So here is a video of a pericardial drain placement for pre-tamponade in a 33 yr old man, presumptively for a viral pericarditis (cultures and cytology pending). In this case, the approach was subxiphoid, because this offered a large pocket of fluid with little or no risk of hitting the RV. The apical approach would have been more risky. Due to technical issues, the video only starts once the guide wire is already in place, but there are a couple of teaching points worth sharing nonetheless.
First, it is useful to confirm guide wire placement prior to dilating. Secondly, in cases such as this where the distance to the pericardium is more than a couple of centimetres (it was about 6 cm here), it is nice to be able to confirm under real-time that the dilator is indeed in the intended area. Because the guide wire is highly echogenic, and the dilator is not, one can see the proximal part of the guide wire “disappear” which indicates that the dilator has covered it, now visibly in the effusion. Once the pigtail is inserted over the guide wire, final confirmation can be obtained by injecting back thru the pigtail and seeing echogenic material (due to minute amounts of air) appear in the pericardium. This is known as the Ajmo sign.