Slowly advance the catheter and needle toward the opposite scapula and into the pericardial sac while monitoring the heart
rhythm (by using an electrocardiograph or by monitoring pulses). Once the catheter is in the pericardial space, a flash of
pericardial fluid will be obtained (most often port wine in color). Advance the stylet and catheter slightly farther, and,
while holding the stylet in place, advance the catheter over the stylet until the catheter is well inside the pericardial
sac. Remove the stylet.
Since most pericardial effusions look like port wine or frank blood, you need to be sure that the fluid you are withdrawing
is the effusion and not blood from iatrogenic puncture of a vessel or cardiac chamber. To make sure, remove a sample with
the 12-ml syringe, and place it in a serum separator or a plain (red-top) tube, and monitor it for clotting. If it does not
clot after one or two minutes, you can usually assume the fluid is effusion, not blood, and you can proceed with rapid pericardial
effusion withdrawal with a larger, 60-ml syringe. However, remember that blood from an active hemorrhage (as in the case of
a left atrial tear or an actively bleeding tumor) also will not clot.
As soon as you have removed the needle from the catheter, attach one end of the extension set to the catheter hub and the
other end to the stopcock and a 60-ml syringe. Apply suction and evacuate the fluid as quickly as possible (Figure 3).
3. The catheter is stabilized against the patient while pericardial fluid is aspirated.