Combination of continuous femoral block with parEcoxib vs placebo. Investigation of morphine consumption, opioid sparing effects, VAS pain scores, haemodynamics, Anxierty scores, transfusion requirements , Range of motion and rehabilitation parameters between two groups

Inclusion Criteria:

• PATIENTS ASA I-II UNDERGOING TOTAL KNEE ATRTHROPLASTY

Exclusion Criteria:

Exclusion criteria for both groups included:

• Age younger than 40 years old or older than 80 years old
• ASA > III
• Obesity (>140 kg body weight)
• Allergy to local anesthetics
• History dependence on opioids
• Contraindications for subarachnoid anesthesia or femoral block (coagulopathy, local infection, pre-existing neurological problems, patient refusal)
• Contraindications to the administration of parecoxib
• Severe hepatic or renal disease (serum creatinine ≥ 1.7 mg/dl)