Intraoperative Measurement of the Pulmonary Artery Pressure: Is It Reliable?

Background: Measurement of pulmonary artery pressure (PAP) is important for therapeutic planning in most types of structural heart diseases. The standard route for measuring PAP is cardiac catheterization. Nevertheless, in some cases, abnormal cardiac structures do not allow for advancing the catheter into the pulmonary artery. Measurement of pulmonary venous wedge pressure is another way, but it is not possible in some cases. During cardiac surgery, it is possible to measure PAP by directly entering a small needle into the pulmonary artery. This study aimed to evaluate the accuracy of PAP measurement during cardiac surgery in patients in a surgical environment. Methods: The study enrolled 105 consecutive patients with congenital heart defects in whom cardiac catheterization was done before cardiac surgery. Systolic and diastolic pressures of the aorta and the pulmonary artery were measured and recorded both during catheterization and during cardiac surgery, and their correlations were assessed. Results: Most of the pressures measured during cardiac surgery were lower than those measured during catheterization; nevertheless, no linear or other clear associations were found between them. There was no meaningful correlation concerning the amount of change between systemic and pulmonary pressures. Conclusions: PAP significantly changes during general anesthesia and with an opened chest cage. PAP measured during surgery could not be relied upon for critical decisions such as univentricular approaches.