# Calculate blood coming out from cut blood vessel per minute

I am probably searching for some math equation which takes BPM and some specific blood vessel index to calculate blood outcome.(maybe including hearth entropy) If for example we took right subclavian artery and cut it in half while the heart is still beating, how can we calculate the blood that will leave the body thought this hemorrhage(in liters per minute)?

• What is the purpose of this question? – Graham Chiu Sep 19 '18 at 20:20
• So I can be able to calculate hemorrhage outcome – Atanas Bobev Sep 20 '18 at 3:49
• What has your research revealed so far? – Carey Gregory Sep 20 '18 at 4:30

## 1 Answer

You can use the formula for blood vessel flowrate by accounting heart rate and radius using flow rate formula: Q=ΔP/R

Wherein; flow rate (volume/time); ΔP = pressure difference (mm Hg); and R = resistance to flow (mm Hg x time/volume).

"This equation may be applied not only to a single vessel, but can also be used to describe flow through a network of vessels (i.e., the vascular bed of an organ or the even your entire systemic circulatory system). It is known that the resistance to flow through a cylindrical tube or vessel depends on several factors (described by Poiseuille) including: 1) radius, 2) length, 3) viscosity of the fluid (blood), and 4) inherent resistance to flow"

In practicality, these parameters will be difficult to measure. We also have to take into account that over time the heart rate will increase and blood vessel diameter will decrease as a compensatory mechanism against blood loss.

Source: University of minnesota; atlas of human cardiac anatomy

http://www.vhlab.umn.edu/atlas/physiology-tutorial/blood-flow.shtml