THORACIC PARAVERTEBRAL BLOCK
THORACIC paravertebral block (TPVB) is the technique of injecting local anesthetic
adjacent to the thoracic vertebra close to where the spinal nerves emerge from the
intervertebral foramina. This results in ipsilateral somatic and sympathetic nerve
blockade in multiple contiguous thoracic dermatomes above and below the site of
injection.
Indications:
TPBV offers several technical and clinical advantages and is indicated for anesthesia and
analgesia when the afferent pain input is predominantly unilateral from the chest and/or
abdomen. Bilateral TPVB has also been used perioperatively during thoracic, major
abdominal vascular, and breast surgeries. Common indications are:
POSTOPERATIVE ANALGESIA:
Thoracic surgery
Breast surgery
Cholecystectomy
Renal and ureteric surgery
Herniorrhaphy
Appendectomy
Video-assisted thoracoscopic surgery
SURGICAL ANESTHESIA:
Breast surgery
Herniorrhaphy
Chest wound exploration
MISCELLANEOUS
Fractured ribs
Therapeutic control of hyperhydrosis
Liver capsule pain after blunt trauma
Acute postherpetic neuralgia
Technical advantages::
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Simple and easy to learn
Safer and easier than thoracic epidural
Palpation of rib not necessary and scapula does not interfere with block
Safe to perform in sedated and ventilated patients
Catheter placement under direct vision during thoracic surgery is safe and accurate
Chest drain loss of local anesthetic is four times lower than that of interpleural block
Clinical advantages:
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Single injection produces multidermatomal ipsilateral somatic and sympathetic nerve
block
Maintains hemodynamic stability
Reduces opioid requirements
Low incidence of complications
Preserves bladder sensation
Preserves lower limb motor power
Promotes early mobilization
Anatomy: The TPVS is a wedge-shaped space that lies on either side of the vertebral
column. Its anatomic features are as follows:
BOUNDARIES:
Anterior/lateral: Parietal pleura
Posterior: Superior costo-transverse ligament
Medial: Postero-lateral aspect of the vertebral body, intervertebral disc and the
intervertebral foramen
COMMUNICATIONS:
Intercostal space laterally
Epidural space medially
Paravertebral space on the other side via the prevertebral and epidural space.
CONTENTS: TPVS contains fatty tissue, within which lies the intercostal (spinal) nerve,
the dorsal ramus, the intercostal vessels, the rami communicantes, and, anteriorly, the
sympathetic chain. The spinal nerves in the TPVS are devoid of a fascial sheath, which
makes them exceptionally susceptible to local anesthetic.
Technique:
Patient position: Sitting, lateral, or prone. The sitting position allows easy identification of
landmarks, and the patients are often more comfortable.
Equipment: 10 cm, 18-22 g. short bevel spinal or epidural needle.
Needle Insertion Point: 2.5 cm lateral to the tip of spinous process.
Saggital section through the thoracic
paravertebral space showing a needle that
has been advanced above the transverse
process.
Procedure:
 Insert needle (attached to tubing or syringe) perpendicular to the skin to contact
transverse process at 2-4 cm depth. Then walk off the superior or inferior aspect of
the transverse process, until ‘pop’/loss of resistance to saline or air. Loss of
resistance is subjective and indefinite.
 The needle may be advanced a fixed distance (1-2 cm) without eliciting loss of
resistance – very effective and low risk of complications.
 Limit insertion to < 2 cm past the transverse process. It is imperative to locate the
transverse process before advancing the needle any further to prevent inadvertent
deep insertion and possible pleural puncture.
 Difficulty is common during catheter insertion, and may require manipulation of
needle. Very easy passage may indicate interpleural placement.
 Medial redirection not recommended because of risk of neuraxial injection.
Local Anesthetic: 3-4 ml/ level for multiple level block, 15-20 ml for single level, and
infusion @ 0.1 ml/kg/h. Appropriate drugs: bupivacaine 0.25-0.5%, ropivacaine 0.250.5%, or lidocaine 1%; with epinephrine (2.5 μg/ml).
Mechanism and Spread of Anesthesia: 15 ml bupivacaine 0.5% in TPVs
produces unilateral somatic block over 5 (range: 1-9) dermatomes, and sympathetic block
over 8 (range 6-10) dermatomes.
Possible areas of spread:
 May remain localized
 May spread to contiguous levels above and below
 Intercostal space laterally
 Epidural space, mostly unilateral and insignificant, in up to 70%
 Single 15-20 ml injection as effective as multiple 3-4 ml/site.
 Increasing volume may predispose to bilateral anesthesia
 If a wide block (≥ 5 dermatomes) is desired, preferable to do multiple injections, or 2
injections several dermatomes apart
Pharmacokinetics: In adults, the commonly used bolus dose of 20 ml 0.5%
bupivacaine results in a mean (SEM) maximum concentration of 1.45 (0.32) μg/ml in a
median time of 25 min (range, 10-60 min. Progressive accumulation of bupivacaine can
occur during continuous thoracic paravertebral infusion without clinical signs of toxicity,
although bupivacaine levels have often exceeded the threshold for central nervous system
toxicity (2-4.5 μg/ml). This may account for the few reported cases of postoperative
confusion that resolved after temporary cessation of the infusion. Lidocaine, with a
shorter elimination half-life and lower cardiotoxicity than bupivacaine, may be an
attractive alternative.
Contraindications:
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Infection at the site of needle insertion,
Empyema
Allergy to local anesthetic drugs, and
Tumor occupying the TPVS.
Relative Contraindications:
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Coagulopathy
Kyphoscoliosis (chest deformity may predispose to pleural or thecal puncture)
Patient with previous thhoracotomy: TPVB may be obliterated by scar tissue and
adhesion of lung to chest wall
Complications:
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Failure rate 6-10%, comparable to other regional techniques.
Inadvertent pleural puncture. May or may not produce pneumothorax.
Clues to pleural puncture:
 ‘Pop’ sensation
 Irritating cough
 Sharp pain in chest or shoulder
 Air not aspirated unless lung punctured.
 Air may enter through the block needle.
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Hypotension is uncommon, even after bilateral blocks.
Dural puncture-related complications such as intrathecal injection, spinal anesthesia,
and postural headache appear to be exclusive to the medial approach to the TPVS
and are probably related to the closer proximity of the needle to the dural cuff and
intervertebral foramen.
Transient Horner’s syndrome, ipsilateral or bilateral, caused by spread of anesthetic
to stellate ganglion, or preganglionic high thoracic fibres.
Ipsilateral arm sensory changes (spread to T1 component of brachial plexus)
Pulmonary hemorrhage (1 report with block following previous thoracic surgery)
Reference:
Karmakar, M. Thoracic Paravertebral Block. Anesthesiology, 2001; 95:771-780