Thread by @NephroP

#POCUS teaching case: #Dialysis patient c/o sob, reports weight gain. BP low to begin with (~100-110 mmHg systolic) & drops further during ultrafiltration. Dr. X performs IVC #ultrasound at the bedside and sees this 👇 - probably volume depleted? See #thread
#MedEd #nephrology

2/ Dr. X orders to stop ultrafiltration. BP stabilized a little bit.
All done?
Wait, something doesn't make sense. Why did the patient gain weight? (usually #dialysis patients know their dry weight well). Why sob?
In the meanwhile, radiology tech performs chest #X-ray 👇

3/ That's not good. Diagnosis is apparent but lets get Dr. Y who does more than just IVC #POCUS
Subcostal view 👇
Significant pericardial effusion

4/ Left lung #POCUS
A huge pleural effusion with spine sign and diaphragmatic flattening

5/ M-mode to assess tamponade physiology
Looks like RV is collapsing in diastole (when the mitral valve opens)

6/ Why didn't the IVC collapse then? Low pressure tamponade where patient is severely volume depleted? 🤔
Time to repeat:

7/ oh no...what happened the first time then?
False collapse due to probe displacement with respiration! - one of the most common pitfalls in IVC #POCUS (in addition to mistaking aorta for IVC 🤦‍♀️)

8/ More teaching points:
- Say NO to single-point #POCUS for volume status assessment
- Clinical integration is the key: question yourself - in this case, why weight gain? why sob? why hepatic vein appears bigger than usual? etc
- Don't hesitate to scan again when in doubt

9/ Patient underwent pericardiocentesis and drainage of left pleural effusion.
Here is the repeat #echofirst

10/ oh...& why did BP improve when Dr. X stopped ultrafiltration initially? - because fluid removal caused decrease in preload - intrapericardial pressure > pressure in cardiac chambers - drop in cardiac output. Large pleural effusion could have contributed as well.

11/ Finally, the famous pericardial effusion #echofirst flashcard

12/ Also, alternative/formal imaging and consultants are available right away in the inpatient setting but in the outpatient dialysis unit, these kind of mistakes/assumptions can lead to mismanagement.