Pericardiocentesis is an invasive procedure in which the physician removes (aspirates) fluid from the pericardium – a protective fluid-filled sac surrounding the heart. This may be an emergency procedure to treat cardiac tamponade, a scheduled procedure to treat less severe fluid buildup, or a diagnostic test to assess for infection or cancer.
The procedure involves the insertion of a needle into the pericardium to withdraw fluid. A catheter may also be inserted to allow further drainage. If necessary, the catheter will remain in place for several days to complete the process. Therefore, the patient should prepare to spend several days in the hospital, though only an overnight stay may be required.
About pericardiocentesis
Pericardiocentesis is an invasive procedure in which the physician removes (aspirates) fluid from the pericardium – a protective fluid-filled sac surrounding the heart. The pericardium is designed to hold a small amount of fluid between its tissue layers, which helps it to cushion, insulate and protect the heart.
In general, physicians recognize two kinds of compressive syndromes that can affect the pericardium and restrict the movement of the heart. The first is constrictive pericarditis, which occurs when the pericardium loses elasticity and becomes thicker and possibly scarred. The second is cardiac tamponade. This occurs when the pericardium fills with excess fluid, thus putting additional pressure on the heart. In addition, these two conditions can occur together. Any number of conditions might cause either constrictive pericarditis or tamponade, including trauma, heart attack, aortic dissection, infection, cancer, or various diseases. If the cause is unknown, it is listed as idiopathic.
Whatever the cause, when fluid begins to build up in the pericardium, the heart's ability to fully fill with blood is reduced due to a limited range of motion. This has a number of effects. First, blood pressure is elevated in the lungs (pulmonary hypertension) because the heart cannot fully expand. In more severe cases, the right side of the heart will be placed under considerable pressure as oxygen-poor blood flows into it. As a result, the muscular wall that separates the right and left sides of the heart (septum) bulges to the left, partially impairing the heart's main pumping chamber, or left ventricle.
Pericardiocentesis is generally reserved for dangerous, acute cases of tamponade. In these instances, it is a life-saving procedure that results in rapid improvement of symptoms. It may also be recommended for patients with subacute tamponade who are beginning to experience symptoms due to fluid accumulation.
The severity of tamponade is related to the filling rate, or the rate at which liquid is pouring into the thin space between the pericardium and the heart muscle. If the problem is acute, it can result in symptoms such as chest pain and difficult breathing. This condition must be treated immediately and is considered a true medical emergency. If the filling rate is slower, it may be known as subacute tamponade and may not have symptoms early on. Later, symptoms are similar to acute tamponade.
Pericardiocentesis has also been used as a diagnostic test, in which a sample of fluid is obtained and analyzed for the presence of viral or bacterial infection or cancer. This test is used most commonly for cases of pericarditis where infection or cancer is suspected. However, its use as a test is somewhat controversial, primarily due to its expense and relatively high risk of complications. Fortunately, the use of fluoroscopy or echocardiogram to help monitor the process is of great help to physicians and has improved both the safety and effectiveness of the procedure. In addition, it can be invaluable for diagnosing or ruling out many forms of pericarditis.
Because of its risk profile, certain patients should not undergo pericardiocentesis. These include patients with aortic dissection. Emergency surgical intervention is warranted in this case.
Before the pericardiocentesis procedure
Pericardiocentesis may be either a scheduled, elective procedure/test or an emergency procedure. If it is scheduled, then at some point beforehand the physician may order blood tests, an electrocardiogram (EKG) and an echocardiogram. The patient may be asked to restrict food and all fluids, particularly if the procedure is scheduled for the afternoon. The physician will likely discuss the patient’s medical history, review the procedure and answer any questions that he or she might have.
During the pericardiocentesis procedure
A pericardiocentesis typically takes place in the cardiac catheterization laboratory of a hospital, although increasingly it is being performed in the intensive care unit. Wherever it is performed, the physician will have immediate access to monitoring equipment, medical devices necessary for the procedure and emergency equipment.
The patient will lie down (or be placed into position, if on critical care) on the operating table with the chest elevated 30 to 60 degrees. An intravenous (I.V.) line will be inserted into the patient’s arm. The puncture site will be cleaned and sterilized, and a local anesthetic will be administered. A long needle is attached to a large sterile syringe and inserted through the chest wall and into the pericardium. The physician can view the movement of the needle on a video monitor if he or she performs an echocardiogram. Alternatively, the progress of the needle may be monitored under a fluoroscope.
