  We show how to treat the superconformal algebras with eight Poincar\'e
supercharges in a unified manner for spacetime dimension $2 < d\leq 6$. This
formalism is ideally suited for analyzing the quadratic Casimir operator of the
superconformal algebra and its use in deriving superconformal blocks. We
illustrate this by an explicit construction of the superconformal blocks, for
any value of the spacetime dimension, for external protected scalar operators
which are the lowest component of flavor current multiplets.
