Nerve Blocks Are a No-Brainer

Nerve blocks are the most targeted form of analgesia available, arming your anesthesia providers with the ability to direct local anesthetics to specific areas of the body to prevent pain impulses from reaching the brain. Given the scope of the opioid epidemic, you’d expect every eligible patient to be on the receiving end of an expertly placed peripheral nerve block (PNB). Oddly enough, that’s not the case. A September 2017 study in Anesthesia & Analgesia (osmag.net/J5xoGN) that examined the use of regional anesthesia for outpatient surgery procedures found that regional anesthesia was used sparingly:

• Frequency was only 3.3% of the 3.3 million possible cases that were amenable to a PNB.
• PNB frequency of the brachial plexus (6.1%), sciatic nerve (1.5%) and femoral nerve (1.9%) was similarly low.
• The procedures in which PNBs were most frequently used were shoulder arthroscopies (41%) and anterior cruciate ligament reconstruction (32%). Countless patients are missing out on targeted pain relief that can reduce opioid use, shorten stays in recovery and lower readmission rates. We talked to leading experts in regional anesthesia to find out how they’re taking advantage of blocks.

Regional blocks are typically placed with the assistance of ultrasound guidance, which offers anesthesia providers great image quality and granular detail of anatomy to help them home in on specific nerve locations. For example, interscalene blocks cover most of the brachial plexus but spare the ulnar nerve, and are widely accepted as the gold standard for providing analgesia during notoriously painful shoulder surgeries.

“Ultrasound imaging technology lets anesthesia providers identify the interscalene nerve, and inject 20cc to 30cc of bupivacaine or ropivacaine,” says Tong J (TJ) Gan, MD, MBA, MHS, FRCA, professor and chairman of the department of anesthesiology at Stony Brook (N.Y.) University.

This is just one of the many blocks anesthesia providers have at their disposal to keep patients’ post-op pain at bay without resorting to powerful painkillers. What’s more, innovations in regional anesthesia offer clinicians more targeted pain control methods. For example, the quadratus lumborum (QL) block is emerging as a superior option to TAP (transversus abdominis plane) blocks for abdominal surgeries. When placing a QL block, anesthesia providers inject a local anesthetic posterior to the QL muscle, the deepest abdominal muscle located in the back on either side of lumbar spine.

Providers at Northeastern Anesthesia, an Ariz.-based anesthesia group, began performing nerve blocks 9 years ago. “Since then, we’ve seen a 90% reduction in intraoperative and PACU opioid usage, and we write 30% to 40% fewer post-op prescriptions,” says Michael A. MacKinnon, MSN, FNP-C, CRNA, a provider at Northeastern Anesthesia.

“QL blocks are more advanced than TAP blocks and do require more skill to place,” says Mr. MacKinnon. But the benefits are clear. It’s a deeper block that provides more visceral pain control, which is great for outpatient procedures such as hernia repairs, says Mr. MacKinnon.

“QL blocks are replacing TAP blocks because TAP blocks are done after the nerves supplying sensation to the abdomen have been bifurcated,” says Girish P. Joshi, MBBS, MD, FFARCSI, a professor of anesthesiology and pain management at the University of Texas Southwestern Medical Center in Dallas.

“QL blocks are performed more posteriorly. They therefore have a higher potential success rate.”

Still, single-shot intraarticular injections can be very effective for patients who don’t want to go home with a catheter or pain pump or during cases involving surgeons who don’t want blocks placed. While the long-acting local anesthetic liposomal bupivacaine (Exparel) has enjoyed a virtual monopoly on the market, that could change in the near future. “There are a lot of exciting formulations in the pipeline,” says Dr. Gan.

For example, Heron Therapeutics has developed a combination of the long-acting local anesthetic bupivacaine and a low dose of the nonsteroidal anti-inflammatory agent meloxicam in a drug called HTX-011, which is slated for FDA review in March. “The nonsteroidal makes the pH level more neutral and therefore improves the absorption of the local anesthetic, which is a prolonged version of bupivacaine,” says Dr. Gan. “The data suggests it can work for 48 hours, and perhaps up to 72 hours.”

Dr. Gan says another long-acting bupivacaine formulation in development by drug manufacturer Durect has been sent to the FDA for review and promises to provide several days of pain relief. He also points to a new local anesthetic collagen matrix, which works by impregnating a local anesthetic into the sponge-like material and gradually releasing it over 48 hours to 72 hours.