[Optimal catheter position for PreSep central venous oximetry catheter]

To evaluate optimal catheter position for PreSep central venous oximetry catheter, we inserted the catheter through a sheath introducer with contamination shield and conducted its in vivo calibration in twenty-eight patients. In the event of calibration failure due to unstable signals, the catheter was advanced until calibration became possible. If SQI rose to 3 or 4 during surgery, we readjusted the catheter position to resume reliable monitoring. At the conclusion of surgery, the catheter position was checked radiologically and the distance between the catheter tip and the upper border of the clavicle was measured.

In 70% of the patients, calibration was performed successfully when the catheter was inserted for 12-14 cm from the top of the groove between the sternal and clavicular heads of the sternocleidomastoid muscle, which led to positioning of the catheter tip 5-7 cm from the upper border of the clavicle. However, there was a considerable variation within the total patient sample and no definite correlation was found between catheter positions and patient's height. In 30% of the patient, readjustment of the catheter was required during surgery.

Use of a sheath introducer with contamination shield seems to be useful for positioning the PreSep catheter.