Continuous Thoracic Paravertebral Block

Patient Position:
Continuous thoracic paravertebral block (TPVB) is performed most easily
with the patient in the sitting position with feet dangling over the
side of the bed. It is also possible to perform the block in the
lateral or prone position.

Needle Size and Catheter:
The use of a Tuohy needle is preferred because its blunt, rounded tip
provides a distinct “pop” on penetrating the costotransverse ligament
and may diminish the chance of perforating parietal pleura. For
continuous TPVB use an 18-gauge Tuohy needle with graduated markings
and 20-gauge polyamide closed-tip, multiport catheter. More flexible
epidural catheters are not recommended as they will be difficult to
insert.

Volume and Infusion Rate:
An initial injection through the needle of 5 mL of ropivacaine 0.5% to
help distend the paravertebral space and facilitate catheter insertion.
This is followed by the injection of an additional 10 mL through the
catheter. After the surgery, the catheter is infused with 0.2%
ropivacaine at a rate of 7 to 10 mL/hr.

Anatomy and Landmarks:
The thoracic paravertebral space is a triangular space whose boundaries
include anteriorly the parietal pleura, posteriorly the superior
costotransverse ligament, and medially the vertebral body,
intervertebral disc, and intervertebral neural foramen. The apex of the
triangle laterally is continuous with the intercostal space. The space
is bisected by the very thin endothoracic fascia which creates two
“compartments.” The anterior compartment contains the sympathetic
chain, and the posterior compartment contains the intercostal nerve,
dorsal ramus, intercostal blood vessels, and

rami
communicantes. Spinal nerves in the paravertebral space are relatively
devoid of fascial covering making them uniquely and exceptionally
sensitive to local anesthetic blockade. The important anatomic surface
landmark for TPVB is the relevant spinous process or processes for the
desired dermatomes to be blocked. Note that the steep angulation of
thoracic spinous processes brings them opposite the transverse
processes of the adjacent more caudad vertebra.

Approach and Technique:
The relevant spinous processes are identified and marked on the skin
and a point 2.5 cm lateral to the spinous process is also marked (Fig. 31-1).
Disinfectant is applied in standard fashion and local anesthetic (1%
lidocaine) injected at each injection point using a 1.5-cm 25-gauge
needle. The Tuohy needle is advanced onto the transverse process and
the depth from skin to paravertebral space marked by placing the index
or third fingers on the needle shaft 1 cm from the skin (Figs. 31-2, 31-3).
This will now serve as both a depth gauge and a guard against excessive
insertion of the needle. The needle is then walked caudally off the
inferior border of the transverse process and inserted to a depth 1 cm
deeper than the transverse process—that is, to the depth allowed by
prior placement of the index fingers on the needle shaft. Typically at
this point one feels a confirmatory “pop” upon penetration of the
costotransverse ligament. A drop of fluid is placed in the needle hub
and the patient is asked to inspire deeply (Fig. 31-4).
Correct placement is denoted by lack of movement of the fluid bubble. A
drawing inward of the fluid indicates intrapleural needle placement, in
which case the needle should be immediately withdrawn. After correct
needle placement is thus confirmed, 5 mL of local anesthetic is
injected through the needle. It is helpful to have an assistant inject
through an extension tube as this helps avoid significant movement of
the needle. Following the injection the extension tube is disconnected
and the catheter inserted a depth of 3 to 5 cm beyond the tip of the
needle (Fig. 31-5). The catheter is affixed in standard fashion using adhesive strips and transparent dressing (Fig. 31-6).

Patient Position:
For blockade above T7, the patient is best positioned sitting with the
arms dangling between the knees to bring the scapulae apart, thereby
allowing better access to the upper thoracic ribs.

Indications:
The indications are similar to those for the classic paravertebral
block. These include all surgical procedures of the chest and abdomen
including thoracic surgery—both open and video assisted, conventional
and minimally invasive cardiac surgery, breast surgery, plastic
reconstructive or cosmetic surgery, and pectus repair. Urologic
surgical indications include renal, adrenal, ureteral, bladder, and
prostatic surgery. General surgical indications include both open and
laparoscopic surgeries such as bariatric surgery, cholecystectomy,
herniorrhaphy, pancreatic and liver surgery, and bowel surgery.
Gynecologic surgical indications include hysterectomy, myomectomy,
fallopian tube, and ovarian surgery. Nonsurgical indications include
liver capsule pain, rib fractures, acute postherpetic neuralgia, and
chronic pain management for both benign and malignant neuralgias. The
surgical site will of course dictate whether unilateral or bilateral
neural blockade is needed. For retroperitoneal and abdominal surgeries,
typically bilateral blockade is necessary. This technique may be
advantageous in situations where the classic technique would be
contraindicated (e.g., coagulopathies, thrombocytopenia,
anticoagulation therapies, spinal trauma, or previous spinal surgery).

Needle Size and Catheter:
An 18-gauge, 2-inch Tuohy needle and 20-gauge closed-end, multiorifice,
stiff plastic catheter. For obese patients a 4-inch Tuohy needle may be
needed.

Anatomic Landmarks:
The intercostal nerve lies with the artery and vein under the rib in
the subcostal groove between the internal and innermost intercostal
muscles. The puncture site is at the angle of the rib about 8 cm
lateral to the midline. The inferior border of the scapulae is marked
bilaterally. The line connecting the two inferior angles usually runs
through the vertebral body of T7. The desired rib is then delineated.
The lower third of the rib 8 cm from the midline is the entry site.

Approach and Technique:
The skin is prepped and draped in a sterile fashion. Thereafter the
skin and subcutaneous tissue under the entry site is anesthetized with
1% lidocaine until the rib is contacted and the periosteum is
generously anesthetized. The Tuohy needle is then advanced directly
inward to contact the lower third of the rib. The needle is then angled
laterally at 45° to 60° with the bevel facing the spinous process and
is gently walked off the inferior border of the rib while maintaining
this orientation. Once under the rib the needle is advanced 5 to 6 mm
to lie within the subcostal groove. After negative aspiration of heme
or air and a negative fluid drop aspiration test, 5 mL of local
anesthetic is injected followed by passage of the catheter toward the
midline. The catheter is left at the combined distance of 8 cm plus the
depth of the needle such that the tip is left at the ipsilateral
paravertebral space. After securing the catheter, bolus another 10 mL
of the local anesthetic to establish adequate spread. Postoperative
infusions are typically run at 10 to 12 mL/hr (Figs. 31-8, 31-9 and 31-10).