Propofol Pharmacokinetics/Anesthesia

3 collaborators

Stanislav Manastirschi (Team member)

Adrian Belii (Team member)

WHAT IS IT?

This model is a system dynamic multicompartment model that describes some of the pharmacokinetic aspects of propofol used as a general anesthetic administered intravenously (bolus dose that may be followed by continuous infusion). After the injection, propofol is distributed in the body fluids, followed by its degradation/metabolism (in the liver, lungs, kidneys, etc.).

Althogh the model is taking care of quantitative aspects it is primarlily of qualitative nature.

To run the model, you need to download it.

HOW IT WORKS

The model is built under the concept of Total Intravenous Anesthesia (TIVA). The target controlled infusion(TCI) approach tends to maintain a sufficient levels (for adequate anesthesia) of propofol in the brain. This cerebral concentration depends on many factors (e.g., cerebral blood flow, membrane permeability, propofol concentration in blood vessels, etc.), which, in turn, are determined by hemodynamic, metabolic parameters, etc. The relationship between the level/concentration of propofol and these factors are often far from linear. In the current model, most of these relationships are determined by ordinary differential equations.

HOW TO USE IT

Sliders can be used to ajust model parameters. The prefix in a slider name or elsewhere means:

F - flow rate
G - decay rate
PS - "between-compartments" exchange coefficients (e.g., influenced by membrane permeability)
C - concentration

IR stands for infusion rate, CO denotes cardiac output, etc.

After pressing the "setup" button one needs to set the sliders values and press "go" button to run the model.

The dynamics of resulting concentrations in various volume compartments (e.g. viens, aorta, etc) and tissues (lung, brain, etc) can be obsrved in the plotting area and are dispayed by respective monitors.

THINGS TO TRY

By adjusting the sliders (e.g. cardiac output) one can observe the effect of this on brain concentration of the drug. Of particular interest may be the time required to achieve the maximum concentration in a particular tissue. With these settings, you can simulate various clinical situations.

EXTENDING THE MODEL

The model can be extended by adding additional parameters (in the form of additional sliders) that may be relevant for a particular clinical condition/scenario.

CREDITS AND REFERENCES

Please email any questions or comments to viapascurta@yahoo.com

The model was created in NetLogo 6.2.0, Wilensky, U. (1999). NetLogo. http://ccl.northwestern.edu/netlogo/. Center for Connected Learning and Computer-Based Modeling, Northwestern University, Evanston, IL.

Comments and Questions

Please start the discussion about this model! (You'll first need to log in.)

Click to Run Model

to setup

  ca
  system-dynamics-setup
end 

to go

  system-dynamics-go
  system-dynamics-do-plot

  tick
end

There is only one version of this model, created about 2 years ago by Victor Iapascurta.

Attached files

File	Type	Description	Last updated
Propofol Pharmacokinetics/Anesthesia.png	preview	Preview for 'Propofol Pharmacokinetics/Anesthesia'	about 2 years ago, by Victor Iapascurta	Download

This model does not have any ancestors.

This model does not have any descendants.

NetLogo