What is the formula for calculating the depth of a high UAC?

The formula to calculate the depth of a high umbilical artery catheter (UAC) is based on both the birth weight (BW) of the neonate and the length of the umbilical stump. In particular, the correct formula takes into account the additional factors that need to be considered for proper placement within the vascular system.

By multiplying the birth weight in kilograms by three, you provide an appropriate scaling that correlates to the typical dimensions of the vascular system in neonates. Adding nine serves as a constant that further adjusts this measurement to ensure the catheter reaches the correct placement site. Additionally, incorporating the length of the umbilical stump in centimeters allows for a tailored adjustment that takes individual anatomical measurements into account, thereby enhancing the accuracy of catheter positioning.

Thus, the combination of these elements ensures that the calculated depth is adequate for proper UAC placement, optimizing both efficacy and safety in the clinical setting.