0.15 mg Spinal Morphine vs. no Treatment for Morphine Requirement After VATs.

Inclusion Criteria: * Age 18 year or over * Patient ASA physical status I-III. * Scheduled for video-assisted thoracoscopic lobectomy or blebectomy with pleurectomy or pleural abrasion * Can operate a patient-controlled analgesia (PCA) device. Exclusion Criteria: * Known hypersensitivity to morphine * History of bleeding tendency. * Known case of infection at the back * Patient refuse for spinal anesthesia * History of cerebrovascular disease. * Need mechanical ventilatory support during postoperative period