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Z. Y. Yu, J. Geng, Z. Q. Li, Y. B. Sun, S. L. Wang, J. Masters, D. X

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Presentation on theme: "Z. Y. Yu, J. Geng, Z. Q. Li, Y. B. Sun, S. L. Wang, J. Masters, D. X"— Presentation transcript:

1 Dexmedetomidine enhances ropivacaine-induced sciatic nerve injury in diabetic rats 
Z.Y. Yu, J. Geng, Z.Q. Li, Y.B. Sun, S.L. Wang, J. Masters, D.X. Wang, X.Y. Guo, M. Li, D. Ma  British Journal of Anaesthesia  Volume 122, Issue 1, Pages (January 2019) DOI: /j.bja Copyright © 2018 The Author(s) Terms and Conditions

2 Fig 1 Duration of sensory and motor block produced by ropivacaine alone or ropivacaine in combination with dexmedetomidine in diabetic and control rats. After receiving sciatic nerve block with ropivacaine 0.5% or ropivacaine 0.5% with dexmedetomidine 20 μg ml−1, sensory block duration was evaluated. (a) Evaluation using foot withdrawal response and motor block duration. (b) Evaluation using the toe-spreading reflex. All responses were rated as present or absent. Data shown are median (inter-quartile range, IQR) (n=4 in the naive control and n=8 in other groups).*P<0.05, **P<0.01. British Journal of Anaesthesia  , DOI: ( /j.bja ) Copyright © 2018 The Author(s) Terms and Conditions

3 Fig 2 Motor nerve conduction velocity at baseline and 1 week after block. Motor nerve conduction velocity (MNCV) at 1 week after block was significantly different from baseline measurements in the DR-DM group only (*P<0.01). #MNCV was significantly different from RD-DM at 1 week after block (P<0.05). D, dexmedetomidine in normal rats; D-DM, dexmedetomidine in in diabetic rats; R, ropivacaine in normal rats; RD, ropivacaine plus dexmedetomidine in normal rats; R-DM, ropivacaine in diabetic rats; RD-DM, ropivacaine plus dexmedetomidine in diabetic rats. Data shown are mean (standard deviation, sd) (n=4 in the naive control and n=8 in other groups). British Journal of Anaesthesia  , DOI: ( /j.bja ) Copyright © 2018 The Author(s) Terms and Conditions

4 Fig 3 TNF-α and IL-1β in sciatic nerves. Levels of pro-inflammatory cytokines measured 1 week after sciatic nerve block by ELISA. Data shown are mean (standard deviation, sd) (n=4 in the naive control and n=8 in other groups), (*P<0.05, **P<0.01). D, dexmedetomidine in normal rats; D-DM, dexmedetomidine in in diabetic rats; ELISA, custom enzyme-linked immunosorbent assay TNF-α, tumour necrosis factor-alpha; IL-1β, interleukin 1beta; R, ropivacaine in normal rats; R-DM, ropivacaine in diabetic rats; RD, ropivacaine plus dexmedetomidine in normal rats; RD-DM, ropivacaine plus dexmedetomidine in diabetic rats; S, saline in normal rats; S-DM, saline in diabetic rats. British Journal of Anaesthesia  , DOI: ( /j.bja ) Copyright © 2018 The Author(s) Terms and Conditions

5 Fig 4 Axon density of all groups at 1 week after injection. (a) Toluidine blue staining of rat sciatic nerves at 1 week after injection. (b) Axon density (number of axons per field) in normal rats. (c) Axon density in diabetic rats. (d) Axon density in rats with ropivacaine with or without dexmedetomidine injection. Data shown are mean (standard deviation, sd) (n=4 in the naive control and n=8 in other groups); *P<0.05, **P<0.01. British Journal of Anaesthesia  , DOI: ( /j.bja ) Copyright © 2018 The Author(s) Terms and Conditions

6 Fig 5 G ratio in different sizes of axons. (a) G ratio for axon diameters of 1–2 μm. (b) G ratio for axon diameters of 2–3 μm. (c) G ratio for axon diameters of 3–4 μm. (d) G ratio for axon diameters of 4–5 μm. (e) G ratio for axon diameters of 5–6 μm. Data are derived from 10 field micrographs of one section in each rat obtained under 100× magnification. The mean G ratio of those 10 fields was calculated for further analysis and expressed as mean (standard deviation, sd) (n=4 in the naive control and n=8 in other groups); *P<0.05. D-DM, dexmedetomidine in in diabetic rats; R-DM, ropivacaine in diabetic rats; RD-DM, ropivacaine plus dexmedetomidine in diabetic rats; S-DM, saline in diabetic rats. British Journal of Anaesthesia  , DOI: ( /j.bja ) Copyright © 2018 The Author(s) Terms and Conditions

7 Fig 6 Electron microscopy of rat sciatic nerves at 1 week after injection. Tissue from all rats (n=4 in naïve control treated with saline and n=8 in all other groups) was used for electron microscopic analysis; one representative micrograph from each group is presented. Segmental demyelination (*) can be seen in all groups. The S-DM and D-DM groups displayed larger areas of demyelination and degeneration of axons (#). These changes were more obvious in the R-DM group. In the RD-DM group there was full-thickness demyelination and vacuole formation (△), which indicated more severe nerve injury. D-DM, dexmedetomidine in in diabetic rats; R-DM, ropivacaine in diabetic rats; RD-DM, ropivacaine plus dexmedetomidine in diabetic rats; S-DM, saline in diabetic rats. British Journal of Anaesthesia  , DOI: ( /j.bja ) Copyright © 2018 The Author(s) Terms and Conditions


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