Step I Phenylephrine --so confused!!!

[Northerncardinal]

Can someone explain the effects of phenylephrine on the following:
1. SBP
2. DBP
3. Stroke volume
4. venous return
5. Pulse pressure

uworld says it increases peripheral vascular resistance and systolic bld pressure and decreases Pulse pressure (because of reflex decrease in Stroke volume and increased afterload)...I don't get this!! 🙁

 

[Gorne]

Can someone explain the effects of phenylephrine on the following:
1. SBP
2. DBP
3. Stroke volume
4. venous return
5. Pulse pressure

uworld says it increases peripheral vascular resistance and systolic bld pressure and decreases Pulse pressure (because of reflex decrease in Stroke volume and increased afterload)...I don't get this!! 🙁

That decrease in stroke volume and increase in afterload is what results in a decreased pulse pressure. You no longer have as great a difference between systolic BP and diastolic as you did prior. I think what may be confusing here is that although it increases systolic pressure, it increases diastolic more so?

 

[Northerncardinal]

That decrease in stroke volume and increase in afterload is what results in a decreased pulse pressure. You no longer have as great a difference between systolic BP and diastolic as you did prior. I think what may be confusing here is that although it increases systolic pressure, it increases diastolic more so?

thanks! this definitely cleared things up.
Can you please explain how it impacts venous return?