PCWP and venous return?

[Fox800]

Just curious, FA2014 on p.222 says that in distributive shock states, PCWP would be decreased while venous return would increase. I'm having trouble getting this. In my mind, increased venous return would increase LA filling pressure and therefore PCWP. More fluid returning = more pressure. What am I not understanding about this?

Thanks!

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[syma]

A complete hazard guess, but you have increased venous return from the vasodilation..??
but could it be that the increased heart rate lowers venous pressure, and ergo LA filling pressure.

 

[CherryRedDracul]

A complete hazard guess, but you have increased venous return from the vasodilation..??
but could it be that the increased heart rate lowers venous pressure, and ergo LA filling pressure.

And the fact that the large drop in systemic vascular resistance causes a baroreflex that increases HR and contractility (increased cardiac output) and attempts--but fails--at arterial vasoconstriction. With the heart trying to shove out as much blood out as it can, wedge pressure is expected to be low.

 

[Fox800]

A complete hazard guess, but you have increased venous return from the vasodilation..??
but could it be that the increased heart rate lowers venous pressure, and ergo LA filling pressure.

And the fact that the large drop in systemic vascular resistance causes a baroreflex that increases HR and contractility (increased cardiac output) and attempts--but fails--at arterial vasoconstriction. With the heart trying to shove out as much blood out as it can, wedge pressure is expected to be low.

Right on. I'll equate that to decrease ventricular filling in tachycardia.

Thanks everyone!