Objective—To determine the relationship between different body positions during recumbency on the cranial migration of epidurally injected methylene blue in canine cadavers.
Sample Population—21 fresh cadavers of clinically normal adult female mixed-breed dogs.
Procedure—Dogs were randomly assigned to the following 3 groups: dogs remaining in right lateral recumbency (n = 7), dogs rotated from left to right lateral recumbency (7), and dogs rotated from dorsal to right lateral recumbency (7). Each dog received an epidural injection of 0.05% methylene blue (0.1 mL/kg) at the lumbosacral space. A dorsal laminectomy of the vertebral column was made, and cranial extent of methylene blue in 4 quadrants (right lateral, left lateral, ventral, and dorsal) was determined by examining dura mater staining.
Results—No significant difference was found among groups in regard to body weight or body condition score. Epidural cranial migration of methylene blue in the right lateral quadrant was significantly greater in dogs that remained in right lateral recumbency than in dogs that were rotated from left to right lateral recumbency. No significant difference was found within groups for epidural cranial migration of methylene blue between each quadrant. No significant relationship was found between body weight or body condition score and epidural cranial migration of methylene blue.
Conclusions and Clinical Relevance—Body positioning and amount of recumbency time influence cranial migration of epidurally injected methylene blue. If greater cranial migration of an epidurally administered drug is desired, placing the patient in lateral recumbency with the surgical site on the dependent side may precede surgery.