What’s New in Companion Animal Anesthesia?

By Jenn Bornkamp, DVM

One of the best aspects of veterinary anesthesia is that even with new anesthetic drugs, techniques, and guidelines that come out, the basics of anesthesia stay the same. Overall, we want to produce an anesthetic experience for the patient that provides multimodal analgesia, unconsciousness, amnesia, and immobility in a safe and effective manner.

Since 2018, there have been various anesthetic and analgesic drug shortages especially with opioids, local anesthetics, nonsteroidal anti-inflammatory agents (NSAID), and anesthetic support drugs such as dopamine, atropine, and intravenous fluids. The Food and Drug Administration (FDA) has a comprehensive list of drugs that are in shortage at their website:

bit.ly/fda-drugshortages.

There are several new additions to the veterinary anesthesia and analgesia market including alfaxalone, robenacoxib, and grapiprant. Alfaxalone (Alfaxan Multidose®) is an induction agent that entered the U.S. market in 2012. In 2018, a multidose bottle was introduced to the U.S. market. Alfaxalone (10 mg/ mL) is a neurosteroid induction agent that provides smooth induction and recovery, has a wide safety margin and minimal cardiorespiratory depression. It can be used for up to 28 days after the vial is broached. It is labeled for use in dogs and cats and some minor species including reptiles, fish, and amphibians. Robenacoxib (Onsior®) is a coxib NSAID that is approved for postoperative pain and inflammation in cats and dogs for up to 3 days. It can be given as an injection or tablet in cats > 5.5 pounds and > 4 months old; but is only available as an injectable for dogs currently. Grapiprant (Galliprant®) is a unique NSAID as it targets the prostaglandin EP4 receptor antagonist that is associated with the pain and inflammation of osteoarthritis only. It can be used in patients older than 9 months and over 8 pounds, but has not been studied in patients that have heart disease.

The use of local anesthetics and various locoregional techniques in addition to sedation and anesthetic drugs can improve peri-operative pain management. The “old” local anesthetic and easy-toperform techniques like infiltrative blocks (i.e., testicular or ring blocks), dental nerve blocks, and epidural techniques are still the most commonly recommended techniques. New, advanced techniques like femoral/sciatic and brachial plexus blocks using nerve-stimulation or ultrasound-guidance are also available but require more advanced training.

A new local anesthetic that is improving postoperative pain management is Nocita®. Nocita® is liposomal bupivacaine, which provides immediate analgesia and extends it at the injection site for up to 72 hours. It is approved for use in dogs for cranial cruciate ligament surgery and in cats for onychectomy procedures. However, many hospitals also use it off-label under AMDUCA for other procedures including abdominal exploratory and nonmalignant mass removal, and has been a game changer for postoperative analgesia in total ear canal ablation and mastectomy procedures.

continued from page 15

Many organizations have improved resources for the veterinary community about managing anesthesia in our veterinary patients. The 2020 American Animal Hospital Association (AAHA) Anesthesia and Monitoring Guidelines for Dogs and Cats are available for free at bit.ly/3c2KMWm. The website is full of information about anesthetic drug recommendations, local anesthetic techniques, and how to manage common anesthetic complications including hypotension, bradycardia, hypoxemia, and hypoventilation. The American Association of Feline Practitioners (AAFP) has several free resources available on their website at bit.ly/30eYdzK; some of my favorites are:

• 2018 AAFP Feline Anesthesia

Guidelines

• 2013 AAHA/AAFP Fluid Therapy

Guidelines

• 2021 AAFP Feline Life Stages

• 2021 AAFP Feline Senior Care

The most interesting development in the world of anesthesia is the changing pet demographic. The geriatric population comprises 30 to 40% of the pet population. The increase in life expectancy is leading to an increased demand for anesthetic and surgical procedures for the geriatric pet population. However, these are not necessarily the straight forward cases most veterinarians and nurses are comfortable anesthetizing as they tend to have comorbidities like hyperthyroidism, diabetes mellitus, chronic pain, obesity, and other diseases that increase the risk of anesthetic morbidity and mortality. There are more resources being produced on this topic by anesthesiologists, and in January 2022, an updated version of the book Canine and Feline Anesthesia & Co-Existing Diseases will be released.

Overall, veterinary anesthesia has not changed a lot in the past few years. Several new anesthetic and analgesic drugs have come onto the veterinary market including alfaxalone, robenacoxib, grapiprant, and liposomal bupivacaine. The use of pre-visit medications like gabapentin and trazodone in addition to fear-free techniques decrease perioperative stress in our patients. In the next few years, I imagine these techniques will become more prevalent in our field as owners want to decrease stress in their pets. One big takeaway is that despite all the advances in the field of veterinary anesthesia, veterinary anesthesiologists are still adjusting to the new patient populations, demands, and challenges just like you are. Do not be afraid to reach out to a specialist in your area for assistance or visit acvaa.org to find one near you.

References:

Grapiprant. Prescription Information. Aratana. 2016.

Robenacoxib. Prescription Information. Elanco. 2017.

Garcia ER. Local Anesthetics. In: Greene SA, et al. Veterinary Anesthesia and Analgesia. 5th ed. Ames: Blackwell Publishing, 2015:332-354.

Lascelles B, Kirkby Shaw K. An extended release local anesthetic: Potential for future use in veterinary surgical patients? Vet Med Sci. 2016 Aug 23;2(4):229-238.

Willems A, Paepe S, Marynissen S, et al. Results of screening of apparently healthy senior and geriatric Ddgs. J Vet Intern Med. 2017;31:8192.

About the Author: Jenn Bornkamp, DVM, graduated from Ross University School of Veterinary Medicine. She did a large animal internship at Iowa State University College of Veterinary Medicien and a residency in anesthesia and pain management at University of Florida College of Veterinary Medicine. She has worked in academia and private practice as a residency-trained anesthesiologist and has recently moved from PA to NJ. She has participated in the Power of Ten Leadership program with the Iowa Veterinary Medical Association and was an AVMA Future Leader. Keep an eye out for her Facebook page, The Anxious DVM, launching soon.