American Society of Regional Anesthesia and Pain Medicine May 2018 - 17

ultrasound guidance. I also do not regularly site thoracic epidurals
for any other parts of my practice, so it is a landmark technique
with which I am becoming less proficient. Second, I believe that the
risk profile associated with a landmark-guided thoracic epidural is
worse than that of an ultrasound-guided paravertebral, especially
in the obese population. Third and perhaps most significantly, if I
consented my regular patients for an epidural for breast surgery,
because of the stigma associated with epidurals, most patients
would refuse to have one instead of either a paravertebral or a
PECS block.
Feinstein: Thoracic epidurals are not used for mastectomy at
our institution. Multiple concerns, including hypotension, urinary
retention, pruritus, contraindications with blood thinners, and
potential difficulties with ambulation, along with an inpatient
requirement, have eliminated the technique from our practice.
Do you routinely use local anesthetic additives as part of your
regional anesthetic?
Warren: I do not add adjuncts to my local anesthetic. Epinephrine
is added as a vascular marker but probably does contribute to
prolonging the duration of block effect as well.
Pawa: As a general rule, I do not use additives perineurally for
paravertebral blocks. The only exception is when performing
anesthesia for awake breast surgery. In those circumstances, I
use lidocaine with epinephrine in addition to levobupivacaine to
speed onset and reduce absorption. For most cases I administer
intravenous dexamethasone, which I think has a beneficial effect
despite the lack of evidence for paravertebral blocks.
Feinstein: Dexamethasone is a standard additive in our singleinjection blocks. Meta-analysis of dexamethasone as an additive
has shown an approximately 50-100% increase in duration of
analgesia. Despite being off-label, dexamethasone has a long
history of safe use in neuraxial as well as peripheral nerve blocks.
How do the patient's obesity and obstructive sleep apnea
impact your intraoperative management plan?
Warren: Obstructive sleep apnea and obesity would probably spur
me to use a regional anesthetic if this patient were undergoing a
procedure at my institution that typically does not include regional
anesthesia. It is important to recognize that obesity is likely to make
a regional technique more challenging and may put patients at
increased risk for pneumothorax. A good multimodal plan with local
anesthetic infiltration and a balanced anesthetic can also work well.
Pawa: Obesity is not a problem restricted to North America and is
certainly something that we are dealing with more frequently in
the United Kingdom. The combination with obstructive sleep apnea

focuses the mind and strengthens my resolve to use as opiate
sparing a technique as possible. I mentioned previously that I prefer
using a transverse, in-plane technique for paravertebral block
insertion in obese patients. I would aim to avoid the perioperative
administration of an intravenous opiate for either block insertion
or intraoperative rescue. Instead, I would use bolus doses of
ketamine for intraoperative rescue. I would also consider extubating
the patient immediately onto CPAP to minimize problems in the
postoperative period. If she were suitable for a general anesthesiafree technique (to have the surgery under blocks and sedation), I
would consider the intraoperative use of her own CPAP or high-flow
nasal oxygen.
Feinstein: Intraoperative management of patients with sleep apnea
and obesity tends to focus on airway management, ventilation
and oxygenation difficulties, and extubation. Using multimodal
analgesics and regional anesthesia to minimize the use of opioids
and other sedatives is valuable in decreasing the risk of respiratory
compromise.
Your patient mentions having read that general anesthesia
makes cancer recurrence more likely. How would you respond?
Warren: The jury is still out, and it appears that the avoidance or
limiting the use of opioids may be the important factor in cancer
recurrence.
Pawa: I would be honest and explain that presently, no definitive
evidence backs up such a statement. Interest had been raised in
breast cancer, based on some work performed 12 years ago.4 The
working hypothesis is that avoiding general anesthetic drugs and
opiates and providing anesthesia via regional techniques using
local anesthesia may retain the immune system's integrity and
have an impact on reducing cancer recurrence. This is currently
being investigated thoroughly via a randomized, multicenter trial,
but at present no conclusive evidence exists either way.
Feinstein: Although animal models have shown some risk
of recurrence with certain anesthetics, previously published
retrospective human studies have not demonstrated conclusive
results when evaluating the risk of recurrence and exposure to
volatile anesthetic. Likewise, the theory that regional anesthesia
may reduce the risk of recurrence has also not been proven, but
ongoing studies will hopefully resolve these questions.
Following a thorough discussion with the patient, you agree to
provide general anesthesia and perform bilateral paravertebral
blocks at T3 and T5 with 10 mL 0.25% bupivacaine at each
level to provide postoperative analgesia. After the last
injection, spread of local anesthetic and needle tip location are
noted to be subpleural. The needle is immediately removed,
and the patient neither coughs nor complains of dyspnea.

American Society of Regional Anesthesia and Pain Medicine
2018

Table of Contents for the Digital Edition of American Society of Regional Anesthesia and Pain Medicine May 2018