Large pericardial effusions that occur in medical conditions lend themselves to pericardiocentesis. However, hemopericardial tamponade from penetrating cardiac wounds should rarely have pericardiocentesis because in the very early stages the pericardial blood usually contains large clots which cannot be aspirated, and these lesions, which may rapidly be fatal, require immediate surgical drainage and repair of the cardiac laceration. Pericardiocentesis is rarely used for diagnostic purposes in acute penetrating trauma because of the high incidence of false-negative results occurring when the aspirating needle enters a clot.
A subxiphoid approach is commonly used, preferably under echocardiographic, fluoroscopic, or CT control. The drainage needle can be connected to the chest wall electrode (V lead) of the ECG as a characteristic injury pattern (ST-segment changes or multiple ventricular ectopics) is produced if the tip comes in contact with the myocardium. No fluid may be aspirated if the cannula tip is in the wrong location or there is a hemopericardium with organized blood clot. Thus a screening technique facilitates placement and reduces the risk of the procedure.
After placing the patient in a semisupine position, skin cleansing, placement of sterile towels, and installation of a local anesthetic into skin and underlying soft tissues, an 18 gauge cannula is advanced from beside the xiphisternum under the costal margin, aiming toward the left scapula, until fluid can be readily aspirated. Samples of the fluid should be taken for microbiological, histological, and biochemical analyses, as appropriate. The pericardial sac can be drained to dryness or, alternatively, a guide wire can be introduced through the cannula which is then removed, allowing placement over the guide wire of an indwelling catheter which is usually of the pigtail type. The catheter can be removed, after several days if necessary, when no further fluid is draining. Complications of pericardiocentesis include damage to the ventricle or a coronary artery, arrhythmias, and pneumothorax.
Was this article helpful?