Single Thoracic Paravertebral Block
A. Thoracic Paravertebral Block
Anna Uskova
Rita Merman
Patient Position: Sitting up across the bed with a stool placed under the feet for stability.
Indications: Anesthesia and immediate postoperative analgesia for inguinal hernia, prostatectomy, and hysterectomy.
Needle size: 22-gauge, 79-mm Tuohy needle.
Volume: 5 mL 0.5% ropivacaine per segment.
Anatomic Landmarks: The paravertebral space is a wedge-shaped space on either side of the vertebral column. Boundaries: anteriorly—parietal pleura; medially—vertebral body, intervertebral discs, and intervertebral foramen; posteriorly—superior costotransverse ligament. The spinous process is the main bony landmark for this block.
Approach and Technique: The spinous processes are palpated and marked with the skin marker. The insertion points are marked 2.5 cm lateral to the superior border of the spinal process and infiltrated with local anesthetic. Then the Tuohy needle is placed perpendicular to the skin with bevel up and advanced up to 3 to 5 cm (Fig. 22-1). When the transverse process is found, the needle is pulled back to the skin and redirected caudally to walk off the inferior aspect or the transverse process, and is then advanced 1.0 cm past the premeasured skin-to-bone distance until a “pop” through the superior costotransverse ligament is appreciated. After the stylet is removed from the needle, the syringe with 0.5% ropivacaine is connected to the needle by extension tubing.After negative aspiration, 5 ml of local anesthetic is injected at each level to be blocked.
 Figure 22-1. The Tuohy needle is placed perpendicular to the skin with bevel up and advanced up to 3 to 5 cm. |
Tips
Inferior angles of the scapulae are used to localize the spinous process of T7 vertebra.
Local anesthesia is performed with two passes of the needle: one perpendicular to the skin (the transverse process can be contacted in thinner patients), then pull the needle back, redirect it caudally, and inject more along the pass to the paravertebral space.
Do not deviate from the parasagittal plane to avoid medial spread and neuroaxial block (postdural puncture headache has been reported after a paravertebral block).
If the needle is redirected caudally and contacts the bone at a shallow distance, reinsert the needle 0.5 cm caudally. (First time was too cephalad and found the rib, instead of the transverse process.)
Too much resistance on injection suggests wrong needle position.
It is not uncommon to see hypotension/bradycardia episodes with this technique in sitting position. Safe practice requires minimal monitoring with noninvasive blood pressure cuff and pulse oxymeter, reliable intravenous access, and supplemental oxygen via nasal cannula. Glycopyrrolate 0.2 mg and ephedrine 50 mg should be always available for treatment. After the episode, extended vital signs monitoring and report to room nurse are recommended.Related posts:
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