Local analgesic techniques for gonadectomy: focus on intraperitoneal lavage

More than 53 million pet dogs (69% of total US dog population) and approximately 47 million pet cats (80% of the total US cat population) had been gonadectomized in the US at the time of the most recent pet ownership survey (2016), according to data from the American Veterinary Medical Association.¹ Surgical pain is most effectively controlled using multimodal analgesia, which should include local anesthetic blockade.^2,3 Advantages of local anesthetics include intraoperative nociception and post-operative pain relief that predictably extends beyond the expected duration of the drug.⁴

Generally, local anesthetics are inexpensive and easy to use. Local anesthetic techniques for gonadectomies include peritoneal lavage and testicular block, which are both highly effective and easy to perform. This article focuses on intraperitoneal lavage, and testicular blocks will be covered in a future issue.

Intraperitoneal lavage for ovariohysterectomy (OHE)⁵

To lavage the peritoneal cavity, first desensitize the incision site by injecting local anesthetics into the skin and subcutaneous tissues. Follow this with surgically incising the skin and abdominal wall, then injecting (or instill or squirt) a standard dose of local anesthetic (Table⁶) into the abdomen through the incision using a sterile syringe (no needle). The drug can be injected immediately after the abdominal wall is incised (more effective) or immediately prior to closing the abdominal incision (may be more practical because the drug isn’t absorbed by sponges used to control bleeding).

At completion of the OHE, close the incision per routine surgical protocol, leaving the drug in the abdomen. This technique desensitizes the serosal surfaces in the abdominal cavity, including ovarian and uterine tissues. Efficacy and safety studies have been done for intraperitoneal lavage in both dogs and cats for the drugs listed in the Table.⁶ In human medicine, intraperitoneal lavage is used not only for hysterectomies but also to decrease intraoperative nociception and postoperative pain from other abdominal surgeries,^7,8 including cesarean section.⁹ Intraperitoneal lavage is commonly used for these surgeries in veterinary medicine.

Although no research is yet published, experts commented that “it is our consensus that [incisional and intraperitoneal local anesthetic administration] should be used for any type of abdominal surgery.”⁶

Frequently asked questions

Should the syringe tip be directed toward the mesovarium ligaments and uterine body to direct the drug administration to the surgical sites?

This has been described as an option,¹⁰ but the impact on efficacy is unknown.

Is there a concern of uptake of the drug into the bloodstream?

See safety studies listed in the Table.⁶

Which drugs are preferred for this technique?

The longer-duration drugs, bupivacaine and ropivacaine, are preferred for this technique.

Is the amount of drug needed for the incisional block included in the total volume of local anesthetic to be injected?

Yes, but the volume used in the skin is minimal for an OHE, so most of the drug is instilled into the abdomen. The high end of the dose range is recommended for this technique.

Is the amount of lidocaine used on the arytenoids for intubation included in the total volume of local anesthetic to be injected?

No; this requires only a few drops of lidocaine.

Tamara Grubb, DVM, PhD, DACVAA is a board-certified veterinary anesthesiologist with a strong clinical interest and research focus in pain management. She is currently an assistant clinical professor of anesthesia and analgesia at Washington State University’s College of Veterinary Medicine
in Pullman. She is also a certified veterinary acupuncturist and a consultant in a private small-animal veterinary practice.

References

1. AVMA Pet Ownership and Demographics Sourcebook: 2017-2018 Edition. American Veterinary Medical Association; 2018.
2. Epstein M, Rodan I, Griffenhagen G, et al. 2015 AAHA/AAFP Pain Management Guidelines for Dogs and Cats. J Am Anim Hosp Assoc. 2015;51(2):67-84. doi:10.5326/JAAHA-MS-7331
3. Mathews K, Kronen PW, Lascelles D, et al. Guidelines for recognition, assessment and treatment of pain. J Small Anim Pract. 2014;55(6):E10-E68. doi:10.1111/jsap.12200
4. Grubb T, Lobprise H. Local and regional anaesthesia in dogs and cats: overview of concepts and drugs (part 1). Vet Med Sci. 2020;6(2):209-217. doi:10.1002/vms3.219
5. Grubb T, Lobprise H. Local and regional anaesthesia in dogs and cats: descriptions of specific local and regional techniques (part 2). Vet Med Sci. 2020;6(2):218-234. doi:10.1002/vms3.218
6. Steagall PVM, Benito J, Monteiro B, et al. Intraperitoneal and incisional analgesia in small animals: simple, cost-effective techniques. J Small Anim Pract. 2020;61(1):19-23. doi:10.1111/jsap.13084
7. Boerboom SL, de Haes A, Vd Wetering L, et al. Preperitoneal bupivacaine infiltration reduces postoperative opioid consumption, acute pain, and chronic postsurgical pain after bariatric surgery: a randomized controlled trial. Obes Surg. 2018;28(10):3102-3110. doi:10.1007/s11695-018-3341-6
8. Ruiz-Tovar J, Gonzalez J, Garcia A, et al. Intraperitoneal ropivacaine irrigation in patients undergoing bariatric surgery: a prospective randomized clinical trial. Obes Surg. 2016;26(11):2616-2621. doi:10.1007/s11695-016-2142-z
9. Patel R, Carvalho JC, Downey K, Kanczuk M, Bernstein P, Siddiqui N. Intraperitoneal instillation of lidocaine improves postoperative analgesia at cesarean delivery: a randomized, double-blind, placebo-controlled trial. Anesth Analg. 2017;124(2):554-559. doi:10.1213/ANE.0000000000001799
10. Benito J, Monteiro BP, Beaudry F, Lavoie AM, Lascelles BD, Steagall PV. Pharmacokinetics of bupivacaine after intraperitoneal administration to cats undergoing ovariohysterectomy. Am J Vet Res. 2016;77(6):641-645. doi:10.2460/ajvr.77.6.641
11. Carpenter RE, Wilson DV, Evans AT. Evaluation of intraperitoneal and incisional lidocaine or bupivacaine for analgesia following ovariohysterectomy in the dog. Vet Anaesth Analg. 2004;31(1):46-52. doi:10.1111/j.1467-2995.2004.00137.x
12. Wilson DV, Barnes KS, Hauptman JG. Pharmacokinetics of combined intraperitoneal and incisional lidocaine in the dog following ovariohysterectomy. J Vet Pharmacol Ther. 2004;27(2):105-109. doi:10.1111/j.1365-2885.2004.00552.x