Regional nerve block is one of the commonly used methods for postoperative analgesia after thoracoscopic surgery. Recent studies have found that rebound pain may occur after regional block, which is defined as acute postoperative pain that occurs after the resolution of sensory block related to regional anesthesia, and seriously affects the quality of postoperative recovery of patients. There is evidence that rebound tenderness is associated with local anesthetic toxicity and proinflammatory effects. The aim of this study was to investigate the effect of dexamethasone on rebound pain after a single intercostal nerve block in patients undergoing thoracoscopic surgery.

Inclusion Criteria:

• Patients scheduled for elective thoracoscopic surgery Age > 18 years old ASA ⅰ-ⅲ Informed consent was signed

Exclusion Criteria:

• Patients with aoagulation disorders Patients with allergy to local anesthetics Patients with severe cardiopulmonary diseases Patients had systemic steroid use Patients with chronic pain Patients with uncontrolled diabetes and mental disorders History of drug abuse; Body Mass Index more than 35 kg.m-2 Pregnant or breastfeeding woman.