The usefulness of interpectoral block as an analgesic technique in breast cancer surgery.

OBJECTIVE: To compare the analgesic efficacy of continuous interpectoral block (CIPB) compared to intravenous analgesia (IV) after breast surgery.

MATERIAL AND METHOD: A prospective, comparative and randomised study of women aged from 18-75years, ASAI-III, operated for breast cancer. In group1 (CIPB) after general anaesthetic, an ultrasound-guided interpectoral catheter was placed and 30mL of 0.5% ropivacaine was administered through it. In the event of an increase in heart rate and blood pressure >15% after the surgical incision, intravenous fentanyl 1μg·kg-1 was administered, repeating the dose as necessary. In the postoperative period, perfusion of ropivacaine 0.2% 5mL·h-1 ; with PCA bolus 5mL/30minutes was administered through the catheter for 24hours and rescue analgesia prescribed with 5mg subcutaneous morphine chloride. In group2 (IV), after induction of general anaesthesia, intravenous fentanyl was administered in the same way as in the other group. The patients received metamizole 2g with dexketoprofen 50mg and ondansetron 4mg postoperatively followed by perfusion of metamizole 4%, tramadol 0.2% and ondansetron 0.08% 2ml·h-1 ; with PCA bolus 2mL/20min for 24hours. The same rescue analgesia was prescribed. The principal variables recorded were pain at rest and during movement, according to a simple verbal scale (VAS 0-10) and the rescue analgesia required on discharge from recovery, at 12 and at 24hours.

RESULTS: 137 patients were included: 81 in group1 (59.12%) and 56 in group2 (40.87%). No significant differences were observed in the analgesia between either group, but differences were observed in the dose of intraoperative fentanyl (P<.05). Differences that were not significant were observed in the rescue analgesia required on recovery (10% fewer on group1).

CONCLUSIONS: Both techniques provided effective postoperative analgesia, but the CIPB group required significantly less intraoperative fentanyl.