2.6 Outcome measures
The primary outcome measures were to compare the effects of US-RIB, ESP, and SAB on postoperative tramadol consumption of patients, and postoperative pain scores of the patients undergoing unilateral MRM surgery. The secondary outcome measures were the dose of remifentanil and propofol, time of the first pain, the satisfaction score of patients (1–10, where 10 was the highest). In addition to these measures, postoperative nausea and vomiting (PONV, which were rated on a four-point verbal scale: none=no nausea, mild=nausea but no vomiting, moderate=vomiting one attack, severe=vomiting>one attack) and block-related complications such as pneumothorax, bleeding, allergy, local anesthetic toxicity were also recorded.