- Primary anesthetic for breast surgery +/- axillary dissection, chest wall procedures,herniorraphy, .
- Post-operative analgesic for video-assisted throcoscopy, thoracotomy, nephrectomy, cholecystectomy, or C-Section.
Level of the Blockade
Spinal roots of the dermatomes within the operative field:
- Mastectomy w/axillary dissection (T1-T6)
- Breast Biopsy ( Dermatome corresponding to biopsy site )
- Umbilical Hernia ( T9-T11)
- Inguinal herniorrhaphy (T10-L2)
Limitations: Optimizing success requires multiple injection sites.
- Midpoint of the most superior aspect of each spinous process to be blocked
- Needle entry is 2.5 cm lateral to each spinous process ipsilateral to the operative site
Note: Due to extreme angulation of the thoracic spinous process, the mark overlies the transverse process of the immediately caudal vertebrae ( i.e. a mark lateral toT6 spinous process overlies the transverse process of T7)
Technique – Landmark Based
- Patient seated upright with neck flexed, back arched, & shoulders dropped forward
- 22g Short beveled needle attached to syringe is advanced perpendicular to back until it comes in contact with transverse process
- Needle is then advanced cauded to transverse approx. 1cm until loss of resistance “pop” is felt.
- Local anesthetic is injected incrementally after negative aspiration
Technique – Ultrasound Guided
1. Positioning same as landmark based technique
- Start scanning with the probe parallel to neuraxis.
- Scan medial to lateral to identify the transverse process
- The hyperechoic cortical surfaces of the transverse processes should be apparent.
- The paraspinal ligament & pleura should appear as hyperechoic membranes delineating deep & superficial limits of paravertebral space.
- In plane needle approach is preferred. Needle is advanced until the tip is in the paravertebral space. Local anesthtic is injected in increment after negative aspiration.
- Local Anesthetic Toxicitiy
- Epidural spread
- Intrathecal or spinal spread
- Vascular puncture