S H O C K

Question 1

Describe why MvO2 is high in SEPTIC shock.

Answer 1

Septic shock is a form of distributive shock due to an underlying systemic infection involving the circulatory system. The systemic inflammatory response causes peripheral vasodilatation and decreased SVR. The decreased blood flow returning to the heart also lowers PCWP. CO is often increased to compensate and maintain adequate tissue perfusion. MvO2 is high due to hyper dynamic circulation, improper distribution of CO, and inability of the tissues to adequately extract oxygen.

Question 2

Is MvO2 high or low in hypovolemic shock?

Answer 2

Hypovolemic shock has reduced preload (PCWP) and reduced CO. SVR increases in an attempt to maintain adequate perfusion to the vital organs. MvO2 is low due to reduced tissue perfusion and increased oxygen extraction by hypo perfused tissue.

Question 3

Define massive PE

Answer 3

PE complicated by hypotension and/or acute right heart strain.

Question 4

Describe why massive PE can lead to cariogenic shock

Answer 4

Right heart strain progresses rapidly to RV dysfunction, decreased return to the left side of the heart, decreased CO, left heart pump failure, and resultant bradycardia. This results in cariogenic shock and causes central nervous system effects, such as dilated pupils and unresponsive mental status.