Cardiac tamponade: 12 pearls in diagnosis and management

PEARL 10: PLAN HOW TO DRAIN

The size and location of the pericardial effusion and the patient’s hemodynamics must be integrated when deciding how to relieve cardiac tamponade. When cardiac tamponade is indeed severe and the patient and physician agree that it must be drained, the options are percutaneous needle aspiration (pericardiocentesis) and surgical pericardiostomy (creation of a pericardial window). Here again, as assessed by echocardiography, the access to the pericardial fluid should influence the choice.

Pericardiocentesis can be safely done if certain criteria are met. The patient must be able to lie still in the supine position, perhaps with the head of the bed elevated 30 degrees. Anticoagulation must be reversed or allowed time to resolve if drainage is not an emergency.

Pericardiocentesis can be risky or unsuccessful if there is not enough pericardial fluid to permit respiratory cardiac motion without perforating the heart with the needle; if the effusion is loculated (confined to a pocket) posteriorly; or if it is too far from the skin to permit precise control and placement of a spinal needle into the pericardial space. In cases of cardiac tamponade in which the anatomy indicates surgical pericardiostomy but severe hypotension prevents the induction of anesthesia and positive-pressure ventilation—which can result in profound, irreversible hypotension—percutaneous needle drainage (pericardiocentesis) should be performed in the operating room to relieve the tamponade before the induction of anesthesia and the surgical drainage.¹¹

To reiterate, a suspected cardiac or aortic rupture that causes cardiac tamponade is usually large and not apt to self-seal. In such cases, the halt in the accumulation of pericardial blood is due to hypotension and not due to spontaneous resolution. Open surgical drainage is required from the outset because an initial success of pericardiocentesis yields to the recurrence of cardiac tamponade.

PEARL 11: ANTICIPATE WHAT THE FLUID SHOULD LOOK LIKE

Before performing pericardiocentesis, anticipate the appearance of the pericardial fluid on the basis of the presumed etiology, ie:

• Sanguinous—trauma, heart surgery, cardiac perforation from a procedure, anticoagulation, uremia, or malignancy
• Serous—congestive heart failure, acute radiation therapy
• Purulent—infections (natural or postoperative)
• Turbid (like gold paint)—mycobacterial infection, rheumatoid arthritis, myxedema
• Chylous—pericardium fistulized to the thoracic duct by a natural or postsurgical cause.

Sanguinous pericardial effusion encountered during a pericardiocentesis, if not anticipated, can be daunting and can cause the operator to question if it is the result of inadvertent needle placement in a cardiac chamber. If the needle is indeed in the heart, blood often surges out under pressure in pulses, which strongly suggests that the needle is not in the pericardial space and should be removed; but if confirmation of the location is needed before removing the needle, it can be done by injecting 2 mL of agitated sterile saline through the pericardiocentesis needle during echocardiographic imaging.¹²

Before inserting the needle, the ideal access location and needle angle must be determined by the operator with echocardiographic transducer in hand. The distance from skin to a point just through the parietal pericardium can also be measured at this time.

Once the needle is in the pericardial fluid (and you are confident of its placement), removal of 50 to 100 mL of the fluid with a large syringe can be enough to afford the patient easier breathing, higher blood pressure, and lower pulsus paradoxus—and even the physician will breathe easier. The same syringe can be filled and emptied multiple times. Less traumatic and more complete removal of pericardial fluid requires insertion of a multihole pigtail catheter over a J-tipped guidewire that is introduced through the needle.

PEARL 12: DRAIN SLOWLY TO AVOID PULMONARY EDEMA

Pulmonary edema is an uncommon complication of pericardiocentesis that might be avoidable. Heralded by sudden coughing and pink, frothy sputum, it can rapidly deteriorate into respiratory failure. The mechanism has been attributed to a sudden increase in right ventricular stroke volume and resultant left ventricular filling after the excess pericardial fluid has been removed, before the systemic arteries, which constrict to keep the systemic blood pressure up during cardiac tamponade, have had time to relax.¹³

To avoid this complication, if the volume of pericardial fluid responsible for cardiac tamponade is large, it should be removed slowly,¹⁴ stopping for a several-minute rest after each 250 mL. Catheter removal of pericardial fluid by gravity drainage over 24 hours has been suggested.¹⁵ A drawback to this approach is catheter clotting or sludging before all the fluid has been removed. It is helpful to keep the drainage catheter close to the patient’s body temperature to make the fluid less viscous. Output should be monitored hourly.

When the pericardial fluid has been completely drained, one must decide how long to leave the catheter in. One reason to remove the catheter at this time is that it causes pleuritic pain; another is to avoid introducing infection. A reason to leave the catheter in is to observe the effect of medical treatment on the hourly pericardial fluid output. Nonsteroidal anti-inflammatory drugs are the drugs of first choice when treating pericardial inflammation and suppressing production of pericardial fluid.¹⁶ In most cases the catheter should not be left in place for more than 3 days.

Laboratory analysis of the pericardial fluid should shed light on its suspected cause. Analysis usually involves chemistry testing, microscopic inspection of blood cell smears, cytology, microbiologic stains and cultures, and immunologic tests. Results often take days. Meyers and colleagues¹⁷ expound on this subject.