Title: Assessment of the use of bilateral infraorbital maxillary nerve blocks to improve analgesia and reduce opioid and inhalant use during brachycephalic airway surgery

Investigators:

Janet Grimes DVM, MS, DACVS-SA (surgery faculty)
Townes Hillier DVM (surgery resident)
Rachel Reed DVM, DACVAA (anesthesia faculty)

If interested, please have your primary veterinarian request additional information from our Clinical Trials office at 706-296-7818 or through the University of Georgia (UGA) service by calling the small animal referral coordinator at 706-542-5362.

Study description:

Brachycephalic dogs are at high risk of peri- and post-anesthetic complications due to their abnormal upper airway conformation including an elongated soft palate, stenotic nares (narrowed nostrils), everted laryngeal saccules, and hypoplastic (small) trachea. For dogs undergoing surgery for brachycephalic obstructive airway syndrome (BOAS), reduction in opioid use has been shown to reduce the incidence of regurgitation postoperatively. This study will evaluate the use of a bilateral maxillary nerve block with lidocaine as a method to reduce the need for opioids and other anesthetic medications while providing adequate analgesia during BOAS surgery.

The following conditions must be met:

Inclusion criteria:

• Brachycephalic dogs with brachycephalic obstructive airway syndrome
  • Dogs undergoing spay, neuter, or cherry eye correction at the time of BOAS surgery can still be included

Exclusion criteria:

• Dogs with severe disease requiring emergency intubation or surgery
• Dogs with planned additional surgery requiring need for extra analgesia (e.g., screw tail correction)

Dogs undergoing surgery for BOAS and consenting to the study will be randomized to receive a bilateral maxillary nerve block using either lidocaine or saline prior to surgery. The BOAS surgery will be standardized for all patients. A board-certified anesthesiologist will perform the bilateral maxillary nerve block once dogs are anesthetized, with a wait time of 5 minutes before start of surgery; complications relating to this block, which is commonly performed for other procedures, are exceedingly rare. Data including heart rate, blood pressure, occurrence of a swallowing reflex, anesthesia complications, and postoperative complications will be recorded and compared between treatment groups. Study funds will pay for the cost of the nerve block in addition to a $100.00 hospital credit for study participation. Dog owners are responsible for all other diagnostic, surgery, and treatment costs. Dogs undergoing BOAS surgery not enrolled in this study typically do not receive a bilateral maxillary nerve block.

Duration of study:

The study is currently OPEN.

Potential benefits to veterinary medicine:

Reduction in opioid use has been shown to reduce the incidence of regurgitation postoperatively in brachycephalic dogs undergoing BOAS surgery. Identification of methods to maintain adequate pain relief while reducing opioid and other anesthetic medication use are needed to improve outcomes in dogs undergoing BOAS surgery; use of a bilateral maxillary nerve block with lidocaine may be one such method.