Hi Fred,
Perhaps you have read from people who have suffered a BO in surface after heavy packing. I have experience near-BO with heavy packing, the reason is the High intrathoracic pressure.
The venous return is the blood that comes from the veins to the right chambers of the heart, and this is pumped to the lungs to get oxygen and leave CO2 mainly, and then it pass to the left chambers of the heart to be pumped to the whole body (Cardiac Output).
When the intrathoracic pressure is very high it affects the venous return (less blood reach the right chambers).
The high pressure also affects the filling of left ventricle, imaging the heart been compressed inward by the pressure, if the left ventricle is not completly full, the Cardiac Output is less than usual.
Puting all together, less venous return and less filling of right ventricle can affect seriously the amount of blood sending to the body (brain included) and predispose to BO.
The immersion can counteract this effect
|
