75 subjects will be randomly allocated into 3 groups, using a computer generated table of random numbers. Group A (study group) will receive a bilateral TAP block using 15 cc of 0.5% ropivacaine on each side. Group B (control group) will receive 15 cc of sterile normal saline. Group C (study group 2) will receive a bilateral TAP block using 15 cc of 0.25% ropivacaine on each side.
Subjects will be premedicated with intravenous (IV) midazolam 0.04 mg/kg. Routine ASA monitors will be applied. Anesthesia will be induced with remifentanil infusion started at 0.1 mcg/kg/minute titrated to keep blood pressure within 20% of the baseline and propofol 1.0 -2.0 mg/kg. Tracheal intubation will be facilitated with rocuronium (0.6 mg/kg) or succinylcholine (1-2mg /kg). After induction, a bilateral TAP block will be performed in both groups, under ultrasound guidance with a transportable ultrasound device (SonoSite, Bothell, WA, USA) and a linear 6-13 MHz ultrasound transducer .Once the EOAM, IOAM and TAM are visualized at the level of the anterior axillary line between the 12th rib and the iliac crest, the puncture area and the ultrasound probe will be prepared in a sterile manner. Then the block will be performed with a 21 G 90mm StimuQuik needle( Arrow International, Reading, PA, USA ) utilizing an "in- plane" ultrasound-guided technique by three investigators (GDO ,AP). Once the tip of the needle is placed in the space between the IOAM and TAM, and after negative aspiration of blood, 15 cc of 0.5% ropivacaine, 15 cc of 0.25% ropivacaine or sterile normal saline will be administered under direct ultrasonographic guidance. The contralateral block will be performed in the same fashion. Anesthesia will be maintained with sevoflurane titrated to maintain a bispectral index (BIS) between 40-60 , remifentanil infusion started at 0.1mcg/kg/min titrated to keep blood pressure within 20 % of baseline values , and rocuronium that will be administered at the discretion of the anesthesiologist. Upon termination of the surgery, neuromuscular blockade will be antagonized with a combination of neostigmine 0.05mg/kg and glycopyrrolate 0.01 mg/kg. Subjects will also receive ketorolac 30 mg IV after discontinuation of remifentanil for postoperative pain control. Ondansetron 4 mg IV will be administered to prevent postoperative nausea and vomiting. Subjects will be assessed in the OR after extubation for their pain using a numerical rating scale and if pain greater than 4/10 they will receive hydromorphone(10 mcg /kg IV) Subjects will receive IV Hydromorphone in divided doses as needed to achieve a verbal rating score for pain \<4 out of 10 In PACU.They will also receive metoclopramide (20 mg IV ) as rescue antiemetic in PACU. The primary and secondary outcomes will be assessed by an independent observer who will be blinded to group allocation (CA, AP, SA, YV, RJM and PF). A study team representative will telephone the participant at 24 hours, to complete the modified quality of recovery (QOR40) survey and ask the following:
1. How much pain they are experiencing 0-10
2. How and what kind of pain medications have been used since discharge.
3. If they have had any nausea
4. What kind of nausea relief medications have been used since discharge
