clinical use of the pulmonary artery catheter (PAC) may depend on the functionality of the catheter itself. all catheter can be used to obtain and monitor intracardiac and pulmonary artery pressures, provide intermittent or continuous thermodilution cardiac output values, and either to obtain intermittent mixed venous samples from the distal lumen or,if fiber optics are housed in the catheter, to monitor venous oxygen saturation continuously. these parameters are used in diagnosis, selection of therapy, and assessment of the response to intervention.