Local Infiltration Analgesia and Other Multicomponent Techniques to Improve Postoperative Outcome-Are We Comparing Oranges and Apples?

Wound infiltration with local anesthetics for perioperative and postoperative pain management has been receiving considerable attention in recent years. Administration of local anesthetics at the surgical site seems to be a rational approach to reduce afferent nociceptive input from the source of surgical pain. Local anesthetics can inhibit local inflammatory response to injury, which sensitizes nociceptive receptors and contributes to pain and hyperalgesia. The technique provides potent, sitespecific analgesia and can be used widely because of its simplicity, safety, and low cost. It can be used alone or in combination with other regional techniques and/or analgesic modalities as an important opioid-sparing component of multimodal strategy for treating postoperative pain. Single-dose local anesthetic infiltration in the surgical wound is effective, but analgesia lasts only a few hours and has a questionable role in major surgery. This has led to the study of several modifications such as wound catheter infusions2; high-volume local anesthetic infiltration; use of adjuvants such as epinephrine, clonidine, and steroids4; or use of alternatives to local anesthetics such as diclofenac and capsaicin. The search for ultra long-acting local anesthetics to eliminate the need for catheter techniques has been ongoing for many years. A recent modification of the technique is high-volume local infiltration analgesia (LIA), as developed by Kerr and Kohan for lower extremity joint replacement surgery. The LIA approach consists of high-dose intraoperative infiltration of the entire surgical area with a combination of ropivacaine, ketolorac, and epinephrine. Infiltrations are performed 1 layer at a time as the surgery progresses. This is combined with intra-articular catheter for analgesic top-up allowing the blockade to last as long as 36 hours. Thrombosis prophylaxis consists of aspirin for 6 weeks. Postoperative pain relief is provided by a combination of acetaminophen (paracetamol), ibuprophen 400 mg every 4 hours, and 10 mg intravenous morphine as needed. After 36 hours, transdermal buprenorphine is administered if necessary. All surgeries in Kerr and Kohan’s report were performed by a single surgeon, and all anesthesia and pain management conducted by a single anesthesiologist. Postoperative mobilization is started 3 to 5 hours after surgery. In this case series of 325 patients, more than half of those undergoing hip or knee replacement could be discharged on the first postoperative day, with most of the remaining patients being discharged the day after. Mean time to independent mobility was less than 25 hours for the entire cohort and 20 hours for patients undergoing total knee replacement. Postoperative pain scores were low, and very few thromboembolic events were noted. The LIA technique has achieved widespread acceptance by orthopedic surgeons especially in the Scandinavian countries, the United Kingdom, and Australia. The 2010 annual report of the Swedish Knee Arthroplasty Register showed that the use of LIA has increased steadily and, in 2009, was used in 75% of all TKA surgeries in the country; a catheter was left in the knee joint in 40% of these patients. Most of the recent literature is from Denmark, Sweden, and Norway; however, none of these studies have been able to replicate the 1to 2-day discharge times reported by the originators of LIA. The discharge times are in the range of 3 to 5 days, which is still considerably shorter than the 6to 10-day hospitalization that was common until recently. A comprehensive research program as a joint venture between Scandinavian clinics has been proposed to address questions such as the role of surgical technique, thromboembolism prophylaxis routines, choice of analgesic drugs, fast-track (FT), multimodal mobilization protocols, and intra-articular topup requirements. In this issue of Regional Anesthesia and Pain Medicine, Lunn et al report on a study that evaluated the role of intraoperative LIA in patients undergoing total hip arthroplasty (THA). In this EDITORIAL