Few would argue that peripheral nerve blocks are an excellent service to patients, yet the myths about PNBs persist. They delay start times and prolong turnover times. They don't last long enough in the OR and last too long in recovery. They're difficult to administer, and good luck getting paid for them. We're here to dispel those and other myths that could keep you from enjoying such benefits as superior pain relief and satisfied surgeons.

Myth 1. Most patients don't need regional blocks because pain from ambulatory procedures is only mild.
Increasingly, more invasive cases are being conducted on an outpatient basis. In our knee surgery practice, for example, we've seen a progression in both surgical complexity and expectations for same-day discharge for such painful procedures as ACL reconstruction with autografts and double-bundle allografts, high-tibial osteotomy and unicompartmental knee arthroplasty. You can only consider such cases for same-day discharge if you have excellent multimodal pain control, including nerve blocks and nerve block catheters. The literature documents that in the absence of an active treatment via a nerve block catheter, patients would suffer terribly during the first two to seven days after such surgeries — likely in the hospital for part of the time, since these patients may not be eligible for same-day discharge. There's no denying that continuous and single-injection peripheral nerve blocks are key reasons why many surgeries formerly thought to be possible only on an inpatient basis can be carried out as ambulatory cases.

Myth 2. Peripheral blocks don't last long enough to provide meaningful relief from painful surgery.
It's true that nerve blocks with long-acting local anesthetics (specifically ropivacaine) can be surprisingly short in duration (about 12 hours) when used as single-shot injections with no analgesic additives. But analgesic adjuvants can contribute meaningfully to the duration of the nerve block, and may help avoid pain-induced middle-of-the-night awakenings, potentially allowing for a better night's sleep after a stressful day of surgery. Adjuncts that can extend a block's duration include clonidine and the opioid analgesic-antihyperalgesic bupernorphine. The familiar (but short-lived) epinephrine doesn't appear to be as effective in prolonging ropivacaine when compared to other local anesthetics. When levobupivacaine was available in the United States (it's now only available in Canada), we were able to achieve a 21-hour duration for interscalene blocks with plain levobupivacaine, and this duration went up to 29 hours when we added buprenorphine 300mcg. However, that perineural buprenorphine dose can induce nausea and vomiting, and more basic scientific research is needed as well.

Continuous peripheral blocks have become much more commonly used on an outpatient basis. Several well-controlled published studies attest to excellent post-op pain control for up to four days after surgery. The frequency of catheter-related malfunction or other technical problems is surprisingly low.

Myth 3. Patients will be uncomfortable and awake during nerve blockade.
We anesthetize the skin before we insert the block needle. And we maintain verbal contact with the patient during a nerve block. This is considered a safety issue, since it's important to recognize when needle placement causes pain in the territory of the nerve being blocked. This phenomenon is called "paresthesia," and generally implies very close contact between the needle and nerve. If the paresthesia is continuous, or occurs during injection, we'll change the needle position until this sensation goes away. Injecting large volumes of local anesthetic at the site at which paresthesia occurs could potentially damage the nerve.

Also consider that we employ sedative and pain medications judiciously during nerve blocks to keep patients comfortable. We sedate most patients to the point that they don't mind the block procedure — and even if they appear to be awake during it, many won't remember it. Different patients require different degrees of sedation. While one patient may be content to feel slightly groggy and interact cheerfully throughout the procedure, another may require sedation to the point of closing his eyes and being in a light sleep during the nerve block. Either way, we can keep the patient relatively comfortable while maintaining his ability to respond to painful stimuli. Interestingly, recent literature suggests that patients receiving ultrasound-guided nerve blocks require less intravenous sedation, perhaps because the image on the ultrasound screen lets the patient feel like a more active participant in the nerve block. Such advances may give patients a better sense of control during surgery.

Myth 4. PNBs prolong turnover time and prolong PACU time due to ongoing numbness and weakness.
When you perform PNBs (and regional anesthesia in general) for the next case in a separate induction room as the current case proceeds, the effect on turnover time is neutral. There are also significant reductions in OR time since the "all-regional" patient is ready for surgical antisepsis and positioning immediately upon entering the OR, and also wakes up faster from intravenous hypnosis. (See propofol-ketamine described in Myth 7 on page 30.) We published this finding in the journal Anesthesiology in 2000.

