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Two views on multimodal pain management

By Mary Ann Porucznik

Protocols share one objective: Reducing narcotic use

“Of all the developments and changes in the way orthopaedic surgeons practice over the past 5 or 6 years, the impact of better pain management has been truly significant,” according to Steven MacDonald, MD, who moderated a panel on the topic during the 2009 annual meeting of the American Association of Hip and Knee Surgeons. “It’s really changed how well our patients do postoperatively.”

As yet, no “gold standard” has emerged for multimodal pain management after total hip or total knee arthroplasty (THA/TKA). The various multimodal pain protocols that have been developed, however, share similar objectives and include similar components, as the following examples show.

Get rid of narcotics
According to Lawrence D. Dorr, MD, of The Arthritis Institute, the first principle in a multimodal pain management program is to eliminate parenteral narcotics.

“The reason for getting rid of narcotics is that they make people sick, resulting in nausea and vomiting. By reducing narcotic use, you can significantly reduce nausea, vomiting, and lethargy, so patients feel better, have a better hospital experience, and go home faster,” says Dr. Dorr.

Mark W. Pagnano, MD, of the Mayo Clinic, agrees. “Although surgeons like to concentrate on surgical technique and bearing surfaces, postoperative pain remains patients’ primary concern before THA or TKA. Parenteral opioids typically do not provide adequate analgesia, particularly when compared to multimodal protocols.”

Get ahead of the pain
“The second principle of multimodal pain management,” says Dr. Dorr, “is to prevent pain before it starts.” That forms the basis for his protocol, which operates on three sensory levels—the wound, the spinal cord, and the brain.

“The most important step in my mind,” says Dr. Dorr, “is to convince the patient that we are going to control any pain. Patients who enter the hospital anticipating a painful procedure are sensitized and magnify any pain they feel.” For this reason, patient education on the surgery, as well as preoperative and postoperative care and rehabilitation, is mandatory.

Prior to surgery, patients receive oral medications, including oxycodone, acetaminophen, a Cox-2 inhibitor, and an antinausea medication. Dr. Dorr prefers to use an epidural anesthesia or a short-acting spinal block, rather than a general anesthesia, for surgery.

“During surgery, we inject the wound to block the inflammatory and the neurogenic pain pathways,” says Dr. Dorr, who uses a cocktail of morphine, ketorolac, and rupivicaine in 60 mL of saline.

“In the recovery room, patients receive intravenous Toradol (Roche Pharmaceuticals, Nutley, N.J.) and a rapid-acting oral oxycodone. Once the patient is transferred to the orthopaedic ward, only oral medications are used, primarily Norco (Watson Pharmaceuticals, Inc., Corona, Calif.) for patients younger than age 65, and Darvocet (Xanodyne, Florence, Ky.) for patients older than age 65. Administration of a Cox-2 inhibitor continues for 48 hours,” says Dr. Dorr, who notes that anti-emetic drugs augment the oral medications in preventing nausea.

Although the nursing staff may initially view the delivery of scheduled oral medications as “more work,” Dr. Dorr notes that nurses quickly become staunch supporters of the multimodal protocol. “They’re much happier delivering regular doses of analgesics and anti-inflammatories instead of dealing with patients who are nauseous, vomiting, and in pain,” he says.

Getting high-quality relief Dr. Pagnano agrees on the need to be pre-emptive to avoid the use of parenteral narcotics. “We use a multimodal pathway that features peripheral nerve blocks, which we’ve found provides a quality of analgesia and functional outcome that is similar to those of continuous epidural analgesia and superior to systemic analgesia, with fewer side effects than either because of their opioid-sparing properties,” he says.

For sustained, low levels of pain in the first two or three days after surgery, particularly for TKA patients, Dr. Pagnano advises using peripheral nerve blocks.

“Pain relief is better if we add more complex techniques, including peripheral nerve blocks, indwelling epidural catheters, or spinal injections,” says Dr. Pagnano. “Each of these techniques has a unique set of benefits and drawbacks (Table 1). For those reasons, individual surgeons or institutions may favor one approach over another.”

Interest in the use of peripheral nerve blocks has been increasing, in part because of the introduction of better nerve stimulating needles and ultrasound techniques that enable the anesthesiologist to visualize the nerves. The blocks can provide dramatic pain relief, particularly when coupled with an indwelling catheter.

“In our pathway,” explains Dr. Pagnano, “patients receive pre-emptive analgesia, intravenous access is established, and the blocks are administered in the preoperative area. Because a femoral block doesn’t affect the posterior knee, TKA patients also receive a single-shot sciatic block.”

Although in certain circumstances, surgery can be performed with just the blocks, Dr. Pagnano generally adds a low-dose spinal block designed to wear off quickly so that the patient regains sensation in the contralateral limb in the recovery room.

Postoperative pain is managed by an anesthesia pain service that is responsible for the nerve catheter itself; the orthopaedist is responsible for all oral medications.

“Most patients have little or no pain in the first 2 days after surgery,” says Dr. Pagnano. “They are alert and oriented; the typical patient is complaining more about limited Internet access than pain on the day after surgery.”

Postoperative issues
Both Dr. Dorr and Dr. Pagnano acknowledged the impact of multimodal pain management techniques on the treatment of venous thromboembolism after joint replacement surgery. According to Dr. Dorr, aspirin and compression are just as effective as anticoagulants. “Getting patients up and walking right away significantly reduces the risk of deep venous thrombosis (DVT), and you don’t have to use all those chemicals,” he says.

Although Dr. Pagnano also prefers to use aspirin for DVT prophylaxis, he acknowledged that many surgeons use Coumadin (Bristol-Myers Squibb, New York City) or low-molecular weight heparin (LMWH). “I’d be concerned if the patient is taking Coumadin or LMWH with a Cox-2 inhibitor and Toradol on an extended basis,” he says.

Another postoperative risk is a patient’s falling. “A well-functioning femoral nerve catheter will result in quadriceps weakening,” says Dr. Pagnano, and can lead to falls if patients try to put all their weight on the operated leg. A fall prevention strategy would involve educating patients, prohibiting them from getting out of bed by themselves for the first 48 hours postoperative, reinforcing the message to nurses, and being proactive by using a knee immobilizer for all patients until the quadriceps functioning returns.

“We put everyone in a knee immobilizer,” says Dr. Dorr. “We also have patients do physical therapy on the first day after surgery, and make them work the quadriceps muscle. Then, most patients can go home the following morning.”

Disclosure information: Dr. Dorr—Zimmer, Mako Surgical Corp.; Dr. Pagnano—DePuy, Mako, Zimmer; Dr. MacDonald—DePuy.

Mary Ann Porucznik is managing editor of AAOS Now. She can be reached at porucznik@aaos.org

References:
Dorr LD, Gendelman V, Maheshwari AV, Boutary M, Wan Z, Long WT. Multimodal Thromboprophylaxis for Total Hip and Knee Arthroplasty Based on Risk Assessment. J Bone Joint Surg(American). 2007;89:2648-2657.

Horlocker TT, Kopp SL, Pagnano MW, Hebl JR: Analgesia for total hip and knee arthroplasty: A multimodal pathway featuring peripheral nerve block. J Am Acad Orthop Surg 2006;14:126-135.

AAOS Now
July 2010 Issue
http://www.aaos.org/news/aaosnow/jul10/clinical8.asp