Sweet Relief After Joint Replacement Surgery

Patients who have their knees and hips replaced at Yale Medicine in New Haven, Conn., are ready to head home the day of surgery in large part because they’re given shots of a medication cocktail mixed by anesthesiologist Jinlei Li, MD, PhD. She came up with the carefully crafted infusion of short-acting dexamethasone and long-acting methylprednisolone, a combination that packs quite an analgesic punch when administered around nerve blocks to extend their pain-relieving effect.

Dexamethasone has been commonly used for decades with longer-acting local anesthetics such as bupivacaine to manage pain for 15 to 24 hours. “Patients enjoy relief when the local anesthetic is effective, but the pain is sometimes too much for patients to bear when it wears off,” says Dr. Li.

She noticed in the literature that dexamethasone is typically administered in epidurals to manage chronic pain and provides days, weeks and even months of relief. “The medication is not FDA approved for peripheral nerve blocks or neuraxial anesthesia, but it can be injected safely into the epidural space, which is more proximal in terms of the nerve roots,” she says.

It’s innovations such as Dr. Li’s idea to enhance local anesthesia techniques at Yale Medicine that lessen providers’ reliance on opioids to manage the significant pain patients experience after knee and hip replacements.

The effective management of post-op pain is one of the key factors in patients being able to go home the day of surgery. Reducing their discomfort with minimal or no use of opioids allows them to ambulate soon after surgery. Doing so also avoids the potential adverse effects of the narcotics, which increase risk of PONV, constipation and respiratory depression — factors that delay discharges, jeopardize positive outcomes and negatively impact patient satisfaction.

Reducing the use of opioids is also part of providing responsible surgical care — the overprescribing of oxycodone, hydrocodone and methadone is a major cause of the opioid epidemic, according to the CDC. Although the nationwide opioid epidemic often loses out to the pandemic in the news cycle, it’s no less dangerous to the overall health and well-being of countless communities across the country. 

Post-op pain is the result of inflammation caused by tissue trauma, a trademark of joint replacement surgery. Managing it effectively requires attacking it from several angles with numbing agents, nerve blocks and drugs that lessen the local physical response to surgical incisions and dissection. Multimodal pain management strategies that target the mechanisms involved in the perception of pain help to minimize the patient’s reliance on opioids, according to Michelle Lespasio, MD, an assistant professor of orthopedic surgery at Boston University School of Medicine.

She says pain control strategies should focus on the needs of individual patients, taking into account their age, medical history, mentality heading into surgery, tolerance and response to therapeutic agents and risk factors for long-term opioid use. Patients at increased risk of chronic post-op opioid use after surgery tend to be on opioids for four months or longer before surgery, have end-stage osteoarthritis, or are women who are older than 50 years and have a history of drug abuse, alcohol abuse, depression, benzodiazepine use or antidepressant use.

It’s more difficult to control pain in knee replacement patients than in individuals who undergo hip arthroplasties, points out Dr. Lespasio, who says the challenge increases in women, who tend to experience more discomfort than men, and in patients with persistent pre-op use of opioids. 

Dr. Lespasio says it’s important to manage a patient’s comorbidities, which have been shown to increase the level of pain they experience after joint replacement surgery. Setting a BMI threshold and having patients stop smoking before surgery — the toxins in smoke permeate tissue to impede the healing process — can help them recover in less pain.

She points out that surgical technique also plays a part. Patients who undergo procedures performed by surgeons who are skilled at dissection and making accurate bone cuts with minimal damage to surrounding tissue tend to experience less post-op pain. Robotic assistance, which employs surgical navigation to guide surgeons to make preplanned cuts in the patient’s specific anatomy, can help limit the amount of discomfort patients feel after surgery.

Anesthesia providers can administer dexamethasone during surgery in moderate doses to produce a consistent analgesic post-op effect, according to Dr. Lespasio, who says the drug is used as an adjunct to multimodal pain management strategies to reduce post-op opioid consumption. “Balancing pain control with the timely resolution of a motor block results in less nausea and less pain in the immediate post-op period,” she says.

Dr. Lespasio says a study comparing the analgesic effects of mepivacaine and bupivacaine in patients who underwent hip replacement surgery found patients who received mepivacaine, which has a shorter and more predictable half-life, ambulated earlier and were more likely to be discharged sooner, making it a better option in the outpatient setting.

Periarticular injections of long-acting anesthetics around the surgical site can provide a pain-relieving effect for up to 48 hours post-op, points out Dr. Lespasio. Cryoanalgesia, which freezes sensory nerves to provide extended pain relief before or after surgery without the use of opioids, is also gaining traction as an adjunct treatment option for joint replacement patients.

Opioids, when used in moderation, can still be used to treat breakthrough pain, and still have a role in the treatment of joint replacement patients. Dr. Lespasio says best practice is to prescribe less than 90 morphine milligram equivalents per day in a taper plan. Surgeons at Boston Medical Center, where she works, prescribe opioids to treat breakthrough pain according to a two-week plan that limits patients’ access to the pain medications as their recovery progresses: 10 tablets on day one; eight on day two; seven on day three; six on day four; five on day five; and four on day six and seven.

atients receive three tablets each for days eight and nine and two tablets each for days 10 to 14. They’re advised to take the tablets only when necessary and safely dispose of the remaining amount.