But sounds like from your post a pouch might revive yourself.
To revive yourself, it's the H-DNA.
The pouch works the same way as resurrection chips; it's not just as good. For instance it has shorter range, so it's hard to revive a teammate since it's likely that the mob that killed him will attack you, and then it will be hard to "charge up" the pouch.
As I see it, the poch is a workaround for those who skilled up biotropic but doesn't have the PEDs needed for collateral of the real chip to achieve "death speak", and also for occasional use.
But again, to clarify, while you are dead you can't use any normal kind of item that you equip, so you can't use the pouch or oldschool reschip. Never tried it, but I think if you have H-DNA carried, you will get a question if you want to use one of those if you get killed.
Besides the H-DNA, there one more way to save the day. If you have the "divine intervention" buff, there is a 70% chance you will survive a deadly hit. (You don't need toe chip yourself, it's enough if you met someone who gave you the buff, and the buff lasts for an hour or until you get that deadly hit.)