So here is our second discussion, where we delve a bit into diuretic physiology, the issue of organ congestion, the myth of the “low-flow” acute renal failure associated with CHF (see earlier post), and a couple other things including a great way to determine if a patient isn’t respecting the low salt diet prescription!
I meant to, but forgot to discuss with Jon what I think is an important end-point in CHF management: the IVC. Yes, it is useful not just to make the diagnosis of congestion, but also target normalization of IVC physiology prior to discharge. It just makes common sense. If you decongest a patient just enough to get them off O2 and send them home, they bounce back a lot quicker than if you make sure you’re given them some intravascular leeway. How do you determine this? Simple enough, make sure your IVC is down at least to below 20mm, and has recovered the classic acxvy and respiratory variation. I personally try to get into the 8-12 mm range, but that’s arbitrary. Here is some good data for 20mm:
So I was in NYC last week and met up with my buddy Jon-Emile Kenny, (@heart_lung), intensivist-physiologist extraordinaire, and we recorded a few discussions on practical matters.
I always love to debunk myths and avoid dogmatic guesswork, and, more often than not, Jon, with his encyclopedic knowledge of the physiology literature, but more importantly a cutting edge understanding of it, can back up my vague ideas and empirically derived ideas, so that the next time someone asks me why this is so, I can have a semi-enlightened answer!
So here is the first, where we discuss the common question about the need (or not) of intravascular volume repletion during or following large volume paracentesis. Yes, there are some formulas out there as to how much albumin or crystalloid one should give, due to the worry of subsequent hypovolemia. Note how those formulas use no data about your patient’s volume status at the time of paracentesis, so as far as I’m concerned, they have no value whatsoever in an era where we can assess this. Yes, ultrasound is the base as far as I’m concerned.