What is the absolute maximum length of time a pneumatic tourniquet should remain on the affected lower extremity before it is released for re-perfusion?

The maximum length of time a pneumatic tourniquet should remain on an affected lower extremity is generally considered to be 2 hours. This duration is based on the need to balance effective hemostasis during surgery and the potential for complications due to muscle and nerve ischemia. Prolonged application beyond this time frame can lead to irreversible damage to the muscles and nerves due to lack of blood flow, which can result in serious postoperative complications, including dysfunction or loss of the limb.

The cut-off of 2 hours serves as a guideline to ensure that tissues remain viable after the tourniquet is released during re-perfusion. It allows sufficient time for surgical procedures requiring a bloodless field but also minimizes the risk of complications associated with ischemia. While some sources may suggest extending tourniquet times under specific conditions, the standard recommendation is to adhere to the 2-hour limit to ensure patient safety.