Otro
The Effects of Subarachnoid Administration of Preservative-Free S(+)-Ketamine on Spinal Cord and Meninges in Dogs
Registro en:
Anesthesia and Analgesia. Philadelphia: Lippincott Williams & Wilkins, v. 114, n. 2, p. 450-455, 2012.
0003-2999
10.1213/ANE.0b013e31823a5d1b
WOS:000299491200026
Autor
Rojas, Alfredo Cury
Alves, Juliana Gaiotto
Moreira e Lima, Rodrigo
Marques, Mariângela Esther Alencar
Barros, Guilherme Antonio Moreira de
Fukushima, Fernanda Bono
Módolo, Norma Sueli Pinheiro
Ganem, Eliana Marisa
Resumen
BACKGROUND: The N-methyl-D-aspartate receptor antagonist ketamine and its active enantiomer, S(+)-ketamine, have been injected in the epidural and subarachnoid spaces to treat acute postoperative pain and relieve neuropathic pain syndrome. In this study we evaluated the effects of a single dose of preservative-free S(+)-ketamine, in doses usually used in clinical practice, in the spinal cord and meninges of dogs.METHODS: Under anesthesia (IV etomidate (2 mg/kg) and fentanyl (0.005 mg/kg), 16 dogs (6 to 15 kg) were randomized to receive a lumbar intrathecal injection (L5/6) of saline solution of 0.9% (control group) or S(+)-ketamine 1 mg/kg(-1) (ketamine group). All doses were administered in a volume of 1 mL over a 10-second interval. Accordingly, injection solution ranged from 0.6% to 1.5%. After 21 days of clinical observation, the animals were killed; spinal cord, cauda equine root, and meninges were removed for histological examination with light microscopy. Tissues were examined for demyelination (Masson trichrome), neuronal death (hematoxylin and eosin) and astrocyte activation (glial fibrillary acidic protein).RESULTS: No clinical or histological alterations of spinal tissue or meninges were found in animals from either control or ketamine groups.CONCLUSION: A single intrathecal injection of preservative-free S(+)-ketamine, at 1 mg/kg-1 dosage, over a concentration range of 6 to 15 mg/mL injected in the subarachnoid space in a single puncture, did not produce histological alterations in this experimental model. (Anesth Analg 2012;114:450-55)