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The decision to use regional anesthesia can be a complex medical
choice. Preexisting medical conditions, type of surgery, anesthetic risks,
and patient characteristics all may have a profound impact on anesthetic
choice and perioperative management. In patients with cardiovascular
disease, regional anesthesia techniques (either alone or in conjunction with
general anesthesia) can offer the potential perioperative benefits of stress
response attenuation, cardiac sympathectomy, earlier extubation, shorter
hospital stay, and intense postoperative analgesia.
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Neuraxial anesthesia has been shown to be useful in treating patients
with coronary artery disease. This includes treatment of anginal symptoms,
primary (or part of a combined) anesthetic for the surgical procedure, and
acute postoperative pain management. Its use in the high-risk patient during
noncardiac surgery can offer reduced blood loss and need for transfusion and
a decreased incidence of thromboembolic events.
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Regional anesthetic options are not limited to neuraxial techniques when
dealing with patients with cardiovascular disease. Paravertebral block has
also been used as an adjunct to general anesthesia in the management of
patients undergoing cardiac surgery. In addition, intercostal nerve blockade
and parasternal block can be used for postoperative pain relief in patients
after cardiac surgery. Cervical plexus block can be used in the anesthetic
management of patients undergoing carotid endarterectomy. Lower extremity
blocks, such as combined sciatic–femoral nerve block can also be used in
high-risk patients in whom even modest alterations in hemodynamics would not
be tolerated.
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Local anesthetics alone or in combination with narcotics are used for
regional anesthesia in patients with cardiovascular disease. Ropivacaine is
a commonly used local anesthetic during neuraxial anesthesia for cardiac
surgery. Although its pharmacologic properties, including onset of action
and duration of action, are essentially the same as those of bupivacaine,
ropivacaine possesses less cardiotoxic properties, produces less central
nervous system depression, and is associated with less motor blockade.
Ropivacaine is often combined with sufentanil when used during epidural
administration for cardiac surgery. Intrathecal narcotics in combination
with general anesthesia can provide intraoperative and postoperative
analgesia. The most common undesirable effects of intrathecal opioids are
respiratory depression, nausea and vomiting, pruritus, and urinary
retention. However, advances in narcotic formulations may allow for
sustained-release delivery and target-specific affinity, which may reduce
the potential of common narcotic side effects. Standard local anesthetic
preparations are used in performing upper and lower extremity blocks in
patients with cardiovascular disease.
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The most severe complication from neuraxial anesthesia is epidural hematoma
formation. The incidence of hematoma formation ranges from 1:150,000 after
epidural instrumentation to 1:220,000 for intrathecal instrumentation. Risk
of hematoma formation after either technique is increased if performed
before systemic heparinization. Currently, only a minority of practicing
anesthesiologists use neuraxial blockade in the management of patients
undergoing cardiac surgery. Patients presenting for major noncardiac surgery
often receive anticoagulation to prevent venous thrombosis and pulmonary
embolism. It appears that anesthesiologists more frequently perform
neuraxial blockade on these patients after weighing the risk of hematoma
formation against the benefits.