Postoperative analgesia by infusion of local anesthetic into the surgical wound after modified radical mastectomy: a randomized clinical trial.

Background: There is no consensus on the efficacy of postoperative infusion of local anesthetics after radical mastectomy.

Methods: A randomized, double-blind, placebo-controlled, parallel-groups clinical trial was conducted in a tertiary hospital. Eighty consecutive women with operable breast cancer with indications for modified radical mastectomy without breast reconstruction were assigned randomly to receive infusion of levobupivacaine (0.5%) or saline at 2 ml/hour for 48 hours through a wound catheter. Seventy-three women finished the study (intervention group, n = 34; control group, n = 39). During surgery, all patients received 0.25% levobupivacaine (30 ml).

Results: The levobupivacaine group reported less pain (p < 0.001) than controls in the postanesthesia care unit (1.6 ± 1.3 versus 6.7 ± 1.8) and on the ward at 24 (0.8 ± 0.9 versus 4.2 ± 1.9) and 48 (0.4 ± 0.7 versus 3.3 ± 2.3) hours. In the postanesthesia care unit, the levobupivacaine group consumed less metamizole (0.4 ± 0.5 versus 0.8 ± 0.4; p < 0.001) and dexketoprofen (0.1 ± 0.3 versus 0.7 ± 0.4; p < 0.001), with differences in paracetamol use being insignificant (0.8 ± 0.4 versus 0.9 ± 0.3; p = 0.140). On the ward, the levobupivacaine group used significantly less paracetamol (0.5 ± 0.7 versus 2.0 ± 2.0; p < 0.001) and metamizole (0.2 ± 0.4 versus 1.2 ± 1.4; p < 0.001), but differences in dexketoprofen were not significant (0.03 ± 0.2 versus 0.2 ± 0.6; p = 0.074). In the postanesthesia care unit, the levobupivacaine and control groups consumed 0 ± 0 and 0.7 ± 1.2 doses of opioids (p = 0.001), respectively. The authors observed no differences in nausea and vomiting at any stage in the postanesthesia care unit (0.2 ± 0.4 versus 0.4 ± 0.5; p = 0.081) or on the ward (0.3 ± 0.5 versus 0.4 ± 0.5; p = 0.563). All participants reported high levels of satisfaction.

Conclusion: Continuous infusion of local anesthetic reduces pain and analgesic consumption, with high satisfaction, but does not affect rates of nausea and vomiting.