Portable Perfusion Kit

A portable perfusion kit is used in the field to washout the patient's blood.

Examples
Alcor's Air Transportable Perfusion kit (ATP) is documented here.
Suspended Animation's Stockert SCPC Mini-Bypass System is documented here.
Ben Best also discusses blood washout here.

Goals
External cooling is simply not efficient enough. The skin is well insulated and the extremities are poorly vascularized.  The cooling curve would be unacceptably long if only external cooling were used.  If the brain is not cooled quickly enough, it will become edematous (swollen). Edema is a very significant problem because it is largely irreversible, and edema sqeezes shut capillaries in the brain which then cannot be perfused later with cryoprotectants.  It is absolutely essential to keep the capillaries open.

In addition to cooling, the washout removes the red blood cells (RBC's) and other whole blood components.  RBC's become stiff as they get colder and have difficulty passing through capillaries, possibly impairing circulation.  Removing RBC's before extensive cooling reduces the risk of impaired circulation of the capillaries in the brain.

Method
One femoral artery and vein are cannulated.  Tubing and a pump are connected to the cannulae.  Cold preservation solution is carefully pumped into the artery. The preservation solution flows retrograde through the artery until it reaches the aorta.  From there, it is able to flow through all four arteries that supply the brain.  Incidentally, most other areas of the body are also washed out, but the brain is the only organ that we are concerned with.  The effluent from the femoral vein is disposed of. 

Our portable perfusion kit is currently being built.  A diagram of the layout will be posted soon.  The equipment below will be described in more detail over time.

Arterial side
1. Perfusate reservoir.
2. Silastic tubing, 3/8" ID.
3. Pump.  Masterflex 7554-80 with 7518-10 head. (the second head showing in the photo will soon be removed)


4. Heat exchanger, 30 plate, 3" wide x 7.5" tall x 4" thick, 5 gpm capacity, 3/4" NPT ports.

5. Ice bath (for heat exchanger).
6. Pump (for heat exchanger)
7. Arterial filter
8. Sample port
9. Pressure gauge, 1/4" NPT, mmHg scale, liquid or gas.

10. Femoral cannula.

Venous side
1. Venous cannula.
2. Sample port.
3. Tubing.
4. Waste reservoir.