Patients consented for the study will be educated about morphine PCA for pain control and about pain reporting using NRS-11 and VAS scale at rest and with cough or during incentive spirometry. They will receive instructions about Remmers Sleep Recorder (SagaTech Calgary, Alberta, Canada), which includes continuous oximetry, and device will be provided for overnight home screening preoperatively {Whitelaw,W.A. 2005;}. The sleep recorder data will be reviewed pre-operatively and patients with respiratory disturbance index (RDI, measured as oxygen desaturation event) >15/hour who do not have OSA diagnosis and do not use CPAP will be referred for sleep study and/or CPAP titration before the surgery, Patients will be educated on QST testing using pressure algometry with 1cm2 padded tip {Coronado 2010} and will be given survey questionnaire (postoperative diary) for self-reporting of pain (VAS at rest and with cough), nausea/vomiting, activity and side effects from medications as well as satisfaction with recovery and pain control. Baseline pressure pain thresholds (N/cm2) will be tested at abdomen (area of postoperative hyperalgesia) and the pulp of third finger finger on the right (reference site) using average of three measurements per site.