Collapse Post Anticoagulation

76yo patient presented with pre-syncopal event while going to the toilet. She was noted to have a new left facial droop. 

PMHx

Isheamic CVA 2 weeks ago, stated on apixaban

CRF, HT, DM, HC

On AV arrival, unrecordable BP, started fluids and Nad 4mcg/min --> BP 95/65

Code stroke CT: nil new changes

On reassessment in ED, the pt complained of vague epigastric pain and had RUQ tenderness, nil guarding. Given the ongoing hypotension (BP now 60/) and escalating Nad requirement (Nad now 10mcg/min), a RUSH exam was done for  revealed (no AAA, no FF):

Subxyphoid

A4C

Yes! The echo images show a 1cm concentric pericardial effusion. There is RV collapse in diastole (most easily seen in A4C) suggesting pericardial tamponade. IVC views would have shown a plethoric IV (ie dilated and not collapsing with inspiration). 

It can be hard to tell when diastole and systole is in these images. But just see in a4C how the RV free wall bulges out when it fills and collapses into a triangle when it's empty (diastole) because of pressure from the pericardial fluid. 

The patient went on to have a US guided pericardial tap (apical needle position) and BP improved, NAd was turned off and she went to the ward for definitive management. 

There is debate about the best needle position for pericardiocentesis. A recent review of ultrasound guided pericardiocentesis suggested that the largest, most shallow pocket of fluid should be the needle location (1). Often this may be para-apical or parasternal rather than the traditional subxyphoid approach. 

Some suggest using the linear transducer if the fluid is superficial. But it has a very narrow field of view and it may be difficult to maintain needle visualisation.  I prefer using the curvilinear (abdominal) or phased array (echo) transducers because they have a wide field of view. 

For information on how to perform a pericardiocentesis click on the button below. 

REFERENCES

1. Alerhand S, Adrian RJ, Long B, Avila J. Pericardial tamponade: A comprehensive emergency medicine and echocardiography review. Am J Emerg Med. 2022 Aug;58:159-174.

2. Tsang T, Freeman W, Sinak L et al Echocardiographically Guided Pericardiocentesis: Evolution and State-of-the-Art TechniqueMayo Clinic Proceedings, 73, 647-652