In hypovolemic shock, decreased intravascular volume leads to reduced cardiac output. Cardiac output is the amount of blood pumped by the heart each minute, and is determined by stroke volume and heart rate. Stroke volume is the amount ejected with each beat. Hypovolemic shock causes decreased preload, the stretch on the heart at the end of diastole, which then decreases stroke volume. With reduced preload and stroke volume, cardiac output in hypovolemic shock would be low.

1. Clinical vignette 2
Shock
Ghaida Al-Rashed

2. Objectives:
What would be the cardiac output (Low,
normal, high )?

3. Introduction

4. Definition
Cardiac output: is the amount of blood that the heart
can pump out in one minute.
Stroke volume: The volume of blood ejected with
each beat.
Preload: is the volume of blood lead to ventricular stretch at the
end of diastole.
Afterload: is the amount of resistance the heart must overcome
to open the aortic valve and push the blood volume out into the
systemic circulation

6. Hypovolemic shock
is a condition characteristic by loss of intravascular
volume
+ reduced tissue perfusion
resulte from decreased blood volume
 caused by blood loss
 leads to reduced cardiac output and organ perfusion.

7. Decrease Intravascular Volume
Decrease Systemic arterial blood
pressure
Decrease Venous return
Decrease Preload (ventricular filling )
Decrease Stroke Volume (the volume
of blood ejected with each beat).
DECREASE CARDIAC OUTPUT

8. Cardiac Output Equation

9. Factors influencing the cardiac
output
Exercise.
Chronic high blood pressure.
Some medication.
Kidney disease.
High cholesterol.

10. In our case :
What would be the cardiac output (Low,
normal, high )?

11. The cardiac output would
be …… ??
Due to ….. ??

12. cardiac output falls.
Since preload is one of the determinants
of stroke volume fall .

13. Summary
Related to
cardiac
output
Pathophysiology
Definition
Hypovolemic shock

14. References
• Guyton & Hall. Text book of Medical physiology
• http://www.emedicinehealth.com/script/main
/mobileart-
emh.asp?articlekey=59301&page=3
• http://www.ems1.com/ems-
products/education/articles/479223-Blood-
Pressure-Assessment-in-the-Hypovolemic-
Shock-Patient/