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Continuous peripheral nerve blocks (CPNBs) provide many advantages in
the perioperative period.1 These techniques provide the
flexibility to prolong intraoperative anesthesia while avoiding the risks
and side effects of general anesthesia. After surgery, CPNBs offer extended
postoperative analgesia. When compared with parenteral opioid analgesia,
CPNBs are associated with superior analgesia, reduced opioid consumption,
and decreased opioid-related side effects such as postoperative nausea and
vomiting, sedation, and respiratory depression.2–12 Analgesia results are of a quality similar to epidural anesthesia results;
however, CPNBs are associated with less hypotension, urinary retention,
pruritus, and mobility restrictions than epidural analgesia.8,13–15 There is also evidence supporting the beneficial effect of
CPNBs on postoperative sleep patterns and cognitive
function16,17 as well as early
rehabilitation.8,9 Concurrent sympathectomy is ideal after
microvascular surgery, reimplantation, and free-flap
surgery18,19 as well as for treatment of accidental
intraarterial drug injection.20–22 Extended analgesia
can also be provided for chronic pain patients23 and those
requiring palliation of terminal illness.24
Despite these benefits, CPNBs have historically been relatively
underused techniques. These reasons for the underutilization were
multifactorial; however, inadequate CPNB equipment likely contributed. Until
recently, there had been few commercially available equipment items
dedicated for CPNBs. A number of relatively new advances in the area of CPNB
needles and catheters have been essential for the safe use and advancement
of these regional anesthesia techniques. This chapter summarizes the
chronology of the development of CPNB equipment, outlines currently
available equipment, and theorizes about possible future directions.
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The earliest report of CPNB is attributed to Ansbro25 in 1946 (Figure 48–1). He attached a malleable blunt needle to
injection tubing and a syringe. The needle was placed in the supraclavicular
area lateral to the pulsations of the subclavian artery and approximately 1 cm cephalad to the midpoint of the clavicle. A cork stopper from an ether
can was used to secure the needle in place. Intermittent injections of
procaine were given to 27 patients to extend the duration of intraoperative
anesthesia for up to 4 hours and 20 minutes.
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