Efficacy of US-guided TAP Block in Breast Reconstruction Surgery With Abdominal Myocutaneous Flap

Ultrasound (US)-guided transversus abdominis plane block (TAP) has demonstrated favourable results in lower abdominal surgery. Literature about its efficacy in breast reconstruction surgery with transversus rectus abdominis myocutaneous (TRAM) flap is still scarce.

In the current study investigators pretend to evaluate the efficacy of US-guided bilateral TAP block for unilateral breast reconstruction using autologous abdominal graft in women with breast cancer's history.

The investigators led a prospective observational study in patients/participants scheduled to unilateral breast reconstruction surgery with TRAM flap (UBR TRAM) or partial/total or totalization mastectomy followed by TRAM reconstruction (M + UBR TRAM). Participants' anesthetic plan was general balanced anesthesia (GBA) or general balanced anesthesia combined with bilateral TAP block (GBA + TAP).

The anesthetic plan was adopted by the anaesthetist assigned to the operating room on surgery's day. Then, two groups were considered for the study: group submitted to GBA and another submitted to GBA + TAP. Anaesthetic information about intra-operative date was consulted. Investigators included patients subjected to general anesthesia with orotracheal intubation. Intravenous (IV) bolus of fentanyl were administered at anesthetic induction and according to analgesic needs. In patients whose anesthetic plan included TAP block investigators considered cases that it was performed after anesthetic induction before surgical incision. TAP block was performed according to Anesthesiology's Department. After aspiration, a volume of 20 mL ropivacaine 0.375% was administered, bilaterally. Investigators didn´t consider for the study participants whose systemic postoperative analgesic protocol wasn't that adopted by Anesthesiology Department for this kind of surgery.

It was evaluated:

* Intraoperative period: fentanyl consumption (mg/kg), antiemetic prophylaxis and anesthesia duration;
* Post-anaesthesia care unit (PACU): consumed opioids, total score and score relative to consciousness, at admission and discharge, pain assessment, at admission and discharge and nausea and vomiting incidence and stay's length
* After discharge of PACU until 4 hours after surgery's end and between 4th until 24th postoperative hour: morphine consumption, pain assessment, nausea and vomiting incidence and other complications.

Eligibility Criteria:
Inclusion Criteria:

* Patients of age superior 18 years-old;
* Patients scheduled to unilateral breast reconstruction surgery with TRAM flap or partial/total or totalization mastectomy followed by TRAM reconstruction whose anesthetic plan was GBA or GBA + TAP.

Exclusion Criteria:

* Refusal to participate in study;
* Inability to sign written informed consent;
* Body mass index superior (BMI) 40 kg/m2;
* Opioid tolerance (defined as previous consume, minimum period of 2 months, ≥ 50 mg morphine equivalents, per os);
* Substance abuse (addiction syndrome)
* Renal chronic disease with creatinine clearance \< 30 mL/min/1.73m2); hepatic disease (Child-Pugh score of 1, 2 or 3);
* Patients subjected to other surgeries within the same operative time
* Patients that TAP block was not performed before surgical incision and the dose and volume of ropivacaine wasn't 20 mL, ropivacaine 0.375%
* Patients whose systemic analgesic protocol wasn't that adopted by Anesthesiology Department for this kind of surgery