Once the needle is in place, fluid is aspirated through the needle and into the sterile syringe. If more fluid must be removed (e.g., due to cardiac tamponade), then a catheter will replace the needle to extract more fluid. In some cases, the catheter may need to remain in place for one to three days to drain all the excess fluid. Any drained fluid is collected in sterile containers for analysis. After enough fluid has been extracted to relieve the symptoms, the needle or catheter is withdrawn and direct pressure is placed immediately onto the site of the incision.
After the pericardiocentesis procedure
Constant monitoring (every 15 minutes for an hour, then every four hours) of pulse, blood pressure and jugular vein bulging (distention) will follow the procedure while the patient is under observation in the intensive care unit. If a catheter must remain in place, the site will be regularly examined for signs of bleeding or infection. The patient should prepare to spend several days in the hospital, although an overnight stay in the intensive care unit may be sufficient.
If pericardiocentesis is not successful, or if fluid builds up again, then further intervention may be necessary. These procedures include:
Percutaneous balloon pericardiotomy uses a balloon-tipped catheter to create a tear in the wall of the pericardium. Fluid drains through the tear and into the pleural cavity, which can accommodate a considerably larger volume of fluid. The procedure only requires local anesthesia. It is used most commonly in patients with cancer where the chief concern is the remaining quality of life.
Surgical pericardiotomy involves giving the patient general anesthesia, so the patient “sleeps” through the procedure. The surgeon then makes an incision in the chest and pericardium to gain access for the drainage tube. Surgery is more likely if the fluid continues to accumulate, if the cause of the fluid accumulation remains obscure, or if the removal of the pericardial sac becomes necessary. This procedure is often preferred over pericardial needle aspiration, particularly when diagnosis or treatment is not an emergency. The advantages include direct visualization of the pericardium by the surgeon, making the procedure safer in general than percutaneous drainage. Also, the procedure allows for a specimen of the pericardium to be evaluated by a pathologist for evidence of cancer or infection. Analysis of both a pericardium sample and collected fluid greatly improves the reliability of a diagnosis made by analysis of the collected fluid alone. Finally, surgical pericardiotomy allows continued draining of the pericardium long after the procedure, which reduces the likelihood of a recurrent effusion.
Pericardiectomy is a type of operation in which part of the pericardium is surgically removed. This procedure may be done if scarring is present with cardiac tamponade. It is usually performed only in severe cases.
Benefits and risks of pericardiocentesis
A successful pericardiocentesis will result in either:
Relief of symptoms from cardiac tamponade, including a restoration of blood flow and a reduction of chest pain.
The extraction of an adequate amount of fluid to conduct diagnostic assessment of the patient. A negative diagnostic will show transparent, straw-colored fluid, no evidence of cancerous cells or infectious pathogens and a white blood cell count less than 1000. An abnormal result may signal pericarditis or other infection, heart failure, cancer, trauma or a ruptured aneurysm.
While the use of imaging to guide the needle and catheter has significantly improved the safety of this procedure and reduced the risk of serious complications from 20 percent in the 1960s to less than 5 percent today, there is a possibility that the following could occur:
Abnormal heart rhythms (arrhythmias), including ventricular fibrillation
Cardiac arrest
Puncture of the heart walls in either the upper chambers (atria) or lower chambers (ventricles) of the heart
Heart attack
Tearing of the coronary arteries, lungs, stomach or liver
Air embolism
Questions for your doctor
Preparing questions in advance can help patients have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions about pericardiocentesis:
What can pericardiocentesis tell you about my condition?
Will I be required to stay in the hospital following this procedure? For how long?
Do you recommend pericardiocentesis for me?
Will I need to stop taking any medications I currently use prior to the surgery?
What side effects might I experience as a result of the surgery?
Will I experience any pain as a result of the procedure?
Are there any other drugs or treatments available to me as an alternative to pericardiocentesis?
What can I expect to feel like after the surgery?
Will I need any additional surgery or treatment following the pericardiocentesis procedure?
Can I undergo pericardiocentesis if I am pregnant?
