Anthropometric estimation of femoral venous cannula length for cardiovascular surgery

Femoral vein cannulation is an alternative method for central cannulation. However, no clinical guidelines have been established for optimal insertion length of femoral venous cannula. The purpose of the present study was to evaluate the correlation between the insertion length of femoral venous cannula (L), and the sum of the length from femoral artery (FA) puncture site to umbilicus (P-U) and the length from umbilicus to lower border of the sternum (U-S) as an anthropometric estimation for adult patients undergoing cardiovascular surgery using femoral vein cannulation. We also attempted to determine the insertion length of femoral venous cannula by the patient's height and weight.

P-U and U-S were measured after anesthesia induction. L was measured after femoral venous cannula tip was positioned at the junction of inferior vena cava and right atrium using transesophageal echocardiography. The relationship between the sum of P-U and U-S (P-U-S), and L was analyzed by Pearson's correlation analysis. Bland-Altman analysis was used to compare the agreement between P-U-S and L. Multiple linear regression analysis was performed to identify the height and weight factors capable of predicting L.

One-hundred study patients were enrolled. P-U-S was highly correlated with L (r = 0.95). The bias and precision were -2.60 ± 8.57 mm. L was predicted from height and weight: L (mm) = 0.82 × height (cm) + 1.18 × weight (kg) + 188.46.

P-U-S can be used as a reliable anthropometric estimation of L during adult cardiovascular surgery using femoral vein cannulation.