At what depth is a diacritic notch seen when floating a pulmonary artery catheter?

The diacritic notch is an important feature observed on the pressure tracing obtained from a pulmonary artery catheter. It occurs due to the changes in pressure that reflect the closure of the pulmonic valve, which is crucial for interpreting hemodynamic findings during cardiovascular assessments.

The diacritic notch is typically seen at a depth of around 40 cm when the catheter is properly positioned in the pulmonary artery. This depth corresponds to the standard measurement used during catheter placement, taking into account the average anatomy and positioning guidelines for accessing the pulmonary artery from the right heart. Recognizing the position marked by the diacritic notch is essential for clinicians to ensure that the catheter is in the correct location and functioning appropriately, enabling accurate monitoring and intervention when necessary.