Surgical facilities performing regional anesthesia and peripheral nerve blocks need to adjust discharge policies and procedures to eliminate the "numbness-weakness" criterion for discharge when a nerve block is known to be in place. In addition, when spinal anesthesia is used it's important to:

• use a one-sided technique (lower doses required, probably less urinary retention and faster recovery times); and
• remember that dextrose added to a spinal will make for a shorter-duration anesthetic. For short-duration knee surgery, we use ipsilateral hyperbaric procaine (10% diluted to 3% to 5% with 10% dextrose, total injectate volume 2ml to 3ml, total dose 50mg to 90mg). Typically, these patients are moving the surgical extremity upon recovery room arrival.

Myth 5. Lower-extremity PNBs prevent safe ambulation at home.
This is a delicate topic. Safe ambulation isn't a problem at home if patients follow the strict instructions not to ambulate. However, some patients may feel falsely secure with the excellent pain relief and ignore their non-weight-bearing instructions, either overtly or as an accidental oversight. (Editor's note: Dr. Williams has a research grant from the National Institutes of Health to examine perineural drug combinations that hope to be equi-analgesic as local anesthetics, but with less motor block.)

Myth 6. Site-specific infusions are as effective as PNBs.
Not surprisingly, continuous infusions of local anesthetic into an incision or a joint have been shown to relieve post-op pain. However, these efforts are not likely to be as effective as blocks of larger nerves at the plexus or peripheral nerve level. Local infusions may or may not "cover" all the dermatomes or peripheral nerve territories involved in a surgical procedure. In particular, infusions into a joint won't likely anesthetize the more superficial skin incisions made to allow access to the joint. Likewise, when an infusion is provided into a subcutaneous region (such as the anterior abdominal wall), deeper structures that have been affected by the surgery (such as the peritoneum) are unlikely to be affected by the local anesthetic solution.

Myth 7. Regional anesthesia is not cost-efficient.
Over the past 13 years at the University of Pittsburgh Medical Center, we've discovered two key things about regional anesthesia:

• it can save up to 10 minutes of OR time per case when compared with general anesthesia; and
• its use can save $400 to $800 per orthopedic patient when administered in an induction room outside the OR.

The cost saving factors are primarily related to less PACU time (specifically, PACU bypass), reliable same-day discharge and less OR time. Nausea, vomiting, pain and somnolence during recovery require salaried or hourly personnel to care for these symptoms, which also prevent staff from discharging well-recovered patients.

Such volatile agents as desflurane and sevoflurane and such airway devices as laryngeal masks add unwanted variability, both in recovery times and in post-op symptoms, when compared with, for example, a spinal, appropriate femoral with or without sciatic nerve blocks (depending on the type of knee surgery) and a propofol-ketamine infusion for effective hypnosis. We also routinely provide multimodal anti-emetic prophylaxis for all patients with off-patent medications (oral perphenazine 8mg and IV dexamethasone 4mg and ondansetron 4mg). In Anesthesiology in 2004, we published that our care plan saved our hospital about $1.2 million per year for 3,000 orthopedic outpatients when compared with "routine general anesthesia care."

Myth 8. You cannot get reimbursed for nerve blocks, nor for ultrasound use with nerve blocks.
The March 2008 issue of Outpatient Surgery Magazine goes into good detail about billing for PNBs (see "The Economics of Peripheral Nerve Blocks" at www.outpatientsurgery.net/2008/03).

Another important consideration involves the separate billing of ultrasound use for ultrasound-guided regional anesthesia. An ultrasound machine is a substantial outlay of money, be it for a hospital, ASC or private anesthesia group. The newer, high-fidelity machines cost in the range of $30,000 to $50,000, depending on manufacturer, model, accessories and transducers. Consider this an investment, not an expenditure. Both your facility and the physicians may bill additionally, over and above the bill for peripheral nerve blockade, when you use ultrasound guidance. This lets either the institution or the physician group recover the cost of the ultrasound machine over time. Appropriate coding and documentation are necessary to capture these facility fees and the providers' fees. In our hospital, where we provide about 1,500 ultrasound-guided blocks each year, we've been able to offset the cost of a $50,000 ultrasound machine in the first year after its purchase, with the promise of substantial revenues in the years to come — which may be applied to new anesthesia equipment or to subsidies provided by the hospital to the anesthesia service.

Overcoming hidden barriers
We hope we've armed you with enough information to dispel the myths about peripheral nerve blocks that you're likely to hear. Regional anesthesia isn't always the right choice, but in the right patients and the right situations it can absolutely improve surgical outcomes.