Tourniquet, a compressing device, otherwise its use in intravenous regional anesthesia, is commonly used in particular orthopedic surgeries. From the previous documented effectiveness and safety of intravenous (IV) administration of ketorolac in the circulatory-isolated limb as a part of intravenous regional anesthesia; we hypothesized that in orthopedic surgeries done with tourniquet, intravenous (IV) administration of ketorolac after tourniquet inflation, will act as intravenous regional analgesia. So, it will prolong the postoperative analgesic duration as a primary outcome.

This is a randomized controlled trial that tests the effecacy of the intravenous regional ketorolac in lower limb orthopedic surgeries with spinal anesthesia. The investigators will compare the effect of 30 mg ketorolac without local anesthetic in the injected intravenously in an isolated lower limb (with torniquet) versus intravenous 30 mg ketorolac administered 10 minutes before toniquet pressuerization on the postoperative analgesia.

All patients will receive spinal anesthesia aiming for at least T12-L1 level. Postoperative standard analgesia will be paracetamol and diclofenac, given for both groups.

Inclusion Criteria:

• American Society of Anesthesiologists physical status I or II
• Elective unilateral lower limb orthopedic surgery with tourniquet under spinal anesthesia

Exclusion Criteria:

• Pregnant females
• Body mass index ≥ 35 kg/m2
• Allergy to ketorolac
• Had renal, asthmatic, vascular (Raynaud's syndrome) disease, hematological anemias
• Had any history of gastrointestinal tract inflammation, bleeding, ulceration, or perforation besides
• Edema in the operated limb grade ≥ 3

An anesthetist, not involved in the study, was responsible for randomization list construction, in blocks, opening the sealed envelopes and so, the preparation of the study drugs. The patient and the data collectors (anesthesia resident) does not know the group assignment.