CHAPTER 52: Ultrasound-Guided Peripheral Nerve Blockade

OVERVIEW

GENERAL DATA AND INFORMATION

Regional anesthesia (often called peripheral nerve blockade) involves injecting a volume of local anesthetic in specific locations around nerves that supply various parts of the body, rendering them insensate to a surgical stimulus and allowing for pain relief postoperatively. It can be combined with general anesthesia or sedation for surgical procedures or may be the sole anesthetic of a surgical procedure. These techniques can also be used in the treatment of patients with chronic pain syndromes. For the purposes of this chapter, neuraxial techniques (e.g., spinal and epidural anesthesia) will not be mentioned because they are discussed elsewhere in this text.

The benefits of regional anesthesia include faster discharge times at ambulatory surgical centers along with improved early pain postoperative control,¹ reduction in opioid use in the immediate postoperative period, and less nausea and vomiting postoperatively.² Another advantage is the potential to avoid general anesthesia, particularly in higher-risk patients with significant comorbidities.

For these reasons, the use of regional anesthesia techniques may translate to higher patient satisfaction rates, overall lower health care costs, and improved patient outcomes and quality. The role of regional anesthesia will likely continue to expand because there continues to be tremendous growth in ambulatory surgical procedures, as well as continually evolving changes in reimbursement coupled with the safety, effectiveness, portability, and affordability of ultrasound techniques. Its use will likely only continue to rise, and the authors believe it should be an important part of any anesthesiologist's armamentarium.

GENERAL INDICATIONS AND PATIENT SELECTION

Indications for regional anesthesia are multifactorial. It is most dependent on the type of procedure performed; preexisting patient comorbidities; and the preferences of the patient, surgeon, and anesthesiologist. It is useful when the discussion of the type of anesthesia starts with the surgeon in the office in order to set patient expectations for the day of surgery to include a regional anesthetic.

For indications for each specific type of block, please refer to each individual block.

GENERAL CONTRAINDICATIONS

Absolute

There are very few absolute contraindications to a regional anesthetic block. These include the following:

• Patient refusal

• Active infection at the site where injection of the local anesthetic is to be performed

• Presence of a history of true allergy or anaphylactic reaction to the medications to be injected (e.g., local anesthetic)

Relative

Several relative contraindications to regional anesthesia are often related to patient factors. Some of these include:

• Inability to perform the block because of poor patient tolerance or cooperation (e.g., an awake young child)

• Preexisting neurologic deficit or need for immediate neurologic examination after the procedure

• Preexisting comorbidities that may worsen with peripheral blockade (e.g., prior respiratory dysfunction would preclude ...