Web-HUMAN Physiology Simulation
Anemia
(Version 10/09/06)


 

Anemia

I. General Information
Web-HUMAN is at http://www.skidmore.edu/academics/human

Excel can be accessed via the Apple menu or in the folder Applications.

II. Anemia
Decreased red cell mass & hemoglobin (i.e. an anemia due to decreased HCT) can accompany several disease states including malnutrition and renal disease. Such an anemia can be progressively be created by reducing basic erythropoeisis to zero (ERYTHB = 0.0). This induces a slowly developing anemia and it is best to record normal values of important variables before starting and then again at several levels of hematocrit (as indicated in the table below).

 HCT

 45

 40

 35

 30

 25

 20

 15

 10
 AP                
 CO                
 RCM                
 PV                
 IFV                
 CELH2O                
 BODH2O                

IV. Analysis

Compensations have occurred at each of the values of HCT tabulated above. Address three of the areas below by picking appropriate variables to view in HUMAN.

1) Hemodynamics - Characterize/explain the rise in cardiac output.

 

 

2) Fluid shifts - Explore the possibilities of the loss of fluid from the vascular space (PV) to the interstitial space due to protein (HHb) and osmotic particle (RBC) loss.

 

 

3) Ventilation - Are arterial O2 tension & content normal? Are venous oxygen tension & content normal?

 

 

4) Cause of death - How long can the simulated subject survive after erythropoeisis is stopped? Examine autopsy data ("Your patients chart") and account for the findings.

 

In addition to the variables listed in the basic table above, via multiple web_HUMAN runs track addition useful hemodynamic, fluid and respiratory variables including AP, COL, HCT, the various plasma fluid pressures involved in transvascular fluid shifts (e.g. PCAP, POSM etc.), lymph flow rates, plasma protein, & hemoglobin, blood viscosity, total peripheral resistance and conductance, resistance to venous return, blood gas content (O2A) and partial pressure (PCO2A), etc.
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A reminder - Some additonal helpful concepts
CO = HR * SV
CO = COND * AP

* adapted from Dr. Randal's Huamn-80 Microcomputer Student Manual