INNER VIEW Ultrasound imaging provides real-time visualization of targeted nerves, the approaching needle and spreading anesthesia.

Less post-op pain, shorter recoveries, reduced side effects and limited complications — regional anesthesia has clearly transformed orthopedic surgery's potential. Ultrasound imaging only adds to regional's widespread benefits by giving anesthesia providers real-time visualization of a target nerve, the needle as it approaches, the structures they're aiming to avoid and the spread of the local anesthesia they've injected. Are ultrasound-guided nerve blocks right for your facility? Consider the answers to these 5 common questions about the imaging technology to find out.

Q. Isn't nerve stimulation effective?
A. Yes. Guided by an assumption of anatomical landmarks, providers insert the nerve stimulator's needle as close as possible to the target nerve and deliver a small amount of current, with the hopes of eliciting a muscle response — a twitch — that verifies they've found the correct location. This technology hasn't seen much in the way of change since its introduction. Many providers have become expert at this method, and many still use it, but it arguably has its drawbacks. The motor response you're seeking can vary from patient to patient, and if you don't get the desired response, continued probing or increased current won't do much for your patients' well-being — or their satisfaction, for that matter. Plus, anatomy can differ slightly from patient to patient, creating inexactness that might result in a block failure or a partial block that isn't as effective as you'd intended.

Q. So why bother with ultrasound guidance?
A. To fully understand ultrasound's true benefit, compare it to how providers have traditionally located nerves. When blocks fail, the provider's skill at applying nerve stimulation may incur the blame, but it's entirely possible that anatomical differences are at fault. That's the most immediate benefit of ultrasound imaging in nerve block placement. A patient has abnormal anatomy? You see it on the monitor screen. Ultrasound verifies anatomy for the provider through visualization — not just a twitch — and enables them literally to see if the anesthesia they've injected is on target and effective. As I tell my CRNA students, if you're walking down a dark hallway at home, you may know where you're going, but wouldn't you feel more confident turning on the light?

Q. Are the techniques complementary?
A. There's still a place for peripheral nerve stimulation, particularly for those just learning ultrasound. Seeking a muscle response in conjunction with visualization of the block site — a technique known as dual guidance regional anesthesia — can serve as a learning device to confirm that what you think is nerve tissue on the screen actually is. But with practice, most providers will be able to place blocks with ultrasound alone. In fact, a major medical device manufacturer that had been promoting dual guidance as ultrasound techniques emerged has recently announced the launch of a line of products designed to assist in ultrasound-only block catheter placement.

Q. Is ultrasound safer?
A. Even though the application of ultrasound to regional anesthesia has been the focus of more than a few published studies, the jury is still out on whether the imaging technology holds evidence-based benefits over nerve stimulation. Plenty of papers demonstrate improved results in terms of safety and fewer complications, while just as many others report no discernible gains. All told, the body of literature on the subject does not as yet establish an absolute judgment that placing blocks with ultrasound is a clinically better method.

Indeed, some nerve-stimulation-only practitioners who sport very low block failure rates argue that skilled anesthesia providers can net good results no matter which method they use. Electric nerve stimulation is easy and effective with few complications, they maintain, questioning whether ultrasound is truly a better option, or just a technologically "cooler" one.

Even without a statistical victory for ultrasound, though, there is anecdotal evidence that shows its usefulness in assisting with block procedures. In general, people are visual beings. If a process lets us see more, it stands to reason that we'll be able to achieve at least the same success rate as we would have with a non-visual process, and most likely in a shorter amount of time, too.

In addition to the improvements that visualization brings to blocks' effectiveness, ultrasound can help providers place them with fewer needle passes, which boosts both workflow efficiency and patient satisfaction.

Q. Can ultrasound increase surgery candidates?
A. Yes. Imaging makes block sites easier to locate in some patients. Diabetics, for example, tend to have different stimulation thresholds, and attempts with the nerve stimulator might not elicit the same muscle response as with other patients. Scanning sedated pediatric patients for a nerve will be a much more cooperative experience than fighting them while they're awake to get a twitch.

Ultrasound even lets you place nerve blocks in patients who might have been risky candidates for surgery, such as obese patients with impaired respiration or airways due to chronic obstructive pulmonary disease. In short, very few patients or providers would not benefit from the advantages that visualization brings to nerve blocks.

START-UP SUCCESS

Ultrasound's Essential Elements

TEACHABLE MOMENT Ashley Westerman, RRNA, places an ultrasound-guided saphenous nerve block under the supervision of Jeff Hensley, CRNA.

Here's what your anesthesia providers need to perform ultrasound-guided nerve block placement:

' Ultrasound unit. Since the object is visualization, trial devices predominantly for image quality. The ability to print and store images may be useful, and a compact, portable unit will let providers work in a dedicated block room, procedure room, pre-op bay or the OR. The $28,000 to $35,000 price tag is a sizeable capital outlay, so be sure to seek your providers' and surgeons' consent to a regional anesthesia program before making any purchase.

' Needles. The rise and growing adoption of ultrasound guidance in regional anesthesia has led medical device manufacturers to create accessories designed to further improve the process. Ultrasound-reflective block needles, for example, are an innovation intended to make the technique even more visible. Once they are inserted, the sheath-coated, spray-coated or etched needles provide increased echo-reflectivity and show up more clearly on the ultrasound reading.

It may be a provider-specific experience as to whether these improved needles deliver improved results, though, since most providers can easily get the job done even with standard and inexpensive needles. In a similar vein, catheters have been developed which, once they've been placed, can be used to stimulate the nearby nerve to confirm that they've been correctly placed. A practiced hand may find this double-duty dual guidance function superfluous, however, especially when the stimulating catheters cost more than traditional ones.

' Training. Equipment and supplies aren't all you need. Your anesthesia team would benefit from hands-on ultrasound training courses and visiting nearby facilities to observe how they perform blocks, and surgeons who are supportive of regional anesthesia in their procedures will have a positive impact on the learning curve.

— Jason P. Whiteley, CRNA, DNAP