In hypovolemic shock, which pattern best describes hemodynamics?

In hypovolemic shock, which pattern best describes hemodynamics?

• A. Increased systemic vascular resistance, decreased PCWP, decreased CO
• B. Decreased systemic vascular resistance, increased PCWP, increased CO
• C. Increased PCWP, increased CO, increased SVR
• D. Decreased SVR, decreased PCWP, increased CO

Answer: (A)

Hypovolemic shock centers on a fall in circulating blood volume, which reduces venous return to the heart. With less blood filling the heart, left ventricular preload drops, reflected by a lower pulmonary capillary wedge pressure. When the heart isn’t filling adequately, stroke volume—and thus cardiac output—falls as well. In response, the sympathetic nervous system constricts peripheral arterioles to preserve blood pressure and maintain perfusion to vital organs, raising systemic vascular resistance. So the hemodynamic pattern you’d expect is increased systemic vascular resistance with decreased preload (lower PCWP) and decreased cardiac output. This combination distinguishes hypovolemic shock from other shock states where afterload, preload, or cardiac output might present differently (for example, vasodilation with low SVR in distributive shock, or high PCWP with reduced CO in cardiogenic shock).

Hypovolemic shock centers on a fall in circulating blood volume, which reduces venous return to the heart. With less blood filling the heart, left ventricular preload drops, reflected by a lower pulmonary capillary wedge pressure. When the heart isn’t filling adequately, stroke volume—and thus cardiac output—falls as well. In response, the sympathetic nervous system constricts peripheral arterioles to preserve blood pressure and maintain perfusion to vital organs, raising systemic vascular resistance.

So the hemodynamic pattern you’d expect is increased systemic vascular resistance with decreased preload (lower PCWP) and decreased cardiac output. This combination distinguishes hypovolemic shock from other shock states where afterload, preload, or cardiac output might present differently (for example, vasodilation with low SVR in distributive shock, or high PCWP with reduced CO in cardiogenic shock).