Pectoralis Block vs Paravertebral Nerve Blocks for Breast Surgery

For Pecs-2 blocks, the needle will be advanced to the tissue plane between the pectoralis major and minor muscles at the vicinity of the pectoral branch of the acromiothoracic artery where 10 mL of local anesthetic will be deposited. In a similar manner, 20 mL will be deposited at the level of the third rib above the serratus anterior muscle with the intent of spreading injectate to the axilla. The study fluid will be ropivacaine 0.3% with epinephrine.

For paravertebral blocks, ropivacaine 0.5% (with epinephrine) 9 mL will be administered at each of two levels per side: the T3 and T5 levels for sides without axillary involvement; and at the T2 and T4 level for sides with axillary involvement.