Study protocol
nausea, ’, vomiting or retching, pain, NRS pain, Nausea or vomiting, NRS
After induction of anesthesia and before surgery, an ultrasound-guided bilateral posterior TAP block was performed by a single, experienced anesthesiologist. Patients were randomly allocated for bilateral injection with one of the following solutions: 20 mL ropivacaine 0.375% (Study group) or the same volume of 0.9% saline (Control group). The block was performed under ultrasonography guidance using a linear probe (6–13 MHz, GE) and a 22-gauge 0.71 × 80 mm needle (Stimuplex D, B-Braun Melsungen AG, Germany) after sterilizing the skin. Following verification of the position of the needle tip, the study solution was injected between the internal oblique and transversus abdominis plane under real-time imaging. The anesthesiologist who performed the block was not involved in patient allocation and assessment during the study period.Both groups received MMA included dexamethasone, acetaminophen, flurbiprofen and celecoxib. All patients received dexamethasone 5 mg and flurbiprofen 50 mg IV immediately before skin incision as preemptive analgesia. After admission to the PACU, pain intensity was assessed with an 11- point numerical rating scale (NRS) (0 meant no pain, and 10 was the worst pain imaginable) by an investigator who was blinded to group allocation. IV boluses of morphine 1–2 were given as a rescue opioid for NRS pain score ≥ 4. Nausea or vomiting was treated with 5 mg IV metoclopramide. Rescue antiemetics were administered on the following conditions: two or more episodes of vomiting or retching, any nausea lasting for more than 30 min, a ‘severe’ degree of nausea or whenever treatment was requested by the patient.After discharge from the PACU, a morphine intravenous patient-controlled analgesia (PCA) was provided as rescue analgesia (no background infusion, 1 mg bolus with a 6-min lockout interval). Another flurbiprofen 50 mg IV was administered 6 h after surgery. All patients received regular oral acetaminophen (650 mg every 8 h), and oral celecoxib (200 mg every 12 h) on postoperative day (POD) 1 and 2.All data were collected by an investigator who was blinded to the group assignment and not involved in patient’s perioperative care. The observation period started from the end of surgery. The researcher assessed the patients at 1, 2, 6, 24 and 48 h after surgery. After discharge, research personnel contacted patients via we-chat on POD 30 to complete the SF-36 Health Survey Questionnaire.