How do you use IVC caliber and collapsibility to guide decisions about diuresis?

I use IVC caliber in conjunction with my lung exam to assist with the assessment of right and left atrial pressures respectively. The IVC assessment has many caveats in different patient populations, and evaluation with POCUS can be done in two planes to better understand IVC shape.

Caveats - IVC size (>2.1 cm measured 2 cm distal from the hepatic vein entry) and >50% collapsibility in a spontaneously breathing patient can be a helpful approximation of central venous pressure. However, IVC can be...

I agree with all the points made by Dr. @Dr. First Last. I rarely use IVC metrics as an isolated marker to guide diuresis (except when measures are at the low end of the extreme - suggesting RAP <5mmHg). Also agree that there are several important technical, mechanical, and physiological pitfalls related to using IVC ultrasound as the sole objective marker of volume status- these “issues” are likely more prevalent in hospitalized/acutely ill patients.

In addition to clinical and laboratory marke...

Static CVP measurements (for which IVC measurements are a proxy) are confounded by several factors, including abdominal pressures and mechanical ventilation. Only in the extreme (CVP <5, or IVC diam <2.1 cm with >50% collapse with respiration) is it potentially informative in diuresis decisions. I might hesitate to diurese if the findings support low CVP, but I would weigh that against other findings.

I think estimating LA pressure is more valuable for deciding whether to diurese. The presence o...

It is pretty reliable to estimate RA pressure in the non-intubated patient.

In the absence of pHTN, this can be used in conjunction with labs to help guide management.

In the ICU patient, they frequently have arterial lines, so I would have the team transduce the central line 1-2 times a day to follow RA pressure.