The effective surface area calculated by:
Surface area=length of the dialyzer capillary x its circumference x total count
Factors minimizing the effective surface area by decreasing capillaries count:
In inappropriate dialyzer priming, presence of air will block blood from passing through some capillaries
Moving blood clot from the blood line to the filter will block some capillaries
Un-smooth cutting capillaries end in some dialyzers will lead to form clot in capillaries
During dialysis, some capillaries might be clotted
Less effective surface area will affect the dialyzer efficiency in term of:
Toxins removal: the clearance will be less
UF coefficient, will be less leading to high trans membrane pressure
