[Forwarded from ANESTHESIA
The first description of a pulmonary arterial catheter (PAC) inserted without the use of fluoroscopy appeared in 1970. It has multiple ports to allow for measurement of intracardiac pressures and thermodilution cardiac output, infusion of medications, and atrial or ventricular pacing. The catheter can be placed at bedside in the ICU without fluoroscopy through a large-bore central venous introducer. The PAC’s position can be identified using the characteristic waveforms as the catheter traverses through the superior vena cava, right atrium, and right ventricle into the pulmonary artery. The figure below shows the waveforms seen as the PAC traverses cardiac structures.
The correlation between the right atrial, ventricular, pulmonary arterial, or pulmonary arterial occlusion pressure (also called pulmonary capillary wedge pressure) and left ventricular pressure is poor and, as such, these measurements can at best be considered surrogates. Fluctuations in intrathoracic and pericardial pressures negatively impact the utility of wedge pressure measurement as well, since left ventricular filling pressure is truly a measurement of the transmural pressure across the ventricular wall. PACs still have an important role in the managemet of pulmonary hypertension, including diagnosis and monitoring response to therapy.
The Berlin criteria for acute respiratory distress syndrome no longer include PAC findings due to poor interobserver reliability in the diagnosis of noncardiogenic extravascular fluid. The use of PACs in the routine management of septic shock and traumatic brain injury is not supported by clinical tri