In 1995, the American Pain Society declared pain as the fifth vital sign. Pain is one of the primary fears of patients undergoing surgery. Pain is inadequately treated in as much as 50% of patients and more than 80% of patients receiving surgery experience some degree of pain1,2.
Orthopaedic procedures, in particular total joint arthroplasty (TJA), are painful. Pain is known to compromise the early outcome of TJA by affecting patient ambulation and compliance with physical therapy. Inadequate pain control increases the length of hospital stay, escalates the cost of care, and is associated with venous thromboembolism, coronary ischemia, myocardial infarction, pneumonia, insomnia, cognitive dysfunction, poor wound-healing, and slowed overall recovery. Experiencing severe pain during the postoperative period can lead to patient demoralization and dissatisfaction1,3,4 and may lead to chronic pain syndrome.
Control of pain following TJA, particularly total knee arthroplasty, remains imperfect. There has been an impetus among orthopaedic surgeons to seek novel, and potentially more effective, pain management strategies. Multimodal pain management, introduced by Wall in 19885 and popularized by Kehlet and Dahl in 19936, has been a great advance in postoperative pain management. The intention of multimodal pain management is to target different pain pathways for effective pain relief, without solely resorting to opioids.
The term multimodal pain management is broad and all encompassing. Injection of a local anesthetic to the periarticular region of the knee, as performed in the three highlighted Evidence-Based Orthopaedics7-9 studies in this issue of The Journal of Bone and Joint Surgery (American Volume), has been used for more effective pain control. These authors conducted high-level studies that add further support for the use of periarticular infiltration of anesthetic agents. Murphy et al.7 showed that periarticular injection of levobupivacaine resulted in a reduction in opiate consumption, although the pain scores were not reduced. The study by Essving et al.8 demonstrated that periarticular injection of ropivacaine, ketorolac, and epinephrine resulted in reduction of morphine consumption during the first forty-eight postoperative hours. Continuous delivery of a local anesthetic through an indwelling catheter placed into a joint after TJA or infiltration of various agents into the periarticular region are other strategies that have been explored recently. The study by Dobrydnjov et al.9 provides evidence that infusion of intra-articular (vs. extra-articular) ropivacaine was effective in reducing the incidence of high-intensity pain and improving initial mobilization.
These studies support the need for orthopaedic surgeons to seek alternative avenues for postoperative pain control. At my institution, and following the execution of a Level-I study, we abandoned the use of epidural anesthetic agents in favor of intra-articular infusion of anesthetic agents. Of note, there may be potential for development of infection with infusion or infiltration of a large volume of fluid periarticularly.
There have also been several other advances in analgesic drug development and delivery. Liposomal delivery of morphine into the epidural space, liposomal delivery of bupivacaine into the surgical wound, intravenous formulations of acetaminophen and ibuprofen, transcutaneous iontophoretic delivery of fentanyl with use of a small credit-card-size electronic device, and intranasal delivery of analgesics are just a few of the advances that have been made in recent years. Preconditioning of the patients (with better preparation for postoperative rehabilitation) and avoidance of excessive soft-tissue dissection (with a shift toward tissue-sparing approaches) may also reduce the degree and intensity of postoperative pain following TJA.
Perhaps the most significant and important advance in the field of pain management has been the recognition that inadequate pain control following surgery is not acceptable in contemporary society. Patient satisfaction data are now being reported through the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS). As part of the Affordable Care Act of 2010, the Centers for Medicare & Medicaid Services (CMS) have established hospital reimbursement levels on the basis of HCAHPS scores.
With the changing climate of health care and emphasis on patient satisfaction with episode of care, and possible identification of pain as a “quality” metric, better management of pain will become even more pressing in the future. The authors of the three articles highlighted here have provided concrete steps in the elimination of this common enemy.