Pulmonary artery catheterization (PAC) is a procedure in which an intravascular catheter is inserted through a central vein (femoral, jugular or brachial) to connect to the right heart and get towards the pulmonary vein for assessment and evaluation of different pressures, cardiac output, intracardiac shunts, and vascular resistance.
Despite the decrease in the use of pulmonary artery catheterization for evaluation and management of critically ill patients, still an excellent tool for assessment of patients with suspicious of pulmonary hypertension, cardiogenic shock, and unexplained dyspnea.
Insertion of the catheter from one of the main central veins (subclavian, internal jugular, femoral) gets into the superior or inferior vena cava and reach the right atrium. From the right atrium through the tricuspid valve, the catheter reaches the right ventricle. At this point, the balloon can be inflated, and this helps the catheter to move to the right ventricular outflow tract and there through the pulmonary artery after getting across the pulmonary valve. The tip of the catheter lays into the main pulmonary artery, where the balloon can be inflated and deflate for measurement of pressure.
During the placement of the catheter, due to the transducer that is in the catheter, a pressure waveform can be seen in the monitor. Each section of the right heart anatomy has a distinctive pattern that can help to assist or helps to determine where is the catheter tips.
The most frequent indications for placement of a pulmonary artery catheter are the following:
Contraindications for placement of right heart catheterization are:
A relative contraindication is the presence of left bundle branch block. If this is the case, due to the risk of right bundle branch block during catheter insertion, external or transvenous pacer should be placed at the moment of the procedure to prevent complete heart block.
A Swan-Ganz catheter or right heart catheter is a quadruple-lumen catheter with a thermodilution sensor that is attached to a pressure transducer outside the body, with this transducer, is possible to determine the central vein pressure, right atrial pressure, right ventricular pressure, and pulmonary artery pressure.
The catheters size range from 60 to 110 cm in length and 4F to 8F in caliber
Each of the 4-lumen is placed in a specific distance through the length of the catheter, and each of them has a specific function, as explained:
Preparation for the pulmonary artery catheter is similar for the placement of every invasive procedure.
Verbal consent is necessary before the procedure. Detail explanation of the procedure, risk, and benefits need to be done before starting the procedure.
Selection of the site of insertion of the catheter needs to be selected before starting the procedure. Especial consideration needs to be taken when selecting the site of insertion as skin or site infection, prior vein thrombosis or anatomical abnormalities to prevent complications. Proper catheter selection according to the insertion site is necessary.
Sterile barriers and techniques need to be done during the procedure. Proper cleaning of the site of insertion and draping of the patient is necessary. Also, the person doing the procedure needs to be wearing protective equipment and sterile barrier as sterile gloves, mask, and surgical gown.
Pulmonary artery catheterization can be done under fluoroscopy (most common) or at the bedside with use of ultrasound and echocardiography for catheter placement.
Complications related to catheter placement are similar to the placement of central catheter placement. Infection of the site of insertion can occur.
Pneumothorax or hemothorax can be a complication after insertion when the catheter is placed in the subclavian vein.
Air embolism caused by entrainment of air from the infusion ports.
Complications related to catheter insertion include the occurrences of atrial or ventricular arrhythmias due to irritation or contact of the catheter with the cardiac walls.
Valve rupture or cardiac wall perforation is another mechanical complication when the catheter is inserted.
An important complication that occurs in approximately in 5% of the catheter placement.
Misplacement of the catheter can occur due to looping of the catheter in the right chambers. This can be prevented with the placement of the catheter under fluoroscopy and to paying attention to the waveforms in the monitor.
Vessel rupture can happen at the moment of balloon inflation into the pulmonary artery. Pulmonary artery perforation, pseudoaneurysm formation, and rupture can develop and has a 30% to 70% mortality.
Pulmonary infarction can occur when the balloon is inflated for long period or migration to the catheter to the distal branches.
Thromboembolism can also occur secondary to inflammation or infection of the catheter that acts as a nidus for thrombus.
As mentioned before, placement of the PAC helps for diagnosis of multiple conditions.
PAC can help to determine causes of shock, as cardiogenic versus other causes as septic shock or distributive shock.
PAC is used to determine the cause of pulmonary hypertension for proper treatment after classification in the different groups of pulmonary hypertension.
PAC can help to determine the intracardiac pressure and with this valvular abnormalities.
PAC also helps to determine intracardiac shunts and to determine hemodynamic state before the procedure.
PAC is an important procedure for diagnosis and management of different conditions and despite the underuse of this procedure, still useful.