Our study is using the independent variables of low CVP coupled with hypotension and dependent variable of physician administered fluids to test how the Venus 1000 can alter physician actions in the emergency department setting.

1. Measured Central Venous Pressure
and Physician Administration of
Intravenous Fluids; Methods
TODD BELOK
PI: NEAL HANDLY, MD
HAHNEMANN UNIVERSITY HOSPITAL, EMERGENCY DEPARTMENT

2. Hypothesis
• Low (< 8mmHg) measured central venous pressure of
hypotensive non-trauma patients correlates with the decision by
physicians to administer intravenous fluids.
• Do doctors treat low BP/low CVP patients with IV fluids more
frequently than they treat low BP/not low CVP patients with IV
fluids?

3. Background and Recap
Central Venous Pressure = Pressure in the Superior Vena
Cava/Right atrium
Alongside other point of care measurements can be used to
guide hemodynamic treatment
◦ Hypotension in the presence of Low CVP indicates, but does
not prove that the low BP is because of low blood volume
Early goal directed resuscitation
Venous compliance = Change in Volume/Change in
Pressure

4. Background and Recap…Ohm’s Law
http://www.physicsclassroom.com/class/circuits/Lesson-3/Ohm-s-Law

5. Background and Recap
Neal Handly, MD, Hahnemann University Hospital, Emergency Department

6. Background and Recap
Neal Handly, MD, Hahnemann University Hospital, Emergency Department

7. Background and Recap
Neal Handly, MD, Hahnemann University Hospital, Emergency Department

8. Study participants, who qualifies?
Adults
Non-pregnant females
Blind to gender
No recent trauma history
No inmates
Implied consent; informed consent is not required

9. Methods
Check with Charge RN/registrar to see if any non-trauma patients have
been admitted
Take CVP measurement and indicate on paperwork low or not low
◦ Low: CVP <8 mmHg
◦ Not low: CVP ≥ 8 mmHg
CVP measurement is not shared with Hahnemann ED staff
Goal of 200 patients (at least 50)

10. Methods
Mespere LifeSciences

11. Statistical methods
1 tailed Chi squared test
1 independent variable with two levels
◦ Independent variable: CVP in hypotensive patients
◦ Two levels: low and not low
Independent variables/levels are considered dichotomous variables
◦ Categorical
Dependent variables: Whether or not the physician orders IV fluids for low
CVP/low BP patients and if physicians order IV fluids for not low CVP/low
BP patients

12. Potential sources of error
Low number of study participants
Hemodynamic sex differences
◦ Baroreflex response to carotid HTN greater in females than males
◦ Larger reduction in cardiac output
◦ Baroreflex responses to carotid hypotension is similar between the
sexes
Type I (False positive) and Type II (false negative) errors
◦ Differences in physician background: Are we assuming that all
physicians have the same approach to hypotension treatment
◦ Differences in pathology behind hypotension in each patient

13. Potential sources of error continued
Physicians may treat patients differently based upon suspected cause of low BP
◦ Decreased SVR vs CO
Stressed vs. unstressed venous volume
Medical News Today

14. Stressed vs. Unstressed Venous
Volume
Venous blood volume = Stressed volume + unstressed volume
◦ Venous compliance = Change in Volume/Change in Pressure
Unstressed volume
◦ Volume of blood that fills venous system without involving venous compliance or distension
Stressed volume
◦ Volume of blood that involves venous compliance and distends venous blood vessels
◦ Important for establishing pressure gradient to drive venous return

15. Stressed vs Unstressed volume
continued
=
University of Alberta Critical Care Medicine Training Program

16. Stressed vs Unstressed volume
continued
Conditions that contribute to low BP may affect stressed vs
unstressed volume
◦ Decreased SVR in sepsis increases venous compliance and reduces
pressure gradient that contributes to venous return
Pregnant females have different stressed and unstressed volumes
because of blood flow in the uterus and fetus/placenta

17. Neal Handly, MD, Hahnemann University Hospital, Emergency Department
Stressed vs Unstressed volume
continued

18. Stressed vs Unstressed volume
continued
Two compartment model for venous circulation
◦ Splanchnic circulation has high compliance and low flow
◦ Nonsplanchnic circulation has low compliance and high flow
Regional circulation and stressed vs unstressed volume
◦ “The constriction of splanchnic veins is not associated with an increase in resistance to VR
because the splanchnic system is outside of the mainstream of blood flow to the heart through
the caval veins”

19. Dr. Sam George, Anesthesia and Intensive Care, Guajarat Cancer and Research Institute (GCRI)

20. Where do we go from here?
Continue to identify patients who qualify for the study
Collect data
Does Mespere’s Venus 1000 have the potential to improve patient care outcomes?
◦ Setting dependent?

21. Thank you
PI: Neal Handly, MD
Dr. Karen Hurley, PhD
Mespere LifeSciences