i have experienced sleep paralysis c, basically due to eating too much just before sleeping.
i found the 'escape' whilst in this semi-sleep state. i was pinned down on my back unable to move.it was a great struggle to turn on my side,pretty frightening.
the last time it happened i simply lifted my knee as one as does when putting patients in a recovery position after first-aid treatment. since that time i have not suffered sleep paralysis thank goodness.
the nde has many connotations, dreams, adrenaline when under anaesthesics,alcahol, endorphins,etc.etc.