Central venous pressure in femoral catheter: correlation with superior approach after heart surgery.

Objective: It is common to obtain femoral venous approach in patients undergoing combined heart surgery or as an alternative to superior approach (internal jugular vein or subclavian vein). The aim of this study was to compare the measures of central venous pressure (CVP) at two different sites (superior versus femoral).
Methods: We prospectively and openly allocated 60 patients who underwent heart surgery between July from November 2006. Three measures were obtained from each patient at each site (admission, 6 and 12 hours after surgery) in two different inclinations of the headboard (zero and 30 degrees) totaling 720 measures.
Results: Fifty five percent of patients who underwent coronary artery bypass grafting, 38% heart valve surgery and 7% other surgeries. The mean of CVP +/- standard deviation (SD) measured in superior approach was 13.0 +/- 5.5 mmHg (zero degree) and 13.3 +/- 6.1 mmHg (30 degrees) while the measures in inferior approach were 11.1 +/- 4.9 mmHg (zero degree) and 13.7 +/- 4.6 mmHg (30 degrees). The linear correlation (r) between the measures in both sites was 0.66 (zero degree) and 0.53 (30 degrees), both with p value<0.0001.
Conclusion: The CVP can be measured with accuracy in the femoral venous approach in the immediate postoperative period of heart surgery with better linear correlation obtained with the measures made with the headboard positioned at zero degree.