Question 1

What is cardiac tamponade and why does it occur?

Accepted Answer

Cardiac tamponade occurs when fluid accumulates rapidly in the pericardial space, causing dramatic pressure increases that compress the ventricles. This rapid accumulation overwhelms the pericardium's ability to stretch, leading to decreased cardiac filling, diminished stroke volume, reduced cardiac output, and ultimately cardiac arrest if untreated. The condition is life-threatening and requires immediate intervention.

Question 2

What are the traumatic and non-traumatic causes of cardiac tamponade?

Accepted Answer

Traumatic causes include stab wounds, gunshot wounds, sternal or rib fractures, and shearing injuries from rapid deceleration. Non-traumatic causes include aortic dissection, myocardial infarction, bleeding from anticoagulant medications, malignancy, and infection. Rapidly accumulating fluid from any source can trigger tamponade physiology, even in small volumes.

Question 3

What physical examination findings suggest cardiac tamponade?

Accepted Answer

Classic findings include distended neck veins, muffled heart sounds, tachycardia, tachypnea, hypotension, and narrow pulse pressure. Patients may also present with diaphoresis, agitation, cyanosis, inability to lie flat, displaced point of maximal impulse, and pulsus paradoxus—a systolic blood pressure decrease exceeding 10 mm Hg during inspiration.

Question 4

How is pericardiocentesis performed using the subxiphoid approach?

Accepted Answer

Position the patient at 45 degrees and cleanse the subxiphoid region with betadine. Insert an 18-gauge spinal needle 1 cm below the xiphoid, aiming toward the left shoulder at a 30-degree angle. Connect the needle to an EKG lead using an alligator clip cable to monitor for myocardial contact. Aspirate continuously while advancing, redirecting as needed until fluid returns.

Question 5

What EKG changes indicate needle contact with the heart during pericardiocentesis?

Accepted Answer

If the needle tip touches the epicardium, the EKG will display an injury pattern resembling a wide-complex premature ventricular contraction with ST elevation. When this occurs, immediately withdraw the needle to prevent myocardial laceration. Electrical alternans—inconsistency in QRS complex height—may also appear on baseline EKGs in tamponade patients.

Question 6

What steps follow successful fluid aspiration during pericardiocentesis?

Accepted Answer

After aspirating fluid, stabilize the needle and remove the syringe. Thread a guidewire through the needle into the pericardial space, then remove the needle. Pass a dilator over the wire to dilate tissue, then remove the dilator. Thread an 8 French pigtail catheter over the guidewire, remove the wire, and place a stopcock on the catheter for future aspiration. Suture the catheter to skin and obtain a chest X-ray.

Question 7

What pre-procedure stabilization measures should be taken before pericardiocentesis in an obtunded patient?

Accepted Answer

Stabilize the patient with IV fluid boluses and vasopressors to support blood pressure. Administer oxygen via nasal cannula or non-rebreather mask. Avoid intubation if possible, as positive pressure in the thorax may strain the heart further. Attach a cardiac monitor and ensure the patient is positioned with chest elevated to 45 degrees before beginning the procedure.

Pericardiocentesis