(See SvO2 Monitoring) 1. Insure PA catheter tip is properly positioned with balloon deflated. 2. Use aseptic technique. 3. Prepare blood gas syringe: Heparinize syringe (see A-line) 4. Remove sterile cap from the distal port of the PA catheter (place in sterile gauze) and attache a 10 ml syringe. 5. Turn stopcock off to flush solution and on to patient. 6. Gently (< 3 ml/min) withdraw 5 ml of blood or until clear line of flush solution. 7. Turn stopcock off to all three ports, remove syringe and discard. 8. Attach the blood gas syringe (3-5cc heparinized). 9. Turn stopcock on to patient, slowly and gently withdraw desired amount of blood (2-3cc). Rapid aspiration will contaminate the sample with capillary blood, resulting in a false increase in SvO2. 10. Close stopcock and remove syringe and prepare for ABG analysis