Ultrasound-guided thoracic pectoralis nerve (PECS I/II) or modified PECS block-serratus anterior plane block are newer ultrasound guided regional anesthesia techniques of the thorax (1). In the last few years many anesthesiologists have evaluated the analgesic efficacy of PECS block in various thoracic surgeries.
The PECS I block was devised to anesthetize the medial and lateral pectoral nerves, which innervate the pectoralis muscles (1). This is accomplished by an injection of local anesthetic (e.g. levobupivacaine 0.25%, ropivacaine 0.5%) in the fascial plane between the pectoralis major and minor muscles. The PECS II block is an extension that involves a second injection lateral to the PECS I injection point in the plane between the pectoralis minor and serratus anterior muscles with the intention of providing blockade of the upper intercostal nerves (2). A further great one modification is the serratus plane block, in which local anesthetic is injected between the serratus anterior and latissimus dorsi muscles (3).
Numerous trials focusing on the analgesic potential of PECS block have been conducted globally. Breast surgery has been the key area of utility for this block.