Retrobulbar and peribulbar regional techniques in cats: a preliminary study in cadavers

Abstract

The single-peribulbar injection technique may be superior to retrobulbar or double-peribulbar injections, however, all techniques require further studies in live cats to determine safety and efficacy prior to clinical use.

Comparison of peribulbar and retrobulbar regional anesthesia with bupivacaine in cats

“…Retrobulbar injections performed without the use of ultrasonographic guidance resulted in successful deposition of injectate (defined as a large volume of distribution intraconally and a contact area > 270° around the optic nerve) in 5 of 7 cat cadavers. 26 We hypothesized *Results are number of cats affected/number of cats treated. †The reflex was only reduced but never absent in these cats.…”

“…Scores were assigned for extraconal and intraconal volume of distribution (0 = none, 1 = moderate, and 2 = large) and approximate contact area of injectate around the optic nerve (0°, 90°, 180°, 270°, or 360°), as described elsewhere. 26 After completion of CT, sedation was reversed by IM administration of atipamezole m at 10 times the administered dose of dexmedetomidine.…”

“…26 Briefly, a 5/8-inch, 25-gauge needle k was inserted through the superior eyelid at the medial region of the orbit and advanced to its full length in close proximity to the wall of the orbit. The entire volume (3 mL) was then injected.…”

“…26 Briefly, a 1.5-inch, 22-gauge spinal needle i was bent at the midpoint to achieve an angle of approximately 20°. The needle was inserted through the superior eyelid at the medial region of the orbit and advanced approximately 30 mm (approx three-fourths of its length) toward the caudal pole of the globe but in close proximity to the orbital wall.…”

“…9,24,25 Recently, retrobulbar and peribulbar injection techniques were assessed in cat cadavers. 26 However, to the authors' knowledge, information regarding the application of these techniques in living cats is limited to a case report 27 in which a life-threatening complication following RBA is described. Therefore, the purpose of the study reported here was to evaluate and compare the effectiveness and describe complications of RBA and PBA in cats.…”