anaphylactic shock causes inc or dec in CO? - chikoo

[ArchivalUser]

anaphylactic shock causes inc or dec in CO? PRELOAD? AFTERLOAD?

PLS HELP

[ArchivalUser]

Decrease TPR ( afterload ) >> decrease blood pressure
Increase venous return ( preload )
Increase Cardiac output
I.V. fluid does not increase blood pressure

[ArchivalUser]

I DONT GET IT .. how does CO INC. i thought it would dec

[ArchivalUser]

Cardiovascular symptoms and signs, which occur in up to 45 percent of episodes, including hypotonia (collapse), syncope, incontinence, dizziness, tachycardia, and hypotension.

[ArchivalUser]

Profound vasodilation >decreased preload>decreased stroke volume
Profound arteriolar dilation> decreased perpheral resistance> decreased bp> baroreceptor stimulation > reflex tachy cardia for some time in order to compensate.
Therefore CO can be decreased or increased.

[ArchivalUser]

In septic or anaphylactic shock- release of c3a and c5a ( anaphylatoxins) ---- histamine- vasodilation
When there is vasodilation, flow increases so TPR decrease ( after load)
So with all the blood going by , tissues cannot extract any oxygen b/c it's not a controlled flow( turbulent)
Therefore, blood returns to the heart faster than usual b/c all the arterioles widely dilated---- so CO increases and the skin feels warm.