Final answer:
The recommended time limit for using a pneumatic tourniquet on the lower extremity in adults is around 90 minutes or less to prevent complications.
Step-by-step explanation:
A pneumatic tourniquet is a medical device that is used to temporarily restrict blood flow to a specific area of the body, typically to create a bloodless surgical field. When using a pneumatic tourniquet on the lower extremity in adults, the recommended time limit is typically around 90 minutes or less. Exceeding this time limit can lead to complications such as nerve and tissue damage. It's important for medical professionals to closely monitor the patient during tourniquet use and make sure the time limit is not exceeded to ensure patient safety.