Abstract

A study was undertaken to determine the blood gas values affected by the flush solution incompletely purged and heparinized in an indwelling arterial catheter and pressure tubing. Arterial blood gases were measured serially after weithdrawing 2,4,6,8,10, and 12 ml of flush-blood solutions from a 20-gauge radial artery catheter which was connected through a transducer to Cobe pressure tubing having the length of 4 or 6 feet, respectively. The pH was nearly unchanged from the sample 2 and PaCO2, PaO2. actual bicarbonate, and base excess were from the sample 3 in 4-ft Cobe pressure tubing. In 6-ft Cobe pressure line pH was nearly unchanged from the sample 3 and PaCO2, actual bicarbonate, and base excess were from the sample 4 PaO2, were unchanged in all samples. So we conclude that arterial blood for the blood gas analysis should be withdrawn at least 4 ml in 4-ft Cobe pressure tubing and 6ml in 6-ft Cobe pressure line,