Background: In this prospective, randomized, placebo-controlled, double-blinded clinical trial we tested the hypothesis that preemptive analgesia with bupivacaine applied in the area of the surgical incision in patients undergoing mastectomy for breast cancer would reduce post-operative acute pain and would reduce the amount of analgesics used during surgery and in the post-operative period.
Material/Methods: Participants were assigned into 1of 2 groups – with bupivacaine applied in the area of surgical incision or with placebo. We assessed the intraoperative consumption of fentanyl, the postoperative consumption of morphine delivered using a PCA method, and the subjective pain intensity according to VAS score reported by patients in the early post-operative period.
Results: Out of 121 consecutive cases qualified for mastectomy, 112 women were allocated randomly to 1 of 2 groups – group A (bupivacaine) and group B (placebo). The final study group comprised 106 breast cancer cases. Between the groups, a statistically significant difference was observed with respect to: lower fentanyl consumption during surgery (p=0.011), lower morphine (delivered by means of a PCA) consumption between the 4–12th postoperative hours (p=0.02) and significantly lower pain intensity assessed according to VAS score at the 4th and 12th hours after surgery (p=0.004 and p=0.02 respectively) for the group A patients.
Conclusions: Preemptive analgesia application in the form of infiltration of the area of planned surgical incisions with bupivacaine in breast cancer patients undergoing mastectomy decreases post-operative pain sensation, limits the amount of fentanyl used during surgery, and reduces the demand for opiates in the hours soon after surgery.

Keywords: Morphine - administration & dosage, Mastectomy - methods, Fentanyl - administration & dosage, Double-Blind Method, Carcinoma - surgery, Bupivacaine - therapeutic use, Breast Neoplasms - surgery, Anesthetics, Local - therapeutic use, Analgesia, Patient-Controlled - statistics & numerical data, Pain Measurement, Pain, Postoperative - prevention & control, Preoperative Care - methods, Prospective Studies