PLAN OF ATTACK Administer a variety of agents with different mechanisms of action to manage both local and systemic pain.

At the Hospital for Special Surgery in New York City, we've been searching for the optimal multimodal pain management regimen for the last 18 years. Although we haven't yet hit on the perfect plan, we've made tremendous strides in developing a protocol that controls pain, improves patient satisfaction, lowers opioid consumption and reduces post-op stays, all while minimizing complications.

Finding the right mix
To keep patients comfortable enough to head home hours after notoriously painful orthopedic procedures, it's essential to attack the various ways pain is perceived in the spinal cord, the peripheral nerves, the dorsal ganglia, and ultimately the central nervous system and brain. Our current protocol has evolved over time, undergoing many modifications as we've seen what works well, and what's not as effective.

We've come to recognize the advantages of regional anesthesia, which we now use on the vast majority of our patients. In addition to reducing blood loss and preventing deep vein thrombosis, it avoids central nervous depression, places less stress on the cardiopulmonary system, may modify the stress response to surgery, provides excellent pain relief, and allows early painless range of motion and weight bearing. We use general anesthesia only in those rare instances in which the anesthesiologist is unable to perform the spinal or epidural anesthesia for medical or technical reasons.

Parenteral opioids are the source of many of the negative effects of analgesic therapy, so limiting their use is also a major principle of our multimodal approach, which I've outlined here:

• In pre-op. About an hour before surgery, we administer preemptive analgesia — usually IV acetaminophen, a relatively recent addition to the field that we've found helpful. As a preemptive measure, IV acetaminophen helps prevent the establishment of central sensitization and the amplification of pain.
• During surgery. Our surgical "cocktail" includes several medications designed to work in different ways on different levels. We inject a steroid-containing local anesthetic into the soft tissues that surround joints. The steroid helps prevent local inflammation, and is combined with just enough morphine to stimulate all 3 opiate receptors in the joint with fewer adverse systemic effects.
KEY INGREDIENTS A multimodal cocktail includes several medications designed to work on different types of pain.

The cocktail also includes an antibiotic, bupivacaine, epinephrine, clonidine and a little saline. Bupivacaine works as a sodium channel blocker and numbs the area. Epinephrine inhibits capillary distribution, which helps keep all the medications we administer in the area of the planned operation. Clonidine helps promote the synergistic action of the local anesthetic and local steroids. Applying clonidine transdermally, via a patch, allows sustained action for several days while minimizing potential adverse effects, including abnormally slow heart rate or blood pressure. We consider these medications the most important and effective component of our pain protocol.

• In post-op. We administer a variety of agents with different mechanisms of action, with a goal of providing both local and systemic pain relief. They include agents that combine anti-inflammatory and analgesic properties, such as acetaminophen and steroids, and in some cases, ketorolac. We also convert patients to oral agents and try to minimize or completely avoid parenteral opioids. If the regimen is deemed ineffective, we augment it with 2 or 4 mg doses of morphine sulfate at 15-minute intervals. Once the patient can tolerate oral medication, we administer oxycodone on a PRN basis. Discharged patients also take 1,000 mg of acetaminophen orally every 6 hours, Celebrex (200 mg once daily) for 10 days total and pantoprazole (40 mg orally) for gastrointestinal prophylaxis.

ADVERSE EVENTS
Study: Pregabalin Linked to Birth Defects

Pregabalin, which is used to treat neuropathic pain and is a component in multimodal pain regimens, has been linked to major birth defects, according to a study (osmag.net/wxwg6u) recently published in the journal Neurology.

Researchers compared 164 pregnant women who had first-trimester exposure to pregabalin with 656 women who did not take the drug. The findings show that major birth defect rate was nearly 3 times as high (6.0% vs. 2.1%) in women who took pregabalin.

But that's far from the final word on the medication. The authors caution that "several limitations" may have impacted the study, including a "small sample size, differences across groups in maternal conditions and concomitant medication exposure."

If confirmed through independent studies, however, the findings have significant implications for all women of child-bearing age, since, as the authors point out, a significant number of pregnancies are unplanned. Widespread use of pregabalin may therefore lead to inadvertent exposure during early pregnancy, notes the study. That's something to monitor and consider if the drug is part of your multimodal pain management regimen.

— Jim Burger

Setting expectations
The goal of pain management is to keep patients comfortable, but cognitively aware, which lets them stand up in the recovery room an hour or so after surgery, and, if all goes well, be ready for same-day discharge. The multimodal approach is a game-changer in that regard.

When the protocol works best, it's not uncommon for us to do major surgery accompanied by an injection of a local anesthetic, and then have patients solely on oral medications in the recovery room. Some patients say they don't even feel as if they've had surgery. They came to the hospital in pain and were never in pain again. They gave up their walking aids after a week of recovery and they never took the opioid painkillers we'd prescribed for them. Amazingly, most patients fall into that category. Of course there are some patients who need higher levels of pain management. They may be opioid-dependent, have borderline depression or just tolerate pain poorly.

Either way, setting patient expectations through educational programs is a key component of any pain management program. Patients are going to be taking control of their post-op care, so they need to be fully versed in what they're doing and what the issues are. We can't just say, Take this pill every 4 hours. That's a simple directive that doesn't help patients understand the basis for the regimen. They need to understand, for example, that if they're having issues, it's better to take 2 medications that work differently, instead of a second medication that works the same way as the other medication they're already on.

Educating patients about the pain they might experience and the several steps you'll take to control that pain will set realistic expectations about how they'll feel after surgery. If patients are na??ve about post-op pain and function in the joint — which they often are — it can lead to high levels of dissatisfaction. We've found that pre-operative classes effectively educate patients and their families about the realities of the recovery process. By explaining what they'll experience during and after surgery we can substantially ease the fears they may have well before they show on the day of surgery. We provide booklets and videos and reinforce the information through oral instruction. Patients have a better idea of what to expect when they have interactive discussions with surgical team members. Decreasing anxiety is also part of the multimodal approach, because failure to do so may increase sensitivity to pain.

SOFT TOUCH Effective pain management provides comfort while keeping patients cognitively aware.

Still striving
Severe post-op pain can prolong stays, increase readmissions and increase opioid use, which may lead to PONV, low patient satisfaction and substance-abuse issues. Arthrofibrosis and diminished range of motion in the joint are also closely related to the degree of post-op pain.

We're still searching for the ideal multimodal techniques that would eliminate the use of opioids or even remove pain entirely from the recovery equation. Many of us had hoped that injections of bupivacaine liposome around the surgical site would be the game-changer we were looking for, but our experience with it has been disappointing. What we need is an extremely long-acting numbing medicine that can be delivered at the surgical site — something that lasts 3 or 4 days. I believe that advancement is going to come and there's little doubt that the most exciting developments in the post-op pain control have yet to be discovered. OSM