfer into a blood gas syringe.