Distribution of new methylene blue injected into the lumbosacral epidural space in cats.
OBJECTIVE
To determine the effects of injection volume and vertebral anatomy on the spread of new methylene blue (NMB) injected into the lumbosacral epidural space in cats.


METHODS
Prospective experimental study.


METHODS
Sixteen cats.


METHODS
Cats were randomly assigned to four groups and received from 0.1 to 0.4 mL kg(-1) of 0.12% NMB in 0.9% saline. Injection was made into the lumbosacral epidural space using a dorsal approach with the cats in sternal recumbency. The extent of cranial migration of the dye as indicated by the staining of epidural fat and dura mater was measured.


RESULTS
The mean +/- SD (range) number of stained vertebrae in the 0.3 and 0.4 mL kg(-1) groups, were 11.5 +/- 1.5 (T7-T11) and 12.4 +/- 1.8 (T6-T10), respectively. This was significantly greater than the number in the 0.1 and 0.2 mL kg(-1) groups, 4.3 +/- 0.6 (L3-L4) and 6.0 +/- 0.7 (L1-L2) vertebrae, respectively (p < 0.001). Linear regression analysis showed that the volume injected correlated significantly with the number of stained vertebrae (R2 = 0.83, p < 0.001). In the dorsal and lateral aspect of the spinal cord, NMB solution distributed between epidural fat and dura mater. Migration under the spinal cord occurred along the two longitudinal epidural veins.


CONCLUSIONS
The larger the volume of solution injected into the lumbosacral epidural space in cats, the greater the spread.
Lee
Inhyung
I
Department of Veterinary Surgery, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro, Hokkaido 080-8555, Japan. inlee@utmb.edu
Yamagishi
Norio
N
Oboshi
Kenji
K
Yamada
Haruo
H
D000767:Anesthesia, Epidural / Q000662:veterinary*; D000818:Animals; D002415:Cats / Q000378:metabolism* / Q000502:physiology; D004824:Epidural Space; D005260:Female; D007268:Injections, Epidural / Q000662:veterinary; D008161:Lumbosacral Region; D008297:Male; D008751:Methylene Blue / Q000008:administration & dosage / Q000493:pharmacokinetics*; D011446:Prospective Studies
D008751:Methylene Blue