There are three established methods to perform pericardiocentesis (Table 15.1). The most widely used is via a subxiphoid approach; other approaches include the apical and left parasternal approaches. The echocardiographic window helps in deciding which approach is most expeditious. Careful examination of the echocardiogram to “map the way” and choose which angle is needed prior to proceeding with pericardiocentesis, is an essential step.

To perform a pericardiocentesis from the subxiphoid approach, the patient is placed in a supine position usually lying on a wedge which elevates the torso to an angle of 30–45° which aids in accumulating the pericardial fluid anteriorly (Fig. 15.2). A sterile field is established. The skin and subcutaneous tissues are infiltrated generously with a local anesthetic. The needle is inserted at a shallow angle just to the left of the xiphoid process immediately inferior to the costal margin (Fig. 15.3). The needle is advanced underneath the ribs, bevel up, while consciously making light contact with the overlying periosteum of the rib. This is done in an effort to avoid contact with the lung. The needle is directed towards the left shoulder. A “pop” can usually be felt when the pericardium is entered. At this time the trochar is removed and, if in the correct location, pericardial fluid will flow under pressure through the central lumen of the syringe. If no fluid is obtained, the syringe is removed and the process is repeated, usually with a slightly different angulation.

Currently, pericardiocentesis is rarely done with live echocardiographic guidance. However, some operators employ electrocardiographic (ECG) guidance in an effort to avoid ventricular perforation. An alligator clip is connected to an ECG lead. While slowly advancing the needle, the ECG is monitored, watching for ST segment elevation (a current of injury) which is indicative of contact with the thin-walled right ventricle. If seen, obviously the needle is withdrawn, the trochar removed and examination for pericardial fluid flow from the needle lumen is performed. If the operator is using fluoroscopy, then a guidewire is advanced through the needle, into the pericardial space and is visualized into the pericardium. If the operator is not sure that the wire is in the pericardial space, injection of a small amount of contrast may help in defining the position of the needle tip [2]. Using echocardiography to confirm placement involves injecting agitated saline into the pericardial space once the needle enters the pericardium and before the guidewire is inserted into the pericardial space. The agitated saline can be visualized in the pericardial space confirming the position of the tip of the needle (Fig. 15.4). If agitated saline is seen in a cardiac chamber the needle should be withdrawn. After passing the guidewire into the pericardial space, a dilator is advanced over the wire to create a tunnel through the subcutaneous tissues for passage of a pigtail catheter over the guidewire. The guidewire is then removed from the pigtail catheter and a three-way stopcock is attached to the proximal end of the pigtail catheter.