[osmano807]

There's some practical limits as neurons start to have irreversible injury after 6 hours of ischemia and 8 hours on muscles. Usually we don't put tourniquets for more than 2h30min in lower limbs because after circa 2h we start to have some reperfusion injuries, lesser time on other segments. The usual protocol is to not use tourniquets unless necessary, for ER care have the tourniquets removed each 30min for a few minutes to reduce reperfusion injuries. For surgery we generally follow this with the intervals no bigger than 2h. (source: Ortho and Trauma surgeon)