Preload is volume measured by CVP (right) and PAOP (left).
Afterload is pressure measured by PVR (lungs) and SVR (body).
Afterload (SVR) is low only in distributive shock (neurogenic, anaphylaxis, sepsis).
Cardiac index is cardiac output divided by BSA (2.5-4.0).
Hypovolemic shock –High HR and SVR; replace fluids and blood products (if hemorrhagic).
Cardiogenic shock - left ventricular dysfunction. Low CO/CI, SV, and SvO2, high SVR and PAOP. TX: manage arrhythmias, + inotropes, IABP, reduce preload and afterload.
Obstructive shock - pressure (cardiac tamponade, tension pneumothorax, massive PE, abdominal compartment syndrome). TX: relieve pressure.
Distributive shock (maldistribution, vasodilation – decreased SVR)
Neurogenic shock – bradycardia (or lack of tachycardia), bradypnea, hypotension.
Septic shock begins with SIRS.
Anaphylactic shock – (IgE mediated) PNC, IVP dye, food, latex.
