Paravertebral Block

Indications:

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.

Landmarks

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.