Abstract
AIM: To test for differences in hemodynamic and analgesic properties in patients with breast cancer undergoing quadrantectomy with paravertebral block (PVB) induced with a solution of either one or two local anesthetics. METHOD: A prospective, single-center, randomized, double-blinded, controlled trial was conducted from June 2014 until September 2015. A total of 85 women with breast cancer were assigned to receive PVB with either 0.5% levobupivacaine (n=42) or 0.5% levobupivacaine with 2% lidocaine (n=43). Hemodynamic variables of interest included intraoperative stroke volume variation (SVV), mean arterial pressure, heart rate, cardiac output, episodes of hypotension, use of crystalloids, and use of inotropes. Analgesic variables of interest were time to block onset, duration of analgesia, and postoperative serial pain assessment using a visual analogue scale. RESULTS: Although the use of 0.5% levobupivacaine with 2% lidocaine solution for PVB decreased the mean time-to-block onset (14 minutes; P<0.001), it also caused significantly higher SVV values over the 60 minutes of monitoring (mean difference: 4.33; P<0.001). Furthermore, the patients who received 0.5% levobupivacaine with 2% lidocaine experienced shorter mean duration of analgesia (105 minutes; P=0.006) and more episodes of hypotension (17.5%; P=0.048) and received more intraoperative crystalloids (mean volume: 550 mL; P<0.001). CONCLUSION: The use of 0.5% levobupivacaine in comparison with 0.5% levobupivacaine with 2% lidocaine solution for PVB had a longer time-to-block onset, but it also reduced hemodynamic disturbances and prolonged the analgesic effect.