BUSINESS BOOM Improvements in pain management techniques have made total knee replacements one of surgery's biggest potential growth markets.

The seismic shift toward same-day total knee replacements is clearly linked to improvements in pain management techniques. Opioids are no longer the first defense, as facilities that perform total knees increasingly turn to multimodal regimens that subordinate, or even eliminate, the need for prescription pain pills.

One result is that outpatient total knees are no longer on the fringe. Nearly one-fourth (24.6%) of our 180 survey respondents discharge total knee patients on the same day, vs. only 8.5% who say that was the case 3 years ago. We'll likely see a sharp spike in volume if, as expected, Medicare starts helping to pay for knee replacements outside the hospital.

But as our survey further suggests, there's no clear consensus on how best to manage pain. Our survey does, however, reflect 2 areas of broad agreement. More than three-fourths (77%) say they've reduced the doses of opioids they prescribe at discharge, and 73% say their pain management for total knees is "very effective." (About 21% say it's "somewhat effective," and 6% admit it's "not as effective as [they'd] like.")

"This is something I've been working on for many years," says orthopedic surgeon Gary Levengood, MD, who's performed hundreds of outpatient total knees at the Gwinnett Medical Center in Duluth, Ga. "I've always been interested in finding something so that when patients wake up, they're not in extreme agony. So I started asking what other people were doing."

His quest led to a multimodal approach that includes regional nerve blocks, NSAIDs, liposomal bupivacaine (Exparel), antiemetics and acetaminophen. The difference compared to years past, he says, is remarkable. "Patients who had surgery 3 or 4 years ago who are coming back to have their other knee done look at me like I'm crazy when I say we can now do it outpatient," he says. "They remember how much agony they were in for a long time after the first surgery. Now, they may end up having some discomfort 3 or 4 days later, but nothing like what they experienced before. Their range of motion is better, the number of falls is down and I haven't had any patients going back to the emergency room for pain control."

Block time
There's no question that regional blocks have become a cornerstone when it comes to the dual goal of managing pain and preparing patients for rapid discharge. Nearly two-thirds (62%) of respondents say single-injection blocks are among the multimodal options they rely on. And those who haven't fully accepted their importance may be paying a price.

A Nebraska CRNA — one of the few who admits that her facility's approach to pain isn't working — bemoans the fact that the "surgeon only allows general anesthesia and infiltrates with a local at the end of the case. He does not allow any other blocks, even though anesthesia is capable and willing."

Femoral blocks are still the most common, but adductor canal blocks are gaining ground, likely spurred in part by a 2014 study (osmag.net/nj2xfv) showing that they provide comparable pain relief with less motor impairment.

"It's an evolution," says Dr. Levengood. "When I first started, we did all femoral blocks, because that was what was out there. Now that anesthesiologists have become more sophisticated, we've moved to adductor canal blocks and have noticed a decrease in the number of falls in those patients. That's allowed me to be more aggressive and get my patients home."

The 2014 study also suggested that the adductor canal serves as a conduit for several nerves in and around the knee, thereby providing a wider area of anesthesia. An OR supervisor from a New Jersey hospital says her facility moved from the femoral perineural catheter to the adductor canal catheter because "it doesn't block the motor pathways post-op." That's made it easier for patients to ambulate without having their knees buckle, she says, adding that "some patients tell us they have no pain at all, or very slight discomfort."

Getting pumped
Less than 20% of our survey respondents provide continuous nerve blocks via catheters and pain pumps. Anesthesiologist Zev Wachtel, MD, of the Carlstadt (N.J.) Surgery Center, thinks all it takes is one bad outcome for surgeons to shy away from catheters. "Surgeons feel they get good outcomes from their single-shot techniques. Why add another modality to potentially cause more issues?" he says.

POWERFUL BLOCK Regional blocks play a key role in managing total knee patients' pain and facilitating rapid discharge.

But that attitude concerns anesthesiologist Gregory Hickman, MD, anesthesia director of the Andrews Institute ASC in Gulf Breeze, Fla., who sees continuous nerve blocks as an important component. "I don't think there's any evidence that shows any increased risk with catheters," says Dr. Hickman, a co-founder of blockjocks.com. "Certainly, we've not experienced any more risk." The point, says Dr. Hickman, is that "when you have a big surgery, like a total knee, the pain is going to last longer than 12 or 18 or 24 hours. There's pretty significant pain for 3 or 4 days."

That's why Dr. Hickman and his Andrews colleagues call their pain-pump patients 24, 36, 48, 72 hours after discharge "every day until their pump is out," he says. Pain scores for Andrews Institute patients, he says, average between 1 and 2 on a scale of 10, and patients take only between 1 and 1.5 prescription painkillers per day once they're home.

NSAIDs next
The second most popular member of the anti-pain arsenal is NSAIDs, trailing blocks only slightly. More than 60% of respondents say they've incorporated NSAIDs into their pain recipes. Not surprising, says anesthesiologist Eugene Viscusi, MD, chief of pain medicine and director of acute pain management at Thomas Jefferson University Hospital in Philadelphia. "Blocks and NSAIDs have the highest impact on pain management. From a pharmacologic standpoint, NSAIDs — including celicoxib, acetaminophen and gabapentinoids — are the triple oral non-opioid backbone to a multimodal platform." Acetaminophen (47%) is also a popular choice among respondents, as it should be, says Dr. Viscusi. OSM