Just a short note to catch you up on the latest developments in regional anesthesia. Good news first.

1. Motor-sparing blocking. It’s called an IPACK block, short for interspace between the popliteal artery and capsule of the posterior knee block. Anesthesiologist David Kim, MD, of the Hospital for Special Surgery in New York City, recently studied whether combining a periarticular injection with an IPACK block and an adductor canal block would lower pain during ambulation on post-op day 1 more than just the periarticular injection alone.

The trial included 86 patients undergoing unilateral total knee arthroplasty, 43 of whom just received a periarticular injection and 43 of whom received the injection plus the 2 blocks. Not only did those who received the injection with the blocks report significantly lower pain scores than those who only received the periarticular injection, but also they were more satisfied with their care and needed fewer opioids.

“Remember the goal is to reduce pain and increase mobility,” says Dr. Kim. “You want to get patients up and moving as quickly as possible, on the same day whenever you can. Motor-sparing blocks are the key to this.”

2. Extend a nerve block’s effect. Here’s a simple way to possibly prolong the duration of sensory block of peripheral nerve blocks in upper limb surgery. Evidence suggests that administering Decadron (dexamethasone) in conjunction with the local anesthetic around the nerve (perineural) or into a vein (intravenous) may prolong the duration of a sensory block, and reduce post-op pain intensity and opioid consumption.

Researchers examined 35 studies involving 2,702 patients who had upper limb surgery. They found the steroid can prolong the pain relief of the initial peripheral nerve block. When compared with placebo, the duration of sensory block was prolonged in the perineural dexamethasone group by 61⁄2 half hours and in the IV dexamethasone group by 6 hours. Researchers say there is not enough evidence to determine the effectiveness of dexamethasone as an adjuvant to peripheral nerve blocks in lower limb surgeries and there is no evidence in children.

3. Fast-track spinal anesthesia. A new fast-on, fast-off spinal anesthetic from B. Braun called Clorotekal (chloroprocaine hydrochloride) is intended for short procedures that last about 40 minutes — because that’s about how long the anesthetic lasts. Arthur Atchabahian, MD, of NYU Langone Medical Center, reports that study patients who underwent procedures with Clorotekal were ready to be discharged 150 minutes after injection, nearly an hour-and-a-half sooner than bupivacaine study patients (230 minutes from injection to discharge).

4. Catheter-over-needle technology. Want to help your anesthetists place continuous blocks in just over 3 minutes? Catheter-over-needle technology reduces the risk of leakage and its echogenic qualities make it easy to see the catheter on the ultrasound screen, says Mitchell Fingerman, MD, an associate professor of anesthesiology at Washington University School of Medicine in St. Louis, Mo.

5. Drug shortages. Local anesthetics like bupivacaine, lidocaine and ropivacaine are in shortage — as are the injectable opioids for which targeted injections of local anesthetic obviate the need, says Edward Mariano, MD, MAS, chief of anesthesiology and perioperative care at the VA Palo Alto Health Care System. “The new crisis of drug shortages threatens to reverse our many advancements in perioperative pain control,” says Dr. Mariano.

6. Exparel falters in study. Researchers found that adding Exparel (liposomal bupivacaine) to a multimodal pain management approach did not reduce in-hospital opioid use or opioid-related complications after knee arthroplasty. Liposomal bupivacaine infiltration is designed to provide long-lasting pain control for up to 72 hours, potentially reducing the need for opioid painkillers. But that was not the case when researchers examined data from 88,830 total knee replacements performed between 2013 and 2016.

“When we tested this hypothesis in a real-world setting where state-of-the-art pain procedures such as peripheral nerve blocks were used, we were unable to show benefit,” says Stavros G. Memtsoudis, MD, PhD, senior study author and director of critical care services in the department of anesthesiology at the Hospital for Special Surgery.

The retrospective analysis was published in May in the Online First edition of Anesthesiology (osmag.net/FR9qjK). Researchers found the addition of Exparel was not associated with a decrease in patients’ risk for opioid-related complications including those affecting the respiratory, gastrointestinal and central nervous system. Further, no clinically relevant decrease in inpatient opioid prescriptions, length of hospital stay and no reduction in cost of hospitalization were seen.

“The routine use of liposomal bupivacaine should be carefully examined, especially given its relatively high cost. It does not seem to be the silver bullet physicians have been hoping for,” says Dr. Memtsoudis.

Pacira, the manufacturer of Exparel, sees more than a few problems with the researchers’ findings. Among other things, Pacira says there was a statistically significant 9.3% decrease in opioid use in patients who received Exparel, but the “authors arbitrarily proposed a minimum of 15% opioid reduction as being clinically meaningful.” Also, there was a statistically significant 8.8% drop in the length of stay for the Exparel group but, again, “the authors arbitrarily deemed this not clinically meaningful.” OSM