Standardization of an experimental model of intradural injection after spinal cord injury in rats

OBJECTIVES: The intrathecal route has not yet been thoroughly standardized and evaluated in an experimental model of spinal cord injury (SCI) in Wistar rats. The objective of this study was to standardize and evaluate the effect of intradural injection in this animal model. METHOD: The animals were divided into 6 groups: 1) laminectomy and intradural catheter; 2) laminectomy, intradural catheter and infusion; 3) only SCI; 4) SCI and intradural catheter; 5) SCI, intradural catheter and infusion; and 6) control (laminectomy only). Motor evaluations were performed using the Basso, Beattie and Bresnahan (BBB) scale and the horizontal ladder test; motor evoked potentials were measured for functional evaluation, and histological evaluation was performed as well. All experimental data underwent statistical analysis. RESULTS: Regarding motor evoked potentials, the groups with experimental SCI had worse results than those without, but neither dural puncture nor the injection of intrathecal solution aggravated the effects of isolated SCI. Regarding histology, adverse tissue effects were observed in animals with SCI. On average, the BBB scores had the same statistical behaviour as the horizontal ladder results, and at every evaluated timepoint, the groups without SCI presented scored significantly better than those with SCI (p<0.05). The difference in performance on motor tests between rats with and without experimental SCI persisted from the first to the last test. CONCLUSIONS: The present work standardizes the model of intradural injection in experimental SCI in rats. Intrathecal puncture and injection did not independently cause significant functional or histological changes.

Comparison Of Racemic Bupivacaine And Levobupivacaine; Combined With Low Dose Fentanyl, Through Intrathecal Route For Transurethral Resection Of Prostate

Background and Objectives: Bupivacaine is available as a racemic mixture of dextro and levobupivacaine. Many studies show that dextrobupivacaine has greater cardiovascular and central nervous system toxicity than levobupiva-caine. The objectives of the present study were to compare the effects of racemic Bupivacaine + Fentanyl and Levo-bupivacaine + Fentanyl on the complete regression of motor block, onset time to reach T10level sensory block, dura-tion of T10level sensory block, onset time of motor block, duration of sensory block. Materials and Method: The study was conducted in 100 patients undergoing transurethral resection of prostate operation, who received either 1.75 ml Bupivacaine (0.5%) + 25 μg Fentanyl (Gr A) or 1.75 ml Levobupivacaine (0.5%) + 25 μg Fentanyl (Gr B) in-trathecally. Results: Time to complete regression of motor block, onset time toT10level sensory block were signifi-cantly prolonged in Gr A compared to Gr B. The onset time of motor block was significantly shorter in Gr A compared to Gr B. There was no statistically significant difference between the two groups in respect to the duration of T10level sensory block, duration of sensory block. Conclusion: Intrathecal Levobupivacaine + Fentanyl used in the present study can be considered as a suitable alternative to Bupivacaine + Fentanyl for spinal anaesthesia in elective TURP surgery