Thiopentone effects?

Question

do you know if thiopentone dilate veins directly and indirectly and how?

Answer 1

As a fast-acting barbituate, thiopentone directly causes venodilation, or dilation of the veins, by decreasing venous tone. Venous tone decreases as a result of relaxation of the smooth muscles of the veins.  Venodilation causes pooling of the blood in the peripheral veins located in the arms, hands, legs and feet as the relaxed condition of the venous muscles prevents them from pushing the deoxygenated blood from extremity capillaries back to the main venous system and heart.  

Normally, the pooling of blood in the peripheral veins is counteracted by sympathetic nervous system activity, increasing heart rate and causing constriction of the veins in order to return blood volume to the heart sufficient to maintain cardiac output.  

Hope that helped!